xref: /openbmc/u-boot/arch/arm/lib/cache-cp15.c (revision 8f695232)
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 	u32 *page_table = (u32 *)gd->arch.tlb_addr;
65 	unsigned long upto, end;
66 
67 	end = ALIGN(start + size, MMU_SECTION_SIZE) >> MMU_SECTION_SHIFT;
68 	start = start >> MMU_SECTION_SHIFT;
69 	debug("%s: start=%pa, size=%zu, option=%d\n", __func__, &start, size,
70 	      option);
71 	for (upto = start; upto < end; upto++)
72 		set_section_dcache(upto, option);
73 	mmu_page_table_flush((u32)&page_table[start], (u32)&page_table[end]);
74 }
75 
76 __weak void dram_bank_mmu_setup(int bank)
77 {
78 	bd_t *bd = gd->bd;
79 	int	i;
80 
81 	debug("%s: bank: %d\n", __func__, bank);
82 	for (i = bd->bi_dram[bank].start >> MMU_SECTION_SHIFT;
83 	     i < (bd->bi_dram[bank].start >> MMU_SECTION_SHIFT) +
84 		 (bd->bi_dram[bank].size >> MMU_SECTION_SHIFT);
85 	     i++) {
86 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
87 		set_section_dcache(i, DCACHE_WRITETHROUGH);
88 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
89 		set_section_dcache(i, DCACHE_WRITEALLOC);
90 #else
91 		set_section_dcache(i, DCACHE_WRITEBACK);
92 #endif
93 	}
94 }
95 
96 /* to activate the MMU we need to set up virtual memory: use 1M areas */
97 static inline void mmu_setup(void)
98 {
99 	int i;
100 	u32 reg;
101 
102 	arm_init_before_mmu();
103 	/* Set up an identity-mapping for all 4GB, rw for everyone */
104 	for (i = 0; i < ((4096ULL * 1024 * 1024) >> MMU_SECTION_SHIFT); i++)
105 		set_section_dcache(i, DCACHE_OFF);
106 
107 	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
108 		dram_bank_mmu_setup(i);
109 	}
110 
111 #ifdef CONFIG_ARMV7_LPAE
112 	/* Set up 4 PTE entries pointing to our 4 1GB page tables */
113 	for (i = 0; i < 4; i++) {
114 		u64 *page_table = (u64 *)(gd->arch.tlb_addr + (4096 * 4));
115 		u64 tpt = gd->arch.tlb_addr + (4096 * i);
116 		page_table[i] = tpt | TTB_PAGETABLE;
117 	}
118 
119 	reg = TTBCR_EAE;
120 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
121 	reg |= TTBCR_ORGN0_WT | TTBCR_IRGN0_WT;
122 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
123 	reg |= TTBCR_ORGN0_WBWA | TTBCR_IRGN0_WBWA;
124 #else
125 	reg |= TTBCR_ORGN0_WBNWA | TTBCR_IRGN0_WBNWA;
126 #endif
127 
128 	if (is_hyp()) {
129 		/* Set HCTR to enable LPAE */
130 		asm volatile("mcr p15, 4, %0, c2, c0, 2"
131 			: : "r" (reg) : "memory");
132 		/* Set HTTBR0 */
133 		asm volatile("mcrr p15, 4, %0, %1, c2"
134 			:
135 			: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
136 			: "memory");
137 		/* Set HMAIR */
138 		asm volatile("mcr p15, 4, %0, c10, c2, 0"
139 			: : "r" (MEMORY_ATTRIBUTES) : "memory");
140 	} else {
141 		/* Set TTBCR to enable LPAE */
142 		asm volatile("mcr p15, 0, %0, c2, c0, 2"
143 			: : "r" (reg) : "memory");
144 		/* Set 64-bit TTBR0 */
145 		asm volatile("mcrr p15, 0, %0, %1, c2"
146 			:
147 			: "r"(gd->arch.tlb_addr + (4096 * 4)), "r"(0)
148 			: "memory");
149 		/* Set MAIR */
