From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ding Tianhong <dingtianhong@huawei.com>,
Mark Rutland <mark.rutland@arm.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
James Morse <james.morse@arm.com>
Subject: [PATCH 4.9 13/43] clocksource/drivers/arm_arch_timer: Introduce generic errata handling infrastructure
Date: Wed, 6 Apr 2022 20:26:22 +0200 [thread overview]
Message-ID: <20220406182437.070605313@linuxfoundation.org> (raw)
In-Reply-To: <20220406182436.675069715@linuxfoundation.org>
From: Ding Tianhong <dingtianhong@huawei.com>
commit 16d10ef29f25aba923779234bb93a451b14d20e6 upstream.
Currently we have code inline in the arch timer probe path to cater for
Freescale erratum A-008585, complete with ifdeffery. This is a little
ugly, and will get worse as we try to add more errata handling.
This patch refactors the handling of Freescale erratum A-008585. Now the
erratum is described in a generic arch_timer_erratum_workaround
structure, and the probe path can iterate over these to detect errata
and enable workarounds.
This will simplify the addition and maintenance of code handling
Hisilicon erratum 161010101.
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
[Mark: split patch, correct Kconfig, reword commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/include/asm/arch_timer.h | 40 +++++----------
drivers/clocksource/Kconfig | 4 +
drivers/clocksource/arm_arch_timer.c | 90 ++++++++++++++++++++++++-----------
3 files changed, 80 insertions(+), 54 deletions(-)
--- a/arch/arm64/include/asm/arch_timer.h
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -29,41 +29,29 @@
#include <clocksource/arm_arch_timer.h>
-#if IS_ENABLED(CONFIG_FSL_ERRATUM_A008585)
+#if IS_ENABLED(CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND)
extern struct static_key_false arch_timer_read_ool_enabled;
-#define needs_fsl_a008585_workaround() \
+#define needs_unstable_timer_counter_workaround() \
static_branch_unlikely(&arch_timer_read_ool_enabled)
#else
-#define needs_fsl_a008585_workaround() false
+#define needs_unstable_timer_counter_workaround() false
#endif
-u32 __fsl_a008585_read_cntp_tval_el0(void);
-u32 __fsl_a008585_read_cntv_tval_el0(void);
-u64 __fsl_a008585_read_cntvct_el0(void);
-
-/*
- * The number of retries is an arbitrary value well beyond the highest number
- * of iterations the loop has been observed to take.
- */
-#define __fsl_a008585_read_reg(reg) ({ \
- u64 _old, _new; \
- int _retries = 200; \
- \
- do { \
- _old = read_sysreg(reg); \
- _new = read_sysreg(reg); \
- _retries--; \
- } while (unlikely(_old != _new) && _retries); \
- \
- WARN_ON_ONCE(!_retries); \
- _new; \
-})
+
+struct arch_timer_erratum_workaround {
+ const char *id; /* Indicate the Erratum ID */
+ u32 (*read_cntp_tval_el0)(void);
+ u32 (*read_cntv_tval_el0)(void);
+ u64 (*read_cntvct_el0)(void);
+};
+
+extern const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround;
#define arch_timer_reg_read_stable(reg) \
({ \
u64 _val; \
- if (needs_fsl_a008585_workaround()) \
- _val = __fsl_a008585_read_##reg(); \
+ if (needs_unstable_timer_counter_workaround()) \
+ _val = timer_unstable_counter_workaround->read_##reg();\
else \
_val = read_sysreg(reg); \
_val; \
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -305,10 +305,14 @@ config ARM_ARCH_TIMER_EVTSTREAM
This must be disabled for hardware validation purposes to detect any
hardware anomalies of missing events.
+config ARM_ARCH_TIMER_OOL_WORKAROUND
+ bool
+
config FSL_ERRATUM_A008585
bool "Workaround for Freescale/NXP Erratum A-008585"
default y
depends on ARM_ARCH_TIMER && ARM64
+ select ARM_ARCH_TIMER_OOL_WORKAROUND
help
This option enables a workaround for Freescale/NXP Erratum
A-008585 ("ARM generic timer may contain an erroneous
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -96,27 +96,58 @@ early_param("clocksource.arm_arch_timer.
*/
#ifdef CONFIG_FSL_ERRATUM_A008585
-DEFINE_STATIC_KEY_FALSE(arch_timer_read_ool_enabled);
-EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled);
-
-static int fsl_a008585_enable = -1;
+/*
+ * The number of retries is an arbitrary value well beyond the highest number
+ * of iterations the loop has been observed to take.
