diff options
Diffstat (limited to 'util/cacheflush.c')
| -rw-r--r-- | util/cacheflush.c | 247 |
1 files changed, 231 insertions, 16 deletions
diff --git a/util/cacheflush.c b/util/cacheflush.c index 4b57186d89..2c2c73e085 100644 --- a/util/cacheflush.c +++ b/util/cacheflush.c @@ -1,5 +1,5 @@ /* - * Flush the host cpu caches. + * Info about, and flushing the host cpu caches. * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. @@ -9,8 +9,218 @@ #include "qemu/cacheflush.h" #include "qemu/cacheinfo.h" #include "qemu/bitops.h" +#include "qemu/host-utils.h" +#include "qemu/atomic.h" +int qemu_icache_linesize = 0; +int qemu_icache_linesize_log; +int qemu_dcache_linesize = 0; +int qemu_dcache_linesize_log; + +/* + * Operating system specific cache detection mechanisms. + */ + +#if defined(_WIN32) + +static void sys_cache_info(int *isize, int *dsize) +{ + SYSTEM_LOGICAL_PROCESSOR_INFORMATION *buf; + DWORD size = 0; + BOOL success; + size_t i, n; + + /* + * Check for the required buffer size first. Note that if the zero + * size we use for the probe results in success, then there is no + * data available; fail in that case. + */ + success = GetLogicalProcessorInformation(0, &size); + if (success || GetLastError() != ERROR_INSUFFICIENT_BUFFER) { + return; + } + + n = size / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION); + size = n * sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION); + buf = g_new0(SYSTEM_LOGICAL_PROCESSOR_INFORMATION, n); + if (!GetLogicalProcessorInformation(buf, &size)) { + goto fail; + } + + for (i = 0; i < n; i++) { + if (buf[i].Relationship == RelationCache + && buf[i].Cache.Level == 1) { + switch (buf[i].Cache.Type) { + case CacheUnified: + *isize = *dsize = buf[i].Cache.LineSize; + break; + case CacheInstruction: + *isize = buf[i].Cache.LineSize; + break; + case CacheData: + *dsize = buf[i].Cache.LineSize; + break; + default: + break; + } + } + } + fail: + g_free(buf); +} + +#elif defined(CONFIG_DARWIN) +# include <sys/sysctl.h> +static void sys_cache_info(int *isize, int *dsize) +{ + /* There's only a single sysctl for both I/D cache line sizes. */ + long size; + size_t len = sizeof(size); + if (!sysctlbyname("hw.cachelinesize", &size, &len, NULL, 0)) { + *isize = *dsize = size; + } +} +#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) +# include <sys/sysctl.h> +static void sys_cache_info(int *isize, int *dsize) +{ + /* There's only a single sysctl for both I/D cache line sizes. */ + int size; + size_t len = sizeof(size); + if (!sysctlbyname("machdep.cacheline_size", &size, &len, NULL, 0)) { + *isize = *dsize = size; + } +} +#else +/* POSIX */ + +static void sys_cache_info(int *isize, int *dsize) +{ +# ifdef _SC_LEVEL1_ICACHE_LINESIZE + int tmp_isize = (int) sysconf(_SC_LEVEL1_ICACHE_LINESIZE); + if (tmp_isize > 0) { + *isize = tmp_isize; + } +# endif +# ifdef _SC_LEVEL1_DCACHE_LINESIZE + int tmp_dsize = (int) sysconf(_SC_LEVEL1_DCACHE_LINESIZE); + if (tmp_dsize > 0) { + *dsize = tmp_dsize; + } +# endif +} +#endif /* sys_cache_info */ + + +/* + * Architecture (+ OS) specific cache detection mechanisms. + */ + +#if defined(__powerpc__) +static bool have_coherent_icache; +#endif + +#if defined(__aarch64__) && !defined(CONFIG_DARWIN) +/* Apple does not expose CTR_EL0, so we must use system interfaces. */ +static uint64_t save_ctr_el0; +static void arch_cache_info(int *isize, int *dsize) +{ + uint64_t ctr; + + /* + * The real cache geometry is in CCSIDR_EL1/CLIDR_EL1/CSSELR_EL1, + * but (at least under Linux) these are marked protected by the + * kernel. However, CTR_EL0 contains the minimum linesize in the + * entire hierarchy, and is used by userspace cache flushing. + * + * We will also use this