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authorMarc Zyngier <marc.zyngier@arm.com>2017-01-19 17:20:59 +0000
committerMarc Zyngier <marc.zyngier@arm.com>2017-04-07 11:22:08 +0100
commit651bb2e9dca6e6dbad3fba5f6e6086a23575b8b5 (patch)
treef7325f49f59ac0b20f78bd66917414005943e86b /drivers/clocksource
parenteeb1efbcb83c0cfe6d567abbacd675bbddf3d658 (diff)
downloadlinux-651bb2e9dca6e6dbad3fba5f6e6086a23575b8b5.tar.bz2
arm64: arch_timer: Add infrastructure for multiple erratum detection methods
We're currently stuck with DT when it comes to handling errata, which is pretty restrictive. In order to make things more flexible, let's introduce an infrastructure that could support alternative discovery methods. No change in functionality. Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/arm_arch_timer.c83
1 files changed, 72 insertions, 11 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 7a8a4117f123..5c5c2af74ad9 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -182,7 +182,9 @@ EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled);
static const struct arch_timer_erratum_workaround ool_workarounds[] = {
#ifdef CONFIG_FSL_ERRATUM_A008585
{
+ .match_type = ate_match_dt,
.id = "fsl,erratum-a008585",
+ .desc = "Freescale erratum a005858",
.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,
@@ -190,13 +192,81 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
#endif
#ifdef CONFIG_HISILICON_ERRATUM_161010101
{
+ .match_type = ate_match_dt,
.id = "hisilicon,erratum-161010101",
+ .desc = "HiSilicon erratum 161010101",
.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,
},
#endif
};
+
+typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,
+ const void *);
+
+static
+bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround *wa,
+ const void *arg)
+{
+ const struct device_node *np = arg;
+
+ return of_property_read_bool(np, wa->id);
+}
+
+static const struct arch_timer_erratum_workaround *
+arch_timer_iterate_errata(enum arch_timer_erratum_match_type type,
+ ate_match_fn_t match_fn,
+ void *arg)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) {
+ if (ool_workarounds[i].match_type != type)
+ continue;
+
+ if (match_fn(&ool_workarounds[i], arg))
+ return &ool_workarounds[i];
+ }
+
+ return NULL;
+}
+
+static
+void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa)
+{
+ timer_unstable_counter_workaround = wa;
+ static_branch_enable(&arch_timer_read_ool_enabled);
+}
+
+static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type type,
+ void *arg)
+{
+ const struct arch_timer_erratum_workaround *wa;
+ ate_match_fn_t match_fn = NULL;
+
+ if (static_branch_unlikely(&arch_timer_read_ool_enabled))
+ return;
+
+ switch (type) {
+ case ate_match_dt:
+ match_fn = arch_timer_check_dt_erratum;
+ break;
+ default:
+ WARN_ON(1);
+ return;
+ }
+
+ wa = arch_timer_iterate_errata(type, match_fn, arg);
+ if (!wa)
+ return;
+
+ arch_timer_enable_workaround(wa);
+ pr_info("Enabling global workaround for %s\n", wa->desc);
+}
+
+#else
+#define arch_timer_check_ool_workaround(t,a) do { } while(0)
#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
static __always_inline
@@ -960,17 +1030,8 @@ static int __init arch_timer_of_init(struct device_node *np)
arch_timer_c3stop = !of_property_read_bool(np, "always-on");
-#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
- for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) {
- if (of_property_read_bool(np, ool_workarounds[i].id)) {
- timer_unstable_counter_workaround = &ool_workarounds[i];
- static_branch_enable(&arch_timer_read_ool_enabled);
- pr_info("arch_timer: Enabling workaround for %s\n",
- timer_unstable_counter_workaround->id);
- break;
- }
- }
-#endif
+ /* Check for globally applicable workarounds */
+ arch_timer_check_ool_workaround(ate_match_dt, np);
/*
* If we cannot rely on firmware initializing the timer registers then