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/* SPDX-License-Identifier: BSD-2-Clause */
/*
* 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__ */
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