+ */
+#define __fsl_a008585_read_reg(reg) ({ \
+ u64 _old, _new; \
+ int _retries = 200; \
+ \
+ do { \
+ _old = read_sysreg(reg); \
+ _new = read_sysreg(reg); \
+ _retries--; \
+ } while (unlikely(_old != _new) && _retries); \
+ \
+ WARN_ON_ONCE(!_retries); \
+ _new; \
+})
-u32 __fsl_a008585_read_cntp_tval_el0(void)
+static u32 notrace fsl_a008585_read_cntp_tval_el0(void)
{
return __fsl_a008585_read_reg(cntp_tval_el0);
}
-u32 __fsl_a008585_read_cntv_tval_el0(void)
+static u32 notrace fsl_a008585_read_cntv_tval_el0(void)
{
return __fsl_a008585_read_reg(cntv_tval_el0);
}
-u64 __fsl_a008585_read_cntvct_el0(void)
+static u64 notrace fsl_a008585_read_cntvct_el0(void)
{
return __fsl_a008585_read_reg(cntvct_el0);
}
-EXPORT_SYMBOL(__fsl_a008585_read_cntvct_el0);
-#endif /* CONFIG_FSL_ERRATUM_A008585 */
+#endif
+
+#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
+const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround = NULL;
+EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
+
+DEFINE_STATIC_KEY_FALSE(arch_timer_read_ool_enabled);
+EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled);
+
+static const struct arch_timer_erratum_workaround ool_workarounds[] = {
+#ifdef CONFIG_FSL_ERRATUM_A008585
+ {
+ .id = "fsl,erratum-a008585",
+ .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,
+ },
+#endif
+};
+#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
static __always_inline
void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
@@ -267,8 +298,8 @@ static __always_inline void set_next_eve
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
-#ifdef CONFIG_FSL_ERRATUM_A008585
-static __always_inline void fsl_a008585_set_next_event(const int access,
+#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
+static __always_inline void erratum_set_next_event_generic(const int access,
unsigned long evt, struct clock_event_device *clk)
{
unsigned long ctrl;
@@ -286,20 +317,20 @@ static __always_inline void fsl_a008585_
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
-static int fsl_a008585_set_next_event_virt(unsigned long evt,
+static int erratum_set_next_event_virt(unsigned long evt,
struct clock_event_device *clk)
{
- fsl_a008585_set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
+ erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
return 0;
}
-static int fsl_a008585_set_next_event_phys(unsigned long evt,
+static int erratum_set_next_event_phys(unsigned long evt,
struct clock_event_device *clk)
{
- fsl_a008585_set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
+ erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
return 0;
}
-#endif /* CONFIG_FSL_ERRATUM_A008585 */
+#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
static int arch_timer_set_next_event_virt(unsigned long evt,
struct clock_event_device *clk)
@@ -329,16 +360,16 @@ static int arch_timer_set_next_event_phy
return 0;
}
-static void fsl_a008585_set_sne(struct clock_event_device *clk)
+static void erratum_workaround_set_sne(struct clock_event_device *clk)
{
-#ifdef CONFIG_FSL_ERRATUM_A008585
+#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
if (!static_branch_unlikely(&arch_timer_read_ool_enabled))
return;
if (arch_timer_uses_ppi == VIRT_PPI)
- clk->set_next_event = fsl_a008585_set_next_event_virt;
+ clk->set_next_event = erratum_set_next_event_virt;
else
- clk->set_next_event = fsl_a008585_set_next_event_phys;
+ clk->set_next_event = erratum_set_next_event_phys;
#endif
}
@@ -371,7 +402,7 @@ static void __arch_timer_setup(unsigned
BUG();
}
- fsl_a008585_set_sne(clk);
+ erratum_workaround_set_sne(clk);
} else {
clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
clk->name = "arch_mem_timer";
@@ -600,7 +631,7 @@ static void __init arch_counter_register
clocksource_counter.archdata.vdso_direct = true;
-#ifdef CONFIG_FSL_ERRATUM_A008585
+#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
/*
* Don't use the vdso fastpath if errata require using
* the out-of-line counter accessor.
