From 38290b2c456ade70db7cedf489332af5e4263fb0 Mon Sep 17 00:00:00 2001 From: Tom St Denis Date: Mon, 18 Sep 2017 07:28:14 -0400 Subject: [PATCH] drm/amd/amdgpu: add support for iova_to_phys to replace TTM trace (v5) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Tom St Denis Reviewed-by: Christian König Signed-off-by: Alex Deucher (v2): Add domain to iova debugfs (v3): Add true read/write methods to access system memory of pages mapped to the device (v4): Move get_domain call out of loop and return on error (v5): Just use kmap/kunmap --- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 99 +++++++++++++++++++++++++ 1 file changed, 99 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 50d20903de4f4..c7f8e081a7724 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -43,6 +43,7 @@ #include #include #include +#include #include "amdgpu.h" #include "amdgpu_trace.h" #include "bif/bif_4_1_d.h" @@ -1809,7 +1810,104 @@ 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) +{ + struct amdgpu_device *adev = file_inode(f)->i_private; + ssize_t result, n; + int r; + uint64_t phys; + void *ptr; + struct iommu_domain *dom; + + dom = iommu_get_domain_for_dev(adev->dev); + if (!dom) + return -EFAULT; + + result = 0; + while (size) { + // get physical address and map + phys = iommu_iova_to_phys(dom, *pos); + + // copy upto one page + if (size > PAGE_SIZE) + n = PAGE_SIZE; + else + n = size; + + // to end of the page + if (((*pos & (PAGE_SIZE - 1)) + n) >= PAGE_SIZE) + n = PAGE_SIZE - (*pos & (PAGE_SIZE - 1)); + + ptr = kmap(pfn_to_page(PFN_DOWN(phys))); + if (!ptr) + return -EFAULT; + + r = copy_to_user(buf, ptr, n); + kunmap(pfn_to_page(PFN_DOWN(phys))); + if (r) + return -EFAULT; + + *pos += n; + size -= n; + result += n; + } + + return result; +} + +static ssize_t amdgpu_iova_to_phys_write(struct file *f, const char __user *buf, + size_t size, loff_t *pos) +{ + struct amdgpu_device *adev = file_inode(f)->i_private; + ssize_t result, n; + int r; + uint64_t phys; + void *ptr; + struct iommu_domain *dom; + + dom = iommu_get_domain_for_dev(adev->dev); + if (!dom) + return -EFAULT; + + result = 0; + while (size) { + // get physical address and map + phys = iommu_iova_to_phys(dom, *pos); + // copy upto one page + if (size > PAGE_SIZE) + n = PAGE_SIZE; + else + n = size; + + // to end of the page + if (((*pos & (PAGE_SIZE - 1)) + n) >= PAGE_SIZE) + n = PAGE_SIZE - (*pos & (PAGE_SIZE - 1)); + + ptr = kmap(pfn_to_page(PFN_DOWN(phys))); + if (!ptr) + return -EFAULT; + + r = copy_from_user(ptr, buf, n); + kunmap(pfn_to_page(PFN_DOWN(phys))); + if (r) + return -EFAULT; + + *pos += n; + size -= n; + result += n; + } + + return result; +} + +static const struct file_operations amdgpu_ttm_iova_fops = { + .owner = THIS_MODULE, + .read = amdgpu_iova_to_phys_read, + .write = amdgpu_iova_to_phys_write, + .llseek = default_llseek +}; static const struct { char *name; @@ -1820,6 +1918,7 @@ 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 }, }; #endif -- 2.39.5