[libcamera-devel,2/2] libcamera: pipeline: ipa: raspberrypi: Use dma heap allocs for LS tables

8798 diff mbox series

Remove use of vcsm allocations and replace with dma heap allocations.
The pipeline handler now passes the fd of the allocation over to the IPA
instead of the raw pointer.

Also use libcamera::FileDescriptor for fd lifetime management.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
---
 include/linux/bcm2835-isp.h                   |   4 +-
 include/linux/vc_sm_cma_ioctl.h               | 135 ----------------
 src/ipa/raspberrypi/raspberrypi.cpp           |  27 +++-
 .../pipeline/raspberrypi/dma-heaps.h          | 102 ++++++++++++
 .../pipeline/raspberrypi/raspberrypi.cpp      |  44 ++----
 src/libcamera/pipeline/raspberrypi/vcsm.h     | 149 ------------------
 6 files changed, 138 insertions(+), 323 deletions(-)
 delete mode 100644 include/linux/vc_sm_cma_ioctl.h
 create mode 100644 src/libcamera/pipeline/raspberrypi/dma-heaps.h
 delete mode 100644 src/libcamera/pipeline/raspberrypi/vcsm.h

Hi Naush,

Thank you for the patch.

On Tue, Jul 14, 2020 at 01:08:44PM +0100, Naushir Patuck wrote:
> Remove use of vcsm allocations and replace with dma heap allocations.
> The pipeline handler now passes the fd of the allocation over to the IPA
> instead of the raw pointer.

Nice :-)

> Also use libcamera::FileDescriptor for fd lifetime management.

Should the commit message mention the dependency on
https://github.com/raspberrypi/linux/pull/3715 ?

> Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
> ---
>  include/linux/bcm2835-isp.h                   |   4 +-
>  include/linux/vc_sm_cma_ioctl.h               | 135 ----------------
>  src/ipa/raspberrypi/raspberrypi.cpp           |  27 +++-
>  .../pipeline/raspberrypi/dma-heaps.h          | 102 ++++++++++++
>  .../pipeline/raspberrypi/raspberrypi.cpp      |  44 ++----
>  src/libcamera/pipeline/raspberrypi/vcsm.h     | 149 ------------------
>  6 files changed, 138 insertions(+), 323 deletions(-)
>  delete mode 100644 include/linux/vc_sm_cma_ioctl.h
>  create mode 100644 src/libcamera/pipeline/raspberrypi/dma-heaps.h
>  delete mode 100644 src/libcamera/pipeline/raspberrypi/vcsm.h
> 
> diff --git a/include/linux/bcm2835-isp.h b/include/linux/bcm2835-isp.h
> index e7afc367..45abb681 100644
> --- a/include/linux/bcm2835-isp.h
> +++ b/include/linux/bcm2835-isp.h
> @@ -108,7 +108,7 @@ enum bcm2835_isp_gain_format {
>   * @grid_stride:	Row to row distance (in grid cells) between grid cells
>   *			in the same horizontal location.
>   * @grid_height:	Height of lens shading tables in grid cells.
> - * @mem_handle_table:	Memory handle to the tables.
> + * @dmabuf:		dmabuf file handle containing the table.
>   * @ref_transform:	Reference transform - unsupported, please pass zero.
>   * @corner_sampled:	Whether the gains are sampled at the corner points
>   *			of the grid cells or in the cell centres.
> @@ -120,7 +120,7 @@ struct bcm2835_isp_lens_shading {
>  	__u32 grid_width;
>  	__u32 grid_stride;
>  	__u32 grid_height;
> -	__u32 mem_handle_table;
> +	__s32 dmabuf;
>  	__u32 ref_transform;
>  	__u32 corner_sampled;
>  	__u32 gain_format;
> diff --git a/include/linux/vc_sm_cma_ioctl.h b/include/linux/vc_sm_cma_ioctl.h
> deleted file mode 100644
> index 21b8758e..00000000
> --- a/include/linux/vc_sm_cma_ioctl.h
> +++ /dev/null
> @@ -1,135 +0,0 @@
> -/*
> -Copyright (c) 2012, Broadcom Europe Ltd
> -All rights reserved.
> -
> -Redistribution and use in source and binary forms, with or without
> -modification, are permitted provided that the following conditions are met:
> -    * Redistributions of source code must retain the above copyright
> -      notice, this list of conditions and the following disclaimer.
> -    * Redistributions in binary form must reproduce the above copyright
> -      notice, this list of conditions and the following disclaimer in the
> -      documentation and/or other materials provided with the distribution.
> -    * Neither the name of the copyright holder nor the
> -      names of its contributors may be used to endorse or promote products
> -      derived from this software without specific prior written permission.
> -
> -THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
> -ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
> -WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
> -DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
> -DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
> -(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
> -LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
> -ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> -(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
> -SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> -*/
> -
> -/*
> - * Copyright 2019 Raspberry Pi (Trading) Ltd.  All rights reserved.
> - *
> - * Based on vmcs_sm_ioctl.h Copyright Broadcom Corporation.
> - */
> -
> -#ifndef __VC_SM_CMA_IOCTL_H
> -#define __VC_SM_CMA_IOCTL_H
> -
> -/* ---- Include Files ---------------------------------------------------- */
> -
> -#include <linux/types.h>	/* Needed for standard types */
> -
> -#include <linux/ioctl.h>
> -
> -/* ---- Constants and Types ---------------------------------------------- */
> -
> -#define VC_SM_CMA_RESOURCE_NAME               32
> -#define VC_SM_CMA_RESOURCE_NAME_DEFAULT       "sm-host-resource"
> -
> -/* Type define used to create unique IOCTL number */
> -#define VC_SM_CMA_MAGIC_TYPE                  'J'
> -
> -/* IOCTL commands on /dev/vc-sm-cma */
> -enum vc_sm_cma_cmd_e {
> -	VC_SM_CMA_CMD_ALLOC = 0x5A,	/* Start at 0x5A arbitrarily */
> -
> -	VC_SM_CMA_CMD_IMPORT_DMABUF,
> -
> -	VC_SM_CMA_CMD_CLEAN_INVALID2,
> -
> -	VC_SM_CMA_CMD_LAST	/* Do not delete */
> -};
> -
> -/* Cache type supported, conveniently matches the user space definition in
> - * user-vcsm.h.
> - */
> -enum vc_sm_cma_cache_e {
> -	VC_SM_CMA_CACHE_NONE,
> -	VC_SM_CMA_CACHE_HOST,
> -	VC_SM_CMA_CACHE_VC,
> -	VC_SM_CMA_CACHE_BOTH,
> -};
> -
> -/* IOCTL Data structures */
> -struct vc_sm_cma_ioctl_alloc {
> -	/* user -> kernel */
> -	__u32 size;
> -	__u32 num;
> -	__u32 cached;		/* enum vc_sm_cma_cache_e */
> -	__u32 pad;
> -	__u8 name[VC_SM_CMA_RESOURCE_NAME];
> -
> -	/* kernel -> user */
> -	__s32 handle;
> -	__u32 vc_handle;
> -	__u64 dma_addr;
> -};
> -
> -struct vc_sm_cma_ioctl_import_dmabuf {
> -	/* user -> kernel */
> -	__s32 dmabuf_fd;
> -	__u32 cached;		/* enum vc_sm_cma_cache_e */
> -	__u8 name[VC_SM_CMA_RESOURCE_NAME];
> -
> -	/* kernel -> user */
> -	__s32 handle;
> -	__u32 vc_handle;
> -	__u32 size;
> -	__u32 pad;
> -	__u64 dma_addr;
> -};
> -
> -/*
> - * Cache functions to be set to struct vc_sm_cma_ioctl_clean_invalid2
> - * invalidate_mode.
> - */
> -#define VC_SM_CACHE_OP_NOP       0x00
> -#define VC_SM_CACHE_OP_INV       0x01
> -#define VC_SM_CACHE_OP_CLEAN     0x02
> -#define VC_SM_CACHE_OP_FLUSH     0x03
> -
> -struct vc_sm_cma_ioctl_clean_invalid2 {
> -	__u32 op_count;
> -	__u32 pad;
> -	struct vc_sm_cma_ioctl_clean_invalid_block {
> -		__u32 invalidate_mode;
> -		__u32 block_count;
> -		void *  /*__user */start_address;
> -		__u32 block_size;
> -		__u32 inter_block_stride;
> -	} s[0];
> -};
> -
> -/* IOCTL numbers */
> -#define VC_SM_CMA_IOCTL_MEM_ALLOC\
> -	_IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_ALLOC,\
> -	 struct vc_sm_cma_ioctl_alloc)
> -
> -#define VC_SM_CMA_IOCTL_MEM_IMPORT_DMABUF\
> -	_IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_IMPORT_DMABUF,\
> -	 struct vc_sm_cma_ioctl_import_dmabuf)
> -
> -#define VC_SM_CMA_IOCTL_MEM_CLEAN_INVALID2\
> -	_IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_CLEAN_INVALID2,\
> -	 struct vc_sm_cma_ioctl_clean_invalid2)
> -
> -#endif /* __VC_SM_CMA_IOCTL_H */
> diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
> index b1f27861..562907e5 100644
> --- a/src/ipa/raspberrypi/raspberrypi.cpp
> +++ b/src/ipa/raspberrypi/raspberrypi.cpp
> @@ -15,6 +15,7 @@
>  #include <libcamera/buffer.h>
>  #include <libcamera/control_ids.h>
>  #include <libcamera/controls.h>
> +#include <libcamera/file_descriptor.h>
>  #include <libcamera/ipa/ipa_interface.h>
>  #include <libcamera/ipa/ipa_module_info.h>
>  #include <libcamera/ipa/raspberrypi.h>
> @@ -65,12 +66,14 @@ public:
>  	IPARPi()
>  		: lastMode_({}), controller_(), controllerInit_(false),
>  		  frame_count_(0), check_count_(0), hide_count_(0),
> -		  mistrust_count_(0), lsTableHandle_(0), lsTable_(nullptr)
> +		  mistrust_count_(0), lsTableHandle_(FileDescriptor()), lsTable_(nullptr)

You can write this

		  mistrust_count_(0), lsTable_(nullptr)

lsTableHandle_ is a FileDescriptor instance so it will be constructed
using the default FileDescriptor constructor by default.

