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authorDing Tianhong <dingtianhong@huawei.com>2017-02-06 16:47:41 +0000
committerDaniel Lezcano <daniel.lezcano@linaro.org>2017-02-08 00:14:03 +0100
commit16d10ef29f25aba923779234bb93a451b14d20e6 (patch)
tree3bec3cde9fcf0bd8e0d9a8940ef29ee9b49aeb18 /arch/arm64/include
parent5444ea6a7f46276876e94ecf8d44615af1ef22f7 (diff)
downloadlinux-16d10ef29f25aba923779234bb93a451b14d20e6.tar.gz
linux-16d10ef29f25aba923779234bb93a451b14d20e6.tar.xz
clocksource/drivers/arm_arch_timer: Introduce generic errata handling infrastructure
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>
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/arch_timer.h38
1 files changed, 13 insertions, 25 deletions
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
index eaa5bbe3fa87..b4b34004a21e 100644
--- 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; \