[RFC PATCH 1/2] powerpc: Remove duplicate cacheable_memcpy/memzero functions

From: Kyle Moffett
Date: Mon Nov 14 2011 - 21:33:08 EST


These functions are only used from one place each. If the cacheable_*
versions really are more efficient, then those changes should be
migrated into the common code instead.

NOTE: The old routines are just flat buggy on kernels that support
hardware with different cacheline sizes.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@xxxxxxxxxx>
---
arch/powerpc/include/asm/system.h | 2 -
arch/powerpc/kernel/ppc_ksyms.c | 2 -
arch/powerpc/lib/copy_32.S | 127 ----------------------------------
arch/powerpc/mm/ppc_mmu_32.c | 2 +-
drivers/net/ethernet/ibm/emac/core.c | 12 +---
5 files changed, 3 insertions(+), 142 deletions(-)

diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h
index e30a13d..25389d1 100644
--- a/arch/powerpc/include/asm/system.h
+++ b/arch/powerpc/include/asm/system.h
@@ -189,8 +189,6 @@ static inline void flush_spe_to_thread(struct task_struct *t)
#endif

extern int call_rtas(const char *, int, int, unsigned long *, ...);
-extern void cacheable_memzero(void *p, unsigned int nb);
-extern void *cacheable_memcpy(void *, const void *, unsigned int);
extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
extern void bad_page_fault(struct pt_regs *, unsigned long, int);
extern int die(const char *, struct pt_regs *, long);
diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c
index d3114a7..acba8ce 100644
--- a/arch/powerpc/kernel/ppc_ksyms.c
+++ b/arch/powerpc/kernel/ppc_ksyms.c
@@ -159,8 +159,6 @@ EXPORT_SYMBOL(screen_info);
#ifdef CONFIG_PPC32
EXPORT_SYMBOL(timer_interrupt);
EXPORT_SYMBOL(tb_ticks_per_jiffy);
-EXPORT_SYMBOL(cacheable_memcpy);
-EXPORT_SYMBOL(cacheable_memzero);
#endif

#ifdef CONFIG_PPC32
diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
index 55f19f9..6813f80 100644
--- a/arch/powerpc/lib/copy_32.S
+++ b/arch/powerpc/lib/copy_32.S
@@ -69,54 +69,6 @@ CACHELINE_BYTES = L1_CACHE_BYTES
LG_CACHELINE_BYTES = L1_CACHE_SHIFT
CACHELINE_MASK = (L1_CACHE_BYTES-1)

-/*
- * Use dcbz on the complete cache lines in the destination
- * to set them to zero. This requires that the destination
- * area is cacheable. -- paulus
- */
-_GLOBAL(cacheable_memzero)
- mr r5,r4
- li r4,0
- addi r6,r3,-4
- cmplwi 0,r5,4
- blt 7f
- stwu r4,4(r6)
- beqlr
- andi. r0,r6,3
- add r5,r0,r5
- subf r6,r0,r6
- clrlwi r7,r6,32-LG_CACHELINE_BYTES
- add r8,r7,r5
- srwi r9,r8,LG_CACHELINE_BYTES
- addic. r9,r9,-1 /* total number of complete cachelines */
- ble 2f
- xori r0,r7,CACHELINE_MASK & ~3
- srwi. r0,r0,2
- beq 3f
- mtctr r0
-4: stwu r4,4(r6)
- bdnz 4b
-3: mtctr r9
- li r7,4
-10: dcbz r7,r6
- addi r6,r6,CACHELINE_BYTES
- bdnz 10b
- clrlwi r5,r8,32-LG_CACHELINE_BYTES
- addi r5,r5,4
-2: srwi r0,r5,2
- mtctr r0
- bdz 6f
-1: stwu r4,4(r6)
- bdnz 1b
-6: andi. r5,r5,3
-7: cmpwi 0,r5,0
- beqlr
- mtctr r5
- addi r6,r6,3
-8: stbu r4,1(r6)
- bdnz 8b
- blr
-
_GLOBAL(memset)
rlwimi r4,r4,8,16,23
rlwimi r4,r4,16,0,15
@@ -142,85 +94,6 @@ _GLOBAL(memset)
bdnz 8b
blr

