Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ebb043f2 authored by Tom St Denis's avatar Tom St Denis Committed by Alex Deucher
Browse files

drm/amdgpu: replace iova debugfs file with iomem (v3) 



This allows access to pages allocated through the driver with optional
IOMMU mapping.

v2: Fix number of bytes copied and add write method
v3: drop check for kmap return

Original-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarTom St Denis <tom.stdenis@amd.com>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 65e4b490

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

+81 −21
Original line number Diff line number Diff line
@@ -1957,38 +1957,98 @@ static const struct file_operations amdgpu_ttm_gtt_fops = { 


#endif



static ssize_t amdgpu_iova_to_phys_read(struct file *f, char __user *buf,

static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,

				 size_t size, loff_t *pos)

{

	struct amdgpu_device *adev = file_inode(f)->i_private;

	int r;

	uint64_t phys;

	struct iommu_domain *dom;

	ssize_t result = 0;

	int r;



	// always return 8 bytes

	if (size != 8)

		return -EINVAL;

	dom = iommu_get_domain_for_dev(adev->dev);



	// only accept page addresses

	if (*pos & 0xFFF)

		return -EINVAL;

	while (size) {

		phys_addr_t addr = *pos & PAGE_MASK;

		loff_t off = *pos & ~PAGE_MASK;

		size_t bytes = PAGE_SIZE - off;

		unsigned long pfn;

		struct page *p;

		void *ptr;



		bytes = bytes < size ? bytes : size;



		addr = dom ? iommu_iova_to_phys(dom, addr) : addr;



		pfn = addr >> PAGE_SHIFT;

		if (!pfn_valid(pfn))

			return -EPERM;



		p = pfn_to_page(pfn);

		if (p->mapping != adev->mman.bdev.dev_mapping)

			return -EPERM;



		ptr = kmap(p);

		r = copy_to_user(buf, ptr, bytes);

		kunmap(p);

		if (r)

			return -EFAULT;



		size -= bytes;

		*pos += bytes;

		result += bytes;

	}



	return result;

}



static ssize_t amdgpu_iomem_write(struct file *f, const char __user *buf,

				 size_t size, loff_t *pos)

{

	struct amdgpu_device *adev = file_inode(f)->i_private;

	struct iommu_domain *dom;

	ssize_t result = 0;

	int r;



	dom = iommu_get_domain_for_dev(adev->dev);

	if (dom)

		phys = iommu_iova_to_phys(dom, *pos);

	else

		phys = *pos;



	r = copy_to_user(buf, &phys, 8);

	while (size) {

		phys_addr_t addr = *pos & PAGE_MASK;

		loff_t off = *pos & ~PAGE_MASK;

		size_t bytes = PAGE_SIZE - off;

		unsigned long pfn;

		struct page *p;

		void *ptr;



		bytes = bytes < size ? bytes : size;



		addr = dom ? iommu_iova_to_phys(dom, addr) : addr;



		pfn = addr >> PAGE_SHIFT;

		if (!pfn_valid(pfn))

			return -EPERM;



		p = pfn_to_page(pfn);

		if (p->mapping != adev->mman.bdev.dev_mapping)

			return -EPERM;



		ptr = kmap(p);

		r = copy_from_user(ptr, buf, bytes);

		kunmap(p);

		if (r)

			return -EFAULT;



	return 8;

		size -= bytes;

		*pos += bytes;

		result += bytes;

	}



	return result;

}



static const struct file_operations amdgpu_ttm_iova_fops = {

static const struct file_operations amdgpu_ttm_iomem_fops = {

	.owner = THIS_MODULE,

	.read = amdgpu_iova_to_phys_read,

	.read = amdgpu_iomem_read,

	.write = amdgpu_iomem_write,

	.llseek = default_llseek

};
@@ -2001,7 +2061,7 @@ static const struct { 
#ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS

	{ "amdgpu_gtt", &amdgpu_ttm_gtt_fops, TTM_PL_TT },

#endif

	{ "amdgpu_iova", &amdgpu_ttm_iova_fops, TTM_PL_SYSTEM },

	{ "amdgpu_iomem", &amdgpu_ttm_iomem_fops, TTM_PL_SYSTEM },

};



#endif