diff options
Diffstat (limited to 'arch/s390/kernel/sthyi.c')
| -rw-r--r-- | arch/s390/kernel/sthyi.c | 113 |
1 files changed, 77 insertions, 36 deletions
diff --git a/arch/s390/kernel/sthyi.c b/arch/s390/kernel/sthyi.c index 4d141e2c132e..5eae2e25997a 100644 --- a/arch/s390/kernel/sthyi.c +++ b/arch/s390/kernel/sthyi.c @@ -5,6 +5,8 @@ * Copyright IBM Corp. 2016 * Author(s): Janosch Frank <frankja@linux.vnet.ibm.com> */ + +#include <linux/export.h> #include <linux/errno.h> #include <linux/pagemap.h> #include <linux/vmalloc.h> @@ -17,6 +19,7 @@ #include <asm/ebcdic.h> #include <asm/facility.h> #include <asm/sthyi.h> +#include <asm/asm.h> #include "entry.h" #define DED_WEIGHT 0xffff @@ -250,7 +253,7 @@ static void fill_diag_mac(struct sthyi_sctns *sctns, sctns->mac.infmval1 |= MAC_CNT_VLD; } -/* Returns a pointer to the the next partition block. */ +/* Returns a pointer to the next partition block. */ static struct diag204_x_part_block *lpar_cpu_inf(struct lpar_cpu_inf *part_inf, bool this_lpar, void *diag224_buf, @@ -300,32 +303,57 @@ 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 fill_diag(struct sthyi_sctns *sctns) +static void *diag204_get_data(bool diag204_allow_busy) { - int i, r, pages; - bool this_lpar; + unsigned long subcode; void *diag204_buf; + int pages, rc; + + subcode = DIAG204_SUBC_RSI; + subcode |= DIAG204_INFO_EXT; + pages = diag204(subcode, 0, NULL); + if (pages < 0) + return ERR_PTR(pages); + if (pages == 0) + return ERR_PTR(-ENODATA); + diag204_buf = __vmalloc_node(array_size(pages, PAGE_SIZE), + PAGE_SIZE, GFP_KERNEL, NUMA_NO_NODE, + __builtin_return_address(0)); + if (!diag204_buf) + 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); + return ERR_PTR(rc); + } + return diag204_buf; +} + +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 *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. */ - pages = diag204((unsigned long)DIAG204_SUBC_RSI | - (unsigned long)DIAG204_INFO_EXT, 0, NULL); - if (pages <= 0) - return; - - diag204_buf = vmalloc(array_size(pages, PAGE_SIZE)); - if (!diag204_buf) - return; - - r = diag204((unsigned long)DIAG204_SUBC_STIB7 | - (unsigned long)DIAG204_INFO_EXT, pages, diag204_buf); - if (r < 0) - goto out; - diag224_buf = (void *)__get_free_page(GFP_KERNEL | GFP_DMA); if (!diag224_buf || diag224(diag224_buf)) goto out; @@ -390,7 +418,6 @@ 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) @@ -401,30 +428,41 @@ static int sthyi(u64 vaddr, u64 *rc) asm volatile( ".insn rre,0xB2560000,%[r1],%[r2]\n" - "ipm %[cc]\n" - "srl %[cc],28\n" - : [cc] "=&d" (cc), [r2] "+&d" (r2.pair) + CC_IPM(cc) + : CC_OUT(cc, cc), [r2] "+&d" (r2.pair) : [r1] "d" (r1.pair) - : "memory", "cc"); + : CC_CLOBBER_LIST("memory")); *rc = r2.odd; - return cc; + return CC_TRANSFORM(cc); } 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; } @@ -443,11 +481,14 @@ 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; } @@ -459,9 +500,9 @@ static int sthyi_update_cache(u64 *rc) * * Fills the destination with system information returned by the STHYI * instruction. The data is generated by emulation or execution of STHYI, - * if available. The return value is the condition code that would be - * returned, the rc parameter is the return code which is passed in - * register R2 + 1. + * if available. The return value is either a negative error value or + * the condition code that would be returned, the rc parameter is the + * return code which is passed in register R2 + 1. */ int sthyi_fill(void *dst, u64 *rc) { |