xref: /openbmc/linux/drivers/gpu/drm/drm_pci.c (revision 7dd65feb)
1 /* drm_pci.h -- PCI DMA memory management wrappers for DRM -*- linux-c -*- */
2 /**
3  * \file drm_pci.c
4  * \brief Functions and ioctls to manage PCI memory
5  *
6  * \warning These interfaces aren't stable yet.
7  *
8  * \todo Implement the remaining ioctl's for the PCI pools.
9  * \todo The wrappers here are so thin that they would be better off inlined..
10  *
11  * \author José Fonseca <jrfonseca@tungstengraphics.com>
12  * \author Leif Delgass <ldelgass@retinalburn.net>
13  */
14 
15 /*
16  * Copyright 2003 José Fonseca.
17  * Copyright 2003 Leif Delgass.
18  * All Rights Reserved.
19  *
20  * Permission is hereby granted, free of charge, to any person obtaining a
21  * copy of this software and associated documentation files (the "Software"),
22  * to deal in the Software without restriction, including without limitation
23  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
24  * and/or sell copies of the Software, and to permit persons to whom the
25  * Software is furnished to do so, subject to the following conditions:
26  *
27  * The above copyright notice and this permission notice (including the next
28  * paragraph) shall be included in all copies or substantial portions of the
29  * Software.
30  *
31  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
32  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
33  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
34  * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
35  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
36  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
37  */
38 
39 #include <linux/pci.h>
40 #include <linux/dma-mapping.h>
41 #include "drmP.h"
42 
43 /**********************************************************************/
44 /** \name PCI memory */
45 /*@{*/
46 
47 /**
48  * \brief Allocate a PCI consistent memory block, for DMA.
49  */
50 drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t align)
51 {
52 	drm_dma_handle_t *dmah;
53 #if 1
54 	unsigned long addr;
55 	size_t sz;
56 #endif
57 
58 	/* pci_alloc_consistent only guarantees alignment to the smallest
59 	 * PAGE_SIZE order which is greater than or equal to the requested size.
60 	 * Return NULL here for now to make sure nobody tries for larger alignment
61 	 */
62 	if (align > size)
63 		return NULL;
64 
65 	dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
66 	if (!dmah)
67 		return NULL;
68 
69 	dmah->size = size;
70 	dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL | __GFP_COMP);
71 
72 	if (dmah->vaddr == NULL) {
73 		kfree(dmah);
74 		return NULL;
75 	}
76 
77 	memset(dmah->vaddr, 0, size);
78 
79 	/* XXX - Is virt_to_page() legal for consistent mem? */
80 	/* Reserve */
81 	for (addr = (unsigned long)dmah->vaddr, sz = size;
82 	     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
83 		SetPageReserved(virt_to_page(addr));
84 	}
85 
86 	return dmah;
87 }
88 
89 EXPORT_SYMBOL(drm_pci_alloc);
90 
91 /**
92  * \brief Free a PCI consistent memory block without freeing its descriptor.
93  *
94  * This function is for internal use in the Linux-specific DRM core code.
95  */
96 void __drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
97 {
98 #if 1
99 	unsigned long addr;
100 	size_t sz;
101 #endif
102 
103 	if (dmah->vaddr) {
104 		/* XXX - Is virt_to_page() legal for consistent mem? */
105 		/* Unreserve */
106 		for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
107 		     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
108 			ClearPageReserved(virt_to_page(addr));
109 		}
110 		dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
111 				  dmah->busaddr);
112 	}
113 }
114 
115 /**
116  * \brief Free a PCI consistent memory block
117  */
118 void drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
119 {
120 	__drm_pci_free(dev, dmah);
121 	kfree(dmah);
122 }
123 
124 EXPORT_SYMBOL(drm_pci_free);
125 
126 /*@}*/
127