[RFC PATCH 03/10] powerpc: A new cache shape aux vectors
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2016-08-17 05:43:02
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
The definition is loosely based on sh and alpha, modified to accomodate larger associativity and cache size for future-proofing. We currently set all the values to -1 which indicates that the information isn't available. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- arch/powerpc/include/asm/elf.h | 8 ++++++++ arch/powerpc/include/uapi/asm/auxvec.h | 27 ++++++++++++++++++++++++++- arch/powerpc/kernel/setup-common.c | 5 ++++- 3 files changed, 38 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h
index 730c27e..402605e 100644
--- a/arch/powerpc/include/asm/elf.h
+++ b/arch/powerpc/include/asm/elf.h@@ -115,6 +115,10 @@ do { \ extern int dcache_bsize; extern int icache_bsize; extern int ucache_bsize; +extern long il1cache_shape; +extern long dl1cache_shape; +extern long l2cache_shape; +extern long l3cache_shape; /* vDSO has arch_setup_additional_pages */ #define ARCH_HAS_SETUP_ADDITIONAL_PAGES
@@ -155,6 +159,10 @@ do { \ NEW_AUX_ENT(AT_DCACHEBSIZE, dcache_bsize); \ NEW_AUX_ENT(AT_ICACHEBSIZE, icache_bsize); \ NEW_AUX_ENT(AT_UCACHEBSIZE, ucache_bsize); \ + NEW_AUX_ENT(AT_L1I_CACHESHAPE, il1cache_shape); \ + NEW_AUX_ENT(AT_L1D_CACHESHAPE, dl1cache_shape); \ + NEW_AUX_ENT(AT_L2_CACHESHAPE, l2cache_shape); \ + NEW_AUX_ENT(AT_L3_CACHESHAPE, l3cache_shape); \ VDSO_AUX_ENT(AT_SYSINFO_EHDR, current->mm->context.vdso_base); \ } while (0)
diff --git a/arch/powerpc/include/uapi/asm/auxvec.h b/arch/powerpc/include/uapi/asm/auxvec.h
index ce17d2c..b3861d8 100644
--- a/arch/powerpc/include/uapi/asm/auxvec.h
+++ b/arch/powerpc/include/uapi/asm/auxvec.h@@ -16,6 +16,31 @@ */ #define AT_SYSINFO_EHDR 33 -#define AT_VECTOR_SIZE_ARCH 6 /* entries in ARCH_DLINFO */ +/* More complete cache descriptions than AT_[DIU]CACHEBSIZE. If the + value is -1, then the cache doesn't exist or information isn't + availble. Otherwise: + + bit 0-9: Cache set-associativity 0 means fully associative. + bit 10-13: Log2 of cacheline size. + bit 14-31: Size of the entire cache >> 10. + bit 32-39: [64-bit only] more bits for total cache size. + bit 40-63: Reserved + + If any of the fields is all 1's, then that field isn't available. + + WARNING: The cache *line* size can be different from the cache *block* + size. The latter, represented by vectors 19,20,21, is the size + used by the cache management instructions such as dcbz. The + cache line size on the other hand is the real HW line size + for a given cache level which might be different and should + only be used for performance related tuning +*/ + +#define AT_L1I_CACHESHAPE 34 +#define AT_L1D_CACHESHAPE 35 +#define AT_L2_CACHESHAPE 36 +#define AT_L3_CACHESHAPE 37 + +#define AT_VECTOR_SIZE_ARCH 10 /* entries in ARCH_DLINFO */ #endif
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index e0eeed4..cfa2a06 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c@@ -94,7 +94,10 @@ EXPORT_SYMBOL_GPL(boot_cpuid); int dcache_bsize; int icache_bsize; int ucache_bsize; - +long il1cache_shape = -1; +long dl1cache_shape = -1; +long l2cache_shape = -1; +long l3cache_shape = -1; unsigned long klimit = (unsigned long) _end;
--
2.7.4