ppc4xx: Rework 4xx cache support

New cache handling functions added and all existing functions
moved from start.S into seperate cache.S.

Signed-off-by: Stefan Roese <sr@denx.de>

1 files changed, 233 insertions, 0 deletions

diff --git a/cpu/ppc4xx/cache.S b/cpu/ppc4xx/cache.S
new file mode 100644
index 0000000..5124dec
--- /dev/null
+++ b/cpu/ppc4xx/cache.S
@@ -0,0 +1,233 @@
+/*
+ * This file contains miscellaneous low-level functions.
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
+ * and Paul Mackerras.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <config.h>
+#include <config.h>
+#include <ppc4xx.h>
+#include <ppc_asm.tmpl>
+#include <ppc_defs.h>
+#include <asm/cache.h>
+#include <asm/mmu.h>
+
+/*
+ * Flush instruction cache.
+ */
+_GLOBAL(invalidate_icache)
+	iccci	r0,r0
+	isync
+	blr
+
+/*
+ * Write any modified data cache blocks out to memory
+ * and invalidate the corresponding instruction cache blocks.
+ *
+ * flush_icache_range(unsigned long start, unsigned long stop)
+ */
+_GLOBAL(flush_icache_range)
+	li	r5,L1_CACHE_BYTES-1
+	andc	r3,r3,r5
+	subf	r4,r3,r4
+	add	r4,r4,r5
+	srwi.	r4,r4,L1_CACHE_SHIFT
+	beqlr
+	mtctr	r4
+	mr	r6,r3
+1:	dcbst	0,r3
+	addi	r3,r3,L1_CACHE_BYTES
+	bdnz	1b
+	sync				/* wait for dcbst's to get to ram */
+	mtctr	r4
+2:	icbi	0,r6
+	addi	r6,r6,L1_CACHE_BYTES
+	bdnz	2b
+	sync				/* additional sync needed on g4 */
+	isync
+	blr
+
+/*
+ * Write any modified data cache blocks out to memory.
+ * Does not invalidate the corresponding cache lines (especially for
+ * any corresponding instruction cache).
+ *
+ * clean_dcache_range(unsigned long start, unsigned long stop)
+ */
+_GLOBAL(clean_dcache_range)
+	li	r5,L1_CACHE_BYTES-1
+	andc	r3,r3,r5
+	subf	r4,r3,r4
+	add	r4,r4,r5
+	srwi.	r4,r4,L1_CACHE_SHIFT
+	beqlr
+	mtctr	r4
+
+1:	dcbst	0,r3
+	addi	r3,r3,L1_CACHE_BYTES
+	bdnz	1b
+	sync				/* wait for dcbst's to get to ram */
+	blr
+
+/*
+ * Write any modified data cache blocks out to memory and invalidate them.
+ * Does not invalidate the corresponding instruction cache blocks.
+ *
+ * flush_dcache_range(unsigned long start, unsigned long stop)
+ */
+_GLOBAL(flush_dcache_range)
+	li	r5,L1_CACHE_BYTES-1
+	andc	r3,r3,r5
+	subf	r4,r3,r4
+	add	r4,r4,r5
+	srwi.	r4,r4,L1_CACHE_SHIFT
+	beqlr
+	mtctr	r4
+
+1:	dcbf	0,r3
+	addi	r3,r3,L1_CACHE_BYTES
+	bdnz	1b
+	sync				/* wait for dcbst's to get to ram */
+	blr
+
+/*
+ * Like above, but invalidate the D-cache.  This is used by the 8xx
+ * to invalidate the cache so the PPC core doesn't get stale data
+ * from the CPM (no cache snooping here :-).
+ *
+ * invalidate_dcache_range(unsigned long start, unsigned long stop)
