arm64: arch_timer: Rework the set_next_event workarounds

The way we work around errata affecting set_next_event is not very
nice, at it imposes this workaround on errata that do not need it.

Add new workaround hooks and let the existing workarounds use them.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
index 1b0d7e994e0c79dac8578f327d52598fd6e0adad..cc1e08127fb4828af64691019d7297380d606d05 100644 (file)
--- a/arch/arm64/include/asm/arch_timer.h
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -42,6 +42,8 @@ enum arch_timer_erratum_match_type {
        ate_match_local_cap_id,
 };
 
+struct clock_event_device;
+
 struct arch_timer_erratum_workaround {
        enum arch_timer_erratum_match_type match_type;
        const void *id;
@@ -49,6 +51,8 @@ struct arch_timer_erratum_workaround {
        u32 (*read_cntp_tval_el0)(void);
        u32 (*read_cntv_tval_el0)(void);
        u64 (*read_cntvct_el0)(void);
+       int (*set_next_event_phys)(unsigned long, struct clock_event_device *);
+       int (*set_next_event_virt)(unsigned long, struct clock_event_device *);
 };
 
 extern const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround;

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 2c02e25d1475196e647781f44d3f2d196975cb96..a0c9ee80147eab29ab488013c21583f9c72a0156 100644 (file)
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -282,6 +282,8 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
                .read_cntp_tval_el0 = fsl_a008585_read_cntp_tval_el0,
                .read_cntv_tval_el0 = fsl_a008585_read_cntv_tval_el0,
                .read_cntvct_el0 = fsl_a008585_read_cntvct_el0,
+               .set_next_event_phys = erratum_set_next_event_tval_phys,
+               .set_next_event_virt = erratum_set_next_event_tval_virt,
        },
 #endif
 #ifdef CONFIG_HISILICON_ERRATUM_161010101
@@ -292,6 +294,8 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
                .read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0,
                .read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0,
                .read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
+               .set_next_event_phys = erratum_set_next_event_tval_phys,
+               .set_next_event_virt = erratum_set_next_event_tval_virt,
        },
 #endif
 };
@@ -377,11 +381,24 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t
                local ? "local" : "global", wa->desc);
 }
 
+#define erratum_handler(fn, r, ...)                                    \
+({                                                                     \
+       bool __val;                                                     \
+       if (needs_unstable_timer_counter_workaround() &&                \
+           timer_unstable_counter_workaround->fn) {                    \
+               r = timer_unstable_counter_workaround->fn(__VA_ARGS__); \
+               __val = true;                                           \
+       } else {                                                        \
+               __val = false;                                          \
+       }                                                               \
+       __val;                                                          \
+})
+
 #else
 #define arch_timer_check_ool_workaround(t,a)           do { } while(0)
 #define erratum_set_next_event_tval_virt(...)          ({BUG(); 0;})
 #define erratum_set_next_event_tval_phys(...)          ({BUG(); 0;})
-#define needs_unstable_timer_counter_workaround()      ({false;})
+#define erratum_handler(fn, r, ...)                    ({false;})
 #endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
 
 static __always_inline irqreturn_t timer_handler(const int access,
@@ -474,8 +491,10 @@ static __always_inline void set_next_event(const int access, unsigned long evt,
 static int arch_timer_set_next_event_virt(unsigned long evt,
                                          struct clock_event_device *clk)
 {
-       if (needs_unstable_timer_counter_workaround())
-               return erratum_set_next_event_tval_virt(evt, clk);
+       int ret;
+
+       if (erratum_handler(set_next_event_virt, ret, evt, clk))
+               return ret;
 
        set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
        return 0;
@@ -484,8 +503,10 @@ static int arch_timer_set_next_event_virt(unsigned long evt,
 static int arch_timer_set_next_event_phys(unsigned long evt,
                                          struct clock_event_device *clk)
 {
-       if (needs_unstable_timer_counter_workaround())
-               return erratum_set_next_event_tval_phys(evt, clk);
+       int ret;
+
+       if (erratum_handler(set_next_event_phys, ret, evt, clk))
+               return ret;
 
        set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
        return 0;