[PATCH 10/14] powerpc/rtas: replace rtas_call_unlocked with raw_rtas_call
Nicholas Piggin
npiggin at gmail.com
Wed Mar 9 00:50:43 AEDT 2022
Use the same calling and rets return convention with the raw rtas
call rather than requiring callers to load and byteswap return
values out of rtas_args.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/include/asm/rtas.h | 4 +-
arch/powerpc/kernel/rtas.c | 53 +++++++++++---------
arch/powerpc/platforms/pseries/hotplug-cpu.c | 2 +-
arch/powerpc/platforms/pseries/ras.c | 7 +--
arch/powerpc/xmon/xmon.c | 2 +-
5 files changed, 33 insertions(+), 35 deletions(-)
diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index 82e5b055fa2a..1014ff140cf8 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -241,8 +241,8 @@ extern int rtas_token(const char *service);
extern int rtas_service_present(const char *service);
extern int rtas_call(int token, int, int, int *, ...);
int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...);
-void rtas_call_unlocked(struct rtas_args *args, int token, int nargs,
- int nret, ...);
+int raw_rtas_call(struct rtas_args *args, int token,
+ int nargs, int nret, int *outputs, ...);
extern void __noreturn rtas_restart(char *cmd);
extern void rtas_power_off(void);
extern void __noreturn rtas_halt(void);
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index fece066115f0..751a20669669 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -123,7 +123,7 @@ static void call_rtas_display_status(unsigned char c)
return;
s = lock_rtas();
- rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c);
+ raw_rtas_call(&rtas.args, 10, 1, 1, NULL, c);
unlock_rtas(s);
}
@@ -434,10 +434,9 @@ static char *__fetch_rtas_last_error(char *altbuf)
#define get_errorlog_buffer() NULL
#endif
-
-static void
-va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
- va_list list)
+static int notrace va_raw_rtas_call(struct rtas_args *args, int token,
+ int nargs, int nret, int *outputs,
+ va_list list)
{
int i;
@@ -453,21 +452,37 @@ va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
args->rets[i] = 0;
do_enter_rtas(__pa(args));
+
+ if (nret > 1 && outputs != NULL) {
+ for (i = 0; i < nret-1; ++i)
+ outputs[i] = be32_to_cpu(args->rets[i+1]);
+ }
+
+ return (nret > 0) ? be32_to_cpu(args->rets[0]) : 0;
}
-void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
+/*
+ * Like rtas_call but no kmalloc or printk etc in error handling, so
+ * error won't go through log_error. No tracing, may be called in real mode.
+ * rtas_args must be supplied, and appropriate synchronization for the rtas
+ * call being made has to be performed by the caller.
+ */
+int notrace raw_rtas_call(struct rtas_args *args, int token,
+ int nargs, int nret, int *outputs, ...)
{
va_list list;
+ int ret;
- va_start(list, nret);
- va_rtas_call_unlocked(args, token, nargs, nret, list);
+ va_start(list, outputs);
+ ret = va_raw_rtas_call(args, token, nargs, nret, outputs, list);
va_end(list);
+
+ return ret;
}
int rtas_call(int token, int nargs, int nret, int *outputs, ...)
{
va_list list;
- int i;
unsigned long s;
struct rtas_args *rtas_args;
char *buff_copy = NULL;
@@ -482,19 +497,14 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...)
rtas_args = &rtas.args;
va_start(list, outputs);
- va_rtas_call_unlocked(rtas_args, token, nargs, nret, list);
+ ret = va_raw_rtas_call(rtas_args, token, nargs, nret, outputs, list);
va_end(list);
/* A -1 return code indicates that the last command couldn't
be completed due to a hardware error. */
- if (be32_to_cpu(rtas_args->rets[0]) == -1)
+ if (ret == -1)
buff_copy = __fetch_rtas_last_error(NULL);
- if (nret > 1 && outputs != NULL)
- for (i = 0; i < nret-1; ++i)
- outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
- ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;
-
unlock_rtas(s);
if (buff_copy) {
@@ -950,7 +960,7 @@ int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
va_list list;
struct rtas_args *args;
unsigned long flags;
- int i, ret = 0;
+ int ret;
if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
return -1;
@@ -962,16 +972,9 @@ int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
args = local_paca->rtas_args_reentrant;
va_start(list, outputs);
- va_rtas_call_unlocked(args, token, nargs, nret, list);
+ ret = va_raw_rtas_call(args, token, nargs, nret, outputs, list);
va_end(list);
- if (nret > 1 && outputs)
- for (i = 0; i < nret - 1; ++i)
- outputs[i] = be32_to_cpu(args->rets[i + 1]);
-
- if (nret > 0)
- ret = be32_to_cpu(args->rets[0]);
-
local_irq_restore(flags);
preempt_enable();
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index b81fc846d99c..17c05650b6b9 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -53,7 +53,7 @@ static void rtas_stop_self(void)
BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE);
- rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL);
+ raw_rtas_call(&args, rtas_stop_self_token, 0, 1, NULL);
panic("Alas, I survived.\n");
}
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 74c9b1b5bc66..b009ed7de1ee 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -465,12 +465,7 @@ static void fwnmi_release_errinfo(void)
struct rtas_args rtas_args;
int ret;
- /*
- * On pseries, the machine check stack is limited to under 4GB, so
- * args can be on-stack.
- */
- rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL);
- ret = be32_to_cpu(rtas_args.rets[0]);
+ ret = raw_rtas_call(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL);
if (ret != 0)
printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
}
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index fd72753e8ad5..6f53e8bccc33 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -410,7 +410,7 @@ static inline void disable_surveillance(void)
if (set_indicator_token == RTAS_UNKNOWN_SERVICE)
return;
- rtas_call_unlocked(&args, set_indicator_token, 3, 1, NULL,
+ raw_rtas_call(&args, set_indicator_token, 3, 1, NULL,
SURVEILLANCE_TOKEN, 0, 0);
#endif /* CONFIG_PPC_PSERIES */
--
2.23.0
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