xref: /openbmc/u-boot/arch/arm/lib/cache-cp15.c (revision 6e87ae1c)
1 /*
2  * (C) Copyright 2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <asm/system.h>
10 #include <asm/cache.h>
11 #include <linux/compiler.h>
12 
13 #if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF))
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 __weak void arm_init_before_mmu(void)
18 {
19 }
20 
21 __weak void arm_init_domains(void)
22 {
23 }
24 
25 static void cp_delay (void)
26 {
27 	volatile int i;
28 
29 	/* copro seems to need some delay between reading and writing */
30 	for (i = 0; i < 100; i++)
31 		nop();
32 	asm volatile("" : : : "memory");
33 }
34 
35 void set_section_dcache(int section, enum dcache_option option)
36 {
37 #ifdef CONFIG_ARMV7_LPAE
38 	u64 *page_table = (u64 *)gd->arch.tlb_addr;
39 	/* Need to set the access flag to not fault */
40 	u64 value = TTB_SECT_AP | TTB_SECT_AF;
41 #else
42 	u32 *page_table = (u32 *)gd->arch.tlb_addr;
43 	u32 value = TTB_SECT_AP;
44 #endif
45 
46 	/* Add the page offset */
47 	value |= ((u32)section << MMU_SECTION_SHIFT);
48 
49 	/* Add caching bits */
50 	value |= option;
51 
52 	/* Set PTE */
53 	page_table[section] = value;
54 }
55 
56 __weak void mmu_page_table_flush(unsigned long start, unsigned long stop)
57 {
58 	debug("%s: Warning: not implemented\n", __func__);
59 }
60 
61 void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
62 				     enum dcache_option option)
63 {
64 #ifdef CONFIG_ARMV7_LPAE
65 	u64 *page_table = (u64 *)gd->arch.tlb_addr;
66 #else
67 	u32 *page_table = (u32 *)gd->arch.tlb_addr;
68 #endif
69 	unsigned long startpt, stoppt;
70 	unsigned long upto, end;
71 
72 	end = ALIGN(start + size, MMU_SECTION_SIZE) >> MMU_SECTION_SHIFT;
73 	start = start >> MMU_SECTION_SHIFT;
74 #ifdef CONFIG_ARMV7_LPAE
75 	debug("%s: start=%pa, size=%zu, option=%llx\n", __func__, &start, size,
76 	      option);
77 #else
78 	debug("%s: start=%pa, size=%zu, option=0x%x\n", __func__, &start, size,
79 	      option);
80 #endif
81 	for (upto = start; upto < end; upto++)
82 		set_section_dcache(upto, option);
83 
84 	/*
85 	 * Make sure range is cache line aligned
86 	 * Only CPU maintains page tables, hence it is safe to always
87 	 * flush complete cache lines...
88 	 */
89 
90 	startpt = (unsigned long)&page_table[start];
91 	startpt &= ~(CONFIG_SYS_CACHELINE_SIZE - 1);
92 	stoppt = (unsigned long)&page_table[end];
93 	stoppt = ALIGN(stoppt, CONFIG_SYS_CACHELINE_SIZE);
94 	mmu_page_table_flush(startpt, stoppt);
95 }
96 
97 __weak void dram_bank_mmu_setup(int bank)
98 {
99 	bd_t *bd = gd->bd;
100 	int	i;
101 
102 	debug("%s: bank: %d\n", __func__, bank);
103 	for (i = bd->bi_dram[bank].start >> MMU_SECTION_SHIFT;
104 	     i < (bd->bi_dram[bank].start >> MMU_SECTION_SHIFT) +
105 		 (bd->bi_dram[bank].size >> MMU_SECTION_SHIFT);
106 	     i++) {
107 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
108 		set_section_dcache(i, DCACHE_WRITETHROUGH);
109 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
110 		set_section_dcache(i, DCACHE_WRITEALLOC);
111 #else
112 		set_section_dcache(i, DCACHE_WRITEBACK);
113 #endif
114 	}
115 }
116 
117 /* to activate the MMU we need to set up virtual memory: use 1M areas */
118 static inline void mmu_setup(void)
119 {
120 	int i;
121 	u32 reg;
122 
123 	arm_init_before_mmu();
124 	/* Set up an identity-mapping for all 4GB, rw for everyone */
125 	for (i = 0; i < ((4096ULL * 1024 * 1024) >> MMU_SECTION_SHIFT); i++)
126 		set_section_dcache(i, DCACHE_OFF);
