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

[Heiko Schocher <hs@denx.de>]

Signed-off-by: Heiko Schocher <hs@denx.de>
---
 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          |   33 +++++++++++----
 arch/arm/lib/cache.c               |    5 ++
 common/cmd_bdinfo.c                |    3 +
 include/configs/omap3_beagle.h     |    1 +
 7 files changed, 130 insertions(+), 8 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 11e64d8..6ab9f84 100644
--- a/arch/arm/lib/cache-cp15.c
+++ b/arch/arm/lib/cache-cp15.c
@@ -25,6 +25,9 @@
 #include <asm/system.h>

 #if !(defined(CONFIG_SYS_NO_ICACHE) && defined(CONFIG_SYS_NO_DCACHE))
+
+DECLARE_GLOBAL_DATA_PTR;
+
 static void cp_delay (void)
 {
 	volatile int i;
@@ -35,21 +38,32 @@ 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 dram_bank_mmu_setup(int bank)
+{
+	u32 *page_table = (u32 *)gd->tlb_addr;
+	int	i;
+
+	debug("%s: bank: %d\n", __func__, bank);
+	for (i = gd->bd->bi_dram[bank].start >> 20;
+	     i < (gd->bd->bi_dram[bank].start + gd->bd->bi_dram[bank].size) >> 20;
+	     i++) {
+		/* C and B bit set */
+		page_table[i] = i << 20 | (3 << 10) | 0x1e;
+	}
+}
+
+/* to activate the MMU we need to set up virtual memory: use 1M areas */
 static inline void mmu_setup(void)
 {
-	static u32 __attribute__((aligned(16384))) page_table[4096];
+	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 (i = PHYS_SDRAM >> 20;
-	     i < ( PHYS_SDRAM + PHYS_SDRAM_SIZE) >> 20;
-	     i++) {
-		page_table[i] = i << 20 | (3 << 10) | 0x1e;
+	for (i=0; i<CONFIG_NR_DRAM_BANKS; ++i) {
+		dram_bank_mmu_setup(i);
 	}
 	/* Copy the page table address to cp15 */
 	asm volatile("mcr p15, 0, %0, c2, c0, 0"
@@ -61,7 +75,6 @@ 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 */
@@ -83,6 +96,10 @@ 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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