new file mode 100644
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef POWERPC_PAPR_SYSPARM_H
+#define POWERPC_PAPR_SYSPARM_H
+
+typedef struct {
+ const u32 token;
+} papr_sysparm_t;
+
+#define mk_papr_sysparm(x_) ((papr_sysparm_t){ .token = x_, })
+
+/*
+ * Derived from the "Defined Parameters" table in PAPR 7.3.16 System
+ * Parameters Option. Where the spec says "characteristics", we use
+ * "attrs" in the symbolic names to keep them from getting too
+ * unwieldy.
+ */
+#define PAPR_SYSPARM_SHARED_PROC_LPAR_ATTRS mk_papr_sysparm(20)
+#define PAPR_SYSPARM_PROC_MODULE_INFO mk_papr_sysparm(43)
+#define PAPR_SYSPARM_COOP_MEM_OVERCOMMIT_ATTRS mk_papr_sysparm(44)
+#define PAPR_SYSPARM_TLB_BLOCK_INVALIDATE_ATTRS mk_papr_sysparm(50)
+#define PAPR_SYSPARM_LPAR_NAME mk_papr_sysparm(55)
+
+enum {
+ PAPR_SYSPARM_MAX_INPUT = 1024,
+ PAPR_SYSPARM_MAX_OUTPUT = 4000,
+};
+
+struct papr_sysparm_buf {
+ __be16 len;
+ char val[PAPR_SYSPARM_MAX_OUTPUT];
+};
+
+struct papr_sysparm_buf *papr_sysparm_buf_alloc(void);
+void papr_sysparm_buf_free(struct papr_sysparm_buf *buf);
+int papr_sysparm_set(papr_sysparm_t param, const struct papr_sysparm_buf *buf);
+int papr_sysparm_get(papr_sysparm_t param, struct papr_sysparm_buf *buf);
+
+#endif /* POWERPC_PAPR_SYSPARM_H */
@@ -3,7 +3,7 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
ccflags-$(CONFIG_PPC_PSERIES_DEBUG) += -DDEBUG
obj-y := lpar.o hvCall.o nvram.o reconfig.o \
- of_helpers.o \
+ of_helpers.o papr-sysparm.o \
setup.o iommu.o event_sources.o ras.o \
firmware.o power.o dlpar.o mobility.o rng.o \
pci.o pci_dlpar.o eeh_pseries.o msi.o \
new file mode 100644
@@ -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_token("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_token("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;
+}