diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/papr-sysparm.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/papr-sysparm.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/papr-sysparm.c b/arch/powerpc/platforms/pseries/papr-sysparm.c new file mode 100644 index 000000000000..fedc61599e6c --- /dev/null +++ b/arch/powerpc/platforms/pseries/papr-sysparm.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define pr_fmt(fmt) "papr-sysparm: " fmt + +#include <linux/bug.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <asm/rtas.h> +#include <asm/papr-sysparm.h> +#include <asm/rtas-work-area.h> + +struct papr_sysparm_buf *papr_sysparm_buf_alloc(void) +{ + struct papr_sysparm_buf *buf = kzalloc(sizeof(*buf), GFP_KERNEL); + + return buf; +} + +void papr_sysparm_buf_free(struct papr_sysparm_buf *buf) +{ + kfree(buf); +} + +/** + * papr_sysparm_get() - Retrieve the value of a PAPR system parameter. + * @param: PAPR system parameter token as described in + * 7.3.16 "System Parameters Option". + * @buf: A &struct papr_sysparm_buf as returned from papr_sysparm_buf_alloc(). + * + * Place the result of querying the specified parameter, if available, + * in @buf. The result includes a be16 length header followed by the + * value, which may be a string or binary data. See &struct papr_sysparm_buf. + * + * Since there is at least one parameter (60, OS Service Entitlement + * Status) where the results depend on the incoming contents of the + * work area, the caller-supplied buffer is copied unmodified into the + * work area before calling ibm,get-system-parameter. + * + * A defined parameter may not be implemented on a given system, and + * some implemented parameters may not be available to all partitions + * on a system. A parameter's disposition may change at any time due + * to system configuration changes or partition migration. + * + * Context: This function may sleep. + * + * Return: 0 on success, -errno otherwise. @buf is unmodified on error. + */ + +int papr_sysparm_get(papr_sysparm_t param, struct papr_sysparm_buf *buf) +{ + const s32 token = rtas_function_token(RTAS_FN_IBM_GET_SYSTEM_PARAMETER); + struct rtas_work_area *work_area; + s32 fwrc; + int ret; + + might_sleep(); + + if (WARN_ON(!buf)) + return -EFAULT; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + work_area = rtas_work_area_alloc(sizeof(*buf)); + + memcpy(rtas_work_area_raw_buf(work_area), buf, sizeof(*buf)); + + do { + fwrc = rtas_call(token, 3, 1, NULL, param.token, + rtas_work_area_phys(work_area), + rtas_work_area_size(work_area)); + } while (rtas_busy_delay(fwrc)); + + switch (fwrc) { + case 0: + ret = 0; + memcpy(buf, rtas_work_area_raw_buf(work_area), sizeof(*buf)); + break; + case -3: /* parameter not implemented */ + ret = -EOPNOTSUPP; + break; + case -9002: /* this partition not authorized to retrieve this parameter */ + ret = -EPERM; + break; + case -9999: /* "parameter error" e.g. the buffer is too small */ + ret = -EINVAL; + break; + default: + pr_err("unexpected ibm,get-system-parameter result %d\n", fwrc); + fallthrough; + case -1: /* Hardware/platform error */ + ret = -EIO; + break; + } + + rtas_work_area_free(work_area); + + return ret; +} + +int papr_sysparm_set(papr_sysparm_t param, const struct papr_sysparm_buf *buf) +{ + const s32 token = rtas_function_token(RTAS_FN_IBM_SET_SYSTEM_PARAMETER); + struct rtas_work_area *work_area; + s32 fwrc; + int ret; + + might_sleep(); + + if (WARN_ON(!buf)) + return -EFAULT; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + work_area = rtas_work_area_alloc(sizeof(*buf)); + + memcpy(rtas_work_area_raw_buf(work_area), buf, sizeof(*buf)); + + do { + fwrc = rtas_call(token, 2, 1, NULL, param.token, + rtas_work_area_phys(work_area)); + } while (rtas_busy_delay(fwrc)); + + switch (fwrc) { + case 0: + ret = 0; + break; + case -3: /* parameter not supported */ + ret = -EOPNOTSUPP; + break; + case -9002: /* this partition not authorized to modify this parameter */ + ret = -EPERM; + break; + case -9999: /* "parameter error" e.g. invalid input data */ + ret = -EINVAL; + break; + default: + pr_err("unexpected ibm,set-system-parameter result %d\n", fwrc); + fallthrough; + case -1: /* Hardware/platform error */ + ret = -EIO; + break; + } + + rtas_work_area_free(work_area); + + return ret; +} |