xref: /openbmc/u-boot/arch/arm/lib/cache.c (revision a2bc4321)
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 /* for now: just dummy functions to satisfy the linker */
9 
10 #include <common.h>
11 #include <malloc.h>
12 
13 __weak void flush_cache(unsigned long start, unsigned long size)
14 {
15 #if defined(CONFIG_CPU_ARM1136)
16 
17 #if !defined(CONFIG_SYS_ICACHE_OFF)
18 	asm("mcr p15, 0, r1, c7, c5, 0"); /* invalidate I cache */
19 #endif
20 
21 #if !defined(CONFIG_SYS_DCACHE_OFF)
22 	asm("mcr p15, 0, r1, c7, c14, 0"); /* Clean+invalidate D cache */
23 #endif
24 
25 #endif /* CONFIG_CPU_ARM1136 */
26 
27 #ifdef CONFIG_CPU_ARM926EJS
28 #if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF))
29 	/* test and clean, page 2-23 of arm926ejs manual */
30 	asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
31 	/* disable write buffer as well (page 2-22) */
32 	asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0));
33 #endif
34 #endif /* CONFIG_CPU_ARM926EJS */
35 	return;
36 }
37 
38 /*
39  * Default implementation:
40  * do a range flush for the entire range
41  */
42 __weak void flush_dcache_all(void)
43 {
44 	flush_cache(0, ~0);
45 }
46 
47 /*
48  * Default implementation of enable_caches()
49  * Real implementation should be in platform code
50  */
51 __weak void enable_caches(void)
52 {
53 	puts("WARNING: Caches not enabled\n");
54 }
55 
56 #ifdef CONFIG_SYS_NONCACHED_MEMORY
57 /*
58  * Reserve one MMU section worth of address space below the malloc() area that
59  * will be mapped uncached.
60  */
61 static unsigned long noncached_start;
62 static unsigned long noncached_end;
63 static unsigned long noncached_next;
64 
65 void noncached_init(void)
66 {
67 	phys_addr_t start, end;
68 	size_t size;
69 
70 	end = ALIGN(mem_malloc_start, MMU_SECTION_SIZE) - MMU_SECTION_SIZE;
71 	size = ALIGN(CONFIG_SYS_NONCACHED_MEMORY, MMU_SECTION_SIZE);
72 	start = end - size;
73 
74 	debug("mapping memory %pa-%pa non-cached\n", &start, &end);
75 
76 	noncached_start = start;
77 	noncached_end = end;
78 	noncached_next = start;
79 
80 #ifndef CONFIG_SYS_DCACHE_OFF
81 	mmu_set_region_dcache_behaviour(noncached_start, size, DCACHE_OFF);
82 #endif
83 }
84 
85 phys_addr_t noncached_alloc(size_t size, size_t align)
86 {
87 	phys_addr_t next = ALIGN(noncached_next, align);
88 
89 	if (next >= noncached_end || (noncached_end - next) < size)
90 		return 0;
91 
92 	debug("allocated %zu bytes of uncached memory @%pa\n", size, &next);
93 	noncached_next = next + size;
94 
95 	return next;
96 }
97 #endif /* CONFIG_SYS_NONCACHED_MEMORY */
98