150 		asm volatile("mcr p15, 0, %0, c10, c2, 0"
151 			: : "r" (MEMORY_ATTRIBUTES) : "memory");
152 	}
153 #elif defined(CONFIG_CPU_V7)
154 	/* Set TTBR0 */
155 	reg = gd->arch.tlb_addr & TTBR0_BASE_ADDR_MASK;
156 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
157 	reg |= TTBR0_RGN_WT | TTBR0_IRGN_WT;
158 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC)
159 	reg |= TTBR0_RGN_WBWA | TTBR0_IRGN_WBWA;
160 #else
161 	reg |= TTBR0_RGN_WB | TTBR0_IRGN_WB;
162 #endif
163 	asm volatile("mcr p15, 0, %0, c2, c0, 0"
164 		     : : "r" (reg) : "memory");
165 #else
166 	/* Copy the page table address to cp15 */
167 	asm volatile("mcr p15, 0, %0, c2, c0, 0"
168 		     : : "r" (gd->arch.tlb_addr) : "memory");
169 #endif
170 	/* Set the access control to all-supervisor */
171 	asm volatile("mcr p15, 0, %0, c3, c0, 0"
172 		     : : "r" (~0));
173 
174 	arm_init_domains();
175 
176 	/* and enable the mmu */
177 	reg = get_cr();	/* get control reg. */
178 	cp_delay();
179 	set_cr(reg | CR_M);
180 }
181 
182 static int mmu_enabled(void)
183 {
184 	return get_cr() & CR_M;
185 }
186 
187 /* cache_bit must be either CR_I or CR_C */
188 static void cache_enable(uint32_t cache_bit)
189 {
190 	uint32_t reg;
191 
192 	/* The data cache is not active unless the mmu is enabled too */
193 	if ((cache_bit == CR_C) && !mmu_enabled())
194 		mmu_setup();
195 	reg = get_cr();	/* get control reg. */
196 	cp_delay();
197 	set_cr(reg | cache_bit);
198 }
199 
200 /* cache_bit must be either CR_I or CR_C */
201 static void cache_disable(uint32_t cache_bit)
202 {
203 	uint32_t reg;
204 
205 	reg = get_cr();
206 	cp_delay();
207 
208 	if (cache_bit == CR_C) {
209 		/* if cache isn;t enabled no need to disable */
210 		if ((reg & CR_C) != CR_C)
211 			return;
212 		/* if disabling data cache, disable mmu too */
213 		cache_bit |= CR_M;
214 	}
215 	reg = get_cr();
216 	cp_delay();
217 	if (cache_bit == (CR_C | CR_M))
218 		flush_dcache_all();
219 	set_cr(reg & ~cache_bit);
220 }
221 #endif
222 
223 #ifdef CONFIG_SYS_ICACHE_OFF
224 void icache_enable (void)
225 {
226 	return;
227 }
228 
229 void icache_disable (void)
230 {
231 	return;
232 }
233 
234 int icache_status (void)
235 {
236 	return 0;					/* always off */
237 }
238 #else
239 void icache_enable(void)
240 {
241 	cache_enable(CR_I);
242 }
243 
244 void icache_disable(void)
245 {
246 	cache_disable(CR_I);
247 }
248 
249 int icache_status(void)
250 {
251 	return (get_cr() & CR_I) != 0;
252 }
253 #endif
254 
255 #ifdef CONFIG_SYS_DCACHE_OFF
256 void dcache_enable (void)
257 {
258 	return;
259 }
260 
261 void dcache_disable (void)
262 {
263 	return;
264 }
265 
266 int dcache_status (void)
267 {
268 	return 0;					/* always off */
269 }
270 #else
271 void dcache_enable(void)
272 {
273 	cache_enable(CR_C);
274 }
275 
276 void dcache_disable(void)
277 {
278 	cache_disable(CR_C);
279 }
280 
281 int dcache_status(void)
282 {
283 	return (get_cr() & CR_C) != 0;
284 }
285 #endif
286