linux/arch/powerpc/include/asm/cache.h
Christophe Leroy 1128bb7813 powerpc/lib: Adjust .balign inside string functions for PPC32
commit 87a156fb18 ("Align hot loops of some string functions")
degraded the performance of string functions by adding useless
nops

A simple benchmark on an 8xx calling 100000x a memchr() that
matches the first byte runs in 41668 TB ticks before this patch
and in 35986 TB ticks after this patch. So this gives an
improvement of approx 10%

Another benchmark doing the same with a memchr() matching the 128th
byte runs in 1011365 TB ticks before this patch and 1005682 TB ticks
after this patch, so regardless on the number of loops, removing
those useless nops improves the test by 5683 TB ticks.

Fixes: 87a156fb18 ("Align hot loops of some string functions")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-04 00:39:19 +10:00

108 lines
2.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_CACHE_H
#define _ASM_POWERPC_CACHE_H
#ifdef __KERNEL__
/* bytes per L1 cache line */
#if defined(CONFIG_PPC_8xx) || defined(CONFIG_403GCX)
#define L1_CACHE_SHIFT 4
#define MAX_COPY_PREFETCH 1
#define IFETCH_ALIGN_SHIFT 2
#elif defined(CONFIG_PPC_E500MC)
#define L1_CACHE_SHIFT 6
#define MAX_COPY_PREFETCH 4
#define IFETCH_ALIGN_SHIFT 3
#elif defined(CONFIG_PPC32)
#define MAX_COPY_PREFETCH 4
#define IFETCH_ALIGN_SHIFT 3 /* 603 fetches 2 insn at a time */
#if defined(CONFIG_PPC_47x)
#define L1_CACHE_SHIFT 7
#else
#define L1_CACHE_SHIFT 5
#endif
#else /* CONFIG_PPC64 */
#define L1_CACHE_SHIFT 7
#define IFETCH_ALIGN_SHIFT 4 /* POWER8,9 */
#endif
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
#define SMP_CACHE_BYTES L1_CACHE_BYTES
#define IFETCH_ALIGN_BYTES (1 << IFETCH_ALIGN_SHIFT)
#if defined(__powerpc64__) && !defined(__ASSEMBLY__)
struct ppc_cache_info {
u32 size;
u32 line_size;
u32 block_size; /* L1 only */
u32 log_block_size;
u32 blocks_per_page;
u32 sets;
u32 assoc;
};
struct ppc64_caches {
struct ppc_cache_info l1d;
struct ppc_cache_info l1i;
struct ppc_cache_info l2;
struct ppc_cache_info l3;
};
extern struct ppc64_caches ppc64_caches;
#endif /* __powerpc64__ && ! __ASSEMBLY__ */
#if defined(__ASSEMBLY__)
/*
* For a snooping icache, we still need a dummy icbi to purge all the
* prefetched instructions from the ifetch buffers. We also need a sync
* before the icbi to order the the actual stores to memory that might
* have modified instructions with the icbi.
*/
#define PURGE_PREFETCHED_INS \
sync; \
icbi 0,r3; \
sync; \
isync
#else
#define __read_mostly __attribute__((__section__(".data..read_mostly")))
#ifdef CONFIG_6xx
extern long _get_L2CR(void);
extern long _get_L3CR(void);
extern void _set_L2CR(unsigned long);
extern void _set_L3CR(unsigned long);
#else
#define _get_L2CR() 0L
#define _get_L3CR() 0L
#define _set_L2CR(val) do { } while(0)
#define _set_L3CR(val) do { } while(0)
#endif
static inline void dcbz(void *addr)
{
__asm__ __volatile__ ("dcbz 0, %0" : : "r"(addr) : "memory");
}
static inline void dcbi(void *addr)
{
__asm__ __volatile__ ("dcbi 0, %0" : : "r"(addr) : "memory");
}
static inline void dcbf(void *addr)
{
__asm__ __volatile__ ("dcbf 0, %0" : : "r"(addr) : "memory");
}
static inline void dcbst(void *addr)
{
__asm__ __volatile__ ("dcbst 0, %0" : : "r"(addr) : "memory");
}
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_CACHE_H */