From: Matt Evans <mev@rivosinc.com>
Date: Wed, 1 Feb 2023 19:49:42 +0000
Subject: [PATCH] clocksource/drivers/riscv: Patch riscv_clock_next_event()
jump before first use
References: bsc#1012628
Patch-mainline: 6.2.3
Git-commit: 225b9596cb0227c1c1b1e4a836dad43595c3e61a
[ Upstream commit 225b9596cb0227c1c1b1e4a836dad43595c3e61a ]
A static key is used to select between SBI and Sstc timer usage in
riscv_clock_next_event(), but currently the direction is resolved
after cpuhp_setup_state() is called (which sets the next event). The
first event will therefore fall through the sbi_set_timer() path; this
breaks Sstc-only systems. So, apply the jump patching before first
use.
Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available")
Signed-off-by: Matt Evans <mev@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/CDDAB2D0-264E-42F3-8E31-BA210BEB8EC1@rivosinc.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/clocksource/timer-riscv.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index a0d66fab..a01c2bd2 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -177,6 +177,11 @@ static int __init riscv_timer_init_dt(struct device_node *n)
return error;
}
+ if (riscv_isa_extension_available(NULL, SSTC)) {
+ pr_info("Timer interrupt in S-mode is available via sstc extension\n");
+ static_branch_enable(&riscv_sstc_available);
+ }
+
error = cpuhp_setup_state(CPUHP_AP_RISCV_TIMER_STARTING,
"clockevents/riscv/timer:starting",
riscv_timer_starting_cpu, riscv_timer_dying_cpu);
@@ -184,11 +189,6 @@ static int __init riscv_timer_init_dt(struct device_node *n)
pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
error);
- if (riscv_isa_extension_available(NULL, SSTC)) {
- pr_info("Timer interrupt in S-mode is available via sstc extension\n");
- static_branch_enable(&riscv_sstc_available);
- }
-
return error;
}
--
2.35.3