xref: /openbmc/linux/drivers/gpu/drm/drm_pci.c (revision 545e4006)
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 				dma_addr_t maxaddr)
52 {
53 	drm_dma_handle_t *dmah;
54 #if 1
55 	unsigned long addr;
56 	size_t sz;
57 #endif
58 #ifdef DRM_DEBUG_MEMORY
59 	int area = DRM_MEM_DMA;
60 
61 	spin_lock(&drm_mem_lock);
62 	if ((drm_ram_used >> PAGE_SHIFT)
63 	    > (DRM_RAM_PERCENT * drm_ram_available) / 100) {
64 		spin_unlock(&drm_mem_lock);
65 		return 0;
66 	}
67 	spin_unlock(&drm_mem_lock);
68 #endif
69 
70 	/* pci_alloc_consistent only guarantees alignment to the smallest
71 	 * PAGE_SIZE order which is greater than or equal to the requested size.
72 	 * Return NULL here for now to make sure nobody tries for larger alignment
73 	 */
74 	if (align > size)
75 		return NULL;
76 
77 	if (pci_set_dma_mask(dev->pdev, maxaddr) != 0) {
78 		DRM_ERROR("Setting pci dma mask failed\n");
79 		return NULL;
80 	}
81 
82 	dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
83 	if (!dmah)
84 		return NULL;
85 
86 	dmah->size = size;
87 	dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL | __GFP_COMP);
88 
89 #ifdef DRM_DEBUG_MEMORY
90 	if (dmah->vaddr == NULL) {
91 		spin_lock(&drm_mem_lock);
92 		++drm_mem_stats[area].fail_count;
93 		spin_unlock(&drm_mem_lock);
94 		kfree(dmah);
95 		return NULL;
96 	}
97 
98 	spin_lock(&drm_mem_lock);
99 	++drm_mem_stats[area].succeed_count;
100 	drm_mem_stats[area].bytes_allocated += size;
101 	drm_ram_used += size;
102 	spin_unlock(&drm_mem_lock);
103 #else
104 	if (dmah->vaddr == NULL) {
105 		kfree(dmah);
106 		return NULL;
107 	}
108 #endif
109 
110 	memset(dmah->vaddr, 0, size);
111 
112 	/* XXX - Is virt_to_page() legal for consistent mem? */
113 	/* Reserve */
114 	for (addr = (unsigned long)dmah->vaddr, sz = size;
115 	     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
116 		SetPageReserved(virt_to_page(addr));
117 	}
118 
119 	return dmah;
120 }
121 
122 EXPORT_SYMBOL(drm_pci_alloc);
123 
124 /**
125  * \brief Free a PCI consistent memory block without freeing its descriptor.
126  *
127  * This function is for internal use in the Linux-specific DRM core code.
128  */
129 void __drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
130 {
131 #if 1
132 	unsigned long addr;
133 	size_t sz;
134 #endif
135 #ifdef DRM_DEBUG_MEMORY
136 	int area = DRM_MEM_DMA;
137 	int alloc_count;
138 	int free_count;
139 #endif
140 
141 	if (!dmah->vaddr) {
142 #ifdef DRM_DEBUG_MEMORY
143 		DRM_MEM_ERROR(area, "Attempt to free address 0\n");
144 #endif
145 	} else {
146 		/* XXX - Is virt_to_page() legal for consistent mem? */
147 		/* Unreserve */
148 		for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
149 		     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
150 			ClearPageReserved(virt_to_page(addr));
151 		}
152 		dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
153 				  dmah->busaddr);
154 	}
155 
156 #ifdef DRM_DEBUG_MEMORY
157 	spin_lock(&drm_mem_lock);
158 	free_count = ++drm_mem_stats[area].free_count;
159 	alloc_count = drm_mem_stats[area].succeed_count;
160 	drm_mem_stats[area].bytes_freed += size;
161 	drm_ram_used -= size;
162 	spin_unlock(&drm_mem_lock);
163 	if (free_count > alloc_count) {
164 		DRM_MEM_ERROR(area,
165 			      "Excess frees: %d frees, %d allocs\n",
166 			      free_count, alloc_count);
167 	}
168 #endif
169 
170 }
171 
172 /**
173  * \brief Free a PCI consistent memory block
174  */
175 void drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
176 {
177 	__drm_pci_free(dev, dmah);
178 	kfree(dmah);
179 }
180 
181 EXPORT_SYMBOL(drm_pci_free);
182 
183 /*@}*/
184