value in flush_idcache_range. + */ + asm volatile("mrs\t%0, ctr_el0" : "=r"(ctr)); + save_ctr_el0 = ctr; + + if (*isize == 0 || *dsize == 0) { + if (*isize == 0) { + *isize = 4 << (ctr & 0xf); + } + if (*dsize == 0) { + *dsize = 4 << ((ctr >> 16) & 0xf); + } + } +} + +#elif defined(_ARCH_PPC) && defined(__linux__) +# include "elf.h" + +static void arch_cache_info(int *isize, int *dsize) +{ + if (*isize == 0) { + *isize = qemu_getauxval(AT_ICACHEBSIZE); + } + if (*dsize == 0) { + *dsize = qemu_getauxval(AT_DCACHEBSIZE); + } + have_coherent_icache = qemu_getauxval(AT_HWCAP) & PPC_FEATURE_ICACHE_SNOOP; +} + +#else +static void arch_cache_info(int *isize, int *dsize) { } +#endif /* arch_cache_info */ + +/* + * ... and if all else fails ... + */ + +static void fallback_cache_info(int *isize, int *dsize) +{ + /* If we can only find one of the two, assume they're the same. */ + if (*isize) { + if (*dsize) { + /* Success! */ + } else { + *dsize = *isize; + } + } else if (*dsize) { + *isize = *dsize; + } else { +#if defined(_ARCH_PPC) + /* + * For PPC, we're going to use the cache sizes computed for + * flush_idcache_range. Which means that we must use the + * architecture minimum. + */ + *isize = *dsize = 16; +#else + /* Otherwise, 64 bytes is not uncommon. */ + *isize = *dsize = 64; +#endif + } +} + +static void __attribute__((constructor)) init_cache_info(void) +{ + int isize = 0, dsize = 0; + + sys_cache_info(&isize, &dsize); + arch_cache_info(&isize, &dsize); + fallback_cache_info(&isize, &dsize); + + assert((isize & (isize - 1)) == 0); + assert((dsize & (dsize - 1)) == 0); + + qemu_icache_linesize = isize; + qemu_icache_linesize_log = ctz32(isize); + qemu_dcache_linesize = dsize; + qemu_dcache_linesize_log = ctz32(dsize); + + qatomic64_init(); +} + + +/* + * Architecture (+ OS) specific cache flushing mechanisms. + */ + #if defined(__i386__) || defined(__x86_64__) || defined(__s390__) /* Caches are coherent and do not require flushing; symbol inline. */ @@ -29,17 +239,6 @@ void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len) #else /* - * TODO: unify this with cacheinfo.c. - * We want to save the whole contents of CTR_EL0, so that we - * have more than the linesize, but also IDC and DIC. - */ -static uint64_t save_ctr_el0; -static void __attribute__((constructor)) init_ctr_el0(void) -{ - asm volatile("mrs\t%0, ctr_el0" : "=r"(save_ctr_el0)); -} - -/* * This is a copy of gcc's __aarch64_sync_cache_range, modified * to fit this three-operand interface. */ @@ -48,8 +247,8 @@ void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len) const unsigned CTR_IDC = 1u << 28; const unsigned CTR_DIC = 1u << 29; const uint64_t ctr_el0 = save_ctr_el0; - const uintptr_t icache_lsize = 4 << extract64(ctr_el0, 0, 4); - const uintptr_t dcache_lsize = 4 << extract64(ctr_el0, 16, 4); + const uintptr_t icache_lsize = qemu_icache_linesize; + const uintptr_t dcache_lsize = qemu_dcache_linesize; uintptr_t p; /* @@ -104,8 +303,24 @@ void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len) void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len) { uintptr_t p, b, e; - size_t dsize = qemu_dcache_linesize; - size_t isize = qemu_icache_linesize; + size_t dsize, isize; + + /* + * Some processors have coherent caches and support a simplified + * flushing procedure. See + * POWER9 UM, 4.6.2.2 Instruction Cache Block Invalidate (icbi) + * https://ibm.ent.box.com/s/tmklq90ze7aj8f4n32er1mu3sy9u8k3k + */ + if (have_coherent_icache) { + asm volatile ("sync\n\t" + "icbi 0,%0\n\t" + "isync" + : : "r"(rx) : "memory"); + return; + } + + dsize = qemu_dcache_linesize; + isize = qemu_icache_linesize; b = rw & ~(dsize - 1); e = (rw + len + dsize - 1) & ~(dsize - 1); |