>  	{
>  	}
>  
>  	~IPARPi()
>  	{
> +		if (lsTable_)
> +			munmap(lsTable_, MAX_LS_GRID_SIZE);
>  	}
>  
>  	int init(const IPASettings &settings) override;
> @@ -137,7 +140,7 @@ private:
>  	/* How many frames we should avoid running control algos on. */
>  	unsigned int mistrust_count_;
>  	/* LS table allocation passed in from the pipeline handler. */
> -	uint32_t lsTableHandle_;
> +	FileDescriptor lsTableHandle_;
>  	void *lsTable_;
>  };
>  
> @@ -357,8 +360,22 @@ void IPARPi::processEvent(const IPAOperationData &event)
>  	}
>  
>  	case RPI_IPA_EVENT_LS_TABLE_ALLOCATION: {
> -		lsTable_ = reinterpret_cast<void *>(event.data[0]);
> -		lsTableHandle_ = event.data[1];
> +		/* Remove any previous table, if there was one. */
> +		if (lsTable_)
> +			munmap(lsTable_, MAX_LS_GRID_SIZE);

			lsTable_ = nullptr;
		}

otherwise if lsTableHandle_.isValid() fails you'll end up with lsTable_
pointing to unmapped memory.

> +
> +		/* Map the LS table buffer into user space. */
> +		lsTableHandle_ = FileDescriptor(event.data[0]);
> +		if (lsTableHandle_.isValid()) {
> +			lsTable_ = mmap(nullptr, MAX_LS_GRID_SIZE, PROT_READ | PROT_WRITE,
> +					MAP_SHARED, lsTableHandle_.fd(), 0);
> +
> +			if (lsTable_ == MAP_FAILED) {
> +				LOG(IPARPI, Error) << "dmaHeap mmap failure for LS table.";
> +				lsTable_ = nullptr;
> +			}
> +		}
> +
>  		break;
>  	}
>  
> @@ -1026,7 +1043,7 @@ void IPARPi::applyLS(const struct AlscStatus *lsStatus, ControlList &ctrls)
>  		.grid_width = w,
>  		.grid_stride = w,
>  		.grid_height = h,
> -		.mem_handle_table = lsTableHandle_,
> +		.dmabuf = lsTableHandle_.fd(),
>  		.ref_transform = 0,
>  		.corner_sampled = 1,
>  		.gain_format = GAIN_FORMAT_U4P10
> diff --git a/src/libcamera/pipeline/raspberrypi/dma-heaps.h b/src/libcamera/pipeline/raspberrypi/dma-heaps.h
> new file mode 100644
> index 00000000..9f9137d8
> --- /dev/null
> +++ b/src/libcamera/pipeline/raspberrypi/dma-heaps.h

Would you mind already splitting this into a .h and a .cpp file ? I
foresee more users for dma heaps, so I'll likely move this to the
libcamera core at some point.

> @@ -0,0 +1,102 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2020, Raspberry Pi (Trading) Limited
> + *
> + * dma-heap.h - Helper class for dma-heap allocations.

s/heap/heaps/

> + */
> +#ifndef __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> +#define __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> +
> +#include <mutex>
> +
> +#include <fcntl.h>
> +#include <linux/dma-buf.h>
> +#include <linux/dma-heap.h>
> +#include <sys/ioctl.h>
> +#include <sys/mman.h>
> +#include <unistd.h>
> +
> +#include <libcamera/file_descriptor.h>
> +#include <libcamera/logging.h>

logging.h is for the public API that allows modifying the log level.
What you need here is libcamera/internal/log.h.

> +
> +namespace libcamera {
> +
> +LOG_DECLARE_CATEGORY(RPI)
> +
> +namespace RPi {
> +
> +/*
> + * /dev/dma-heap/linux,cma is the dma-heap allocator, which allows dmaheap-cma to
> + * only have to worry about importing.
> + *
> + * Annoyingly, should the cma heap size be specified on the kernel command line
> + * instead of DT, the heap gets named "reserved" instead.
> + */
> +#define DMA_HEAP_CMA_NAME "/dev/dma_heap/linux,cma"
> +#define DMA_HEAP_CMA_ALT_NAME "/dev/dma_heap/reserved"
> +
> +class DmaHeap
> +{
> +public:
> +	DmaHeap()
> +	{
> +		dmaHeapHandle_ = ::open(DMA_HEAP_CMA_NAME, O_RDWR, 0);
> +		if (dmaHeapHandle_ == -1) {
> +			dmaHeapHandle_ = ::open(DMA_HEAP_CMA_ALT_NAME, O_RDWR, 0);
> +			if (dmaHeapHandle_ == -1) {
> +				LOG(RPI, Error) << "Could not open dmaHeap device";
> +			}
> +		}
> +	}
> +
> +	~DmaHeap()
> +	{
> +		if (dmaHeapHandle_)
> +			::close(dmaHeapHandle_);
> +	}
> +
> +	FileDescriptor alloc(const char *name, unsigned int size)

Maybe std::size_t instead of unsigned int ?

> +	{
> +		unsigned int pageSize = getpagesize();
> +		int ret;
> +
> +		if (!name)
> +			return FileDescriptor();

You can also write this

			return {};

(same below). Up to you.

> +
> +		/* Ask for page aligned allocation. */
> +		size = (size + pageSize - 1) & ~(pageSize - 1);
> +
> +		struct dma_heap_allocation_data alloc;
> +
> +		memset(&alloc, 0, sizeof(alloc));

These two lines can be replaced with

		struct dma_heap_allocation_data alloc = {};

> +		alloc.len = size;
> +		alloc.fd_flags = O_CLOEXEC | O_RDWR;
> +
> +		ret = ::ioctl(dmaHeapHandle_, DMA_HEAP_IOCTL_ALLOC, &alloc);
> +
> +		if (ret < 0) {
> +			LOG(RPI, Error) << "dmaHeap allocation failure for "
> +					<< name;
> +			return FileDescriptor();
> +		}
> +
> +		ret = ::ioctl(alloc.fd, DMA_BUF_SET_NAME, name);

What is the name used for, is it only for debugging purpose inside the
kernel, or does it have more uses ? Does the name have to be unique ?

> +		if (ret < 0) {
> +			LOG(RPI, Error) << "dmaHeap naming failure for "
> +					<< name;
> +			::close(alloc.fd);
> +			return FileDescriptor();
> +		}
> +
> +		return FileDescriptor(std::move(alloc.fd));
> +	}
> +
> +private:
> +	int dmaHeapHandle_;
> +};
> +
> +} /* namespace RPi */
> +
> +} /* namespace libcamera */
> +
> +#endif /* __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__ */
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index 7450062f..4486e04e 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -13,6 +13,7 @@
>  
>  #include <libcamera/camera.h>
>  #include <libcamera/control_ids.h>
> +#include <libcamera/file_descriptor.h>
>  #include <libcamera/formats.h>
>  #include <libcamera/ipa/raspberrypi.h>
>  #include <libcamera/logging.h>
> @@ -30,8 +31,8 @@
>  #include "libcamera/internal/v4l2_controls.h"
>  #include "libcamera/internal/v4l2_videodevice.h"
>  
> +#include "dma-heaps.h"
>  #include "staggered_ctrl.h"
> -#include "vcsm.h"
>  
>  namespace libcamera {
>  
> @@ -285,23 +286,13 @@ class RPiCameraData : public CameraData
>  {
>  public:
>  	RPiCameraData(PipelineHandler *pipe)
> -		: CameraData(pipe), sensor_(nullptr), lsTable_(nullptr),
> +		: CameraData(pipe), sensor_(nullptr), lsTable_(FileDescriptor()),

Same as above, just drop lsTable_.

>  		  state_(State::Stopped), dropFrame_(false), ispOutputCount_(0)
>  	{
>  	}
>  
>  	~RPiCameraData()
>  	{
> -		/*
> -		 * Free the LS table if we have allocated one. Another
> -		 * allocation will occur in applyLS() with the appropriate
> -		 * size.
> -		 */
> -		if (lsTable_) {
> -			vcsm_.free(lsTable_);
> -			lsTable_ = nullptr;
> -		}
> -
>  		/* Stop the IPA proxy thread. */
>  		if (ipa_)
>  			ipa_->stop();
> @@ -330,9 +321,9 @@ public:
>  	/* Buffers passed to the IPA. */
>  	std::vector<IPABuffer> ipaBuffers_;
>  
> -	/* VCSM allocation helper. */
> -	::RPi::Vcsm vcsm_;
> -	void *lsTable_;
> +	/* DMAHEAP allocation helper. */
> +	RPi::DmaHeap dmaHeap_;
> +	FileDescriptor lsTable_;
>  
>  	RPi::StaggeredCtrl staggeredCtrl_;
>  	uint32_t expectedSequence_;
> @@ -1006,27 +997,16 @@ int PipelineHandlerRPi::configureIPA(Camera *camera)
>  	entityControls.emplace(0, data->unicam_[Unicam::Image].dev()->controls());
>  	entityControls.emplace(1, data->isp_[Isp::Input].dev()->controls());
>  
> -	/* Allocate the lens shading table via vcsm and pass to the IPA. */
> -	if (!data->lsTable_) {
> -		data->lsTable_ = data->vcsm_.alloc("ls_grid", MAX_LS_GRID_SIZE);
> -		uintptr_t ptr = reinterpret_cast<uintptr_t>(data->lsTable_);
> -
> -		if (!data->lsTable_)
> +	/* Allocate the lens shading table via dmaHeap and pass to the IPA. */
> +	if (!data->lsTable_.isValid()) {
> +		data->lsTable_ = data->dmaHeap_.alloc("ls_grid", MAX_LS_GRID_SIZE);
> +		if (!data->lsTable_.isValid())
>  			return -ENOMEM;
>  
> -		/*
> -		 * The vcsm allocation will always be in the memory region
> -		 * < 32-bits to allow Videocore to access the memory.
> -		 *
> -		 * \todo Sending a pointer to the IPA is a workaround for
> -		 * vc_sm_cma not yet supporting dmabuf. This will not work with
> -		 * IPA module isolation and should be reworked when vc_sma_cma
> -		 * will permit.
> -		 */
> +		/* Allow the IPA to mmap the LS table via the file descriptor. */
>  		IPAOperationData op;
>  		op.operation = RPI_IPA_EVENT_LS_TABLE_ALLOCATION;
> -		op.data = { static_cast<uint32_t>(ptr & 0xffffffff),
> -			    data->vcsm_.getVCHandle(data->lsTable_) };
> +		op.data = { static_cast<unsigned int>(data->lsTable_.fd()) };

Very nice ! As the Raspberry Pi IPA runs in the same process without IPC
this change will not have an immediately visible effect, but it moves
towards more standard APIs and will allow us to test IPA isolation on
Raspberry Pi too.

