Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1593231

[PATCH 01/17] arm64: arch_timer: Add infrastructure for multiple erratum detection methods

Show all headers | View raw

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 functionnality.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/include/asm/arch_timer.h  |  7 +++-
 drivers/clocksource/arm_arch_timer.c | 80 +++++++++++++++++++++++++++++++-----
 2 files changed, 75 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
index b4b34004a21e..1c92d52619a6 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;		/* Indicate the Erratum ID */
+	const char *desc_str;
 	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 7a8a4117f123..36980cdd5c0a 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_str = "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 +192,78 @@ 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_str = "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;
+	}
+
+	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_str);
+}
+
+#else
+#define arch_timer_check_ool_workaround(t,a)		do { } while(0)
 #endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
 
 static __always_inline
@@ -960,17 +1027,8 @@ 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
-- 
2.11.0

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 00/17] clocksource/arch_timer: Errara workaround infrastructure rework Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
  [PATCH 05/17] arm64: arch_timer: Move arch_timer_reg_read/write around Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
  [PATCH 01/17] arm64: arch_timer: Add infrastructure for multiple erratum detection methods Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
    Re: [PATCH 01/17] arm64: arch_timer: Add infrastructure for multiple  erratum detection methods Hanjun Guo <hanjun.guo@linaro.org> - 2017-03-07 18:00 +0100
  [PATCH 04/17] arm64: arch_timer: Add erratum handler for CPU-specific capability Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
  [PATCH 07/17] arm64: arch_timer: Rework the set_next_event workarounds Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
    Re: [PATCH 07/17] arm64: arch_timer: Rework the set_next_event  workarounds Hanjun Guo <hanjun.guo@linaro.org> - 2017-03-07 14:30 +0100
  [PATCH 06/17] arm64: arch_timer: Get rid of erratum_workaround_set_sne Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
  [PATCH 13/17] arm64: cpu_errata: Allow an erratum to be match for all revisions of a core Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
  [PATCH 08/17] arm64: arch_timer: Make workaround methods optional Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
  [PATCH 02/17] arm64: arch_timer: Add erratum handler for globally defined capability Marc Zyngier <marc.zyngier@arm.com> - 2017-03-06 12:40 +0100
  Re: [PATCH 00/17] clocksource/arch_timer: Errara workaround  infrastructure rework dann frazier <dann.frazier@canonical.com> - 2017-03-06 23:10 +0100
  Re: [PATCH 00/17] clocksource/arch_timer: Errara workaround  infrastructure rework Hanjun Guo <hanjun.guo@linaro.org> - 2017-03-07 14:30 +0100

csiph-web