From ebb043f267511a6e6ba2ee92e0146552432e8db2 Mon Sep 17 00:00:00 2001 From: Tom St Denis Date: Fri, 23 Feb 2018 09:46:23 -0500 Subject: [PATCH] drm/amdgpu: replace iova debugfs file with iomem (v3) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: Christian König Signed-off-by: Tom St Denis Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 102 +++++++++++++++++++----- 1 file changed, 81 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index b19a4f7a845e..28c33d711bab 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -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, - size_t size, loff_t *pos) +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); - if (r) - return -EFAULT; + 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; - return 8; + 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; + + 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 -- 2.30.2