@@ -364,6 +364,17 @@ config ARM64_ERRATUM_858921
The workaround will be dynamically enabled when an affected
core is detected.
+config ARCH_TIMER_REGISTERS_NOT_FW_CONFIGURED
+ bool "Workaround for arch timer registers not configured by firmware"
+ default y
+ select ARM_ARCH_TIMER_OOL_WORKAROUND
+ depends on ARM_ARCH_TIMER && ARM64
+ help
+ This option enables a workaround for boards, on which arch timer
+ registers are not properly configured by the board firmware.
+ The workaround will be dynamically enabled when an affected
+ board is detected.
+
config ARM_GLOBAL_TIMER
bool "Support for the ARM global timer" if COMPILE_TEST
select TIMER_OF if OF
@@ -423,6 +423,14 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
.read_cntvct_el0 = arm64_1188873_read_cntvct_el0,
},
#endif
+#ifdef CONFIG_ARCH_TIMER_REGISTERS_NOT_FW_CONFIGURED
+ {
+ .match_type = ate_match_dt,
+ .id = "arm,cpu-registers-not-fw-configured",
+ .desc = "broken CPU firmware (timer registers not configured)",
+ .read_cntvct_el0 = arch_counter_get_cntpct,
+ },
+#endif
};
typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,
@@ -1234,9 +1242,10 @@ static int __init arch_timer_of_init(struct device_node *np)
* If we cannot rely on firmware initializing the timer registers then
* we should use the physical timers instead.
*/
- if (IS_ENABLED(CONFIG_ARM) &&
- of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
- arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;
+ if (of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
+ arch_timer_uses_ppi = IS_ENABLED(CONFIG_ARM64) ?
+ ARCH_TIMER_PHYS_NONSECURE_PPI :
+ ARCH_TIMER_PHYS_SECURE_PPI;
else
arch_timer_uses_ppi = arch_timer_select_ppi();
Use common infrastructure for ARM Architected Timers erratum to enable support for systems with broken CPU firmware (timer registers not properly configured). This mode has been already availabled on ARM (32bits) architecture. This enables to run Linux kernel on ARM64 boards using physical architected timers instead of the virtual ones. Examples of such system with broken firmware are Samsung Exynos5433 SoC based TM2(e) boards, which is already deployed for years and updating firmware is not possible. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- drivers/clocksource/Kconfig | 11 +++++++++++ drivers/clocksource/arm_arch_timer.c | 15 ++++++++++++--- 2 files changed, 23 insertions(+), 3 deletions(-) -- 2.17.1