127 
128 	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
129 		dram_bank_mmu_setup(i);
130 	}
131 
132 #ifdef CONFIG_ARMV7_LPAE
133 	/* Set up 4 PTE entries pointing to our 4 1GB page tables */
134 	for (i = 0; i < 4; i++) {
135 		u64 *page_table = (u64 *)(gd->arch.tlb_addr + (4096 * 4));
136 		u64 tpt = gd->arch.tlb_addr + (4096 * i);
137 		page_table[i] = tpt | TTB_PAGETABLE;
138 	}
139 
140 	reg = TTBCR_EAE;
141 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
142 	reg |= TTBCR_ORGN0_WT | TTBCR_IRGN0_WT;
143 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
144 	reg |= TTBCR_ORGN0_WBWA | TTBCR_IRGN0_WBWA;
145 #else
146 	reg |= TTBCR_ORGN0_WBNWA | TTBCR_IRGN0_WBNWA;
147 #endif
148 
149 	if (is_hyp()) {
150 		/* Set HCTR to enable LPAE */
151 		asm volatile("mcr p15, 4, %0, c2, c0, 2"
152 			: : "r" (reg) : "memory");
153 		/* Set HTTBR0 */
154 		asm volatile("mcrr p15, 4, %0, %1, c2"
155 			:
156 			: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
157 			: "memory");
158 		/* Set HMAIR */
159 		asm volatile("mcr p15, 4, %0, c10, c2, 0"
160 			: : "r" (MEMORY_ATTRIBUTES) : "memory");
161 	} else {
162 		/* Set TTBCR to enable LPAE */
163 		asm volatile("mcr p15, 0, %0, c2, c0, 2"
164 			: : "r" (reg) : "memory");
165 		/* Set 64-bit TTBR0 */
166 		asm volatile("mcrr p15, 0, %0, %1, c2"
167 			:
168 			: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
169 			: "memory");
170 		/* Set MAIR */
171 		asm volatile("mcr p15, 0, %0, c10, c2, 0"
172 			: : "r" (MEMORY_ATTRIBUTES) : "memory");
173 	}
174 #elif defined(CONFIG_CPU_V7)
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 	cp_delay();
200 	set_cr(reg | CR_M);
201 }
202 
203 static int mmu_enabled(void)
204 {
205 	return get_cr() & CR_M;
206 }
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 is enabled too */
214 	if ((cache_bit == CR_C) && !mmu_enabled())
215 		mmu_setup();
216 	reg = get_cr();	/* get control reg. */
217 	cp_delay();
218 	set_cr(reg | cache_bit);
219 }
220 
221 /* cache_bit must be either CR_I or CR_C */
222 static void cache_disable(uint32_t cache_bit)
223 {
224 	uint32_t reg;
225 
226 	reg = get_cr();
227 	cp_delay();
228 
229 	if (cache_bit == CR_C) {
230 		/* if cache isn;t enabled no need to disable */
231 		if ((reg & CR_C) != CR_C)
232 			return;
233 		/* if disabling data cache, disable mmu too */
234 		cache_bit |= CR_M;
235 	}
236 	reg = get_cr();
237 	cp_delay();
238 	if (cache_bit == (CR_C | CR_M))
239 		flush_dcache_all();
240 	set_cr(reg & ~cache_bit);
241 }
242 #endif
243 
244 #ifdef CONFIG_SYS_ICACHE_OFF
245 void icache_enable (void)
246 {
247 	return;
248 }
249 
250 void icache_disable (void)
251 {
252 	return;
253 }
254 
255 int icache_status (void)
256 {
257 	return 0;					/* always off */
258 }
259 #else
260 void icache_enable(void)
261 {
262 	cache_enable(CR_I);
263 }
264 
265 void icache_disable(void)
266 {
267 	cache_disable(CR_I);
268 }
269 
270 int icache_status(void)
271 {
272 	return (get_cr() & CR_I) != 0;
273 }
274 #endif
275 
276 #ifdef CONFIG_SYS_DCACHE_OFF
277 void dcache_enable (void)
278 {
279 	return;
280 }
281 
282 void dcache_disable (void)
283 {
284 	return;
285 }
286 
287 int dcache_status (void)
288 {
289 	return 0;					/* always off */
290 }
291 #else
292 void dcache_enable(void)
293 {
294 	cache_enable(CR_C);
295 }
296 
297 void dcache_disable(void)
298 {
299 	cache_disable(CR_C);
300 }
301 
302 int dcache_status(void)
303 {
304 	return (get_cr() & CR_C) != 0;
305 }
306 #endif
307