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| author | Vineet Gupta | 2017-05-03 01:23:57 +0200 |
|---|---|---|
| committer | Vineet Gupta | 2017-05-03 01:40:29 +0200 |
| commit | f734a31083324b8f4f24b2c5cba178c7459db309 (patch) | |
| tree | 32812dba08e72cff8a76d14091c294cd6c701418 /arch/arc/include | |
| parent | ARCv2: mm: Merge 2 updates to DC_CTRL for region flush (diff) | |
| download | kernel-qcow2-linux-f734a31083324b8f4f24b2c5cba178c7459db309.tar.gz kernel-qcow2-linux-f734a31083324b8f4f24b2c5cba178c7459db309.tar.xz kernel-qcow2-linux-f734a31083324b8f4f24b2c5cba178c7459db309.zip | |
ARCv2: mm: micro-optimize region flush generated code
DC_CTRL.RGN_OP is 3 bits wide, however only 1 bit is used in current
programming model (0: flush, 1: invalidate)
The current code targetting 3 bits leads to additional 8 byte AND
operation which can be elided given that only 1 bit is ever set by
software and/or looked at by hardware
before
------
| 80b63324 <__dma_cache_wback_inv_l1>:
| 80b63324: clri r3
| 80b63328: lr r2,[dc_ctrl]
| 80b6332c: and r2,r2,0xfffff1ff <--- 8 bytes insn
| 80b63334: or r2,r2,576
| 80b63338: sr r2,[dc_ctrl]
| ...
| ...
| 80b63360 <__dma_cache_inv_l1>:
| 80b63360: clri r3
| 80b63364: lr r2,[dc_ctrl]
| 80b63368: and r2,r2,0xfffff1ff <--- 8 bytes insn
| 80b63370: bset_s r2,r2,0x9
| 80b63372: sr r2,[dc_ctrl]
| ...
| ...
| 80b6338c <__dma_cache_wback_l1>:
| 80b6338c: clri r3
| 80b63390: lr r2,[dc_ctrl]
| 80b63394: and r2,r2,0xfffff1ff <--- 8 bytes insn
| 80b6339c: sr r2,[dc_ctrl]
after (AND elided totally in 2 cases, replaced with 2 byte BCLR in 3rd)
-----
| 80b63324 <__dma_cache_wback_inv_l1>:
| 80b63324: clri r3
| 80b63328: lr r2,[dc_ctrl]
| 80b6332c: or r2,r2,576
| 80b63330: sr r2,[dc_ctrl]
| ...
| ...
| 80b63358 <__dma_cache_inv_l1>:
| 80b63358: clri r3
| 80b6335c: lr r2,[dc_ctrl]
| 80b63360: bset_s r2,r2,0x9
| 80b63362: sr r2,[dc_ctrl]
| ...
| ...
| 80b6337c <__dma_cache_wback_l1>:
| 80b6337c: clri r3
| 80b63380: lr r2,[dc_ctrl]
| 80b63384: bclr_s r2,r2,0x9
| 80b63386: sr r2,[dc_ctrl]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/include')
| -rw-r--r-- | arch/arc/include/asm/cache.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arc/include/asm/cache.h b/arch/arc/include/asm/cache.h index 16e457706129..19ebddffb279 100644 --- a/arch/arc/include/asm/cache.h +++ b/arch/arc/include/asm/cache.h @@ -88,7 +88,7 @@ extern unsigned long perip_base, perip_end; #define DC_CTRL_INV_MODE_FLUSH 0x040 #define DC_CTRL_FLUSH_STATUS 0x100 #define DC_CTRL_RGN_OP_INV 0x200 -#define DC_CTRL_RGN_OP_MSK 0xE00 +#define DC_CTRL_RGN_OP_MSK 0x200 /*System-level cache (L2 cache) related Auxiliary registers */ #define ARC_REG_SLC_CFG 0x901 |