diff options
Diffstat (limited to 'arch/s390/kernel/diag/diag310.c')
| -rw-r--r-- | arch/s390/kernel/diag/diag310.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/arch/s390/kernel/diag/diag310.c b/arch/s390/kernel/diag/diag310.c new file mode 100644 index 000000000000..d6a34454aa5a --- /dev/null +++ b/arch/s390/kernel/diag/diag310.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Request memory topology information via diag0x310. + * + * Copyright IBM Corp. 2025 + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/vmalloc.h> +#include <asm/diag.h> +#include <asm/sclp.h> +#include <uapi/asm/diag.h> +#include "diag_ioctl.h" + +#define DIAG310_LEVELMIN 1 +#define DIAG310_LEVELMAX 6 + +enum diag310_sc { + DIAG310_SUBC_0 = 0, + DIAG310_SUBC_1 = 1, + DIAG310_SUBC_4 = 4, + DIAG310_SUBC_5 = 5 +}; + +enum diag310_retcode { + DIAG310_RET_SUCCESS = 0x0001, + DIAG310_RET_BUSY = 0x0101, + DIAG310_RET_OPNOTSUPP = 0x0102, + DIAG310_RET_SC4_INVAL = 0x0401, + DIAG310_RET_SC4_NODATA = 0x0402, + DIAG310_RET_SC5_INVAL = 0x0501, + DIAG310_RET_SC5_NODATA = 0x0502, + DIAG310_RET_SC5_ESIZE = 0x0503 +}; + +union diag310_response { + u64 response; + struct { + u64 result : 32; + u64 : 16; + u64 rc : 16; + }; +}; + +union diag310_req_subcode { + u64 subcode; + struct { + u64 : 48; + u64 st : 8; + u64 sc : 8; + }; +}; + +union diag310_req_size { + u64 size; + struct { + u64 page_count : 32; + u64 : 32; + }; +}; + +static inline unsigned long diag310(unsigned long subcode, unsigned long size, void *addr) +{ + union register_pair rp = { .even = (unsigned long)addr, .odd = size }; + + diag_stat_inc(DIAG_STAT_X310); + asm volatile("diag %[rp],%[subcode],0x310\n" + : [rp] "+d" (rp.pair) + : [subcode] "d" (subcode) + : "memory"); + return rp.odd; +} + +static int diag310_result_to_errno(unsigned int result) +{ + switch (result) { + case DIAG310_RET_BUSY: + return -EBUSY; + case DIAG310_RET_OPNOTSUPP: + return -EOPNOTSUPP; + default: + return -EINVAL; + } +} + +static int diag310_get_subcode_mask(unsigned long *mask) +{ + union diag310_response res; + + res.response = diag310(DIAG310_SUBC_0, 0, NULL); + if (res.rc != DIAG310_RET_SUCCESS) + return diag310_result_to_errno(res.rc); + *mask = res.response; + return 0; +} + +static int diag310_get_memtop_stride(unsigned long *stride) +{ + union diag310_response res; + + res.response = diag310(DIAG310_SUBC_1, 0, NULL); + if (res.rc != DIAG310_RET_SUCCESS) + return diag310_result_to_errno(res.rc); + *stride = res.result; + return 0; +} + +static int diag310_get_memtop_size(unsigned long *pages, unsigned long level) +{ + union diag310_req_subcode req = { .sc = DIAG310_SUBC_4, .st = level }; + union diag310_response res; + + res.response = diag310(req.subcode, 0, NULL); + switch (res.rc) { + case DIAG310_RET_SUCCESS: + *pages = res.result; + return 0; + case DIAG310_RET_SC4_NODATA: + return -ENODATA; + case DIAG310_RET_SC4_INVAL: + return -EINVAL; + default: + return diag310_result_to_errno(res.rc); + } +} + +static int diag310_store_topology_map(void *buf, unsigned long pages, unsigned long level) +{ + union diag310_req_subcode req_sc = { .sc = DIAG310_SUBC_5, .st = level }; + union diag310_req_size req_size = { .page_count = pages }; + union