xref: /openbmc/u-boot/arch/arm/lib/cache-cp15.c (revision 1f0dfa1f)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2002
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  */
6 
7 #include <common.h>
8 #include <asm/system.h>
9 #include <asm/cache.h>
10 #include <linux/compiler.h>
11 #include <asm/armv7_mpu.h>
12 
13 #if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF))
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 #ifdef CONFIG_SYS_ARM_MMU
18 __weak void arm_init_before_mmu(void)
19 {
20 }
21 
22 __weak void arm_init_domains(void)
23 {
24 }
25 
26 void set_section_dcache(int section, enum dcache_option option)
27 {
28 #ifdef CONFIG_ARMV7_LPAE
29 	u64 *page_table = (u64 *)gd->arch.tlb_addr;
30 	/* Need to set the access flag to not fault */
31 	u64 value = TTB_SECT_AP | TTB_SECT_AF;
32 #else
33 	u32 *page_table = (u32 *)gd->arch.tlb_addr;
34 	u32 value = TTB_SECT_AP;
35 #endif
36 
37 	/* Add the page offset */
38 	value |= ((u32)section << MMU_SECTION_SHIFT);
39 
40 	/* Add caching bits */
41 	value |= option;
42 
43 	/* Set PTE */
44 	page_table[section] = value;
45 }
46 
47 __weak void mmu_page_table_flush(unsigned long start, unsigned long stop)
48 {
49 	debug("%s: Warning: not implemented\n", __func__);
50 }
51 
52 void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
53 				     enum dcache_option option)
54 {
55 #ifdef CONFIG_ARMV7_LPAE
56 	u64 *page_table = (u64 *)gd->arch.tlb_addr;
57 #else
58 	u32 *page_table = (u32 *)gd->arch.tlb_addr;
59 #endif
60 	unsigned long startpt, stoppt;
61 	unsigned long upto, end;
62 
63 	end = ALIGN(start + size, MMU_SECTION_SIZE) >> MMU_SECTION_SHIFT;
64 	start = start >> MMU_SECTION_SHIFT;
65 #ifdef CONFIG_ARMV7_LPAE
66 	debug("%s: start=%pa, size=%zu, option=%llx\n", __func__, &start, size,
67 	      option);
68 #else
69 	debug("%s: start=%pa, size=%zu, option=0x%x\n", __func__, &start, size,
70 	      option);
71 #endif
72 	for (upto = start; upto < end; upto++)
73 		set_section_dcache(upto, option);
74 
75 	/*
76 	 * Make sure range is cache line aligned
77 	 * Only CPU maintains page tables, hence it is safe to always
78 	 * flush complete cache lines...
79 	 */
80 
81 	startpt = (unsigned long)&page_table[start];
82 	startpt &= ~(CONFIG_SYS_CACHELINE_SIZE - 1);
83 	stoppt = (unsigned long)&page_table[end];
84 	stoppt = ALIGN(stoppt, CONFIG_SYS_CACHELINE_SIZE);
85 	mmu_page_table_flush(startpt, stoppt);
86 }
87 
88 __weak void dram_bank_mmu_setup(int bank)
89 {
90 	bd_t *bd = gd->bd;
91 	int	i;
92 
93 	debug("%s: bank: %d\n", __func__, bank);
94 	for (i = bd->bi_dram[bank].start >> MMU_SECTION_SHIFT;
95 	     i < (bd->bi_dram[bank].start >> MMU_SECTION_SHIFT) +
96 		 (bd->bi_dram[bank].size >> MMU_SECTION_SHIFT);
97 	     i++) {
98 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
99 		set_section_dcache(i, DCACHE_WRITETHROUGH);
100 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
101 		set_section_dcache(i, DCACHE_WRITEALLOC);
102 #else
103 		set_section_dcache(i, DCACHE_WRITEBACK);
104 #endif
105 	}
106 }
107 
108 /* to activate the MMU we need to set up virtual memory: use 1M areas */
109 static inline void mmu_setup(void)
110 {
111 	int i;
112 	u32 reg;
113 
114 	arm_init_before_mmu();
115 	/* Set up an identity-mapping for all 4GB, rw for everyone */
116 	for (i = 0; i < ((4096ULL * 1024 * 1024) >> MMU_SECTION_SHIFT); i++)
117 		set_section_dcache(i, DCACHE_OFF);
118 
119 	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
120 		dram_bank_mmu_setup(i);
121 	}
122 
123 #if defined(CONFIG_ARMV7_LPAE) && __LINUX_ARM_ARCH__ != 4
124 	/* Set up 4 PTE entries pointing to our 4 1GB page tables */
125 	for (i = 0; i < 4; i++) {
126 		u64 *page_table = (u64 *)(gd->arch.tlb_addr + (4096 * 4));
127 		u64 tpt = gd->arch.tlb_addr + (4096 * i);
128 		page_table[i] = tpt | TTB_PAGETABLE;
129 	}
130 
131 	reg = TTBCR_EAE;
132 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
133 	reg |= TTBCR_ORGN0_WT | TTBCR_IRGN0_WT;
134 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
135 	reg |= TTBCR_ORGN0_WBWA | TTBCR_IRGN0_WBWA;
136 #else
137 	reg |= TTBCR_ORGN0_WBNWA | TTBCR_IRGN0_WBNWA;
138 #endif
139 
