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authorGeorge Sapountzis <gsap7@yahoo.gr>2006-10-24 12:03:04 -0700
committerairlied <airlied@linux.ie>2006-12-07 15:53:31 +1100
commit3417f33e762bf7d4277031a655e3ad07e73ce0be (patch)
tree255d4871a0a7affbeab8d35f5b072a70ef064cfd /drivers/char
parent5c2df2bfb121a77d925dba580f53da08b4020528 (diff)
downloadblackbird-op-linux-3417f33e762bf7d4277031a655e3ad07e73ce0be.tar.gz
blackbird-op-linux-3417f33e762bf7d4277031a655e3ad07e73ce0be.zip
drm: add flag for mapping PCI DMA buffers read-only.
Add DRM_PCI_BUFFER_RO flag for mapping PCI DMA buffer read-only. An additional flag is needed, since PCI DMA buffers do not have an associated map. Signed-off-by: Dave Airlie <airlied@linux.ie>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/drm/drm.h3
-rw-r--r--drivers/char/drm/drmP.h3
-rw-r--r--drivers/char/drm/drm_bufs.c10
-rw-r--r--drivers/char/drm/drm_vm.c16
4 files changed, 27 insertions, 5 deletions
diff --git a/drivers/char/drm/drm.h b/drivers/char/drm/drm.h
index 3f28a1551621..8db9041e306c 100644
--- a/drivers/char/drm/drm.h
+++ b/drivers/char/drm/drm.h
@@ -356,7 +356,8 @@ typedef struct drm_buf_desc {
_DRM_PAGE_ALIGN = 0x01, /**< Align on page boundaries for DMA */
_DRM_AGP_BUFFER = 0x02, /**< Buffer is in AGP space */
_DRM_SG_BUFFER = 0x04, /**< Scatter/gather memory buffer */
- _DRM_FB_BUFFER = 0x08 /**< Buffer is in frame buffer */
+ _DRM_FB_BUFFER = 0x08, /**< Buffer is in frame buffer */
+ _DRM_PCI_BUFFER_RO = 0x10 /**< Map PCI DMA buffer read-only */
} flags;
unsigned long agp_start; /**<
* Start address of where the AGP buffers are
diff --git a/drivers/char/drm/drmP.h b/drivers/char/drm/drmP.h
index 2f18329c5eb8..0bbb04f2390f 100644
--- a/drivers/char/drm/drmP.h
+++ b/drivers/char/drm/drmP.h
@@ -431,7 +431,8 @@ typedef struct drm_device_dma {
enum {
_DRM_DMA_USE_AGP = 0x01,
_DRM_DMA_USE_SG = 0x02,
- _DRM_DMA_USE_FB = 0x04
+ _DRM_DMA_USE_FB = 0x04,
+ _DRM_DMA_USE_PCI_RO = 0x08
} flags;
} drm_device_dma_t;
diff --git a/drivers/char/drm/drm_bufs.c b/drivers/char/drm/drm_bufs.c
index 6eafff13dab6..9f65f5697ba8 100644
--- a/drivers/char/drm/drm_bufs.c
+++ b/drivers/char/drm/drm_bufs.c
@@ -887,6 +887,9 @@ int drm_addbufs_pci(drm_device_t * dev, drm_buf_desc_t * request)
request->count = entry->buf_count;
request->size = size;
+ if (request->flags & _DRM_PCI_BUFFER_RO)
+ dma->flags = _DRM_DMA_USE_PCI_RO;
+
atomic_dec(&dev->buf_alloc);
return 0;
@@ -1471,9 +1474,10 @@ int drm_freebufs(struct inode *inode, struct file *filp,
* \param arg pointer to a drm_buf_map structure.
* \return zero on success or a negative number on failure.
*
- * Maps the AGP or SG buffer region with do_mmap(), and copies information
- * about each buffer into user space. The PCI buffers are already mapped on the
- * addbufs_pci() call.
+ * Maps the AGP, SG or PCI buffer region with do_mmap(), and copies information
+ * about each buffer into user space. For PCI buffers, it calls do_mmap() with
+ * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
+ * drm_mmap_dma().
*/
int drm_mapbufs(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
diff --git a/drivers/char/drm/drm_vm.c b/drivers/char/drm/drm_vm.c
index b40ae438f531..74686e9a2d34 100644
--- a/drivers/char/drm/drm_vm.c
+++ b/drivers/char/drm/drm_vm.c
@@ -473,6 +473,22 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
}
unlock_kernel();
+ if (!capable(CAP_SYS_ADMIN) &&
+ (dma->flags & _DRM_DMA_USE_PCI_RO)) {
+ vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
+#if defined(__i386__) || defined(__x86_64__)
+ pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
+#else
+ /* Ye gads this is ugly. With more thought
+ we could move this up higher and use
+ `protection_map' instead. */
+ vma->vm_page_prot =
+ __pgprot(pte_val
+ (pte_wrprotect
+ (__pte(pgprot_val(vma->vm_page_prot)))));
+#endif
+ }
+
vma->vm_ops = &drm_vm_dma_ops;
vma->vm_flags |= VM_RESERVED; /* Don't swap */
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