[U-Boot] [PATCH v2 18/19] beagle, cache: activate cache command

Heiko Schocher
2010-08-06T05:30:53Z

Signed-off-by: Heiko Schocher <hs@denx.de>
---
- changes since v1:
rebased as patch "arm cp15: setup mmu and enable dcache"
changed.

arch/arm/cpu/armv7/omap3/cache.S | 82 ++++++++++++++++++++++++++++++++++++
arch/arm/include/asm/global_data.h | 3 +
arch/arm/lib/board.c | 11 +++++
arch/arm/lib/cache-cp15.c | 35 ++++++++++-----
arch/arm/lib/cache.c | 5 ++
common/cmd_bdinfo.c | 3 +
include/configs/omap3_beagle.h | 1 +
7 files changed, 128 insertions(+), 12 deletions(-)

diff --git a/arch/arm/cpu/armv7/omap3/cache.S b/arch/arm/cpu/armv7/omap3/cache.S
index 4b65ac5..b983d23 100644
--- a/arch/arm/cpu/armv7/omap3/cache.S
+++ b/arch/arm/cpu/armv7/omap3/cache.S
@@ -189,3 +189,85 @@ l2_cache_disable_EARLIER_THAN_ES2:
str r3, [sp, #4]
l2_cache_disable_END:
ldmfd r13!, {r1, r2, r3, pc}
+
+.align 5
+.global v7_flush_dcache_all
+.global v7_flush_cache_all
+
+/*
+ * v7_flush_dcache_all()
+ *
+ * Flush the whole D-cache.
+ *
+ * Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
+ *
+ * - mm - mm_struct describing address space
+ */
+v7_flush_dcache_all:
+# dmb @ ensure ordering with previous memory accesses
+ mrc p15, 1, r0, c0, c0, 1 @ read clidr
+ ands r3, r0, #0x7000000 @ extract loc from clidr
+ mov r3, r3, lsr #23 @ left align loc bit field
+ beq finished @ if loc is 0, then no need to clean
+ mov r10, #0 @ start clean at cache level 0
+loop1:
+ add r2, r10, r10, lsr #1 @ work out 3x current cache level
+ mov r1, r0, lsr r2 @ extract cache type bits from clidr
+ and r1, r1, #7 @ mask of the bits for current cache only
+ cmp r1, #2 @ see what cache we have at this level
+ blt skip @ skip if no cache, or just i-cache
+ mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
+ mcr p15, 0, r10, c7, c5, 4 @ flush prefetch buffer,
+ @ with armv7 this is 'isb',
+ @ but we compile with armv5
+ mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
+ and r2, r1, #7 @ extract the length of the cache lines
+ add r2, r2, #4 @ add 4 (line length offset)
+ ldr r4, =0x3ff
+ ands r4, r4, r1, lsr #3 @ find maximum number on the way size
+ clz r5, r4 @ find bit position of way size increment
+ ldr r7, =0x7fff
+ ands r7, r7, r1, lsr #13 @ extract max number of the index size
+loop2:
+ mov r9, r4 @ create working copy of max way size
+loop3:
+ orr r11, r10, r9, lsl r5 @ factor way and cache number into r11
+ orr r11, r11, r7, lsl r2 @ factor index number into r11
+ mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
+ subs r9, r9, #1 @ decrement the way
+ bge loop3
+ subs r7, r7, #1 @ decrement the index
+ bge loop2
+skip:
+ add r10, r10, #2 @ increment cache number
+ cmp r3, r10
+ bgt loop1
+finished:
+ mov r10, #0 @ swith back to cache level 0
+ mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
+# dsb
+ mcr p15, 0, r10, c7, c5, 4 @ flush prefetch buffer,
+ @ with armv7 this is 'isb',
+ @ but we compile with armv5
+ mov pc, lr
+
+/*
+ * v7_flush_cache_all()
+ *
+ * Flush the entire cache system.
+ * The data cache flush is now achieved using atomic clean / invalidates
+ * working outwards from L1 cache. This is done using Set/Way based cache
+ * maintainance instructions.
+ * The instruction cache can still be invalidated back to the point of
+ * unification in a single instruction.
+ *
+ */
+v7_flush_cache_all:
+ stmfd sp!, {r0-r7, r9-r11, lr}
+ bl v7_flush_dcache_all
+ mov r0, #0
+ mcr p15, 0, r0, c7, c5, 0 @ I+BTB cache invalidate
+ ldmfd sp!, {r0-r7, r9-r11, lr}
+ mov pc, lr
+
+
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 192db7e..2636281 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -59,6 +59,9 @@ typedef struct global_data {
unsigned long irq_sp; /* irq stack pointer */
unsigned long start_addr_sp; /* start_addr_stackpointer */
unsigned long reloc_off;
+#if !(defined(CONFIG_SYS_NO_ICACHE) && defined(CONFIG_SYS_NO_DCACHE))
+ unsigned long tlb_addr;
+#endif
void **jt; /* jump table */
} gd_t;

diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index 18ac183..6428c8b 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -320,6 +320,17 @@ void board_init_f (ulong bootflag)
debug ("Reserving %ldk for protected RAM at %08lx\n", reg, addr);
#endif /* CONFIG_PRAM */

