diff options
| author | Julien Thierry <julien.thierry@arm.com> | 2019-01-31 14:58:55 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-02-06 10:05:20 +0000 |
| commit | e79321883842ca7b77d8a58fe8303e8da35c085e (patch) | |
| tree | c2210ec0335b1defbe951cb93276181f1d44e3eb | |
| parent | b5cf607370d0ee257e4bfa80740952fa6110c2c7 (diff) | |
arm64: Switch to PMR masking when starting CPUs
Once the boot CPU has been prepared or a new secondary CPU has been
brought up, use ICC_PMR_EL1 to mask interrupts on that CPU and clear
PSR.I bit.
Since ICC_PMR_EL1 is initialized at CPU bringup, avoid overwriting
it in the GICv3 driver.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/kernel/smp.c | 26 | ||||
| -rw-r--r-- | drivers/irqchip/irq-gic-v3.c | 8 |
2 files changed, 33 insertions, 1 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index a944edd39d2d..824de7038967 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -35,6 +35,7 @@ #include <linux/smp.h> #include <linux/seq_file.h> #include <linux/irq.h> +#include <linux/irqchip/arm-gic-v3.h> #include <linux/percpu.h> #include <linux/clockchips.h> #include <linux/completion.h> @@ -180,6 +181,24 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) return ret; } +static void init_gic_priority_masking(void) +{ + u32 cpuflags; + + if (WARN_ON(!gic_enable_sre())) + return; + + cpuflags = read_sysreg(daif); + + WARN_ON(!(cpuflags & PSR_I_BIT)); + + gic_write_pmr(GIC_PRIO_IRQOFF); + + /* We can only unmask PSR.I if we can take aborts */ + if (!(cpuflags & PSR_A_BIT)) + write_sysreg(cpuflags & ~PSR_I_BIT, daif); +} + /* * This is the secondary CPU boot entry. We're using this CPUs * idle thread stack, but a set of temporary page tables. @@ -206,6 +225,9 @@ asmlinkage notrace void secondary_start_kernel(void) */ cpu_uninstall_idmap(); + if (system_uses_irq_prio_masking()) + init_gic_priority_masking(); + preempt_disable(); trace_hardirqs_off(); @@ -426,6 +448,10 @@ void __init smp_prepare_boot_cpu(void) * and/or scheduling is enabled. */ apply_boot_alternatives(); + + /* Conditionally switch to GIC PMR for interrupt masking */ + if (system_uses_irq_prio_masking()) + init_gic_priority_masking(); } static u64 __init of_get_cpu_mpidr(struct device_node *dn) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index da547e013c1a..5a703ae09ce5 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -415,6 +415,9 @@ static u32 gic_get_pribits(void) static bool gic_has_group0(void) { u32 val; + u32 old_pmr; + + old_pmr = gic_read_pmr(); /* * Let's find out if Group0 is under control of EL3 or not by @@ -430,6 +433,8 @@ static bool gic_has_group0(void) gic_write_pmr(BIT(8 - gic_get_pribits())); val = gic_read_pmr(); + gic_write_pmr(old_pmr); + return val != 0; } @@ -591,7 +596,8 @@ static void gic_cpu_sys_reg_init(void) group0 = gic_has_group0(); /* Set priority mask register */ - write_gicreg(DEFAULT_PMR_VALUE, ICC_PMR_EL1); + if (!gic_prio_masking_enabled()) + write_gicreg(DEFAULT_PMR_VALUE, ICC_PMR_EL1); /* * Some firmwares hand over to the kernel with the BPR changed from |