xref: /openbmc/linux/arch/arm/mm/pmsa-v8.c (revision 6f4eaea2)
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/memory.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 
25 static inline u32 prlar_read(void)
26 {
27 	return read_sysreg(PRLAR);
28 }
29 
30 static inline u32 prbar_read(void)
31 {
32 	return read_sysreg(PRBAR);
33 }
34 
35 static inline void prsel_write(u32 v)
36 {
37 	write_sysreg(v, PRSEL);
38 }
39 
40 static inline void prbar_write(u32 v)
41 {
42 	write_sysreg(v, PRBAR);
43 }
44 
45 static inline void prlar_write(u32 v)
46 {
47 	write_sysreg(v, PRLAR);
48 }
49 #else
50 
51 static inline u32 prlar_read(void)
52 {
53 	return readl_relaxed(BASEADDR_V7M_SCB + PMSAv8_RLAR);
54 }
55 
56 static inline u32 prbar_read(void)
57 {
58 	return readl_relaxed(BASEADDR_V7M_SCB + PMSAv8_RBAR);
59 }
60 
61 static inline void prsel_write(u32 v)
62 {
63 	writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RNR);
64 }
65 
66 static inline void prbar_write(u32 v)
67 {
68 	writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RBAR);
69 }
70 
71 static inline void prlar_write(u32 v)
72 {
73 	writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RLAR);
74 }
75 
76 #endif
77 
78 static struct range __initdata io[MPU_MAX_REGIONS];
79 static struct range __initdata mem[MPU_MAX_REGIONS];
80 
81 static unsigned int __initdata mpu_max_regions;
82 
83 static __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 
94 void __init pmsav8_adjust_lowmem_bounds(void)
95 {
96 	phys_addr_t mem_end;
97 	phys_addr_t reg_start, reg_end;
98 	u64 i;
99 
100 	for_each_mem_range(i, &reg_start, &reg_end) {
101 		if (i == 0) {
102 			phys_addr_t phys_offset = PHYS_OFFSET;
103 
104 			/*
105 			 * Initially only use memory continuous from
106 			 * PHYS_OFFSET */
107 			if (reg_start != phys_offset)
108 				panic("First memory bank must be contiguous from PHYS_OFFSET");
109 			mem_end = reg_end;
110 		} else {
111 			/*
112 			 * memblock auto merges contiguous blocks, remove
113 			 * all blocks afterwards in one go (we can't remove
114 			 * blocks separately while iterating)
115 			 */
116 			pr_notice("Ignoring RAM after %pa, memory at %pa ignored\n",
117 				  &mem_end, &reg_start);
118 			memblock_remove(reg_start, 0 - reg_start);
119 			break;
120 		}
121 	}
122 }
123 
124 static int __init __mpu_max_regions(void)
125 {
126 	static int max_regions;
127 	u32 mpuir;
128 
129 	if (max_regions)
130 		return max_regions;
131 
132 	mpuir = read_cpuid_mputype();
133 
134 	max_regions  = (mpuir & MPUIR_DREGION_SZMASK) >> MPUIR_DREGION;
135 
136 	return max_regions;
137 }
138 
139 static int __init __pmsav8_setup_region(unsigned int number, u32 bar, u32 lar)
140 {
141 	if (number > mpu_max_regions
142 	    || number >= MPU_MAX_REGIONS)
143 		return -ENOENT;
144 
145 	dsb();
146 	prsel_write(number);
147 	isb();
148 	prbar_write(bar);
149 	prlar_write(lar);
150 
151 	mpu_rgn_info.rgns[number].prbar = bar;
152 	mpu_rgn_info.rgns[number].prlar = lar;
153 
154 	mpu_rgn_info.used++;
155 
156 	return 0;
157 }
158 
159 static int __init pmsav8_setup_ram(unsigned int number, phys_addr_t start,phys_addr_t end)
160 {
161 	u32 bar, lar;
162 
163 	if (is_region_fixed(number))
164 		return -EINVAL;
165 
166 	bar = start;
167 	lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
168 
169 	bar |= PMSAv8_AP_PL1RW_PL0RW | PMSAv8_RGN_SHARED;
170 	lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
171 
172 	return __pmsav8_setup_region(number, bar, lar);
173 }
174 
175 static int __init pmsav8_setup_io(unsigned int number, phys_addr_t start,phys_addr_t end)
176 {
177 	u32 bar, lar;
178 
179 	if (is_region_fixed(number))
180 		return -EINVAL;
181 
182 	bar = start;
183 	lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
184 
185 	bar |= PMSAv8_AP_PL1RW_PL0RW | PMSAv8_RGN_SHARED | PMSAv8_BAR_XN;
