Bug 6242: [mach64] Use private DMA buffers, part #3.
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.
diff --git a/libdrm/xf86drm.h b/libdrm/xf86drm.h
index 2ad7080..d58baa7 100644
--- a/libdrm/xf86drm.h
+++ b/libdrm/xf86drm.h
@@ -149,7 +149,8 @@
DRM_PAGE_ALIGN = 0x01,
DRM_AGP_BUFFER = 0x02,
DRM_SG_BUFFER = 0x04,
- DRM_FB_BUFFER = 0x08
+ DRM_FB_BUFFER = 0x08,
+ DRM_PCI_BUFFER_RO = 0x10
} drmBufDescFlags;
typedef enum {
diff --git a/linux-core/drmP.h b/linux-core/drmP.h
index 5c9644e..2bbec70 100644
--- a/linux-core/drmP.h
+++ b/linux-core/drmP.h
@@ -449,7 +449,8 @@
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/linux-core/drm_bufs.c b/linux-core/drm_bufs.c
index abd7c82..a2a3dbf 100644
--- a/linux-core/drm_bufs.c
+++ b/linux-core/drm_bufs.c
@@ -942,6 +942,9 @@
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;
@@ -1528,9 +1531,10 @@
* \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/linux-core/drm_vm.c b/linux-core/drm_vm.c
index 9672269..adff7d1 100644
--- a/linux-core/drm_vm.c
+++ b/linux-core/drm_vm.c
@@ -506,6 +506,22 @@
}
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;
#if LINUX_VERSION_CODE <= 0x02040e /* KERNEL_VERSION(2,4,14) */
diff --git a/shared-core/drm.h b/shared-core/drm.h
index 7f90a96..8c0c5d2 100644
--- a/shared-core/drm.h
+++ b/shared-core/drm.h
@@ -416,7 +416,8 @@
_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