On a side note, sending a file descriptor over IPC in a IPAOperationData
is not something we support currently, but that's a shortcoming of the
current implementation, not something you need to be concerned about.
We'll fix it as part of the ongoing work on IPC.

>  		data->ipa_->processEvent(op);
>  	}
>  
> diff --git a/src/libcamera/pipeline/raspberrypi/vcsm.h b/src/libcamera/pipeline/raspberrypi/vcsm.h
> deleted file mode 100644
> index bebe86a7..00000000
> --- a/src/libcamera/pipeline/raspberrypi/vcsm.h
> +++ /dev/null
> @@ -1,149 +0,0 @@
> -/* SPDX-License-Identifier: LGPL-2.1-or-later */
> -/*
> - * Copyright (C) 2019, Raspberry Pi (Trading) Limited
> - *
> - * vcsm.h - Helper class for vcsm allocations.
> - */
> -#ifndef __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__
> -#define __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__
> -
> -#include <iostream>
> -#include <mutex>
> -
> -#include <fcntl.h>
> -#include <linux/vc_sm_cma_ioctl.h>
> -#include <sys/ioctl.h>
> -#include <sys/mman.h>
> -#include <unistd.h>
> -
> -namespace RPi {
> -
> -#define VCSM_CMA_DEVICE_NAME "/dev/vcsm-cma"
> -
> -class Vcsm
> -{
> -public:
> -	Vcsm()
> -	{
> -		vcsmHandle_ = ::open(VCSM_CMA_DEVICE_NAME, O_RDWR, 0);
> -		if (vcsmHandle_ == -1) {
> -			std::cerr << "Could not open vcsm device: "
> -				  << VCSM_CMA_DEVICE_NAME;
> -		}
> -	}
> -
> -	~Vcsm()
> -	{
> -		/* Free all existing allocations. */
> -		auto it = allocMap_.begin();
> -		while (it != allocMap_.end())
> -			it = remove(it->first);
> -
> -		if (vcsmHandle_)
> -			::close(vcsmHandle_);
> -	}
> -
> -	void *alloc(const char *name, unsigned int size,
> -		    vc_sm_cma_cache_e cache = VC_SM_CMA_CACHE_NONE)
> -	{
> -		unsigned int pageSize = getpagesize();
> -		void *user_ptr;
> -		int ret;
> -
> -		if (!name)
> -			return nullptr;
> -
> -		/* Ask for page aligned allocation. */
> -		size = (size + pageSize - 1) & ~(pageSize - 1);
> -
> -		struct vc_sm_cma_ioctl_alloc alloc;
> -		memset(&alloc, 0, sizeof(alloc));
> -		alloc.size = size;
> -		alloc.num = 1;
> -		alloc.cached = cache;
> -		alloc.handle = 0;
> -		memcpy(alloc.name, name, 32);
> -
> -		ret = ::ioctl(vcsmHandle_, VC_SM_CMA_IOCTL_MEM_ALLOC, &alloc);
> -
> -		if (ret < 0 || alloc.handle < 0) {
> -			std::cerr << "vcsm allocation failure for "
> -				  << name << std::endl;
> -			return nullptr;
> -		}
> -
> -		/* Map the buffer into user space. */
> -		user_ptr = ::mmap(0, alloc.size, PROT_READ | PROT_WRITE,
> -				  MAP_SHARED, alloc.handle, 0);
> -
> -		if (user_ptr == MAP_FAILED) {
> -			std::cerr << "vcsm mmap failure for " << name << std::endl;
> -			::close(alloc.handle);
> -			return nullptr;
> -		}
> -
> -		std::lock_guard<std::mutex> lock(lock_);
> -		allocMap_.emplace(user_ptr, AllocInfo(alloc.handle,
> -						      alloc.size, alloc.vc_handle));
> -
> -		return user_ptr;
> -	}
> -
> -	void free(void *user_ptr)
> -	{
> -		std::lock_guard<std::mutex> lock(lock_);
> -		remove(user_ptr);
> -	}
> -
> -	unsigned int getVCHandle(void *user_ptr)
> -	{
> -		std::lock_guard<std::mutex> lock(lock_);
> -		auto it = allocMap_.find(user_ptr);
> -		if (it != allocMap_.end())
> -			return it->second.vcHandle;
> -
> -		return 0;
> -	}
> -
> -private:
> -	struct AllocInfo {
> -		AllocInfo(int handle_, int size_, int vcHandle_)
> -			: handle(handle_), size(size_), vcHandle(vcHandle_)
> -		{
> -		}
> -
> -		int handle;
> -		int size;
> -		uint32_t vcHandle;
> -	};
> -
> -	/* Map of all allocations that have been requested. */
> -	using AllocMap = std::map<void *, AllocInfo>;
> -
> -	AllocMap::iterator remove(void *user_ptr)
> -	{
> -		auto it = allocMap_.find(user_ptr);
> -		if (it != allocMap_.end()) {
> -			int handle = it->second.handle;
> -			int size = it->second.size;
> -			::munmap(user_ptr, size);
> -			::close(handle);
> -			/*
> -			 * Remove the allocation from the map. This returns
> -			 * an iterator to the next element.
> -			 */
> -			it = allocMap_.erase(it);
> -		}
> -
> -		/* Returns an iterator to the next element. */
> -		return it;
> -	}
> -
> -	AllocMap allocMap_;
> -	int vcsmHandle_;
> -	std::mutex lock_;
> -};
> -
> -} /* namespace RPi */
> -
> -#endif /* __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__ */

Hi Laurent,

Thank you for the review comments.

On Wed, 15 Jul 2020 at 00:06, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Naush,
>
> Thank you for the patch.
>
> On Tue, Jul 14, 2020 at 01:08:44PM +0100, Naushir Patuck wrote:
> > Remove use of vcsm allocations and replace with dma heap allocations.
> > The pipeline handler now passes the fd of the allocation over to the IPA
> > instead of the raw pointer.
>
> Nice :-)
>
> > Also use libcamera::FileDescriptor for fd lifetime management.
>
> Should the commit message mention the dependency on
> https://github.com/raspberrypi/linux/pull/3715 ?

