diff options
| -rw-r--r-- | arch/s390/kernel/sthyi.c | 55 |
1 files changed, 38 insertions, 17 deletions
diff --git a/arch/s390/kernel/sthyi.c b/arch/s390/kernel/sthyi.c index 9f9bac01f5f2..1cf2ad04f8e9 100644 --- a/arch/s390/kernel/sthyi.c +++ b/arch/s390/kernel/sthyi.c @@ -300,7 +300,7 @@ static struct diag204_x_part_block *lpar_cpu_inf(struct lpar_cpu_inf *part_inf, return (struct diag204_x_part_block *)&block->cpus[i]; } -static void *diag204_get_data(void) +static void *diag204_get_data(bool diag204_allow_busy) { unsigned long subcode; void *diag204_buf; @@ -320,6 +320,8 @@ static void *diag204_get_data(void) return ERR_PTR(-ENOMEM); subcode = DIAG204_SUBC_STIB7; subcode |= DIAG204_INFO_EXT; + if (diag204_has_bif() && diag204_allow_busy) + subcode |= DIAG204_BIF_BIT; rc = diag204(subcode, pages, diag204_buf); if (rc < 0) { vfree(diag204_buf); @@ -328,22 +330,27 @@ static void *diag204_get_data(void) return diag204_buf; } -static void fill_diag(struct sthyi_sctns *sctns) +static bool is_diag204_cached(struct sthyi_sctns *sctns) +{ + /* + * Check if validity bits are set when diag204 data + * is gathered. + */ + if (sctns->par.infpval1) + return true; + return false; +} + +static void fill_diag(struct sthyi_sctns *sctns, void *diag204_buf) { int i; bool this_lpar; - void *diag204_buf; void *diag224_buf = NULL; struct diag204_x_info_blk_hdr *ti_hdr; struct diag204_x_part_block *part_block; struct diag204_x_phys_block *phys_block; struct lpar_cpu_inf lpar_inf = {}; - /* Errors are handled through the validity bits in the response. */ - diag204_buf = diag204_get_data(); - if (IS_ERR(diag204_buf)) - return; - diag224_buf = (void *)__get_free_page(GFP_KERNEL | GFP_DMA); if (!diag224_buf || diag224(diag224_buf)) goto out; @@ -408,7 +415,6 @@ static void fill_diag(struct sthyi_sctns *sctns) out: free_page((unsigned long)diag224_buf); - vfree(diag204_buf); } static int sthyi(u64 vaddr, u64 *rc) @@ -430,19 +436,31 @@ static int sthyi(u64 vaddr, u64 *rc) static int fill_dst(void *dst, u64 *rc) { + void *diag204_buf; + struct sthyi_sctns *sctns = (struct sthyi_sctns *)dst; /* * If the facility is on, we don't want to emulate the instruction. * We ask the hypervisor to provide the data. */ - if (test_facility(74)) + if (test_facility(74)) { + memset(dst, 0, PAGE_SIZE); return sthyi((u64)dst, rc); - + } + /* + * When emulating, if diag204 returns BUSY don't reset dst buffer + * and use cached data. + */ + *rc = 0; + diag204_buf = diag204_get_data(is_diag204_cached(sctns)); + if (IS_ERR(diag204_buf)) + return PTR_ERR(diag204_buf); + memset(dst, 0, PAGE_SIZE); fill_hdr(sctns); fill_stsi(sctns); - fill_diag(sctns); - *rc = 0; + fill_diag(sctns, diag204_buf); + vfree(diag204_buf); return 0; } @@ -461,11 +479,14 @@ static int sthyi_update_cache(u64 *rc) { int r; - memset(sthyi_cache.info, 0, PAGE_SIZE); r = fill_dst(sthyi_cache.info, rc); - if (r) - return r; - sthyi_cache.end = jiffies + CACHE_VALID_JIFFIES; + if (r == 0) { + sthyi_cache.end = jiffies + CACHE_VALID_JIFFIES; + } else if (r == -EBUSY) { + /* mark as expired and return 0 to keep using cached data */ + sthyi_cache.end = jiffies - 1; + r = 0; + } return r; } |