diff options
Diffstat (limited to 'arch/s390/kernel/diag/diag324.c')
| -rw-r--r-- | arch/s390/kernel/diag/diag324.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/arch/s390/kernel/diag/diag324.c b/arch/s390/kernel/diag/diag324.c new file mode 100644 index 000000000000..7fa4c0b7eb6c --- /dev/null +++ b/arch/s390/kernel/diag/diag324.c @@ -0,0 +1,224 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Request power readings for resources in a computing environment via + * diag 0x324. diag 0x324 stores the power readings in the power information + * block (pib). + * + * Copyright IBM Corp. 2024 + */ + +#define pr_fmt(fmt) "diag324: " fmt +#include <linux/fs.h> +#include <linux/gfp.h> +#include <linux/ioctl.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/ktime.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/timer.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/vmalloc.h> + +#include <asm/diag.h> +#include <asm/sclp.h> +#include <asm/timex.h> +#include <uapi/asm/diag.h> +#include "diag_ioctl.h" + +enum subcode { + DIAG324_SUBC_0 = 0, + DIAG324_SUBC_1 = 1, + DIAG324_SUBC_2 = 2, +}; + +enum retcode { + DIAG324_RET_SUCCESS = 0x0001, + DIAG324_RET_SUBC_NOTAVAIL = 0x0103, + DIAG324_RET_INSUFFICIENT_SIZE = 0x0104, + DIAG324_RET_READING_UNAVAILABLE = 0x0105, +}; + +union diag324_response { + u64 response; + struct { + u64 installed : 32; + u64 : 16; + u64 rc : 16; + } sc0; + struct { + u64 format : 16; + u64 : 16; + u64 pib_len : 16; + u64 rc : 16; + } sc1; + struct { + u64 : 48; + u64 rc : 16; + } sc2; +}; + +union diag324_request { + u64 request; + struct { + u64 : 32; + u64 allocated : 16; + u64 : 12; + u64 sc : 4; + } sc2; +}; + +struct pib { + u32 : 8; + u32 num : 8; + u32 len : 16; + u32 : 24; + u32 hlen : 8; + u64 : 64; + u64 intv; + u8 r[]; +} __packed; + +struct pibdata { + struct pib *pib; + ktime_t expire; + u64 sequence; + size_t len; + int rc; +}; + +static DEFINE_MUTEX(pibmutex); +static struct pibdata pibdata; + +#define PIBWORK_DELAY (5 * NSEC_PER_SEC) + +static void pibwork_handler(struct work_struct *work); +static DECLARE_DELAYED_WORK(pibwork, pibwork_handler); + +static unsigned long diag324(unsigned long subcode, void *addr) +{ + union register_pair rp = { .even = (unsigned long)addr }; + + diag_stat_inc(DIAG_STAT_X324); + asm volatile("diag %[rp],%[subcode],0x324\n" + : [rp] "+d" (rp.pair) + : [subcode] "d" (subcode) + : "memory"); + return rp.odd; +} + +static void pibwork_handler(struct work_struct *work) +{ + struct pibdata *data = &pibdata; + ktime_t timedout; + + mutex_lock(&pibmutex); + timedout = ktime_add_ns(data->expire, PIBWORK_DELAY); + if (ktime_before(ktime_get(), timedout)) { + mod_delayed_work(system_wq, &pibwork, nsecs_to_jiffies(PIBWORK_DELAY)); + goto out; + } + vfree(data->pib); + data->pib = NULL; +out: + mutex_unlock(&pibmutex); +} + +static void pib_update(struct pibdata *data) +{ + union diag324_request req = { .sc2.sc = DIAG324_SUBC_2, .sc2.allocated = data->len }; + union diag324_response res; + int rc; + + memset(data->pib, 0, data->len); + res.response = diag324(req.request, data->pib); + switch (res.sc2.rc) { + case DIAG324_RET_SUCCESS: + rc = 0; + break; + case DIAG324_RET_SUBC_NOTAVAIL: + rc = -ENOENT; + break; + case DIAG324_RET_INSUFFICIENT_SIZE: + rc = -EMSGSIZE; + break; + case DIAG324_RET_READING_UNAVAILABLE: + rc = -EBUSY; + break; + default: + rc = -EINVAL; + } + data->rc = rc; +} + +long diag324_pibbuf(unsigned long arg) +{ + struct diag324_pib __user *udata = (struct diag324_pib __user *)arg; + struct pibdata *data = &pibdata; + static bool first = true; + u64 address; + int rc; + + if (!data->len) + return -EOPNOTSUPP; + if (get_user(address, &udata->address)) + return -EFAULT; + mutex_lock(&pibmutex); + rc = -ENOMEM; + if (!data->pib) + data->pib = vmalloc(data->len); + if (!data->pib) + goto out; + if (first || ktime_after(ktime_get(), data->expire)) { + pib_update(data); + data->sequence++; + data->expire = ktime_add_ns(ktime_get(), tod_to_ns(data->pib->intv)); + mod_delayed_work(system_wq, &pibwork, nsecs_to_jiffies(PIBWORK_DELAY)); + first = false; + } + rc = data->rc; + if (rc != 0 && rc != -EBUSY) + goto out; + rc = copy_to_user((void __user *)address, data->pib, data->pib->len); + rc |= put_user(data->sequence, &udata->sequence); + if (rc) + rc = -EFAULT; +out: + mutex_unlock(&pibmutex); + return rc; +} + +long diag324_piblen(unsigned long arg) +{ + struct pibdata *data = &pibdata; + + if (!data->len) + return -EOPNOTSUPP; + if (put_user(data->len, (size_t __user *)arg)) + return -EFAULT; + return 0; +} + +static int __init diag324_init(void) +{ + union diag324_response res; + unsigned long installed; + + if (!sclp.has_diag324) + return -EOPNOTSUPP; + res.response = diag324(DIAG324_SUBC_0, NULL); + if (res.sc0.rc != DIAG324_RET_SUCCESS) + return -EOPNOTSUPP; + installed = res.response; + if (!test_bit_inv(DIAG324_SUBC_1, &installed)) + return -EOPNOTSUPP; + if (!test_bit_inv(DIAG324_SUBC_2, &installed)) + return -EOPNOTSUPP; + res.response = diag324(DIAG324_SUBC_1, NULL); + if (res.sc1.rc != DIAG324_RET_SUCCESS) + return -EOPNOTSUPP; + pibdata.len = res.sc1.pib_len; + return 0; +} +device_initcall(diag324_init); 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