diff mbox series

[RFC,1/4] ACPI/AEST: Initial AEST driver

Message ID 1562086280-5351-2-git-send-email-baicar@os.amperecomputing.com (mailing list archive)
State RFC, archived
Headers show
Series ARM Error Source Table Support | expand

Commit Message

Tyler Baicar July 2, 2019, 4:51 p.m. UTC
Add support for parsing the ARM Error Source Table and basic handling of
errors reported through both memory mapped and system register interfaces.

Signed-off-by: Tyler Baicar <baicar@os.amperecomputing.com>
---
 arch/arm64/include/asm/ras.h |  41 +++++
 arch/arm64/kernel/Makefile   |   2 +-
 arch/arm64/kernel/ras.c      |  67 ++++++++
 drivers/acpi/arm64/Kconfig   |   3 +
 drivers/acpi/arm64/Makefile  |   1 +
 drivers/acpi/arm64/aest.c    | 362 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi_aest.h    |  94 +++++++++++
 7 files changed, 569 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/include/asm/ras.h
 create mode 100644 arch/arm64/kernel/ras.c
 create mode 100644 drivers/acpi/arm64/aest.c
 create mode 100644 include/linux/acpi_aest.h

Comments

Andrew Murray July 3, 2019, 9:25 a.m. UTC | #1
On Tue, Jul 02, 2019 at 04:51:38PM +0000, Tyler Baicar OS wrote:
> Add support for parsing the ARM Error Source Table and basic handling of
> errors reported through both memory mapped and system register interfaces.
> 
> Signed-off-by: Tyler Baicar <baicar@os.amperecomputing.com>
> ---
>  arch/arm64/include/asm/ras.h |  41 +++++
>  arch/arm64/kernel/Makefile   |   2 +-
>  arch/arm64/kernel/ras.c      |  67 ++++++++
>  drivers/acpi/arm64/Kconfig   |   3 +
>  drivers/acpi/arm64/Makefile  |   1 +
>  drivers/acpi/arm64/aest.c    | 362 +++++++++++++++++++++++++++++++++++++++++++
>  include/linux/acpi_aest.h    |  94 +++++++++++
>  7 files changed, 569 insertions(+), 1 deletion(-)
>  create mode 100644 arch/arm64/include/asm/ras.h
>  create mode 100644 arch/arm64/kernel/ras.c
>  create mode 100644 drivers/acpi/arm64/aest.c
>  create mode 100644 include/linux/acpi_aest.h
> 
> diff --git a/arch/arm64/include/asm/ras.h b/arch/arm64/include/asm/ras.h
> new file mode 100644
> index 0000000..36bfff4
> --- /dev/null
> +++ b/arch/arm64/include/asm/ras.h
> @@ -0,0 +1,41 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ASM_RAS_H
> +#define __ASM_RAS_H
> +
> +#define ERR_STATUS_AV		BIT(31)
> +#define ERR_STATUS_V		BIT(30)
> +#define ERR_STATUS_UE		BIT(29)
> +#define ERR_STATUS_ER		BIT(28)
> +#define ERR_STATUS_OF		BIT(27)
> +#define ERR_STATUS_MV		BIT(26)
> +#define ERR_STATUS_CE_SHIFT	24
> +#define ERR_STATUS_CE_MASK	0x3
> +#define ERR_STATUS_DE		BIT(23)
> +#define ERR_STATUS_PN		BIT(22)
> +#define ERR_STATUS_UET_SHIFT	20
> +#define ERR_STATUS_UET_MASK	0x3
> +#define ERR_STATUS_IERR_SHIFT	8
> +#define ERR_STATUS_IERR_MASK	0xff
> +#define ERR_STATUS_SERR_SHIFT	0
> +#define ERR_STATUS_SERR_MASK	0xff

Some of these (_ER, _OF, _CE*, _PN, _UET*) are not used anywhere in the series,
I'd suggest you drop the unused ones.

There may be some merit in renaming these to match the register names in the
spec, e.g. ERXSTATUS_EL1 instead of ERR_STATUS.

> +
> +#define ERR_FR_CEC_SHIFT	12
> +#define ERR_FR_CEC_MASK		0x7
> +
> +#define ERR_FR_8B_CEC		BIT(1)
> +#define ERR_FR_16B_CEC		BIT(2)

All of these ERR_FR_ defines aren't used anywhere either.

