drm/radeon: add VRAM debugfs access v3
Not very fast, but makes it possible to access even the
normally inaccessible parts of VRAM from userspace.
v2: use MM_INDEX_HI for >2GB mem access, 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>
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 2059237..a29d7cb 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -39,12 +39,14 @@
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/swiotlb.h>
+#include <linux/debugfs.h>
#include "radeon_reg.h"
#include "radeon.h"
#define DRM_FILE_PAGE_OFFSET (0x100000000ULL >> PAGE_SHIFT)
static int radeon_ttm_debugfs_init(struct radeon_device *rdev);
+static void radeon_ttm_debugfs_fini(struct radeon_device *rdev);
static struct radeon_device *radeon_get_rdev(struct ttm_bo_device *bdev)
{
@@ -753,6 +755,7 @@
if (!rdev->mman.initialized)
return;
+ radeon_ttm_debugfs_fini(rdev);
if (rdev->stollen_vga_memory) {
r = radeon_bo_reserve(rdev->stollen_vga_memory, false);
if (r == 0) {
@@ -862,12 +865,75 @@
#endif
};
+static int radeon_ttm_vram_open(struct inode *inode, struct file *filep)
+{
+ struct radeon_device *rdev = inode->i_private;
+ i_size_write(inode, rdev->mc.mc_vram_size);
+ filep->private_data = inode->i_private;
+ return 0;
+}
+
+static ssize_t radeon_ttm_vram_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;
+
+ if (size & 0x3 || *pos & 0x3)
+ return -EINVAL;
+
+ while (size) {
+ unsigned long flags;
+ uint32_t value;
+
+ if (*pos >= rdev->mc.mc_vram_size)
+ return result;
+
+ spin_lock_irqsave(&rdev->mmio_idx_lock, flags);
+ WREG32(RADEON_MM_INDEX, ((uint32_t)*pos) | 0x80000000);
+ if (rdev->family >= CHIP_CEDAR)
+ WREG32(EVERGREEN_MM_INDEX_HI, *pos >> 31);
+ value = RREG32(RADEON_MM_DATA);
+ spin_unlock_irqrestore(&rdev->mmio_idx_lock, flags);
+
+ r = put_user(value, (uint32_t *)buf);
+ if (r)
+ return r;
+
+ result += 4;
+ buf += 4;
+ *pos += 4;
+ size -= 4;
+ }
+
+ return result;
+}
+
+static const struct file_operations radeon_ttm_vram_fops = {
+ .owner = THIS_MODULE,
+ .open = radeon_ttm_vram_open,
+ .read = radeon_ttm_vram_read,
+ .llseek = default_llseek
+};
+
#endif
static int radeon_ttm_debugfs_init(struct radeon_device *rdev)
{
#if defined(CONFIG_DEBUG_FS)
- unsigned count = ARRAY_SIZE(radeon_ttm_debugfs_list);
+ unsigned count;
+
+ struct drm_minor *minor = rdev->ddev->primary;
+ struct dentry *ent, *root = minor->debugfs_root;
+
+ ent = debugfs_create_file("radeon_vram", S_IFREG | S_IRUGO, root,
+ rdev, &radeon_ttm_vram_fops);
+ if (IS_ERR(ent))
+ return PTR_ERR(ent);
+ rdev->mman.vram = ent;
+
+ count = ARRAY_SIZE(radeon_ttm_debugfs_list);
#ifdef CONFIG_SWIOTLB
if (!swiotlb_nr_tbl())
@@ -880,3 +946,12 @@
return 0;
#endif
}
+
+static void radeon_ttm_debugfs_fini(struct radeon_device *rdev)
+{
+#if defined(CONFIG_DEBUG_FS)
+
+ debugfs_remove(rdev->mman.vram);
+ rdev->mman.vram = NULL;
+#endif
+}