Patch "clocksource/drivers/riscv: Patch riscv_clock_next_event() jump before first use" has been added to the 6.2-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    clocksource/drivers/riscv: Patch riscv_clock_next_event() jump before first use

to the 6.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     clocksource-drivers-riscv-patch-riscv_clock_next_eve.patch
and it can be found in the queue-6.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 16168c8940697f00a4d58f353dddc5763e312424
Author: Matt Evans <mev@xxxxxxxxxxxx>
Date:   Wed Feb 1 19:49:42 2023 +0000

    clocksource/drivers/riscv: Patch riscv_clock_next_event() jump before first use
    
    [ 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@xxxxxxxxxxxx>
    Reviewed-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
    Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
    Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/CDDAB2D0-264E-42F3-8E31-BA210BEB8EC1@xxxxxxxxxxxx
    Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index a0d66fabf0732..a01c2bd241349 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;
 }