Ack

>
> > Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
> > ---
> >  include/linux/bcm2835-isp.h                   |   4 +-
> >  include/linux/vc_sm_cma_ioctl.h               | 135 ----------------
> >  src/ipa/raspberrypi/raspberrypi.cpp           |  27 +++-
> >  .../pipeline/raspberrypi/dma-heaps.h          | 102 ++++++++++++
> >  .../pipeline/raspberrypi/raspberrypi.cpp      |  44 ++----
> >  src/libcamera/pipeline/raspberrypi/vcsm.h     | 149 ------------------
> >  6 files changed, 138 insertions(+), 323 deletions(-)
> >  delete mode 100644 include/linux/vc_sm_cma_ioctl.h
> >  create mode 100644 src/libcamera/pipeline/raspberrypi/dma-heaps.h
> >  delete mode 100644 src/libcamera/pipeline/raspberrypi/vcsm.h
> >
> > diff --git a/include/linux/bcm2835-isp.h b/include/linux/bcm2835-isp.h
> > index e7afc367..45abb681 100644
> > --- a/include/linux/bcm2835-isp.h
> > +++ b/include/linux/bcm2835-isp.h
> > @@ -108,7 +108,7 @@ enum bcm2835_isp_gain_format {
> >   * @grid_stride:     Row to row distance (in grid cells) between grid cells
> >   *                   in the same horizontal location.
> >   * @grid_height:     Height of lens shading tables in grid cells.
> > - * @mem_handle_table:        Memory handle to the tables.
> > + * @dmabuf:          dmabuf file handle containing the table.
> >   * @ref_transform:   Reference transform - unsupported, please pass zero.
> >   * @corner_sampled:  Whether the gains are sampled at the corner points
> >   *                   of the grid cells or in the cell centres.
> > @@ -120,7 +120,7 @@ struct bcm2835_isp_lens_shading {
> >       __u32 grid_width;
> >       __u32 grid_stride;
> >       __u32 grid_height;
> > -     __u32 mem_handle_table;
> > +     __s32 dmabuf;
> >       __u32 ref_transform;
> >       __u32 corner_sampled;
> >       __u32 gain_format;
> > diff --git a/include/linux/vc_sm_cma_ioctl.h b/include/linux/vc_sm_cma_ioctl.h
> > deleted file mode 100644
> > index 21b8758e..00000000
> > --- a/include/linux/vc_sm_cma_ioctl.h
> > +++ /dev/null
> > @@ -1,135 +0,0 @@
> > -/*
> > -Copyright (c) 2012, Broadcom Europe Ltd
> > -All rights reserved.
> > -
> > -Redistribution and use in source and binary forms, with or without
> > -modification, are permitted provided that the following conditions are met:
> > -    * Redistributions of source code must retain the above copyright
> > -      notice, this list of conditions and the following disclaimer.
> > -    * Redistributions in binary form must reproduce the above copyright
> > -      notice, this list of conditions and the following disclaimer in the
> > -      documentation and/or other materials provided with the distribution.
> > -    * Neither the name of the copyright holder nor the
> > -      names of its contributors may be used to endorse or promote products
> > -      derived from this software without specific prior written permission.
> > -
> > -THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
> > -ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
> > -WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
> > -DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
> > -DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
> > -(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
> > -LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
> > -ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> > -(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
> > -SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> > -*/
> > -
> > -/*
> > - * Copyright 2019 Raspberry Pi (Trading) Ltd.  All rights reserved.
> > - *
> > - * Based on vmcs_sm_ioctl.h Copyright Broadcom Corporation.
> > - */
> > -
> > -#ifndef __VC_SM_CMA_IOCTL_H
> > -#define __VC_SM_CMA_IOCTL_H
> > -
> > -/* ---- Include Files ---------------------------------------------------- */
> > -
> > -#include <linux/types.h>     /* Needed for standard types */
> > -
> > -#include <linux/ioctl.h>
> > -
> > -/* ---- Constants and Types ---------------------------------------------- */
> > -
> > -#define VC_SM_CMA_RESOURCE_NAME               32
> > -#define VC_SM_CMA_RESOURCE_NAME_DEFAULT       "sm-host-resource"
> > -
> > -/* Type define used to create unique IOCTL number */
> > -#define VC_SM_CMA_MAGIC_TYPE                  'J'
> > -
> > -/* IOCTL commands on /dev/vc-sm-cma */
> > -enum vc_sm_cma_cmd_e {
> > -     VC_SM_CMA_CMD_ALLOC = 0x5A,     /* Start at 0x5A arbitrarily */
> > -
> > -     VC_SM_CMA_CMD_IMPORT_DMABUF,
> > -
> > -     VC_SM_CMA_CMD_CLEAN_INVALID2,
> > -
> > -     VC_SM_CMA_CMD_LAST      /* Do not delete */
> > -};
> > -
> > -/* Cache type supported, conveniently matches the user space definition in
> > - * user-vcsm.h.
> > - */
> > -enum vc_sm_cma_cache_e {
> > -     VC_SM_CMA_CACHE_NONE,
> > -     VC_SM_CMA_CACHE_HOST,
> > -     VC_SM_CMA_CACHE_VC,
> > -     VC_SM_CMA_CACHE_BOTH,
> > -};
> > -
> > -/* IOCTL Data structures */
> > -struct vc_sm_cma_ioctl_alloc {
> > -     /* user -> kernel */
> > -     __u32 size;
> > -     __u32 num;
> > -     __u32 cached;           /* enum vc_sm_cma_cache_e */
> > -     __u32 pad;
> > -     __u8 name[VC_SM_CMA_RESOURCE_NAME];
> > -
> > -     /* kernel -> user */
> > -     __s32 handle;
> > -     __u32 vc_handle;
> > -     __u64 dma_addr;
> > -};
> > -
> > -struct vc_sm_cma_ioctl_import_dmabuf {
> > -     /* user -> kernel */
> > -     __s32 dmabuf_fd;
> > -     __u32 cached;           /* enum vc_sm_cma_cache_e */
> > -     __u8 name[VC_SM_CMA_RESOURCE_NAME];
> > -
> > -     /* kernel -> user */
> > -     __s32 handle;
> > -     __u32 vc_handle;
> > -     __u32 size;
> > -     __u32 pad;
> > -     __u64 dma_addr;
> > -};
> > -
> > -/*
> > - * Cache functions to be set to struct vc_sm_cma_ioctl_clean_invalid2
> > - * invalidate_mode.
> > - */
> > -#define VC_SM_CACHE_OP_NOP       0x00
> > -#define VC_SM_CACHE_OP_INV       0x01
> > -#define VC_SM_CACHE_OP_CLEAN     0x02
> > -#define VC_SM_CACHE_OP_FLUSH     0x03
> > -
> > -struct vc_sm_cma_ioctl_clean_invalid2 {
> > -     __u32 op_count;
> > -     __u32 pad;
> > -     struct vc_sm_cma_ioctl_clean_invalid_block {
> > -             __u32 invalidate_mode;
> > -             __u32 block_count;
> > -             void *  /*__user */start_address;
> > -             __u32 block_size;
> > -             __u32 inter_block_stride;
> > -     } s[0];
> > -};
> > -
> > -/* IOCTL numbers */
> > -#define VC_SM_CMA_IOCTL_MEM_ALLOC\
> > -     _IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_ALLOC,\
> > -      struct vc_sm_cma_ioctl_alloc)
> > -
> > -#define VC_SM_CMA_IOCTL_MEM_IMPORT_DMABUF\
> > -     _IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_IMPORT_DMABUF,\
> > -      struct vc_sm_cma_ioctl_import_dmabuf)
> > -
> > -#define VC_SM_CMA_IOCTL_MEM_CLEAN_INVALID2\
> > -     _IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_CLEAN_INVALID2,\
> > -      struct vc_sm_cma_ioctl_clean_invalid2)
> > -
> > -#endif /* __VC_SM_CMA_IOCTL_H */
> > diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
> > index b1f27861..562907e5 100644
> > --- a/src/ipa/raspberrypi/raspberrypi.cpp
> > +++ b/src/ipa/raspberrypi/raspberrypi.cpp
> > @@ -15,6 +15,7 @@
> >  #include <libcamera/buffer.h>
> >  #include <libcamera/control_ids.h>
> >  #include <libcamera/controls.h>
> > +#include <libcamera/file_descriptor.h>
> >  #include <libcamera/ipa/ipa_interface.h>
> >  #include <libcamera/ipa/ipa_module_info.h>
> >  #include <libcamera/ipa/raspberrypi.h>
> > @@ -65,12 +66,14 @@ public:
> >       IPARPi()
> >               : lastMode_({}), controller_(), controllerInit_(false),
> >                 frame_count_(0), check_count_(0), hide_count_(0),
> > -               mistrust_count_(0), lsTableHandle_(0), lsTable_(nullptr)
> > +               mistrust_count_(0), lsTableHandle_(FileDescriptor()), lsTable_(nullptr)
>
> You can write this
>
>                   mistrust_count_(0), lsTable_(nullptr)
>
> lsTableHandle_ is a FileDescriptor instance so it will be constructed
> using the default FileDescriptor constructor by default.

Ack

>
> >       {
> >       }
> >
> >       ~IPARPi()
> >       {
> > +             if (lsTable_)
> > +                     munmap(lsTable_, MAX_LS_GRID_SIZE);
> >       }
> >
> >       int init(const IPASettings &settings) override;
> > @@ -137,7 +140,7 @@ private:
> >       /* How many frames we should avoid running control algos on. */
> >       unsigned int mistrust_count_;
> >       /* LS table allocation passed in from the pipeline handler. */
> > -     uint32_t lsTableHandle_;
> > +     FileDescriptor lsTableHandle_;
> >       void *lsTable_;
> >  };
> >
> > @@ -357,8 +360,22 @@ void IPARPi::processEvent(const IPAOperationData &event)
> >       }
> >
> >       case RPI_IPA_EVENT_LS_TABLE_ALLOCATION: {
> > -             lsTable_ = reinterpret_cast<void *>(event.data[0]);
> > -             lsTableHandle_ = event.data[1];
> > +             /* Remove any previous table, if there was one. */
> > +             if (lsTable_)
> > +                     munmap(lsTable_, MAX_LS_GRID_SIZE);
>
>                         lsTable_ = nullptr;
>                 }

Ack

>
> otherwise if lsTableHandle_.isValid() fails you'll end up with lsTable_
> pointing to unmapped memory.
>
> > +
> > +             /* Map the LS table buffer into user space. */
> > +             lsTableHandle_ = FileDescriptor(event.data[0]);
> > +             if (lsTableHandle_.isValid()) {
> > +                     lsTable_ = mmap(nullptr, MAX_LS_GRID_SIZE, PROT_READ | PROT_WRITE,
> > +                                     MAP_SHARED, lsTableHandle_.fd(), 0);
> > +
> > +                     if (lsTable_ == MAP_FAILED) {
> > +                             LOG(IPARPI, Error) << "dmaHeap mmap failure for LS table.";
> > +                             lsTable_ = nullptr;
> > +                     }
> > +             }
> > +
> >               break;
> >       }
> >
> > @@ -1026,7 +1043,7 @@ void IPARPi::applyLS(const struct AlscStatus *lsStatus, ControlList &ctrls)
> >               .grid_width = w,
> >               .grid_stride = w,
> >               .grid_height = h,
> > -             .mem_handle_table = lsTableHandle_,
> > +             .dmabuf = lsTableHandle_.fd(),
> >               .ref_transform = 0,
> >               .corner_sampled = 1,
> >               .gain_format = GAIN_FORMAT_U4P10
> > diff --git a/src/libcamera/pipeline/raspberrypi/dma-heaps.h b/src/libcamera/pipeline/raspberrypi/dma-heaps.h
> > new file mode 100644
> > index 00000000..9f9137d8
> > --- /dev/null
> > +++ b/src/libcamera/pipeline/raspberrypi/dma-heaps.h
>
> Would you mind already splitting this into a .h and a .cpp file ? I
> foresee more users for dma heaps, so I'll likely move this to the
> libcamera core at some point.

Will do.

>
> > @@ -0,0 +1,102 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2020, Raspberry Pi (Trading) Limited
> > + *
> > + * dma-heap.h - Helper class for dma-heap allocations.
>
> s/heap/heaps/

Ack.

>
> > + */
> > +#ifndef __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> > +#define __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> > +
> > +#include <mutex>
> > +
> > +#include <fcntl.h>
> > +#include <linux/dma-buf.h>
> > +#include <linux/dma-heap.h>
> > +#include <sys/ioctl.h>
> > +#include <sys/mman.h>
> > +#include <unistd.h>
> > +
> > +#include <libcamera/file_descriptor.h>
> > +#include <libcamera/logging.h>
>
> logging.h is for the public API that allows modifying the log level.
> What you need here is libcamera/internal/log.h.

Ack.

>
> > +
> > +namespace libcamera {
> > +
> > +LOG_DECLARE_CATEGORY(RPI)
> > +
> > +namespace RPi {
> > +
> > +/*
> > + * /dev/dma-heap/linux,cma is the dma-heap allocator, which allows dmaheap-cma to
> > + * only have to worry about importing.
> > + *
> > + * Annoyingly, should the cma heap size be specified on the kernel command line
> > + * instead of DT, the heap gets named "reserved" instead.
> > + */
> > +#define DMA_HEAP_CMA_NAME "/dev/dma_heap/linux,cma"
> > +#define DMA_HEAP_CMA_ALT_NAME "/dev/dma_heap/reserved"
> > +
> > +class DmaHeap
> > +{
> > +public:
> > +     DmaHeap()
> > +     {
> > +             dmaHeapHandle_ = ::open(DMA_HEAP_CMA_NAME, O_RDWR, 0);
> > +             if (dmaHeapHandle_ == -1) {
> > +                     dmaHeapHandle_ = ::open(DMA_HEAP_CMA_ALT_NAME, O_RDWR, 0);
> > +                     if (dmaHeapHandle_ == -1) {
> > +                             LOG(RPI, Error) << "Could not open dmaHeap device";
> > +                     }
> > +             }
> > +     }
> > +
> > +     ~DmaHeap()
> > +     {
> > +             if (dmaHeapHandle_)
> > +                     ::close(dmaHeapHandle_);
> > +     }
> > +
> > +     FileDescriptor alloc(const char *name, unsigned int size)
>
> Maybe std::size_t instead of unsigned int ?

Ack.

>
> > +     {
> > +             unsigned int pageSize = getpagesize();
> > +             int ret;
> > +
> > +             if (!name)
> > +                     return FileDescriptor();
>
> You can also write this
>
>                         return {};
>
> (same below). Up to you.

If it's ok, I would prefer FileDescriptor() - feels more descriptive to me.

