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authorShinya Kuribayashi <skuribay@ruby.dti.ne.jp>2008-03-25 21:30:06 +0900
committerShinya Kuribayashi <skuribay@ruby.dti.ne.jp>2008-03-25 21:30:06 +0900
commit2e0e5271aac917812a76c72030a2b2c6f1d3387d (patch)
treed2f724aa31ea7d3696170910069b6168437c7b0f /cpu
parent1898840797c7f50799377bd5b285a8a93a82c419 (diff)
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[MIPS] Fix I-/D-cache initialization loops
Currently we do 1) Index_Store_Tag_I, 2) Fill and 3) Index_Store_Tag_I again per a loop for I-cache initialization. But according to 'See MIPS Run', we're encouraged to use three separate loops rather than combining them *for both I- and D-cache*. This patch tries to fix this. In accordance with fixing above, mips_init_[id]cache are separated from mips_cache_reset(), and rewrite cache loops are completely rewritten with useful macros. Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
Diffstat (limited to 'cpu')
-rw-r--r--cpu/mips/cache.S115
1 files changed, 76 insertions, 39 deletions
diff --git a/cpu/mips/cache.S b/cpu/mips/cache.S
index 6d39ba9..bb42616 100644
--- a/cpu/mips/cache.S
+++ b/cpu/mips/cache.S
@@ -30,11 +30,23 @@
#include <asm/addrspace.h>
#include <asm/cacheops.h>
+#define RA t8
+
/* 16KB is the maximum size of instruction and data caches on
* MIPS 4K.
*/
#define MIPS_MAX_CACHE_SIZE 0x4000
+#define INDEX_BASE KSEG0
+
+ .macro cache_op op addr
+ .set push
+ .set noreorder
+ .set mips3
+ cache \op, 0(\addr)
+ .set pop
+ .endm
+
/*
* cacheop macro to automate cache operations
* first some helpers...
@@ -125,6 +137,56 @@
#endif
.endm
+/*
+ * mips_init_icache(uint PRId, ulong icache_size, unchar icache_linesz)
+ */
+LEAF(mips_init_icache)
+ blez a1, 9f
+ mtc0 zero, CP0_TAGLO
+ /* clear tag to invalidate */
+ PTR_LI t0, INDEX_BASE
+ PTR_ADDU t1, t0, a1
+1: cache_op Index_Store_Tag_I t0
+ PTR_ADDU t0, a2
+ bne t0, t1, 1b
+ /* fill once, so data field parity is correct */
+ PTR_LI t0, INDEX_BASE
+2: cache_op Fill t0
+ PTR_ADDU t0, a2
+ bne t0, t1, 2b
+ /* invalidate again - prudent but not strictly neccessary */
+ PTR_LI t0, INDEX_BASE
+1: cache_op Index_Store_Tag_I t0
+ PTR_ADDU t0, a2
+ bne t0, t1, 1b
+9: jr ra
+ END(mips_init_icache)
+
+/*
+ * mips_init_dcache(uint PRId, ulong dcache_size, unchar dcache_linesz)
+ */
+LEAF(mips_init_dcache)
+ blez a1, 9f
+ mtc0 zero, CP0_TAGLO
+ /* clear all tags */
+ PTR_LI t0, INDEX_BASE
+ PTR_ADDU t1, t0, a1
+1: cache_op Index_Store_Tag_D t0
+ PTR_ADDU t0, a2
+ bne t0, t1, 1b
+ /* load from each line (in cached space) */
+ PTR_LI t0, INDEX_BASE
+2: LONG_L zero, 0(t0)
+ PTR_ADDU t0, a2
+ bne t0, t1, 2b
+ /* clear all tags */
+ PTR_LI t0, INDEX_BASE
+1: cache_op Index_Store_Tag_D t0
+ PTR_ADDU t0, a2
+ bne t0, t1, 1b
+9: jr ra
+ END(mips_init_dcache)
+
/*******************************************************************************
*
* mips_cache_reset - low level initialisation of the primary caches
@@ -142,6 +204,7 @@
*
*/
NESTED(mips_cache_reset, 0, ra)
+ move RA, ra
li t2, CFG_ICACHE_SIZE
li t3, CFG_DCACHE_SIZE
li t4, CFG_CACHELINE_SIZE
@@ -158,57 +221,31 @@ NESTED(mips_cache_reset, 0, ra)
f_fill64 a0, -64, zero
bne a0, a1, 2b
- /* Set invalid tag.
- */
-
- mtc0 zero, CP0_TAGLO
-
/*
* The caches are probably in an indeterminate state,
* so we force good parity into them by doing an
* invalidate, load/fill, invalidate for each line.
*/
- /* Assume bottom of RAM will generate good parity for the cache.
- */
-
- li a0, K0BASE
- move a2, t2 # icacheSize
- move a3, t4 # icacheLineSize
- move a1, a2
- icacheopn(a0,a1,a2,a3,121,(Index_Store_Tag_I,Fill))
-
- /* To support Orion/R4600, we initialise the data cache in 3 passes.
- */
-
- /* 1: initialise dcache tags.
+ /*
+ * Assume bottom of RAM will generate good parity for the cache.
*/
- li a0, K0BASE
- move a2, t3 # dcacheSize
- move a3, t5 # dcacheLineSize
- move a1, a2
- icacheop(a0,a1,a2,a3,Index_Store_Tag_D)
-
- /* 2: fill dcache.
+ /*
+ * Initialize the I-cache first,
*/
+ move a1, t2
+ move a2, t4
+ bal mips_init_icache
- li a0, K0BASE
- move a2, t3 # dcacheSize
- move a3, t5 # dcacheLineSize
- move a1, a2
- icacheopn(a0,a1,a2,a3,1lw,(dummy))
-
- /* 3: clear dcache tags.
+ /*
+ * then initialize D-cache.
*/
+ move a1, t3
+ move a2, t5
+ bal mips_init_dcache
- li a0, K0BASE
- move a2, t3 # dcacheSize
- move a3, t5 # dcacheLineSize
- move a1, a2
- icacheop(a0,a1,a2,a3,Index_Store_Tag_D)
-
- j ra
+ jr RA
END(mips_cache_reset)
/*******************************************************************************