diag310_response res; + + res.response = diag310(req_sc.subcode, req_size.size, buf); + switch (res.rc) { + case DIAG310_RET_SUCCESS: + return 0; + case DIAG310_RET_SC5_NODATA: + return -ENODATA; + case DIAG310_RET_SC5_ESIZE: + return -EOVERFLOW; + case DIAG310_RET_SC5_INVAL: + return -EINVAL; + default: + return diag310_result_to_errno(res.rc); + } +} + +static int diag310_check_features(void) +{ + static int features_available; + unsigned long mask; + int rc; + + if (READ_ONCE(features_available)) + return 0; + if (!sclp.has_diag310) + return -EOPNOTSUPP; + rc = diag310_get_subcode_mask(&mask); + if (rc) + return rc; + if (!test_bit_inv(DIAG310_SUBC_1, &mask)) + return -EOPNOTSUPP; + if (!test_bit_inv(DIAG310_SUBC_4, &mask)) + return -EOPNOTSUPP; + if (!test_bit_inv(DIAG310_SUBC_5, &mask)) + return -EOPNOTSUPP; + WRITE_ONCE(features_available, 1); + return 0; +} + +static int memtop_get_stride_len(unsigned long *res) +{ + static unsigned long memtop_stride; + unsigned long stride; + int rc; + + stride = READ_ONCE(memtop_stride); + if (!stride) { + rc = diag310_get_memtop_stride(&stride); + if (rc) + return rc; + WRITE_ONCE(memtop_stride, stride); + } + *res = stride; + return 0; +} + +static int memtop_get_page_count(unsigned long *res, unsigned long level) +{ + static unsigned long memtop_pages[DIAG310_LEVELMAX]; + unsigned long pages; + int rc; + + if (level > DIAG310_LEVELMAX || level < DIAG310_LEVELMIN) + return -EINVAL; + pages = READ_ONCE(memtop_pages[level - 1]); + if (!pages) { + rc = diag310_get_memtop_size(&pages, level); + if (rc) + return rc; + WRITE_ONCE(memtop_pages[level - 1], pages); + } + *res = pages; + return 0; +} + +long diag310_memtop_stride(unsigned long arg) +{ + size_t __user *argp = (void __user *)arg; + unsigned long stride; + int rc; + + rc = diag310_check_features(); + if (rc) + return rc; + rc = memtop_get_stride_len(&stride); + if (rc) + return rc; + if (put_user(stride, argp)) + return -EFAULT; + return 0; +} + +long diag310_memtop_len(unsigned long arg) +{ + size_t __user *argp = (void __user *)arg; + unsigned long pages, level; + int rc; + + rc = diag310_check_features(); + if (rc) + return rc; + if (get_user(level, argp)) + return -EFAULT; + rc = memtop_get_page_count(&pages, level); + if (rc) + return rc; + if (put_user(pages * PAGE_SIZE, argp)) + return -EFAULT; + return 0; +} + +long diag310_memtop_buf(unsigned long arg) +{ + struct diag310_memtop __user *udata = (struct diag310_memtop __user *)arg; + unsigned long level, pages, data_size; + u64 address; + void *buf; + int rc; + + rc = diag310_check_features(); + if (rc) + return rc; + if (get_user(level, &udata->nesting_lvl)) + return -EFAULT; + if (get_user(address, &udata->address)) + return -EFAULT; + rc = memtop_get_page_count(&pages, level); + if (rc) + return rc; + data_size = pages * PAGE_SIZE; + buf = __vmalloc_node(data_size, PAGE_SIZE, GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT, + NUMA_NO_NODE, __builtin_return_address(0)); + if (!buf) + return -ENOMEM; + rc = diag310_store_topology_map(buf, pages, level); + if (rc) + goto out; + if (copy_to_user((void __user *)address, buf, data_size)) + rc = -EFAULT; +out: + vfree(buf); + return rc; +} |