>
> > +
> > +             /* Ask for page aligned allocation. */
> > +             size = (size + pageSize - 1) & ~(pageSize - 1);
> > +
> > +             struct dma_heap_allocation_data alloc;
> > +
> > +             memset(&alloc, 0, sizeof(alloc));
>
> These two lines can be replaced with
>
>                 struct dma_heap_allocation_data alloc = {};

Ack

>
> > +             alloc.len = size;
> > +             alloc.fd_flags = O_CLOEXEC | O_RDWR;
> > +
> > +             ret = ::ioctl(dmaHeapHandle_, DMA_HEAP_IOCTL_ALLOC, &alloc);
> > +
> > +             if (ret < 0) {
> > +                     LOG(RPI, Error) << "dmaHeap allocation failure for "
> > +                                     << name;
> > +                     return FileDescriptor();
> > +             }
> > +
> > +             ret = ::ioctl(alloc.fd, DMA_BUF_SET_NAME, name);
>
> What is the name used for, is it only for debugging purpose inside the
> kernel, or does it have more uses ? Does the name have to be unique ?

It is only for debug purposes.  I don't think there is anything
enforcing them to be unique.

>
> > +             if (ret < 0) {
> > +                     LOG(RPI, Error) << "dmaHeap naming failure for "
> > +                                     << name;
> > +                     ::close(alloc.fd);
> > +                     return FileDescriptor();
> > +             }
> > +
> > +             return FileDescriptor(std::move(alloc.fd));
> > +     }
> > +
> > +private:
> > +     int dmaHeapHandle_;
> > +};
> > +
> > +} /* namespace RPi */
> > +
> > +} /* namespace libcamera */
> > +
> > +#endif /* __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__ */
> > diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > index 7450062f..4486e04e 100644
> > --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > @@ -13,6 +13,7 @@
> >
> >  #include <libcamera/camera.h>
> >  #include <libcamera/control_ids.h>
> > +#include <libcamera/file_descriptor.h>
> >  #include <libcamera/formats.h>
> >  #include <libcamera/ipa/raspberrypi.h>
> >  #include <libcamera/logging.h>
> > @@ -30,8 +31,8 @@
> >  #include "libcamera/internal/v4l2_controls.h"
> >  #include "libcamera/internal/v4l2_videodevice.h"
> >
> > +#include "dma-heaps.h"
> >  #include "staggered_ctrl.h"
> > -#include "vcsm.h"
> >
> >  namespace libcamera {
> >
> > @@ -285,23 +286,13 @@ class RPiCameraData : public CameraData
> >  {
> >  public:
> >       RPiCameraData(PipelineHandler *pipe)
> > -             : CameraData(pipe), sensor_(nullptr), lsTable_(nullptr),
> > +             : CameraData(pipe), sensor_(nullptr), lsTable_(FileDescriptor()),
>
> Same as above, just drop lsTable_.
>
> >                 state_(State::Stopped), dropFrame_(false), ispOutputCount_(0)
> >       {
> >       }
> >
> >       ~RPiCameraData()
> >       {
> > -             /*
> > -              * Free the LS table if we have allocated one. Another
> > -              * allocation will occur in applyLS() with the appropriate
> > -              * size.
> > -              */
> > -             if (lsTable_) {
> > -                     vcsm_.free(lsTable_);
> > -                     lsTable_ = nullptr;
> > -             }
> > -
> >               /* Stop the IPA proxy thread. */
> >               if (ipa_)
> >                       ipa_->stop();
> > @@ -330,9 +321,9 @@ public:
> >       /* Buffers passed to the IPA. */
> >       std::vector<IPABuffer> ipaBuffers_;
> >
> > -     /* VCSM allocation helper. */
> > -     ::RPi::Vcsm vcsm_;
> > -     void *lsTable_;
> > +     /* DMAHEAP allocation helper. */
> > +     RPi::DmaHeap dmaHeap_;
> > +     FileDescriptor lsTable_;
> >
> >       RPi::StaggeredCtrl staggeredCtrl_;
> >       uint32_t expectedSequence_;
> > @@ -1006,27 +997,16 @@ int PipelineHandlerRPi::configureIPA(Camera *camera)
> >       entityControls.emplace(0, data->unicam_[Unicam::Image].dev()->controls());
> >       entityControls.emplace(1, data->isp_[Isp::Input].dev()->controls());
> >
> > -     /* Allocate the lens shading table via vcsm and pass to the IPA. */
> > -     if (!data->lsTable_) {
> > -             data->lsTable_ = data->vcsm_.alloc("ls_grid", MAX_LS_GRID_SIZE);
> > -             uintptr_t ptr = reinterpret_cast<uintptr_t>(data->lsTable_);
> > -
> > -             if (!data->lsTable_)
> > +     /* Allocate the lens shading table via dmaHeap and pass to the IPA. */
> > +     if (!data->lsTable_.isValid()) {
> > +             data->lsTable_ = data->dmaHeap_.alloc("ls_grid", MAX_LS_GRID_SIZE);
> > +             if (!data->lsTable_.isValid())
> >                       return -ENOMEM;
> >
> > -             /*
> > -              * The vcsm allocation will always be in the memory region
> > -              * < 32-bits to allow Videocore to access the memory.
> > -              *
> > -              * \todo Sending a pointer to the IPA is a workaround for
> > -              * vc_sm_cma not yet supporting dmabuf. This will not work with
> > -              * IPA module isolation and should be reworked when vc_sma_cma
> > -              * will permit.
> > -              */
> > +             /* Allow the IPA to mmap the LS table via the file descriptor. */
> >               IPAOperationData op;
> >               op.operation = RPI_IPA_EVENT_LS_TABLE_ALLOCATION;
> > -             op.data = { static_cast<uint32_t>(ptr & 0xffffffff),
> > -                         data->vcsm_.getVCHandle(data->lsTable_) };
> > +             op.data = { static_cast<unsigned int>(data->lsTable_.fd()) };
>
> Very nice ! As the Raspberry Pi IPA runs in the same process without IPC
> this change will not have an immediately visible effect, but it moves
> towards more standard APIs and will allow us to test IPA isolation on
> Raspberry Pi too.
>
> On a side note, sending a file descriptor over IPC in a IPAOperationData
> is not something we support currently, but that's a shortcoming of the
> current implementation, not something you need to be concerned about.
> We'll fix it as part of the ongoing work on IPC.

Yes, I was hoping you would take care of that :-)

>
> >               data->ipa_->processEvent(op);
> >       }
> >
> > diff --git a/src/libcamera/pipeline/raspberrypi/vcsm.h b/src/libcamera/pipeline/raspberrypi/vcsm.h
> > deleted file mode 100644
> > index bebe86a7..00000000
> > --- a/src/libcamera/pipeline/raspberrypi/vcsm.h
> > +++ /dev/null
> > @@ -1,149 +0,0 @@
> > -/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > -/*
> > - * Copyright (C) 2019, Raspberry Pi (Trading) Limited
> > - *
> > - * vcsm.h - Helper class for vcsm allocations.
> > - */
> > -#ifndef __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__
> > -#define __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__
> > -
> > -#include <iostream>
> > -#include <mutex>
> > -
> > -#include <fcntl.h>
> > -#include <linux/vc_sm_cma_ioctl.h>
> > -#include <sys/ioctl.h>
> > -#include <sys/mman.h>
> > -#include <unistd.h>
> > -
> > -namespace RPi {
> > -
> > -#define VCSM_CMA_DEVICE_NAME "/dev/vcsm-cma"
> > -
> > -class Vcsm
> > -{
> > -public:
> > -     Vcsm()
> > -     {
> > -             vcsmHandle_ = ::open(VCSM_CMA_DEVICE_NAME, O_RDWR, 0);
> > -             if (vcsmHandle_ == -1) {
> > -                     std::cerr << "Could not open vcsm device: "
> > -                               << VCSM_CMA_DEVICE_NAME;
> > -             }
> > -     }
> > -
> > -     ~Vcsm()
> > -     {
> > -             /* Free all existing allocations. */
> > -             auto it = allocMap_.begin();
> > -             while (it != allocMap_.end())
> > -                     it = remove(it->first);
> > -
> > -             if (vcsmHandle_)
> > -                     ::close(vcsmHandle_);
> > -     }
> > -
> > -     void *alloc(const char *name, unsigned int size,
> > -                 vc_sm_cma_cache_e cache = VC_SM_CMA_CACHE_NONE)
> > -     {
> > -             unsigned int pageSize = getpagesize();
> > -             void *user_ptr;
> > -             int ret;
> > -
> > -             if (!name)
> > -                     return nullptr;
> > -
> > -             /* Ask for page aligned allocation. */
> > -             size = (size + pageSize - 1) & ~(pageSize - 1);
> > -
> > -             struct vc_sm_cma_ioctl_alloc alloc;
> > -             memset(&alloc, 0, sizeof(alloc));
> > -             alloc.size = size;
> > -             alloc.num = 1;
> > -             alloc.cached = cache;
> > -             alloc.handle = 0;
> > -             memcpy(alloc.name, name, 32);
> > -
> > -             ret = ::ioctl(vcsmHandle_, VC_SM_CMA_IOCTL_MEM_ALLOC, &alloc);
> > -
> > -             if (ret < 0 || alloc.handle < 0) {
> > -                     std::cerr << "vcsm allocation failure for "
> > -                               << name << std::endl;
> > -                     return nullptr;
> > -             }
> > -
> > -             /* Map the buffer into user space. */
> > -             user_ptr = ::mmap(0, alloc.size, PROT_READ | PROT_WRITE,
> > -                               MAP_SHARED, alloc.handle, 0);
> > -
> > -             if (user_ptr == MAP_FAILED) {
> > -                     std::cerr << "vcsm mmap failure for " << name << std::endl;
> > -                     ::close(alloc.handle);
> > -                     return nullptr;
> > -             }
> > -
> > -             std::lock_guard<std::mutex> lock(lock_);
> > -             allocMap_.emplace(user_ptr, AllocInfo(alloc.handle,
> > -                                                   alloc.size, alloc.vc_handle));
> > -
> > -             return user_ptr;
> > -     }
> > -
> > -     void free(void *user_ptr)
> > -     {
> > -             std::lock_guard<std::mutex> lock(lock_);
> > -             remove(user_ptr);
> > -     }
> > -
> > -     unsigned int getVCHandle(void *user_ptr)
> > -     {
> > -             std::lock_guard<std::mutex> lock(lock_);
> > -             auto it = allocMap_.find(user_ptr);
> > -             if (it != allocMap_.end())
> > -                     return it->second.vcHandle;
> > -
> > -             return 0;
> > -     }
> > -
> > -private:
> > -     struct AllocInfo {
> > -             AllocInfo(int handle_, int size_, int vcHandle_)
> > -                     : handle(handle_), size(size_), vcHandle(vcHandle_)
> > -             {
> > -             }
> > -
> > -             int handle;
> > -             int size;
> > -             uint32_t vcHandle;
> > -     };
> > -
> > -     /* Map of all allocations that have been requested. */
> > -     using AllocMap = std::map<void *, AllocInfo>;
> > -
> > -     AllocMap::iterator remove(void *user_ptr)
> > -     {
> > -             auto it = allocMap_.find(user_ptr);
> > -             if (it != allocMap_.end()) {
> > -                     int handle = it->second.handle;
> > -                     int size = it->second.size;
> > -                     ::munmap(user_ptr, size);
> > -                     ::close(handle);
> > -                     /*
> > -                      * Remove the allocation from the map. This returns
> > -                      * an iterator to the next element.
> > -                      */
> > -                     it = allocMap_.erase(it);
> > -             }
> > -
> > -             /* Returns an iterator to the next element. */
> > -             return it;
> > -     }
> > -
> > -     AllocMap allocMap_;
> > -     int vcsmHandle_;
> > -     std::mutex lock_;
> > -};
> > -
> > -} /* namespace RPi */
> > -
> > -#endif /* __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__ */
>
> --
> Regards,
>
> Laurent Pinchart

Will post and update with the changes shortly.

