1 /*
2 * ioremap.c
3 *
4 * Support for mapping between dma_addr_t values a phys_addr_t values.
5 *
6 * Copyright (C) 2005-2009 Scientific-Atlanta, Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 * Author: David VomLehn <dvomlehn@cisco.com>
23 *
24 * Description: Defines the platform resources for the SA settop.
25 *
26 * NOTE: The bootloader allocates persistent memory at an address which is
27 * 16 MiB below the end of the highest address in KSEG0. All fixed
28 * address memory reservations must avoid this region.
29 */
30
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33
34 #include <asm/mach-powertv/ioremap.h>
35
36 /*
37 * Define the sizes of and masks for grains in physical and DMA space. The
38 * values are the same but the types are not.
39 */
40 #define IOR_PHYS_GRAIN ((phys_addr_t) 1 << IOR_LSBITS)
41 #define IOR_PHYS_GRAIN_MASK (IOR_PHYS_GRAIN - 1)
42
43 #define IOR_DMA_GRAIN ((dma_addr_t) 1 << IOR_LSBITS)
44 #define IOR_DMA_GRAIN_MASK (IOR_DMA_GRAIN - 1)
45
46 /*
47 * Values that, when accessed by an index derived from a phys_addr_t and
48 * added to phys_addr_t value, yield a DMA address
49 */
50 struct ior_phys_to_dma _ior_phys_to_dma[IOR_NUM_PHYS_TO_DMA];
51 EXPORT_SYMBOL(_ior_phys_to_dma);
52
53 /*
54 * Values that, when accessed by an index derived from a dma_addr_t and
55 * added to that dma_addr_t value, yield a physical address
56 */
57 struct ior_dma_to_phys _ior_dma_to_phys[IOR_NUM_DMA_TO_PHYS];
58 EXPORT_SYMBOL(_ior_dma_to_phys);
59
60 /**
61 * setup_dma_to_phys - set up conversion from DMA to physical addresses
62 * @dma_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
63 * into the array _dma_to_phys.
64 * @delta: Value that, when added to the DMA address, will yield the
65 * physical address
66 * @s: Number of bytes in the section of memory with the given delta
67 * between DMA and physical addresses.
68 */
setup_dma_to_phys(dma_addr_t dma,phys_addr_t delta,dma_addr_t s)69 static void setup_dma_to_phys(dma_addr_t dma, phys_addr_t delta, dma_addr_t s)
70 {
71 int dma_idx, first_idx, last_idx;
72 phys_addr_t first, last;
73
74 /*
75 * Calculate the first and last indices, rounding the first up and
76 * the second down.
77 */
78 first = dma & ~IOR_DMA_GRAIN_MASK;
79 last = (dma + s - 1) & ~IOR_DMA_GRAIN_MASK;
80 first_idx = first >> IOR_LSBITS; /* Convert to indices */
81 last_idx = last >> IOR_LSBITS;
82
83 for (dma_idx = first_idx; dma_idx <= last_idx; dma_idx++)
84 _ior_dma_to_phys[dma_idx].offset = delta >> IOR_DMA_SHIFT;
85 }
86
87 /**
88 * setup_phys_to_dma - set up conversion from DMA to physical addresses
89 * @phys_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
90 * into the array _phys_to_dma.
91 * @delta: Value that, when added to the DMA address, will yield the
92 * physical address
93 * @s: Number of bytes in the section of memory with the given delta
94 * between DMA and physical addresses.
95 */
setup_phys_to_dma(phys_addr_t phys,dma_addr_t delta,phys_addr_t s)96 static void setup_phys_to_dma(phys_addr_t phys, dma_addr_t delta, phys_addr_t s)
97 {
98 int phys_idx, first_idx, last_idx;
99 phys_addr_t first, last;
100
101 /*
102 * Calculate the first and last indices, rounding the first up and
103 * the second down.
104 */
105 first = phys & ~IOR_PHYS_GRAIN_MASK;
106 last = (phys + s - 1) & ~IOR_PHYS_GRAIN_MASK;
107 first_idx = first >> IOR_LSBITS; /* Convert to indices */
108 last_idx = last >> IOR_LSBITS;
109
110 for (phys_idx = first_idx; phys_idx <= last_idx; phys_idx++)
111 _ior_phys_to_dma[phys_idx].offset = delta >> IOR_PHYS_SHIFT;
112 }
113
114 /**
115 * ioremap_add_map - add to the physical and DMA address conversion arrays
116 * @phys: Process's view of the address of the start of the memory chunk
117 * @dma: DMA address of the start of the memory chunk
118 * @size: Size, in bytes, of the chunk of memory
119 *
120 * NOTE: It might be obvious, but the assumption is that all @size bytes have
121 * the same offset between the physical address and the DMA address.
122 */
ioremap_add_map(phys_addr_t phys,phys_addr_t dma,phys_addr_t size)123 void ioremap_add_map(phys_addr_t phys, phys_addr_t dma, phys_addr_t size)
124 {
125 if (size == 0)
126 return;
127
128 if ((dma & IOR_DMA_GRAIN_MASK) != 0 ||
129 (phys & IOR_PHYS_GRAIN_MASK) != 0 ||
130 (size & IOR_PHYS_GRAIN_MASK) != 0)
131 pr_crit("Memory allocation must be in chunks of 0x%x bytes\n",
132 IOR_PHYS_GRAIN);
133
134 setup_dma_to_phys(dma, phys - dma, size);
135 setup_phys_to_dma(phys, dma - phys, size);
136 }
137