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Commit 0064030c authored by Marc Zyngier's avatar Marc Zyngier
Browse files

arm64: arch_timer: Add erratum handler for CPU-specific capability 



Should we ever have a workaround for an erratum that is detected using
a capability and affecting a particular CPU, it'd be nice to have
a way to probe them directly.

Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 651bb2e9

arch/arm64/include/asm/arch_timer.h

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ extern struct static_key_false arch_timer_read_ool_enabled; 


enum arch_timer_erratum_match_type {

	ate_match_dt,

	ate_match_local_cap_id,

};



struct arch_timer_erratum_workaround {

drivers/clocksource/arm_arch_timer.c

+24 −4
Original line number Diff line number Diff line
@@ -214,6 +214,13 @@ bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround *wa, 
	return of_property_read_bool(np, wa->id);

}



static

bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workaround *wa,

					const void *arg)

{

	return this_cpu_has_cap((uintptr_t)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,
@@ -244,14 +251,16 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t 
{

	const struct arch_timer_erratum_workaround *wa;

	ate_match_fn_t match_fn = NULL;



	if (static_branch_unlikely(&arch_timer_read_ool_enabled))

		return;

	bool local = false;



	switch (type) {

	case ate_match_dt:

		match_fn = arch_timer_check_dt_erratum;

		break;

	case ate_match_local_cap_id:

		match_fn = arch_timer_check_local_cap_erratum;

		local = true;

		break;

	default:

		WARN_ON(1);

		return;
@@ -261,8 +270,17 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t 
	if (!wa)

		return;



	if (needs_unstable_timer_counter_workaround()) {

		if (wa != timer_unstable_counter_workaround)

			pr_warn("Can't enable workaround for %s (clashes with %s\n)",

				wa->desc,

				timer_unstable_counter_workaround->desc);

		return;

	}



	arch_timer_enable_workaround(wa);

	pr_info("Enabling global workaround for %s\n", wa->desc);

	pr_info("Enabling %s workaround for %s\n",

		local ? "local" : "global", wa->desc);

}



#else
@@ -522,6 +540,8 @@ static void __arch_timer_setup(unsigned type, 
			BUG();

		}



		arch_timer_check_ool_workaround(ate_match_local_cap_id, NULL);



		erratum_workaround_set_sne(clk);

	} else {

		clk->features |= CLOCK_EVT_FEAT_DYNIRQ;