+#if !(defined(CONFIG_SYS_NO_ICACHE) && defined(CONFIG_SYS_NO_DCACHE))
+ /* reserve TLB table */
+ addr -= (4096 * 4);
+
+ /* round down to next 64 kB limit */
+ addr &= ~(0x10000 - 1);
+
+ gd->tlb_addr = addr;
+ debug ("TLB table at: %08lx\n", addr);
+#endif
+
/* round down to next 4 kB limit */
addr &= ~(4096 - 1);
debug ("Top of RAM usable for U-Boot at: %08lx\n", addr);
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
index 5cbfe42..b9ecd12 100644
--- a/arch/arm/lib/cache-cp15.c
+++ b/arch/arm/lib/cache-cp15.c
@@ -44,24 +44,32 @@ static void cp_delay (void)
asm volatile("" : : : "memory");
}

-/* to activate the MMU we need to set up virtual memory: use 1M areas in bss */
-static inline void mmu_setup(void)
+static inline void dram_bank_mmu_setup(int bank)
{
- static u32 __attribute__((aligned(16384))) page_table[4096];
+ u32 *page_table = (u32 *)gd->tlb_addr;
bd_t *bd = gd->bd;
- int i, j;
+ int i;
+
+ debug("%s: bank: %d\n", __func__, bank);
+ for (i = bd->bi_dram[bank].start >> 20;
+ i < (bd->bi_dram[bank].start + bd->bi_dram[bank].size) >> 20;
+ i++) {
+ page_table[i] = i << 20 | (3 << 10) | CACHE_SETUP;
+ }
+}
+
+/* to activate the MMU we need to set up virtual memory: use 1M areas */
+static inline void mmu_setup(void)
+{
+ u32 *page_table = (u32 *)gd->tlb_addr;
+ int i;
u32 reg;

/* Set up an identity-mapping for all 4GB, rw for everyone */
for (i = 0; i < 4096; i++)
page_table[i] = i << 20 | (3 << 10) | 0x12;
- /* Then, enable cacheable and bufferable for RAM only */
- for (j = 0 < CONFIG_NR_DRAM_BANKS; j++) {
- for (i = bd->bi_dram[j].start >> 20;
- i < (bd->bi_dram[j].start + bd->bi_dram[j].size) >> 20;
- i++) {
- page_table[i] = i << 20 | (3 << 10) | CACHE_SETUP;
- }
+ for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
+ dram_bank_mmu_setup(i);
}

/* Copy the page table address to cp15 */
@@ -74,7 +82,6 @@ static inline void mmu_setup(void)
reg = get_cr(); /* get control reg. */
cp_delay();
set_cr(reg | CR_M);
-
}

/* cache_bit must be either CR_I or CR_C */
@@ -96,6 +103,10 @@ static void cache_disable(uint32_t cache_bit)
uint32_t reg;

if (cache_bit == CR_C) {
+ /* if cache isn;t enabled no need to disable */
+ reg = get_cr();
+ if ((reg & CR_C) != CR_C)
+ return;
/* if disabling data cache, disable mmu too */
cache_bit |= CR_M;
flush_cache(0, ~0);
diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index b36fd24..3684cad 100644
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -38,5 +38,10 @@ void flush_cache (unsigned long dummy1, unsigned long dummy2)
/* disable write buffer as well (page 2-22) */
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0));
#endif
+#ifdef CONFIG_ARMCORTEXA8
+ void v7_flush_cache_all(void);
+
+ v7_flush_cache_all();
+#endif
return;
}
diff --git a/common/cmd_bdinfo.c b/common/cmd_bdinfo.c
index 4b289ca..c590a0d 100644
--- a/common/cmd_bdinfo.c
+++ b/common/cmd_bdinfo.c
@@ -343,6 +343,9 @@ int do_bdinfo ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
printf ("ip_addr = %pI4\n", &bd->bi_ip_addr);
#endif
printf ("baudrate = %d bps\n", bd->bi_baudrate);
+#if !(defined(CONFIG_SYS_NO_ICACHE) && defined(CONFIG_SYS_NO_DCACHE))
+ print_num ("TLB addr", gd->tlb_addr);
+#endif
print_num ("relocaddr", gd->relocaddr);
print_num ("reloc off", gd->reloc_off);
print_num ("irq_sp", gd->irq_sp); /* irq stack pointer */
diff --git a/include/configs/omap3_beagle.h b/include/configs/omap3_beagle.h
index e10fb89..5e8b48f 100644
--- a/include/configs/omap3_beagle.h
+++ b/include/configs/omap3_beagle.h
@@ -120,6 +120,7 @@
/* commands to include */
#include <config_cmd_default.h>

+#define CONFIG_CMD_CACHE
#define CONFIG_CMD_EXT2 /* EXT2 Support */
#define CONFIG_CMD_FAT /* FAT support */
#define CONFIG_CMD_JFFS2 /* JFFS2 Support */
--
1.6.2.5

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