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arm64: Switch to PMR masking when starting CPUs

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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>
This commit is contained in:
Julien Thierry 2019-01-31 14:58:55 +00:00 committed by Catalin Marinas
parent b5cf607370
commit e793218838
2 changed files with 33 additions and 1 deletions
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26
arch/arm64/kernel/smp.c
View File

@ -35,6 +35,7 @@
#include <linux/smp.h> #include <linux/smp.h>
#include <linux/seq_file.h> #include <linux/seq_file.h>
#include <linux/irq.h> #include <linux/irq.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/percpu.h> #include <linux/percpu.h>
#include <linux/clockchips.h> #include <linux/clockchips.h>
#include <linux/completion.h> #include <linux/completion.h>
@ -180,6 +181,24 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
return ret; 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 * This is the secondary CPU boot entry. We're using this CPUs
* idle thread stack, but a set of temporary page tables. * idle thread stack, but a set of temporary page tables.
@ -206,6 +225,9 @@ asmlinkage notrace void secondary_start_kernel(void)
*/ */
cpu_uninstall_idmap(); cpu_uninstall_idmap();
if (system_uses_irq_prio_masking())
init_gic_priority_masking();
preempt_disable(); preempt_disable();
trace_hardirqs_off(); trace_hardirqs_off();
@ -426,6 +448,10 @@ void __init smp_prepare_boot_cpu(void)
* and/or scheduling is enabled. * and/or scheduling is enabled.
*/ */
apply_boot_alternatives(); 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) static u64 __init of_get_cpu_mpidr(struct device_node *dn)

8
drivers/irqchip/irq-gic-v3.c
View File

@ -415,6 +415,9 @@ static u32 gic_get_pribits(void)
static bool gic_has_group0(void) static bool gic_has_group0(void)
{ {
u32 val; u32 val;
u32 old_pmr;
old_pmr = gic_read_pmr();
/* /*
* Let's find out if Group0 is under control of EL3 or not by * 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())); gic_write_pmr(BIT(8 - gic_get_pribits()));
val = gic_read_pmr(); val = gic_read_pmr();
gic_write_pmr(old_pmr);
return val != 0; return val != 0;
} }
@ -591,7 +596,8 @@ static void gic_cpu_sys_reg_init(void)
group0 = gic_has_group0(); group0 = gic_has_group0();
/* Set priority mask register */ /* 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 * Some firmwares hand over to the kernel with the BPR changed from