Regards,
Naush

Hi Laurent

On Wed, 15 Jul 2020 at 10:05, Naushir Patuck <naush@raspberrypi.com> wrote:
>
> Hi Laurent,
>
> Thank you for the review comments.
>
> On Wed, 15 Jul 2020 at 00:06, Laurent Pinchart
> <laurent.pinchart@ideasonboard.com> wrote:
> >
> > Hi Naush,
> >
> > Thank you for the patch.
> >
> > On Tue, Jul 14, 2020 at 01:08:44PM +0100, Naushir Patuck wrote:
> > > Remove use of vcsm allocations and replace with dma heap allocations.
> > > The pipeline handler now passes the fd of the allocation over to the IPA
> > > instead of the raw pointer.
> >
> > Nice :-)
> >
> > > Also use libcamera::FileDescriptor for fd lifetime management.
> >
> > Should the commit message mention the dependency on
> > https://github.com/raspberrypi/linux/pull/3715 ?
>
> Ack
>
> >
> > > Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
> > > ---
> > >  include/linux/bcm2835-isp.h                   |   4 +-
> > >  include/linux/vc_sm_cma_ioctl.h               | 135 ----------------
> > >  src/ipa/raspberrypi/raspberrypi.cpp           |  27 +++-
> > >  .../pipeline/raspberrypi/dma-heaps.h          | 102 ++++++++++++
> > >  .../pipeline/raspberrypi/raspberrypi.cpp      |  44 ++----
> > >  src/libcamera/pipeline/raspberrypi/vcsm.h     | 149 ------------------
> > >  6 files changed, 138 insertions(+), 323 deletions(-)
> > >  delete mode 100644 include/linux/vc_sm_cma_ioctl.h
> > >  create mode 100644 src/libcamera/pipeline/raspberrypi/dma-heaps.h
> > >  delete mode 100644 src/libcamera/pipeline/raspberrypi/vcsm.h
> > >
> > > diff --git a/include/linux/bcm2835-isp.h b/include/linux/bcm2835-isp.h
> > > index e7afc367..45abb681 100644
> > > --- a/include/linux/bcm2835-isp.h
> > > +++ b/include/linux/bcm2835-isp.h
> > > @@ -108,7 +108,7 @@ enum bcm2835_isp_gain_format {
> > >   * @grid_stride:     Row to row distance (in grid cells) between grid cells
> > >   *                   in the same horizontal location.
> > >   * @grid_height:     Height of lens shading tables in grid cells.
> > > - * @mem_handle_table:        Memory handle to the tables.
> > > + * @dmabuf:          dmabuf file handle containing the table.
> > >   * @ref_transform:   Reference transform - unsupported, please pass zero.
> > >   * @corner_sampled:  Whether the gains are sampled at the corner points
> > >   *                   of the grid cells or in the cell centres.
> > > @@ -120,7 +120,7 @@ struct bcm2835_isp_lens_shading {
> > >       __u32 grid_width;
> > >       __u32 grid_stride;
> > >       __u32 grid_height;
> > > -     __u32 mem_handle_table;
> > > +     __s32 dmabuf;
> > >       __u32 ref_transform;
> > >       __u32 corner_sampled;
> > >       __u32 gain_format;
> > > diff --git a/include/linux/vc_sm_cma_ioctl.h b/include/linux/vc_sm_cma_ioctl.h
> > > deleted file mode 100644
> > > index 21b8758e..00000000
> > > --- a/include/linux/vc_sm_cma_ioctl.h
> > > +++ /dev/null
> > > @@ -1,135 +0,0 @@
> > > -/*
> > > -Copyright (c) 2012, Broadcom Europe Ltd
> > > -All rights reserved.
> > > -
> > > -Redistribution and use in source and binary forms, with or without
> > > -modification, are permitted provided that the following conditions are met:
> > > -    * Redistributions of source code must retain the above copyright
> > > -      notice, this list of conditions and the following disclaimer.
> > > -    * Redistributions in binary form must reproduce the above copyright
> > > -      notice, this list of conditions and the following disclaimer in the
> > > -      documentation and/or other materials provided with the distribution.
> > > -    * Neither the name of the copyright holder nor the
> > > -      names of its contributors may be used to endorse or promote products
> > > -      derived from this software without specific prior written permission.
> > > -
> > > -THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
> > > -ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
> > > -WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
> > > -DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
> > > -DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
> > > -(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
> > > -LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
> > > -ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> > > -(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
> > > -SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> > > -*/
> > > -
> > > -/*
> > > - * Copyright 2019 Raspberry Pi (Trading) Ltd.  All rights reserved.
> > > - *
> > > - * Based on vmcs_sm_ioctl.h Copyright Broadcom Corporation.
> > > - */
> > > -
> > > -#ifndef __VC_SM_CMA_IOCTL_H
> > > -#define __VC_SM_CMA_IOCTL_H
> > > -
> > > -/* ---- Include Files ---------------------------------------------------- */
> > > -
> > > -#include <linux/types.h>     /* Needed for standard types */
> > > -
> > > -#include <linux/ioctl.h>
> > > -
> > > -/* ---- Constants and Types ---------------------------------------------- */
> > > -
> > > -#define VC_SM_CMA_RESOURCE_NAME               32
> > > -#define VC_SM_CMA_RESOURCE_NAME_DEFAULT       "sm-host-resource"
> > > -
> > > -/* Type define used to create unique IOCTL number */
> > > -#define VC_SM_CMA_MAGIC_TYPE                  'J'
> > > -
> > > -/* IOCTL commands on /dev/vc-sm-cma */
> > > -enum vc_sm_cma_cmd_e {
> > > -     VC_SM_CMA_CMD_ALLOC = 0x5A,     /* Start at 0x5A arbitrarily */
> > > -
> > > -     VC_SM_CMA_CMD_IMPORT_DMABUF,
> > > -
> > > -     VC_SM_CMA_CMD_CLEAN_INVALID2,
> > > -
> > > -     VC_SM_CMA_CMD_LAST      /* Do not delete */
> > > -};
> > > -
> > > -/* Cache type supported, conveniently matches the user space definition in
> > > - * user-vcsm.h.
> > > - */
> > > -enum vc_sm_cma_cache_e {
> > > -     VC_SM_CMA_CACHE_NONE,
> > > -     VC_SM_CMA_CACHE_HOST,
> > > -     VC_SM_CMA_CACHE_VC,
> > > -     VC_SM_CMA_CACHE_BOTH,
> > > -};
> > > -
> > > -/* IOCTL Data structures */
> > > -struct vc_sm_cma_ioctl_alloc {
> > > -     /* user -> kernel */
> > > -     __u32 size;
> > > -     __u32 num;
> > > -     __u32 cached;           /* enum vc_sm_cma_cache_e */
> > > -     __u32 pad;
> > > -     __u8 name[VC_SM_CMA_RESOURCE_NAME];
> > > -
> > > -     /* kernel -> user */
> > > -     __s32 handle;
> > > -     __u32 vc_handle;
> > > -     __u64 dma_addr;
> > > -};
> > > -
> > > -struct vc_sm_cma_ioctl_import_dmabuf {
> > > -     /* user -> kernel */
> > > -     __s32 dmabuf_fd;
> > > -     __u32 cached;           /* enum vc_sm_cma_cache_e */
> > > -     __u8 name[VC_SM_CMA_RESOURCE_NAME];
> > > -
> > > -     /* kernel -> user */
> > > -     __s32 handle;
> > > -     __u32 vc_handle;
> > > -     __u32 size;
> > > -     __u32 pad;
> > > -     __u64 dma_addr;
> > > -};
> > > -
> > > -/*
> > > - * Cache functions to be set to struct vc_sm_cma_ioctl_clean_invalid2
> > > - * invalidate_mode.
> > > - */
> > > -#define VC_SM_CACHE_OP_NOP       0x00
> > > -#define VC_SM_CACHE_OP_INV       0x01
> > > -#define VC_SM_CACHE_OP_CLEAN     0x02
> > > -#define VC_SM_CACHE_OP_FLUSH     0x03
> > > -
> > > -struct vc_sm_cma_ioctl_clean_invalid2 {
> > > -     __u32 op_count;
> > > -     __u32 pad;
> > > -     struct vc_sm_cma_ioctl_clean_invalid_block {
> > > -             __u32 invalidate_mode;
> > > -             __u32 block_count;
> > > -             void *  /*__user */start_address;
> > > -             __u32 block_size;
> > > -             __u32 inter_block_stride;
> > > -     } s[0];
> > > -};
> > > -
> > > -/* IOCTL numbers */
> > > -#define VC_SM_CMA_IOCTL_MEM_ALLOC\
> > > -     _IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_ALLOC,\
> > > -      struct vc_sm_cma_ioctl_alloc)
> > > -
> > > -#define VC_SM_CMA_IOCTL_MEM_IMPORT_DMABUF\
> > > -     _IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_IMPORT_DMABUF,\
> > > -      struct vc_sm_cma_ioctl_import_dmabuf)
> > > -
> > > -#define VC_SM_CMA_IOCTL_MEM_CLEAN_INVALID2\