+ */
+_GLOBAL(invalidate_dcache_range)
+	li	r5,L1_CACHE_BYTES-1
+	andc	r3,r3,r5
+	subf	r4,r3,r4
+	add	r4,r4,r5
+	srwi.	r4,r4,L1_CACHE_SHIFT
+	beqlr
+	mtctr	r4
+
+1:	dcbi	0,r3
+	addi	r3,r3,L1_CACHE_BYTES
+	bdnz	1b
+	sync				/* wait for dcbi's to get to ram */
+	blr
+
+/*
+ * 40x cores have 8K or 16K dcache and 32 byte line size.
+ * 44x has a 32K dcache and 32 byte line size.
+ * 8xx has 1, 2, 4, 8K variants.
+ * For now, cover the worst case of the 44x.
+ * Must be called with external interrupts disabled.
+ */
+#define CACHE_NWAYS     64
+#define CACHE_NLINES    32
+
+_GLOBAL(flush_dcache)
+	li	r4,(2 * CACHE_NWAYS * CACHE_NLINES)
+	mtctr	r4
+	lis	r5,0
+1:	lwz	r3,0(r5)		/* Load one word from every line */
+	addi	r5,r5,L1_CACHE_BYTES
+	bdnz	1b
+	sync
+	blr
+
+_GLOBAL(invalidate_dcache)
+	addi	r6,0,0x0000		/* clear GPR 6 */
+	/* Do loop for # of dcache congruence classes. */
+	lis	r7,(CFG_DCACHE_SIZE / L1_CACHE_BYTES / 2)@ha	/* TBS for large sized cache */
+	ori	r7,r7,(CFG_DCACHE_SIZE / L1_CACHE_BYTES / 2)@l
+					/* NOTE: dccci invalidates both */
+	mtctr	r7			/* ways in the D cache */
+..dcloop:
+	dccci	0,r6			/* invalidate line */
+	addi	r6,r6,L1_CACHE_BYTES	/* bump to next line */
+	bdnz	..dcloop
+	sync
+	blr
+
+/*
+ * Cache functions.
+ *
+ * NOTE: currently the 440s run with dcache _disabled_ once relocated to DRAM,
+ * although for some cache-ralated calls stubs have to be provided to satisfy
+ * symbols resolution.
+ * Icache-related functions are used in POST framework.
+ *
+ */
+#ifdef CONFIG_440
+
+       .globl  dcache_disable
+       .globl  icache_disable
+       .globl  icache_enable
+dcache_disable:
+icache_disable:
+icache_enable:
+	blr
+
+	.globl	dcache_status
+	.globl	icache_status
+dcache_status:
+icache_status:
+	mr	r3,  0
+	blr
+
+#else /* CONFIG_440 */
+
+	.globl	icache_enable
+icache_enable:
+	mflr	r8
+	bl	invalidate_icache
+	mtlr	r8
+	isync
+	addis	r3,r0, 0xc000	      /* set bit 0 */
+	mticcr	r3
+	blr
+
+	.globl	icache_disable
+icache_disable:
+	addis	r3,r0, 0x0000	      /* clear bit 0 */
+	mticcr	r3
+	isync
+	blr
+
+	.globl	icache_status
+icache_status:
+	mficcr	r3
+	srwi	r3, r3, 31	/* >>31 => select bit 0 */
+	blr
+
+	.globl	dcache_enable
+dcache_enable:
+	mflr	r8
+	bl	invalidate_dcache
+	mtlr	r8
+	isync
+	addis	r3,r0, 0x8000	      /* set bit 0 */
+	mtdccr	r3
+	blr
+
+	.globl	dcache_disable
+dcache_disable:
+	mflr	r8
+	bl	flush_dcache
+	mtlr	r8
+	addis	r3,r0, 0x0000	      /* clear bit 0 */
+	mtdccr	r3
+	blr
+
+	.globl	dcache_status
+dcache_status:
+	mfdccr	r3
+	srwi	r3, r3, 31	/* >>31 => select bit 0 */
+	blr
+
+#endif /* CONFIG_440 */