drm/radeon: add GART debugfs access v3

v2: add default_llseek
v3: set inode size in the open callback

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 64 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 49f210c14796..572476b61d89 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -416,6 +416,7 @@ struct radeon_mman {
 
 #if defined(CONFIG_DEBUG_FS)
         struct dentry                   *vram;
+        struct dentry                   *gtt;
 #endif
 };
 
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index a29d7cbd62e7..77f5b0c3edb8 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -917,6 +917,60 @@ static const struct file_operations radeon_ttm_vram_fops = {
         .llseek = default_llseek
 };
 
+static int radeon_ttm_gtt_open(struct inode *inode, struct file *filep)
+{
+        struct radeon_device *rdev = inode->i_private;
+        i_size_write(inode, rdev->mc.gtt_size);
+        filep->private_data = inode->i_private;
+        return 0;
+}
+
+static ssize_t radeon_ttm_gtt_read(struct file *f, char __user *buf,
+                                   size_t size, loff_t *pos)
+{
+        struct radeon_device *rdev = f->private_data;
+        ssize_t result = 0;
+        int r;
+
+        while (size) {
+                loff_t p = *pos / PAGE_SIZE;
+                unsigned off = *pos & ~PAGE_MASK;
+                ssize_t cur_size = min(size, PAGE_SIZE - off);
+                struct page *page;
+                void *ptr;
+
+                if (p >= rdev->gart.num_cpu_pages)
+                        return result;
+
+                page = rdev->gart.pages[p];
+                if (page) {
+                        ptr = kmap(page);
+                        ptr += off;
+
+                        r = copy_to_user(buf, ptr, cur_size);
+                        kunmap(rdev->gart.pages[p]);
+                } else
+                        r = clear_user(buf, cur_size);
+
+                if (r)
+                        return -EFAULT;
+
+                result += cur_size;
+                buf += cur_size;
+                *pos += cur_size;
+                size -= cur_size;
+        }
+
+        return result;
+}
+
+static const struct file_operations radeon_ttm_gtt_fops = {
+        .owner = THIS_MODULE,
+        .open = radeon_ttm_gtt_open,
+        .read = radeon_ttm_gtt_read,
+        .llseek = default_llseek
+};
+
 #endif
 
 static int radeon_ttm_debugfs_init(struct radeon_device *rdev)
@@ -933,6 +987,12 @@ static int radeon_ttm_debugfs_init(struct radeon_device *rdev)
                 return PTR_ERR(ent);
         rdev->mman.vram = ent;
 
+        ent = debugfs_create_file("radeon_gtt", S_IFREG | S_IRUGO, root,
+                                  rdev, &radeon_ttm_gtt_fops);
+        if (IS_ERR(ent))
+                return PTR_ERR(ent);
+        rdev->mman.gtt = ent;
+
         count = ARRAY_SIZE(radeon_ttm_debugfs_list);
 
 #ifdef CONFIG_SWIOTLB
@@ -953,5 +1013,8 @@ static void radeon_ttm_debugfs_fini(struct radeon_device *rdev)
 
         debugfs_remove(rdev->mman.vram);
         rdev->mman.vram = NULL;
+
+        debugfs_remove(rdev->mman.gtt);
+        rdev->mman.gtt = NULL;
 #endif
 }