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irqchip/gicv3: Workaround for Cavium ThunderX erratum 23154

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This patch implements Cavium ThunderX erratum 23154.

The gicv3 of ThunderX requires a modified version for reading the IAR
status to ensure data synchronization. Since this is in the fast-path
and called with each interrupt, runtime patching is used using jump
label patching for smallest overhead (no-op). This is the same
technique as used for tracepoints.

Signed-off-by: Robert Richter <rrichter@cavium.com>
Reviewed-by: Marc Zygnier <marc.zyngier@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1442869119-1814-3-git-send-email-rric@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Robert Richter 2015-09-21 22:58:35 +02:00 committed by Thomas Gleixner
parent 30f2136346
commit 6d4e11c5e2
5 changed files with 72 additions and 9 deletions
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10
arch/arm64/Kconfig
View File

@ -348,6 +348,16 @@ config ARM64_ERRATUM_843419
If unsure, say Y.
config CAVIUM_ERRATUM_23154
bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
default y
help
The gicv3 of ThunderX requires a modified version for
reading the IAR status to ensure data synchronization
(access to icc_iar1_el1 is not sync'ed before and after).
If unsure, say Y.
endmenu

3
arch/arm64/include/asm/cpufeature.h
View File

@ -27,8 +27,9 @@
#define ARM64_HAS_SYSREG_GIC_CPUIF 3
#define ARM64_HAS_PAN 4
#define ARM64_HAS_LSE_ATOMICS 5
#define ARM64_WORKAROUND_CAVIUM_23154 6
#define ARM64_NCAPS 6
#define ARM64_NCAPS 7
#ifndef __ASSEMBLY__

17
arch/arm64/include/asm/cputype.h
View File

@ -62,15 +62,18 @@
(0xf << MIDR_ARCHITECTURE_SHIFT) | \
((partnum) << MIDR_PARTNUM_SHIFT))
#define ARM_CPU_IMP_ARM 0x41
#define ARM_CPU_IMP_APM 0x50
#define ARM_CPU_IMP_ARM 0x41
#define ARM_CPU_IMP_APM 0x50
#define ARM_CPU_IMP_CAVIUM 0x43
#define ARM_CPU_PART_AEM_V8 0xD0F
#define ARM_CPU_PART_FOUNDATION 0xD00
#define ARM_CPU_PART_CORTEX_A57 0xD07
#define ARM_CPU_PART_CORTEX_A53 0xD03
#define ARM_CPU_PART_AEM_V8 0xD0F
#define ARM_CPU_PART_FOUNDATION 0xD00
#define ARM_CPU_PART_CORTEX_A57 0xD07
#define ARM_CPU_PART_CORTEX_A53 0xD03
#define APM_CPU_PART_POTENZA 0x000
#define APM_CPU_PART_POTENZA 0x000
#define CAVIUM_CPU_PART_THUNDERX 0x0A1
#define ID_AA64MMFR0_BIGENDEL0_SHIFT 16
#define ID_AA64MMFR0_BIGENDEL0_MASK (0xf << ID_AA64MMFR0_BIGENDEL0_SHIFT)

9
arch/arm64/kernel/cpu_errata.c
View File

@ -23,6 +23,7 @@
#define MIDR_CORTEX_A53 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
#define MIDR_CORTEX_A57 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)
#define MIDR_THUNDERX MIDR_CPU_PART(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
#define CPU_MODEL_MASK (MIDR_IMPLEMENTOR_MASK | MIDR_PARTNUM_MASK | \
MIDR_ARCHITECTURE_MASK)
@ -81,6 +82,14 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
.capability = ARM64_WORKAROUND_845719,
MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x04),
},
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_23154
{
/* Cavium ThunderX, pass 1.x */
.desc = "Cavium erratum 23154",
.capability = ARM64_WORKAROUND_CAVIUM_23154,
MIDR_RANGE(MIDR_THUNDERX, 0x00, 0x01),
},
#endif
{
}

42
drivers/irqchip/irq-gic-v3.c
View File

@ -109,7 +109,7 @@ static void gic_redist_wait_for_rwp(void)
}
/* Low level accessors */
static u64 __maybe_unused gic_read_iar(void)
static u64 gic_read_iar_common(void)
{
u64 irqstat;
@ -117,6 +117,38 @@ static u64 __maybe_unused gic_read_iar(void)
return irqstat;
}
/*
* Cavium ThunderX erratum 23154
*
* The gicv3 of ThunderX requires a modified version for reading the
* IAR status to ensure data synchronization (access to icc_iar1_el1
* is not sync'ed before and after).
*/
static u64 gic_read_iar_cavium_thunderx(void)
{
u64 irqstat;
asm volatile(
"nop;nop;nop;nop\n\t"
"nop;nop;nop;nop\n\t"
"mrs_s %0, " __stringify(ICC_IAR1_EL1) "\n\t"
"nop;nop;nop;nop"
: "=r" (irqstat));
mb();
return irqstat;
}
static struct static_key is_cavium_thunderx = STATIC_KEY_INIT_FALSE;
static u64 __maybe_unused gic_read_iar(void)
{
if (static_key_false(&is_cavium_thunderx))
return gic_read_iar_cavium_thunderx();
else
return gic_read_iar_common();
}
static void __maybe_unused gic_write_pmr(u64 val)
{
asm volatile("msr_s " __stringify(ICC_PMR_EL1) ", %0" : : "r" (val));
@ -836,6 +868,12 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
.free = gic_irq_domain_free,
};
static void gicv3_enable_quirks(void)
{
if (cpus_have_cap(ARM64_WORKAROUND_CAVIUM_23154))
static_key_slow_inc(&is_cavium_thunderx);
}
static int __init gic_of_init(struct device_node *node, struct device_node *parent)
{
void __iomem *dist_base;
@ -901,6 +939,8 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare
gic_data.nr_redist_regions = nr_redist_regions;
gic_data.redist_stride = redist_stride;
gicv3_enable_quirks();
/*
* Find out how many interrupts are supported.
* The GIC only supports up to 1020 interrupt sources (SGI+PPI+SPI)