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Commit 3417f33e authored by George Sapountzis's avatar George Sapountzis Committed by airlied
Browse files

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: default avatarDave Airlie <airlied@linux.ie>
parent 5c2df2bf

drivers/char/drm/drm.h

+2 −1
Original line number Diff line number Diff line
@@ -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

drivers/char/drm/drmP.h

+2 −1
Original line number Diff line number Diff line
@@ -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;

drivers/char/drm/drm_bufs.c

+7 −3
Original line number Diff line number Diff line
@@ -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)

drivers/char/drm/drm_vm.c

+16 −0
Original line number Diff line number Diff line
@@ -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 */