> > > -     _IOR(VC_SM_CMA_MAGIC_TYPE, VC_SM_CMA_CMD_CLEAN_INVALID2,\
> > > -      struct vc_sm_cma_ioctl_clean_invalid2)
> > > -
> > > -#endif /* __VC_SM_CMA_IOCTL_H */
> > > diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
> > > index b1f27861..562907e5 100644
> > > --- a/src/ipa/raspberrypi/raspberrypi.cpp
> > > +++ b/src/ipa/raspberrypi/raspberrypi.cpp
> > > @@ -15,6 +15,7 @@
> > >  #include <libcamera/buffer.h>
> > >  #include <libcamera/control_ids.h>
> > >  #include <libcamera/controls.h>
> > > +#include <libcamera/file_descriptor.h>
> > >  #include <libcamera/ipa/ipa_interface.h>
> > >  #include <libcamera/ipa/ipa_module_info.h>
> > >  #include <libcamera/ipa/raspberrypi.h>
> > > @@ -65,12 +66,14 @@ public:
> > >       IPARPi()
> > >               : lastMode_({}), controller_(), controllerInit_(false),
> > >                 frame_count_(0), check_count_(0), hide_count_(0),
> > > -               mistrust_count_(0), lsTableHandle_(0), lsTable_(nullptr)
> > > +               mistrust_count_(0), lsTableHandle_(FileDescriptor()), lsTable_(nullptr)
> >
> > You can write this
> >
> >                   mistrust_count_(0), lsTable_(nullptr)
> >
> > lsTableHandle_ is a FileDescriptor instance so it will be constructed
> > using the default FileDescriptor constructor by default.
>
> Ack
>
> >
> > >       {
> > >       }
> > >
> > >       ~IPARPi()
> > >       {
> > > +             if (lsTable_)
> > > +                     munmap(lsTable_, MAX_LS_GRID_SIZE);
> > >       }
> > >
> > >       int init(const IPASettings &settings) override;
> > > @@ -137,7 +140,7 @@ private:
> > >       /* How many frames we should avoid running control algos on. */
> > >       unsigned int mistrust_count_;
> > >       /* LS table allocation passed in from the pipeline handler. */
> > > -     uint32_t lsTableHandle_;
> > > +     FileDescriptor lsTableHandle_;
> > >       void *lsTable_;
> > >  };
> > >
> > > @@ -357,8 +360,22 @@ void IPARPi::processEvent(const IPAOperationData &event)
> > >       }
> > >
> > >       case RPI_IPA_EVENT_LS_TABLE_ALLOCATION: {
> > > -             lsTable_ = reinterpret_cast<void *>(event.data[0]);
> > > -             lsTableHandle_ = event.data[1];
> > > +             /* Remove any previous table, if there was one. */
> > > +             if (lsTable_)
> > > +                     munmap(lsTable_, MAX_LS_GRID_SIZE);
> >
> >                         lsTable_ = nullptr;
> >                 }
>
> Ack
>
> >
> > otherwise if lsTableHandle_.isValid() fails you'll end up with lsTable_
> > pointing to unmapped memory.
> >
> > > +
> > > +             /* Map the LS table buffer into user space. */
> > > +             lsTableHandle_ = FileDescriptor(event.data[0]);
> > > +             if (lsTableHandle_.isValid()) {
> > > +                     lsTable_ = mmap(nullptr, MAX_LS_GRID_SIZE, PROT_READ | PROT_WRITE,
> > > +                                     MAP_SHARED, lsTableHandle_.fd(), 0);
> > > +
> > > +                     if (lsTable_ == MAP_FAILED) {
> > > +                             LOG(IPARPI, Error) << "dmaHeap mmap failure for LS table.";
> > > +                             lsTable_ = nullptr;
> > > +                     }
> > > +             }
> > > +
> > >               break;
> > >       }
> > >
> > > @@ -1026,7 +1043,7 @@ void IPARPi::applyLS(const struct AlscStatus *lsStatus, ControlList &ctrls)
> > >               .grid_width = w,
> > >               .grid_stride = w,
> > >               .grid_height = h,
> > > -             .mem_handle_table = lsTableHandle_,
> > > +             .dmabuf = lsTableHandle_.fd(),
> > >               .ref_transform = 0,
> > >               .corner_sampled = 1,
> > >               .gain_format = GAIN_FORMAT_U4P10
> > > diff --git a/src/libcamera/pipeline/raspberrypi/dma-heaps.h b/src/libcamera/pipeline/raspberrypi/dma-heaps.h
> > > new file mode 100644
> > > index 00000000..9f9137d8
> > > --- /dev/null
> > > +++ b/src/libcamera/pipeline/raspberrypi/dma-heaps.h
> >
> > Would you mind already splitting this into a .h and a .cpp file ? I
> > foresee more users for dma heaps, so I'll likely move this to the
> > libcamera core at some point.
>
> Will do.
>
> >
> > > @@ -0,0 +1,102 @@
> > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > +/*
> > > + * Copyright (C) 2020, Raspberry Pi (Trading) Limited
> > > + *
> > > + * dma-heap.h - Helper class for dma-heap allocations.
> >
> > s/heap/heaps/
>
> Ack.
>
> >
> > > + */
> > > +#ifndef __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> > > +#define __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__
> > > +
> > > +#include <mutex>
> > > +
> > > +#include <fcntl.h>
> > > +#include <linux/dma-buf.h>
> > > +#include <linux/dma-heap.h>
> > > +#include <sys/ioctl.h>
> > > +#include <sys/mman.h>
> > > +#include <unistd.h>
> > > +
> > > +#include <libcamera/file_descriptor.h>
> > > +#include <libcamera/logging.h>
> >
> > logging.h is for the public API that allows modifying the log level.
> > What you need here is libcamera/internal/log.h.
>
> Ack.
>
> >
> > > +
> > > +namespace libcamera {
> > > +
> > > +LOG_DECLARE_CATEGORY(RPI)
> > > +
> > > +namespace RPi {
> > > +
> > > +/*
> > > + * /dev/dma-heap/linux,cma is the dma-heap allocator, which allows dmaheap-cma to
> > > + * only have to worry about importing.
> > > + *
> > > + * Annoyingly, should the cma heap size be specified on the kernel command line
> > > + * instead of DT, the heap gets named "reserved" instead.
> > > + */
> > > +#define DMA_HEAP_CMA_NAME "/dev/dma_heap/linux,cma"
> > > +#define DMA_HEAP_CMA_ALT_NAME "/dev/dma_heap/reserved"
> > > +
> > > +class DmaHeap
> > > +{
> > > +public:
> > > +     DmaHeap()
> > > +     {
> > > +             dmaHeapHandle_ = ::open(DMA_HEAP_CMA_NAME, O_RDWR, 0);
> > > +             if (dmaHeapHandle_ == -1) {
> > > +                     dmaHeapHandle_ = ::open(DMA_HEAP_CMA_ALT_NAME, O_RDWR, 0);
> > > +                     if (dmaHeapHandle_ == -1) {
> > > +                             LOG(RPI, Error) << "Could not open dmaHeap device";
> > > +                     }
> > > +             }
> > > +     }
> > > +
> > > +     ~DmaHeap()
> > > +     {
> > > +             if (dmaHeapHandle_)
> > > +                     ::close(dmaHeapHandle_);
> > > +     }
> > > +
> > > +     FileDescriptor alloc(const char *name, unsigned int size)
> >
> > Maybe std::size_t instead of unsigned int ?
>
> Ack.
>
> >
> > > +     {
> > > +             unsigned int pageSize = getpagesize();
> > > +             int ret;
> > > +
> > > +             if (!name)
> > > +                     return FileDescriptor();
> >
> > You can also write this
> >
> >                         return {};
> >
> > (same below). Up to you.
>
> If it's ok, I would prefer FileDescriptor() - feels more descriptive to me.
>
> >
> > > +
> > > +             /* Ask for page aligned allocation. */
> > > +             size = (size + pageSize - 1) & ~(pageSize - 1);
> > > +
> > > +             struct dma_heap_allocation_data alloc;
> > > +
> > > +             memset(&alloc, 0, sizeof(alloc));
> >
> > These two lines can be replaced with
> >
> >                 struct dma_heap_allocation_data alloc = {};
>
> Ack
>
> >
> > > +             alloc.len = size;
> > > +             alloc.fd_flags = O_CLOEXEC | O_RDWR;
> > > +
> > > +             ret = ::ioctl(dmaHeapHandle_, DMA_HEAP_IOCTL_ALLOC, &alloc);
> > > +
> > > +             if (ret < 0) {
> > > +                     LOG(RPI, Error) << "dmaHeap allocation failure for "
> > > +                                     << name;
> > > +                     return FileDescriptor();
> > > +             }
> > > +
> > > +             ret = ::ioctl(alloc.fd, DMA_BUF_SET_NAME, name);
> >
> > What is the name used for, is it only for debugging purpose inside the
> > kernel, or does it have more uses ? Does the name have to be unique ?
>
> It is only for debug purposes.  I don't think there is anything
> enforcing them to be unique.