186 	lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_DEVICE_nGnRnE) | PMSAv8_LAR_EN;
187 
188 	return __pmsav8_setup_region(number, bar, lar);
189 }
190 
191 static int __init pmsav8_setup_fixed(unsigned int number, phys_addr_t start,phys_addr_t end)
192 {
193 	u32 bar, lar;
194 
195 	if (!is_region_fixed(number))
196 		return -EINVAL;
197 
198 	bar = start;
199 	lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
200 
201 	bar |= PMSAv8_AP_PL1RW_PL0NA | PMSAv8_RGN_SHARED;
202 	lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
203 
204 	prsel_write(number);
205 	isb();
206 
207 	if (prbar_read() != bar || prlar_read() != lar)
208 		return -EINVAL;
209 
210 	/* Reserved region was set up early, we just need a record for secondaries */
211 	mpu_rgn_info.rgns[number].prbar = bar;
212 	mpu_rgn_info.rgns[number].prlar = lar;
213 
214 	mpu_rgn_info.used++;
215 
216 	return 0;
217 }
218 
219 #ifndef CONFIG_CPU_V7M
220 static int __init pmsav8_setup_vector(unsigned int number, phys_addr_t start,phys_addr_t end)
221 {
222 	u32 bar, lar;
223 
224 	if (number == PMSAv8_KERNEL_REGION)
225 		return -EINVAL;
226 
227 	bar = start;
228 	lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
229 
230 	bar |= PMSAv8_AP_PL1RW_PL0NA | PMSAv8_RGN_SHARED;
231 	lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
232 
233 	return __pmsav8_setup_region(number, bar, lar);
234 }
235 #endif
236 
237 void __init pmsav8_setup(void)
238 {
239 	int i, err = 0;
240 	int region = PMSAv8_KERNEL_REGION;
241 
242 	/* How many regions are supported ? */
243 	mpu_max_regions = __mpu_max_regions();
244 
245 	/* RAM: single chunk of memory */
246 	add_range(mem,  ARRAY_SIZE(mem), 0,  memblock.memory.regions[0].base,
247 		  memblock.memory.regions[0].base + memblock.memory.regions[0].size);
248 
249 	/* IO: cover full 4G range */
250 	add_range(io, ARRAY_SIZE(io), 0, 0, 0xffffffff);
251 
252 	/* RAM and IO: exclude kernel */
253 	subtract_range(mem, ARRAY_SIZE(mem), __pa(KERNEL_START), __pa(KERNEL_END));
254 	subtract_range(io, ARRAY_SIZE(io),  __pa(KERNEL_START), __pa(KERNEL_END));
255 
256 #ifdef CONFIG_XIP_KERNEL
257 	/* RAM and IO: exclude xip */
258 	subtract_range(mem, ARRAY_SIZE(mem), CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
259 	subtract_range(io, ARRAY_SIZE(io), CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
260 #endif
261 
262 #ifndef CONFIG_CPU_V7M
263 	/* RAM and IO: exclude vectors */
264 	subtract_range(mem, ARRAY_SIZE(mem),  vectors_base, vectors_base + 2 * PAGE_SIZE);
265 	subtract_range(io, ARRAY_SIZE(io),  vectors_base, vectors_base + 2 * PAGE_SIZE);
266 #endif
267 	/* IO: exclude RAM */
268 	for (i = 0; i < ARRAY_SIZE(mem); i++)
269 		subtract_range(io, ARRAY_SIZE(io), mem[i].start, mem[i].end);
270 
271 	/* Now program MPU */
272 
273 #ifdef CONFIG_XIP_KERNEL
274 	/* ROM */
275 	err |= pmsav8_setup_fixed(PMSAv8_XIP_REGION, CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
276 #endif
277 	/* Kernel */
278 	err |= pmsav8_setup_fixed(region++, __pa(KERNEL_START), __pa(KERNEL_END));
279 
280 
281 	/* IO */
282 	for (i = 0; i < ARRAY_SIZE(io); i++) {
283 		if (!io[i].end)
284 			continue;
285 
286 		err |= pmsav8_setup_io(region++, io[i].start, io[i].end);
287 	}
288 
289 	/* RAM */
290 	for (i = 0; i < ARRAY_SIZE(mem); i++) {
291 		if (!mem[i].end)
292 			continue;
293 
294 		err |= pmsav8_setup_ram(region++, mem[i].start, mem[i].end);
295 	}
296 
297 	/* Vectors */
298 #ifndef CONFIG_CPU_V7M
299 	err |= pmsav8_setup_vector(region++, vectors_base, vectors_base + 2 * PAGE_SIZE);
300 #endif
301 	if (err)
302 		pr_warn("MPU region initialization failure! %d", err);
303 	else
304 		pr_info("Using ARM PMSAv8 Compliant MPU. Used %d of %d regions\n",
305 			mpu_rgn_info.used, mpu_max_regions);
306 }
307