Commit 225b9596 authored Feb 01, 2023 by Matt Evans Committed by Daniel Lezcano Feb 13, 2023

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



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: 9f7a8ff6 ("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>

parent f3af3dc7

drivers/clocksource/timer-riscv.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -192,6 +192,11 @@ 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);
		@@ -199,11 +204,6 @@ 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;
		}