1/*
2 * Based on linux/arch/arm/pmsa-v7.c
3 *
4 * ARM PMSAv8 supporting functions.
5 */
6
7#include <linux/memblock.h>
8#include <linux/range.h>
9
10#include <asm/cp15.h>
11#include <asm/cputype.h>
12#include <asm/mpu.h>
13
14#include <asm/page.h>
15#include <asm/sections.h>
16
17#include "mm.h"
18
19#ifndef CONFIG_CPU_V7M
20
21#define PRSEL __ACCESS_CP15(c6, 0, c2, 1)
22#define PRBAR __ACCESS_CP15(c6, 0, c3, 0)
23#define PRLAR __ACCESS_CP15(c6, 0, c3, 1)
24
25static inline u32 prlar_read(void)
26{
27 return read_sysreg(PRLAR);
28}
29
30static inline u32 prbar_read(void)
31{
32 return read_sysreg(PRBAR);
33}
34
35static inline void prsel_write(u32 v)
36{
37 write_sysreg(v, PRSEL);
38}
39
40static inline void prbar_write(u32 v)
41{
42 write_sysreg(v, PRBAR);
43}
44
45static inline void prlar_write(u32 v)
46{
47 write_sysreg(v, PRLAR);
48}
49#else
50
51static inline u32 prlar_read(void)
52{
53 return readl_relaxed(BASEADDR_V7M_SCB + PMSAv8_RLAR);
54}
55
56static inline u32 prbar_read(void)
57{
58 return readl_relaxed(BASEADDR_V7M_SCB + PMSAv8_RBAR);
59}
60
61static inline void prsel_write(u32 v)
62{
63 writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RNR);
64}
65
66static inline void prbar_write(u32 v)
67{
68 writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RBAR);
69}
70
71static inline void prlar_write(u32 v)
72{
73 writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RLAR);
74}
75
76#endif
77
78static struct range __initdata io[MPU_MAX_REGIONS];
79static struct range __initdata mem[MPU_MAX_REGIONS];
80
81static unsigned int __initdata mpu_max_regions;
82
83static __init bool is_region_fixed(int number)
84{
85 switch (number) {
86 case PMSAv8_XIP_REGION:
87 case PMSAv8_KERNEL_REGION:
88 return true;
89 default:
90 return false;
91 }
92}
93
94void __init pmsav8_adjust_lowmem_bounds(void)
95{
96 phys_addr_t mem_end;
97 phys_addr_t reg_start, reg_end;
98 bool first = true;
99 u64 i;
100
101 for_each_mem_range(i, &reg_start, &reg_end) {
102 if (first) {
103 phys_addr_t phys_offset = PHYS_OFFSET;
104
105 /*
106 * Initially only use memory continuous from
107 * PHYS_OFFSET */
108 if (reg_start != phys_offset)
109 panic(fmt: "First memory bank must be contiguous from PHYS_OFFSET");
110 mem_end = reg_end;
111 first = false;
112 } else {
113 /*
114 * memblock auto merges contiguous blocks, remove
115 * all blocks afterwards in one go (we can't remove
116 * blocks separately while iterating)
117 */
118 pr_notice("Ignoring RAM after %pa, memory at %pa ignored\n",
119 &mem_end, &reg_start);
120 memblock_remove(base: reg_start, size: 0 - reg_start);
121 break;
122 }
123 }
124}
125
126static int __init __mpu_max_regions(void)
127{
128 static int max_regions;
129 u32 mpuir;
130
131 if (max_regions)
132 return max_regions;
133
134 mpuir = read_cpuid_mputype();
135
136 max_regions = (mpuir & MPUIR_DREGION_SZMASK) >> MPUIR_DREGION;
137
138 return max_regions;
139}
140
141static int __init __pmsav8_setup_region(unsigned int number, u32 bar, u32 lar)
142{
143 if (number > mpu_max_regions
144 || number >= MPU_MAX_REGIONS)
145 return -ENOENT;
146
147 dsb();
148 prsel_write(v: number);
149 isb();
150 prbar_write(v: bar);
151 prlar_write(v: lar);
152
153 mpu_rgn_info.rgns[number].prbar = bar;
154 mpu_rgn_info.rgns[number].prlar = lar;
155
156 mpu_rgn_info.used++;
157
158 return 0;
159}
160
161static int __init pmsav8_setup_ram(unsigned int number, phys_addr_t start,phys_addr_t end)
162{
163 u32 bar, lar;
164
165 if (is_region_fixed(number))
166 return -EINVAL;
167
168 bar = start;
169 lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
170
171 bar |= PMSAv8_AP_PL1RW_PL0RW | PMSAv8_RGN_SHARED;
172 lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
173
174 return __pmsav8_setup_region(number, bar, lar);
175}
176
177static int __init pmsav8_setup_io(unsigned int number, phys_addr_t start,phys_addr_t end)
178{
179 u32 bar, lar;
180
181 if (is_region_fixed(number))
182 return -EINVAL;