@@ -888,12 +919,15 @@ static int __init arch_timer_of_init(str
arch_timer_c3stop = !of_property_read_bool(np, "always-on");
-#ifdef CONFIG_FSL_ERRATUM_A008585
- if (fsl_a008585_enable < 0)
- fsl_a008585_enable = of_property_read_bool(np, "fsl,erratum-a008585");
- if (fsl_a008585_enable) {
- static_branch_enable(&arch_timer_read_ool_enabled);
- pr_info("Enabling workaround for FSL erratum A-008585\n");
+#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
next prev parent reply other threads:[~2022-04-06 19:59 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-06 18:26 [PATCH 4.9 00/43] 4.9.310-rc1 review Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 01/43] arm64: errata: Provide macro for major and minor cpu revisions Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 02/43] arm64: Remove useless UAO IPI and describe how this gets enabled Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 03/43] arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35 Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 04/43] arm64: capabilities: Update prototype for enable call back Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 05/43] arm64: capabilities: Move errata work around check on boot CPU Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 06/43] arm64: capabilities: Move errata processing code Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 07/43] arm64: capabilities: Prepare for fine grained capabilities Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 08/43] arm64: capabilities: Add flags to handle the conflicts on late CPU Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 09/43] arm64: capabilities: Clean up midr range helpers Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 10/43] arm64: Add helpers for checking CPU MIDR against a range Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 11/43] arm64: capabilities: Add support for checks based on a list of MIDRs Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 12/43] clocksource/drivers/arm_arch_timer: Remove fsl-a008585 parameter Greg Kroah-Hartman
2022-04-06 18:26 ` Greg Kroah-Hartman [this message]
2022-04-06 18:26 ` [PATCH 4.9 14/43] arm64: arch_timer: Add infrastructure for multiple erratum detection methods Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 15/43] arm64: arch_timer: Add erratum handler for CPU-specific capability Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 16/43] arm64: arch_timer: Add workaround for ARM erratum 1188873 Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 17/43] arm64: arch_timer: avoid unused function warning Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 18/43] arm64: Add silicon-errata.txt entry for ARM erratum 1188873 Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 19/43] arm64: Make ARM64_ERRATUM_1188873 depend on COMPAT Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 20/43] arm64: Add part number for Neoverse N1 Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 21/43] arm64: Add part number for Arm Cortex-A77 Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 22/43] arm64: Add Neoverse-N2, Cortex-A710 CPU part definition Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 23/43] arm64: Add Cortex-X2 " Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 24/43] arm64: Add helper to decode register from instruction Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 25/43] arm64: entry.S: Add ventry overflow sanity checks Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 26/43] arm64: entry: Make the trampoline cleanup optional Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 27/43] arm64: entry: Free up another register on kptis tramp_exit path Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 28/43] arm64: entry: Move the trampoline data page before the text page Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 29/43] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 30/43] arm64: entry: Dont assume tramp_vectors is the start of the vectors Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 31/43] arm64: entry: Move trampoline macros out of ifdefd section Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 32/43] arm64: entry: Make the kpti trampolines kpti sequence optional Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 33/43] arm64: entry: Allow the trampoline text to occupy multiple pages Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 34/43] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 35/43] arm64: Move arm64_update_smccc_conduit() out of SSBD ifdef Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 36/43] arm64: entry: Add vectors that have the bhb mitigation sequences Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 37/43] arm64: entry: Add macro for reading symbol addresses from the trampoline Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 38/43] arm64: Add percpu vectors for EL1 Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 39/43] KVM: arm64: Add templates for BHB mitigation sequences Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 40/43] arm64: Mitigate spectre style branch history side channels Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 41/43] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 42/43] arm64: add ID_AA64ISAR2_EL1 sys register Greg Kroah-Hartman
2022-04-06 18:26 ` [PATCH 4.9 43/43] arm64: Use the clearbhb instruction in mitigations Greg Kroah-Hartman
2022-04-06 20:57 ` [PATCH 4.9 00/43] 4.9.310-rc1 review Florian Fainelli
2022-04-06 21:55 ` Pavel Machek
2022-04-06 22:51 ` Shuah Khan
2022-04-07 9:32 ` Guenter Roeck
2022-04-07 10:23 ` Greg Kroah-Hartman
2022-04-07 17:20 ` James Morse
2022-04-12 5:51 ` Greg Kroah-Hartman
2022-04-07 11:20 ` Naresh Kamboju
2022-04-07 11:28 ` Naresh Kamboju
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220406182437.070605313@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=daniel.lezcano@linaro.org \
--cc=dingtianhong@huawei.com \
--cc=james.morse@arm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).