Commit-ID: 651bb2e9dca6e6dbad3fba5f6e6086a23575b8b5
Gitweb: http://git.kernel.org/tip/651bb2e9dca6e6dbad3fba5f6e6086a23575b8b5
Author: Marc Zyngier <marc.zyngier@xxxxxxx>
AuthorDate: Thu, 19 Jan 2017 17:20:59 +0000
Committer: Marc Zyngier <marc.zyngier@xxxxxxx>
CommitDate: Fri, 7 Apr 2017 11:22:08 +0100
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@xxxxxxxxxxxxx>
Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm64/include/asm/arch_timer.h | 7 ++-
drivers/clocksource/arm_arch_timer.c | 83 +++++++++++++++++++++++++++++++-----
2 files changed, 78 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
index b4b3400..5cd964e 100644
--- a/arch/arm64/include/asm/arch_timer.h
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -37,9 +37,14 @@ extern struct static_key_false arch_timer_read_ool_enabled;
#define needs_unstable_timer_counter_workaround() false
#endif
+enum arch_timer_erratum_match_type {
+ ate_match_dt,
+};
struct arch_timer_erratum_workaround {
- const char *id; /* Indicate the Erratum ID */
+ enum arch_timer_erratum_match_type match_type;
+ const void *id;
+ const char *desc;
u32 (*read_cntp_tval_el0)(void);
u32 (*read_cntv_tval_el0)(void);
u64 (*read_cntvct_el0)(void);
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 7a8a411..5c5c2af 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
--
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