183
184 bar = start;
185 lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
186
187 bar |= PMSAv8_AP_PL1RW_PL0RW | PMSAv8_RGN_SHARED | PMSAv8_BAR_XN;
188 lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_DEVICE_nGnRnE) | PMSAv8_LAR_EN;
189
190 return __pmsav8_setup_region(number, bar, lar);
191}
192
193static int __init pmsav8_setup_fixed(unsigned int number, phys_addr_t start,phys_addr_t end)
194{
195 u32 bar, lar;
196
197 if (!is_region_fixed(number))
198 return -EINVAL;
199
200 bar = start;
201 lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
202
203 bar |= PMSAv8_AP_PL1RW_PL0NA | PMSAv8_RGN_SHARED;
204 lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
205
206 prsel_write(v: number);
207 isb();
208
209 if (prbar_read() != bar || prlar_read() != lar)
210 return -EINVAL;
211
212 /* Reserved region was set up early, we just need a record for secondaries */
213 mpu_rgn_info.rgns[number].prbar = bar;
214 mpu_rgn_info.rgns[number].prlar = lar;
215
216 mpu_rgn_info.used++;
217
218 return 0;
219}
220
221#ifndef CONFIG_CPU_V7M
222static int __init pmsav8_setup_vector(unsigned int number, phys_addr_t start,phys_addr_t end)
223{
224 u32 bar, lar;
225
226 if (number == PMSAv8_KERNEL_REGION)
227 return -EINVAL;
228
229 bar = start;
230 lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
231
232 bar |= PMSAv8_AP_PL1RW_PL0NA | PMSAv8_RGN_SHARED;
233 lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
234
235 return __pmsav8_setup_region(number, bar, lar);
236}
237#endif
238
239void __init pmsav8_setup(void)
240{
241 int i, err = 0;
242 int region = PMSAv8_KERNEL_REGION;
243
244 /* How many regions are supported ? */
245 mpu_max_regions = __mpu_max_regions();
246
247 /* RAM: single chunk of memory */
248 add_range(range: mem, ARRAY_SIZE(mem), nr_range: 0, start: memblock.memory.regions[0].base,
249 end: memblock.memory.regions[0].base + memblock.memory.regions[0].size);
250
251 /* IO: cover full 4G range */
252 add_range(range: io, ARRAY_SIZE(io), nr_range: 0, start: 0, end: 0xffffffff);
253
254 /* RAM and IO: exclude kernel */
255 subtract_range(mem, ARRAY_SIZE(mem), __pa(KERNEL_START), __pa(KERNEL_END));
256 subtract_range(io, ARRAY_SIZE(io), __pa(KERNEL_START), __pa(KERNEL_END));
257
258#ifdef CONFIG_XIP_KERNEL
259 /* RAM and IO: exclude xip */
260 subtract_range(mem, ARRAY_SIZE(mem), CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
261 subtract_range(io, ARRAY_SIZE(io), CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
262#endif
263
264#ifndef CONFIG_CPU_V7M
265 /* RAM and IO: exclude vectors */
266 subtract_range(mem, ARRAY_SIZE(mem), vectors_base, vectors_base + 2 * PAGE_SIZE);
267 subtract_range(io, ARRAY_SIZE(io), vectors_base, vectors_base + 2 * PAGE_SIZE);
268#endif
269 /* IO: exclude RAM */
270 for (i = 0; i < ARRAY_SIZE(mem); i++)
271 subtract_range(range: io, ARRAY_SIZE(io), start: mem[i].start, end: mem[i].end);
272
273 /* Now program MPU */
274
275#ifdef CONFIG_XIP_KERNEL
276 /* ROM */
277 err |= pmsav8_setup_fixed(PMSAv8_XIP_REGION, CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
278#endif
279 /* Kernel */
280 err |= pmsav8_setup_fixed(region++, __pa(KERNEL_START), __pa(KERNEL_END));
281
282
283 /* IO */
284 for (i = 0; i < ARRAY_SIZE(io); i++) {
285 if (!io[i].end)
286 continue;
287
288 err |= pmsav8_setup_io(number: region++, start: io[i].start, end: io[i].end);
289 }
290
291 /* RAM */
292 for (i = 0; i < ARRAY_SIZE(mem); i++) {
293 if (!mem[i].end)
294 continue;
295
296 err |= pmsav8_setup_ram(number: region++, start: mem[i].start, end: mem[i].end);
297 }
298
299 /* Vectors */
300#ifndef CONFIG_CPU_V7M
301 err |= pmsav8_setup_vector(region++, vectors_base, vectors_base + 2 * PAGE_SIZE);
302#endif
303 if (err)
304 pr_warn("MPU region initialization failure! %d", err);
305 else
306 pr_info("Using ARM PMSAv8 Compliant MPU. Used %d of %d regions\n",
307 mpu_rgn_info.used, mpu_max_regions);
308}
309

source code of linux/arch/arm/mm/pmsa-v8.c