Yes, it's only debug. It should show up if you do cat
/sys/kernel/debug/dma_buf/bufinfo, otherwise you get a long list of
anonymous allocations and have to try to guess their usage based on
size and exporter.
No need for it to be unique.

Added in 5.3 - https://github.com/torvalds/linux/commit/bb2bb903042517b8fb17b2bc21e00512f2dcac01,
although there are a couple of later fixes.

> > > +             if (ret < 0) {
> > > +                     LOG(RPI, Error) << "dmaHeap naming failure for "
> > > +                                     << name;
> > > +                     ::close(alloc.fd);
> > > +                     return FileDescriptor();
> > > +             }
> > > +
> > > +             return FileDescriptor(std::move(alloc.fd));
> > > +     }
> > > +
> > > +private:
> > > +     int dmaHeapHandle_;
> > > +};
> > > +
> > > +} /* namespace RPi */
> > > +
> > > +} /* namespace libcamera */
> > > +
> > > +#endif /* __LIBCAMERA_PIPELINE_RASPBERRYPI_DMA_HEAPS_H__ */
> > > diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > > index 7450062f..4486e04e 100644
> > > --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > > +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> > > @@ -13,6 +13,7 @@
> > >
> > >  #include <libcamera/camera.h>
> > >  #include <libcamera/control_ids.h>
> > > +#include <libcamera/file_descriptor.h>
> > >  #include <libcamera/formats.h>
> > >  #include <libcamera/ipa/raspberrypi.h>
> > >  #include <libcamera/logging.h>
> > > @@ -30,8 +31,8 @@
> > >  #include "libcamera/internal/v4l2_controls.h"
> > >  #include "libcamera/internal/v4l2_videodevice.h"
> > >
> > > +#include "dma-heaps.h"
> > >  #include "staggered_ctrl.h"
> > > -#include "vcsm.h"
> > >
> > >  namespace libcamera {
> > >
> > > @@ -285,23 +286,13 @@ class RPiCameraData : public CameraData
> > >  {
> > >  public:
> > >       RPiCameraData(PipelineHandler *pipe)
> > > -             : CameraData(pipe), sensor_(nullptr), lsTable_(nullptr),
> > > +             : CameraData(pipe), sensor_(nullptr), lsTable_(FileDescriptor()),
> >
> > Same as above, just drop lsTable_.
> >
> > >                 state_(State::Stopped), dropFrame_(false), ispOutputCount_(0)
> > >       {
> > >       }
> > >
> > >       ~RPiCameraData()
> > >       {
> > > -             /*
> > > -              * Free the LS table if we have allocated one. Another
> > > -              * allocation will occur in applyLS() with the appropriate
> > > -              * size.
> > > -              */
> > > -             if (lsTable_) {
> > > -                     vcsm_.free(lsTable_);
> > > -                     lsTable_ = nullptr;
> > > -             }
> > > -
> > >               /* Stop the IPA proxy thread. */
> > >               if (ipa_)
> > >                       ipa_->stop();
> > > @@ -330,9 +321,9 @@ public:
> > >       /* Buffers passed to the IPA. */
> > >       std::vector<IPABuffer> ipaBuffers_;
> > >
> > > -     /* VCSM allocation helper. */
> > > -     ::RPi::Vcsm vcsm_;
> > > -     void *lsTable_;
> > > +     /* DMAHEAP allocation helper. */
> > > +     RPi::DmaHeap dmaHeap_;
> > > +     FileDescriptor lsTable_;
> > >
> > >       RPi::StaggeredCtrl staggeredCtrl_;
> > >       uint32_t expectedSequence_;
> > > @@ -1006,27 +997,16 @@ int PipelineHandlerRPi::configureIPA(Camera *camera)
> > >       entityControls.emplace(0, data->unicam_[Unicam::Image].dev()->controls());
> > >       entityControls.emplace(1, data->isp_[Isp::Input].dev()->controls());
> > >
> > > -     /* Allocate the lens shading table via vcsm and pass to the IPA. */
> > > -     if (!data->lsTable_) {
> > > -             data->lsTable_ = data->vcsm_.alloc("ls_grid", MAX_LS_GRID_SIZE);
> > > -             uintptr_t ptr = reinterpret_cast<uintptr_t>(data->lsTable_);
> > > -
> > > -             if (!data->lsTable_)
> > > +     /* Allocate the lens shading table via dmaHeap and pass to the IPA. */
> > > +     if (!data->lsTable_.isValid()) {
> > > +             data->lsTable_ = data->dmaHeap_.alloc("ls_grid", MAX_LS_GRID_SIZE);
> > > +             if (!data->lsTable_.isValid())
> > >                       return -ENOMEM;
> > >
> > > -             /*
> > > -              * The vcsm allocation will always be in the memory region
> > > -              * < 32-bits to allow Videocore to access the memory.
> > > -              *
> > > -              * \todo Sending a pointer to the IPA is a workaround for
> > > -              * vc_sm_cma not yet supporting dmabuf. This will not work with
> > > -              * IPA module isolation and should be reworked when vc_sma_cma
> > > -              * will permit.
> > > -              */
> > > +             /* Allow the IPA to mmap the LS table via the file descriptor. */
> > >               IPAOperationData op;
> > >               op.operation = RPI_IPA_EVENT_LS_TABLE_ALLOCATION;
> > > -             op.data = { static_cast<uint32_t>(ptr & 0xffffffff),
> > > -                         data->vcsm_.getVCHandle(data->lsTable_) };
> > > +             op.data = { static_cast<unsigned int>(data->lsTable_.fd()) };
> >
> > Very nice ! As the Raspberry Pi IPA runs in the same process without IPC
> > this change will not have an immediately visible effect, but it moves
> > towards more standard APIs and will allow us to test IPA isolation on
> > Raspberry Pi too.
> >
> > On a side note, sending a file descriptor over IPC in a IPAOperationData
> > is not something we support currently, but that's a shortcoming of the
> > current implementation, not something you need to be concerned about.
> > We'll fix it as part of the ongoing work on IPC.
>
> Yes, I was hoping you would take care of that :-)
>
> >
> > >               data->ipa_->processEvent(op);
> > >       }
> > >
> > > diff --git a/src/libcamera/pipeline/raspberrypi/vcsm.h b/src/libcamera/pipeline/raspberrypi/vcsm.h
> > > deleted file mode 100644
> > > index bebe86a7..00000000
> > > --- a/src/libcamera/pipeline/raspberrypi/vcsm.h
> > > +++ /dev/null
> > > @@ -1,149 +0,0 @@
> > > -/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > -/*
> > > - * Copyright (C) 2019, Raspberry Pi (Trading) Limited
> > > - *
> > > - * vcsm.h - Helper class for vcsm allocations.
> > > - */
> > > -#ifndef __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__
> > > -#define __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__
> > > -
> > > -#include <iostream>
> > > -#include <mutex>
> > > -
> > > -#include <fcntl.h>
> > > -#include <linux/vc_sm_cma_ioctl.h>
> > > -#include <sys/ioctl.h>
> > > -#include <sys/mman.h>
> > > -#include <unistd.h>
> > > -
> > > -namespace RPi {
> > > -
> > > -#define VCSM_CMA_DEVICE_NAME "/dev/vcsm-cma"
> > > -
> > > -class Vcsm
> > > -{
> > > -public:
> > > -     Vcsm()
> > > -     {
> > > -             vcsmHandle_ = ::open(VCSM_CMA_DEVICE_NAME, O_RDWR, 0);
> > > -             if (vcsmHandle_ == -1) {
> > > -                     std::cerr << "Could not open vcsm device: "
> > > -                               << VCSM_CMA_DEVICE_NAME;
> > > -             }
> > > -     }
> > > -
> > > -     ~Vcsm()
> > > -     {
> > > -             /* Free all existing allocations. */
> > > -             auto it = allocMap_.begin();
> > > -             while (it != allocMap_.end())
> > > -                     it = remove(it->first);
> > > -
> > > -             if (vcsmHandle_)
> > > -                     ::close(vcsmHandle_);
> > > -     }
> > > -
> > > -     void *alloc(const char *name, unsigned int size,
> > > -                 vc_sm_cma_cache_e cache = VC_SM_CMA_CACHE_NONE)
> > > -     {
> > > -             unsigned int pageSize = getpagesize();
> > > -             void *user_ptr;
> > > -             int ret;
> > > -
> > > -             if (!name)
> > > -                     return nullptr;
> > > -
> > > -             /* Ask for page aligned allocation. */
> > > -             size = (size + pageSize - 1) & ~(pageSize - 1);
> > > -
> > > -             struct vc_sm_cma_ioctl_alloc alloc;
> > > -             memset(&alloc, 0, sizeof(alloc));
> > > -             alloc.size = size;
> > > -             alloc.num = 1;
> > > -             alloc.cached = cache;
> > > -             alloc.handle = 0;
> > > -             memcpy(alloc.name, name, 32);
> > > -
> > > -             ret = ::ioctl(vcsmHandle_, VC_SM_CMA_IOCTL_MEM_ALLOC, &alloc);
> > > -
> > > -             if (ret < 0 || alloc.handle < 0) {
> > > -                     std::cerr << "vcsm allocation failure for "
> > > -                               << name << std::endl;
> > > -                     return nullptr;
> > > -             }
> > > -
> > > -             /* Map the buffer into user space. */
> > > -             user_ptr = ::mmap(0, alloc.size, PROT_READ | PROT_WRITE,
> > > -                               MAP_SHARED, alloc.handle, 0);
> > > -
> > > -             if (user_ptr == MAP_FAILED) {
> > > -                     std::cerr << "vcsm mmap failure for " << name << std::endl;
> > > -                     ::close(alloc.handle);
> > > -                     return nullptr;
> > > -             }
> > > -
> > > -             std::lock_guard<std::mutex> lock(lock_);
> > > -             allocMap_.emplace(user_ptr, AllocInfo(alloc.handle,
> > > -                                                   alloc.size, alloc.vc_handle));
> > > -
> > > -             return user_ptr;
> > > -     }
> > > -
> > > -     void free(void *user_ptr)
> > > -     {
> > > -             std::lock_guard<std::mutex> lock(lock_);
> > > -             remove(user_ptr);
> > > -     }
> > > -
> > > -     unsigned int getVCHandle(void *user_ptr)
> > > -     {
> > > -             std::lock_guard<std::mutex> lock(lock_);
> > > -             auto it = allocMap_.find(user_ptr);
> > > -             if (it != allocMap_.end())
> > > -                     return it->second.vcHandle;
> > > -
> > > -             return 0;
> > > -     }
> > > -
> > > -private:
> > > -     struct AllocInfo {
> > > -             AllocInfo(int handle_, int size_, int vcHandle_)
> > > -                     : handle(handle_), size(size_), vcHandle(vcHandle_)
> > > -             {
> > > -             }
> > > -
> > > -             int handle;
> > > -             int size;
> > > -             uint32_t vcHandle;
> > > -     };
> > > -
> > > -     /* Map of all allocations that have been requested. */
> > > -     using AllocMap = std::map<void *, AllocInfo>;
> > > -
> > > -     AllocMap::iterator remove(void *user_ptr)
> > > -     {
> > > -             auto it = allocMap_.find(user_ptr);
> > > -             if (it != allocMap_.end()) {
> > > -                     int handle = it->second.handle;
> > > -                     int size = it->second.size;
> > > -                     ::munmap(user_ptr, size);
> > > -                     ::close(handle);
> > > -                     /*
> > > -                      * Remove the allocation from the map. This returns
> > > -                      * an iterator to the next element.
> > > -                      */
> > > -                     it = allocMap_.erase(it);
> > > -             }
> > > -
> > > -             /* Returns an iterator to the next element. */
> > > -             return it;
> > > -     }
> > > -
> > > -     AllocMap allocMap_;
> > > -     int vcsmHandle_;
> > > -     std::mutex lock_;
> > > -};
> > > -
> > > -} /* namespace RPi */
> > > -
> > > -#endif /* __LIBCAMERA_PIPELINE_RASPBERRYPI_VCSM_H__ */
> >
> > --
> > Regards,
> >
> > Laurent Pinchart
>
> Will post and update with the changes shortly.
>
> Regards,
> Naush
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