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* [PATCH] drm/amdgpu: replace iova debugfs file with iomem (v2)
@ 2018-02-09 17:27 Tom St Denis
       [not found] ` <20180209172750.15675-1-tom.stdenis-5C7GfCeVMHo@public.gmane.org>
  0 siblings, 1 reply; 8+ messages in thread
From: Tom St Denis @ 2018-02-09 17:27 UTC (permalink / raw)
  To: amd-gfx; +Cc: Tom St Denis, Christian König, dri-devel

From: Christian König <ckoenig.leichtzumerken@gmail.com>

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

v2: Fix number of bytes copied and add write method

Original-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 110 ++++++++++++++++++++++++++------
 1 file changed, 89 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index b372d8d650a5..d6c56b001a2c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1929,38 +1929,106 @@ 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);
+		if (ptr) {
+			r = copy_to_user(buf, ptr, bytes);
+			kunmap(p);
+			if (r)
+				return -EFAULT;
+		} else {
+			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;
+
+		addr = dom ? iommu_iova_to_phys(dom, addr) : addr;
 
-	return 8;
+		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);
+		if (ptr) {
+			r = copy_from_user(ptr, buf, bytes);
+			kunmap(p);
+			if (r)
+				return -EFAULT;
+		} else {
+			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
 };
 
@@ -1973,7 +2041,7 @@ 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
-- 
2.14.3

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end of thread, other threads:[~2018-02-12 19:08 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-09 17:27 [PATCH] drm/amdgpu: replace iova debugfs file with iomem (v2) Tom St Denis
     [not found] ` <20180209172750.15675-1-tom.stdenis-5C7GfCeVMHo@public.gmane.org>
2018-02-09 17:28   ` Tom St Denis
     [not found]     ` <4708aad9-9ff0-d09f-9bb6-453c01c848a4-5C7GfCeVMHo@public.gmane.org>
2018-02-09 18:17       ` Christian König
     [not found]         ` <50edcafc-23dd-3c44-021f-cf5989d06dc2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-02-09 18:19           ` Tom St Denis
2018-02-09 18:44             ` Christian König
     [not found]               ` <50cdbb8f-3b64-bed3-322c-bcce05b39370-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-02-12 16:40                 ` Tom St Denis
2018-02-12 17:16                   ` Christian König
     [not found]                     ` <8c42ceb6-4c95-d82f-d347-37ee793855a6-5C7GfCeVMHo@public.gmane.org>
2018-02-12 19:08                       ` Tom St Denis

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