-/*
- * This version uses dcbz on the complete cache lines in the
- * destination area to reduce memory traffic. This requires that
- * the destination area is cacheable.
- * We only use this version if the source and dest don't overlap.
- * -- paulus.
- */
-_GLOBAL(cacheable_memcpy)
- add r7,r3,r5 /* test if the src & dst overlap */
- add r8,r4,r5
- cmplw 0,r4,r7
- cmplw 1,r3,r8
- crand 0,0,4 /* cr0.lt &= cr1.lt */
- blt memcpy /* if regions overlap */
-
- addi r4,r4,-4
- addi r6,r3,-4
- neg r0,r3
- andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */
- beq 58f
-
- cmplw 0,r5,r0 /* is this more than total to do? */
- blt 63f /* if not much to do */
- andi. r8,r0,3 /* get it word-aligned first */
- subf r5,r0,r5
- mtctr r8
- beq+ 61f
-70: lbz r9,4(r4) /* do some bytes */
- stb r9,4(r6)
- addi r4,r4,1
- addi r6,r6,1
- bdnz 70b
-61: srwi. r0,r0,2
- mtctr r0
- beq 58f
-72: lwzu r9,4(r4) /* do some words */
- stwu r9,4(r6)
- bdnz 72b
-
-58: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
- clrlwi r5,r5,32-LG_CACHELINE_BYTES
- li r11,4
- mtctr r0
- beq 63f
-53:
- dcbz r11,r6
- COPY_16_BYTES
-#if L1_CACHE_BYTES >= 32
- COPY_16_BYTES
-#if L1_CACHE_BYTES >= 64
- COPY_16_BYTES
- COPY_16_BYTES
-#if L1_CACHE_BYTES >= 128
- COPY_16_BYTES
- COPY_16_BYTES
- COPY_16_BYTES
- COPY_16_BYTES
-#endif
-#endif
-#endif
- bdnz 53b
-
-63: srwi. r0,r5,2
- mtctr r0
- beq 64f
-30: lwzu r0,4(r4)
- stwu r0,4(r6)
- bdnz 30b
-
-64: andi. r0,r5,3
- mtctr r0
- beq+ 65f
-40: lbz r0,4(r4)
- stb r0,4(r6)
- addi r4,r4,1
- addi r6,r6,1
- bdnz 40b
-65: blr
-
_GLOBAL(memmove)
cmplw 0,r3,r4
bgt backwards_memcpy
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index 11571e1..9f16b9f 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -224,7 +224,7 @@ void __init MMU_init_hw(void)
*/
if ( ppc_md.progress ) ppc_md.progress("hash:find piece", 0x322);
Hash = __va(memblock_alloc(Hash_size, Hash_size));
- cacheable_memzero(Hash, Hash_size);
+ memset(Hash, 0, Hash_size);
_SDR1 = __pa(Hash) | SDR1_LOW_BITS;

Hash_end = (struct hash_pte *) ((unsigned long)Hash + Hash_size);
diff --git a/drivers/net/ethernet/ibm/emac/core.c b/drivers/net/ethernet/ibm/emac/core.c
index ed79b2d..be214ad 100644
--- a/drivers/net/ethernet/ibm/emac/core.c
+++ b/drivers/net/ethernet/ibm/emac/core.c
@@ -77,13 +77,6 @@ MODULE_AUTHOR
("Eugene Surovegin <eugene.surovegin@xxxxxxxxxx> or <ebs@xxxxxxxxxxx>");
MODULE_LICENSE("GPL");

-/*
- * PPC64 doesn't (yet) have a cacheable_memcpy
- */
-#ifdef CONFIG_PPC64
-#define cacheable_memcpy(d,s,n) memcpy((d),(s),(n))
-#endif
-
/* minimum number of free TX descriptors required to wake up TX process */
#define EMAC_TX_WAKEUP_THRESH (NUM_TX_BUFF / 4)

@@ -1637,7 +1630,7 @@ static inline int emac_rx_sg_append(struct emac_instance *dev, int slot)
dev_kfree_skb(dev->rx_sg_skb);
dev->rx_sg_skb = NULL;
} else {
- cacheable_memcpy(skb_tail_pointer(dev->rx_sg_skb),
+ memcpy(skb_tail_pointer(dev->rx_sg_skb),
dev->rx_skb[slot]->data, len);
skb_put(dev->rx_sg_skb, len);
emac_recycle_rx_skb(dev, slot, len);
@@ -1694,8 +1687,7 @@ static int emac_poll_rx(void *param, int budget)
goto oom;

skb_reserve(copy_skb, EMAC_RX_SKB_HEADROOM + 2);
- cacheable_memcpy(copy_skb->data - 2, skb->data - 2,
- len + 2);
+ memcpy(copy_skb->data - 2, skb->data - 2, len + 2);
emac_recycle_rx_skb(dev, slot, len);
skb = copy_skb;
} else if (unlikely(emac_alloc_rx_skb(dev, slot, GFP_ATOMIC)))
--
1.7.2.5

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