140 	if (is_hyp()) {
141 		/* Set HTCR to enable LPAE */
142 		asm volatile("mcr p15, 4, %0, c2, c0, 2"
143 			: : "r" (reg) : "memory");
144 		/* Set HTTBR0 */
145 		asm volatile("mcrr p15, 4, %0, %1, c2"
146 			:
147 			: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
148 			: "memory");
149 		/* Set HMAIR */
150 		asm volatile("mcr p15, 4, %0, c10, c2, 0"
151 			: : "r" (MEMORY_ATTRIBUTES) : "memory");
152 	} else {
153 		/* Set TTBCR to enable LPAE */
154 		asm volatile("mcr p15, 0, %0, c2, c0, 2"
155 			: : "r" (reg) : "memory");
156 		/* Set 64-bit TTBR0 */
157 		asm volatile("mcrr p15, 0, %0, %1, c2"
158 			:
159 			: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
160 			: "memory");
161 		/* Set MAIR */
162 		asm volatile("mcr p15, 0, %0, c10, c2, 0"
163 			: : "r" (MEMORY_ATTRIBUTES) : "memory");
164 	}
165 #elif defined(CONFIG_CPU_V7A)
166 	if (is_hyp()) {
167 		/* Set HTCR to disable LPAE */
168 		asm volatile("mcr p15, 4, %0, c2, c0, 2"
169 			: : "r" (0) : "memory");
170 	} else {
171 		/* Set TTBCR to disable LPAE */
172 		asm volatile("mcr p15, 0, %0, c2, c0, 2"
173 			: : "r" (0) : "memory");
174 	}
175 	/* Set TTBR0 */
176 	reg = gd->arch.tlb_addr & TTBR0_BASE_ADDR_MASK;
177 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
178 	reg |= TTBR0_RGN_WT | TTBR0_IRGN_WT;
179 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
180 	reg |= TTBR0_RGN_WBWA | TTBR0_IRGN_WBWA;
181 #else
182 	reg |= TTBR0_RGN_WB | TTBR0_IRGN_WB;
183 #endif
184 	asm volatile("mcr p15, 0, %0, c2, c0, 0"
185 		     : : "r" (reg) : "memory");
186 #else
187 	/* Copy the page table address to cp15 */
188 	asm volatile("mcr p15, 0, %0, c2, c0, 0"
189 		     : : "r" (gd->arch.tlb_addr) : "memory");
190 #endif
191 	/* Set the access control to all-supervisor */
192 	asm volatile("mcr p15, 0, %0, c3, c0, 0"
193 		     : : "r" (~0));
194 
195 	arm_init_domains();
196 
197 	/* and enable the mmu */
198 	reg = get_cr();	/* get control reg. */
199 	set_cr(reg | CR_M);
200 }
201 
202 static int mmu_enabled(void)
203 {
204 	return get_cr() & CR_M;
205 }
206 #endif /* CONFIG_SYS_ARM_MMU */
207 
208 /* cache_bit must be either CR_I or CR_C */
209 static void cache_enable(uint32_t cache_bit)
210 {
211 	uint32_t reg;
212 
213 	/* The data cache is not active unless the mmu/mpu is enabled too */
214 #ifdef CONFIG_SYS_ARM_MMU
215 	if ((cache_bit == CR_C) && !mmu_enabled())
216 		mmu_setup();
217 #elif defined(CONFIG_SYS_ARM_MPU)
218 	if ((cache_bit == CR_C) && !mpu_enabled()) {
219 		printf("Consider enabling MPU before enabling caches\n");
220 		return;
221 	}
222 #endif
223 	reg = get_cr();	/* get control reg. */
224 	set_cr(reg | cache_bit);
225 }
226 
227 /* cache_bit must be either CR_I or CR_C */
228 static void cache_disable(uint32_t cache_bit)
229 {
230 	uint32_t reg;
231 
232 	reg = get_cr();
233 
234 	if (cache_bit == CR_C) {
235 		/* if cache isn;t enabled no need to disable */
236 		if ((reg & CR_C) != CR_C)
237 			return;
238 		/* if disabling data cache, disable mmu too */
239 		cache_bit |= CR_M;
240 	}
241 	reg = get_cr();
242 
243 	if (cache_bit == (CR_C | CR_M))
244 		flush_dcache_all();
245 	set_cr(reg & ~cache_bit);
246 }
247 #endif
248 
249 #ifdef CONFIG_SYS_ICACHE_OFF
250 void icache_enable (void)
251 {
252 	return;
253 }
254 
255 void icache_disable (void)
256 {
257 	return;
258 }
259 
260 int icache_status (void)
261 {
262 	return 0;					/* always off */
263 }
264 #else
265 void icache_enable(void)
266 {
267 	cache_enable(CR_I);
268 }
269 
270 void icache_disable(void)
271 {
272 	cache_disable(CR_I);
273 }
274 
275 int icache_status(void)
276 {
277 	return (get_cr() & CR_I) != 0;
278 }
279 #endif
280 
281 #ifdef CONFIG_SYS_DCACHE_OFF
282 void dcache_enable (void)
283 {
284 	return;
285 }
286 
287 void dcache_disable (void)
288 {
289 	return;
290 }
291 
292 int dcache_status (void)
293 {
294 	return 0;					/* always off */
295 }
296 #else
297 void dcache_enable(void)
298 {
299 	cache_enable(CR_C);
300 }
301 
302 void dcache_disable(void)
303 {
304 	cache_disable(CR_C);
305 }
306 
307 int dcache_status(void)
308 {
309 	return (get_cr() & CR_C) != 0;
310 }
311 #endif
312