> +
> +struct ras_ext_regs {
> +	u64 err_fr;
> +	u64 err_ctlr;
> +	u64 err_status;
> +	u64 err_addr;
> +	u64 err_misc0;
> +	u64 err_misc1;
> +	u64 err_misc2;
> +	u64 err_misc3;
> +};
> +
> +void arch_arm_ras_report_error(void);
> +
> +#endif	/* __ASM_RAS_H */
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 9e7dcb2..294f602 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -19,7 +19,7 @@ obj-y			:= debug-monitors.o entry.o irq.o fpsimd.o		\
>  			   return_address.o cpuinfo.o cpu_errata.o		\
>  			   cpufeature.o alternative.o cacheinfo.o		\
>  			   smp.o smp_spin_table.o topology.o smccc-call.o	\
> -			   syscall.o
> +			   syscall.o ras.o

Given that arch_arm_ras_report_error depends on the ARM64_HAS_RAS_EXTN
capability, which in turn depends on CONFIG_ARM64_RAS_EXTN - you should
probably conditionally build ras.o only if CONFIG_ARM64_RAS_EXTN is defined
(and provide a stub in the header for when it isn't defined).

>  
>  extra-$(CONFIG_EFI)			:= efi-entry.o
>  
> diff --git a/arch/arm64/kernel/ras.c b/arch/arm64/kernel/ras.c
> new file mode 100644
> index 0000000..ca47efa
> --- /dev/null
> +++ b/arch/arm64/kernel/ras.c
> @@ -0,0 +1,67 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/kernel.h>
> +#include <linux/cpu.h>
> +#include <linux/smp.h>
> +
> +#include <asm/ras.h>
> +
> +void arch_arm_ras_report_error(void)
> +{
> +	u64 num_records;
> +	unsigned int i, cpu_num;
> +	bool fatal = false;
> +	struct ras_ext_regs regs;
> +
> +	if (!this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
> +		return;
> +
> +	cpu_num = get_cpu();
> +	num_records = read_sysreg_s(SYS_ERRIDR_EL1);

This value should be masked to exclude the reserved bits. This will
also prevent you writing to reserved bits in ERRSELR.

> +
> +	for (i = 0; i < num_records; i++) {
> +		write_sysreg_s(i, SYS_ERRSELR_EL1);

There should be an isb here, this will ensure the record selection has
happened before reading the record.

> +		regs.err_status = read_sysreg_s(SYS_ERXSTATUS_EL1);
> +
> +		if (!(regs.err_status & ERR_STATUS_V))
> +			continue;
> +
> +		pr_err("CPU%u: ERR%uSTATUS: 0x%llx\n", cpu_num, i,
> +		       regs.err_status);
> +
> +		if (regs.err_status & ERR_STATUS_AV) {
> +			regs.err_addr = read_sysreg_s(SYS_ERXSTATUS_EL1);

This should be SYS_ERXADDR_EL1 not SYS_ERXSTATUS_EL1!

> +			pr_err("CPU%u: ERR%uADDR: 0x%llx\n", cpu_num, i,
> +			       regs.err_addr);
> +		} else
> +			regs.err_addr = 0;

Or perhaps set "regs = { }" at the start of the function instead?

> +
> +		regs.err_fr = read_sysreg_s(SYS_ERXFR_EL1);
> +		pr_err("CPU%u: ERR%uFR: 0x%llx\n", cpu_num, i, regs.err_fr);
> +		regs.err_ctlr = read_sysreg_s(SYS_ERXCTLR_EL1);
> +		pr_err("CPU%u: ERR%uCTLR: 0x%llx\n", cpu_num, i, regs.err_ctlr);
> +
> +		if (regs.err_status & ERR_STATUS_MV) {
> +			regs.err_misc0 = read_sysreg_s(SYS_ERXMISC0_EL1);
> +			pr_err("CPU%u: ERR%uMISC0: 0x%llx\n", cpu_num, i,
> +			       regs.err_misc0);
> +			regs.err_misc1 = read_sysreg_s(SYS_ERXMISC1_EL1);
> +			pr_err("CPU%u: ERR%uMISC1: 0x%llx\n", cpu_num, i,
> +			       regs.err_misc1);
> +		}
> +
> +		/*
> +		 * In the future, we will treat UER conditions as potentially
> +		 * recoverable.
> +		 */
> +		if (regs.err_status & ERR_STATUS_UE)
> +			fatal = true;
> +
> +		write_sysreg_s(regs.err_status, SYS_ERXSTATUS_EL1);
> +	}
> +
> +	if (fatal)
> +		panic("uncorrectable error encountered");

On the do_serror path, we will already panic if arm64_is_fatal_ras_serror
indicates uncorrectable errors. Is this here for the other paths?

> +
> +	put_cpu();
> +}

Finally, should we clear the errors when we see them?

> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> index 6dba187..8d5cf99 100644
> --- a/drivers/acpi/arm64/Kconfig
> +++ b/drivers/acpi/arm64/Kconfig
> @@ -8,3 +8,6 @@ config ACPI_IORT
>  
>  config ACPI_GTDT
>  	bool
> +
> +config ACPI_AEST
> +	bool "ARM Error Source Table Support"
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> index 6ff50f4..ea1ba28 100644
> --- a/drivers/acpi/arm64/Makefile
> +++ b/drivers/acpi/arm64/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  obj-$(CONFIG_ACPI_IORT) 	+= iort.o
>  obj-$(CONFIG_ACPI_GTDT) 	+= gtdt.o
> +obj-$(CONFIG_ACPI_AEST) 	+= aest.o
> diff --git a/drivers/acpi/arm64/aest.c b/drivers/acpi/arm64/aest.c
> new file mode 100644
> index 0000000..fd4f3b5
> --- /dev/null
> +++ b/drivers/acpi/arm64/aest.c
> @@ -0,0 +1,362 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/* ARM Error Source Table Support */
> +
> +#include <linux/acpi.h>
> +#include <linux/acpi_aest.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/kernel.h>
> +#include <linux/percpu.h>
> +#include <linux/ratelimit.h>
> +
> +#include <asm/ras.h>
> +
> +#undef pr_fmt
> +#define pr_fmt(fmt) "ACPI AEST: " fmt
> +
> +static struct acpi_table_header *aest_table;
> +
> +static struct aest_node_data __percpu **ppi_data;
> +static u8 num_ppi;
> +static u8 ppi_idx;
> +
> +static void aest_print(struct aest_node_data *data, struct ras_ext_regs regs,
> +		       int index)
> +{
> +	/* No more than 2 corrected messages every 5 seconds */
> +	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
> +
> +	if (regs.err_status & ERR_STATUS_UE ||
> +	    regs.err_status & ERR_STATUS_DE ||
> +	    __ratelimit(&ratelimit_corrected)) {
> +		switch (data->node_type) {
> +		case AEST_NODE_TYPE_PROC:
> +			pr_err("error from processor 0x%x\n",
> +			       data->data.proc.id);
> +			break;
> +		case AEST_NODE_TYPE_MEM:
> +			pr_err("error from memory domain 0x%x\n",
> +			       data->data.mem.domain);
> +			break;
> +		case AEST_NODE_TYPE_VENDOR:
> +			pr_err("error from vendor specific source 0x%x\n",
> +			       data->data.vendor.id);
> +		}
> +
> +		pr_err("ERR%dSTATUS = 0x%llx\n", index, regs.err_status);
> +		if (regs.err_status & ERR_STATUS_AV)
> +			pr_err("ERR%dADDR = 0x%llx\n", index, regs.err_addr);
> +
> +		pr_err("ERR%dFR = 0x%llx\n", index, regs.err_fr);
> +		pr_err("ERR%dCTLR = 0x%llx\n", index, regs.err_ctlr);
> +
> +		if (regs.err_status & ERR_STATUS_MV) {
> +			pr_err("ERR%dMISC0 = 0x%llx\n", index, regs.err_misc0);
> +			pr_err("ERR%dMISC1 = 0x%llx\n", index, regs.err_misc1);
> +		}

Given that we have a ras_ext_regs struct, can't we use a single function to
print the error - rather than have duplicate pr_err's here and in
arch_arm_ras_report_error?

Thanks,

Andrew Murray

> +	}
> +}
> +
> +static void aest_proc(struct aest_node_data *data)
> +{
> +	struct ras_ext_regs *regs_p, regs;
> +	int i;
> +	bool fatal = false;
> +
> +	/*
> +	 * Currently SR based handling is done through the architected
> +	 * discovery exposed through SRs. That may change in the future
> +	 * if there is supplemental information in the AEST that is
> +	 * needed.
> +	 */
> +	if (data->interface.type == AEST_SYSTEM_REG_INTERFACE) {
> +		arch_arm_ras_report_error();
> +		return;
> +	}
> +
> +	regs_p = data->interface.regs;
> +
> +	for (i = data->interface.start; i < data->interface.end; i++) {
> +		regs.err_status = readq(&regs_p[i].err_status);
> +		if (!(regs.err_status & ERR_STATUS_V))
> +			continue;
> +
> +		if (regs.err_status & ERR_STATUS_AV)
> +			regs.err_addr = readq(&regs_p[i].err_addr);
> +		else
> +			regs.err_addr = 0;
> +
> +		regs.err_fr = readq(&regs_p[i].err_fr);
> +		regs.err_ctlr = readq(&regs_p[i].err_ctlr);
> +
> +		if (regs.err_status & ERR_STATUS_MV) {
> +			regs.err_misc0 = readq(&regs_p[i].err_misc0);
> +			regs.err_misc1 = readq(&regs_p[i].err_misc1);
> +		} else {
> +			regs.err_misc0 = 0;
> +			regs.err_misc1 = 0;
> +		}
> +
> +		aest_print(data, regs, i);
> +
> +		if (regs.err_status & ERR_STATUS_UE)
> +			fatal = true;
> +
> +		writeq(regs.err_status, &regs_p[i].err_status);
> +	}
> +
> +	if (fatal)
> +		panic("AEST: uncorrectable error encountered");
> +
> +}
> +
> +static irqreturn_t aest_irq_func(int irq, void *input)
> +{
> +	struct aest_node_data *data = input;
> +
> +	aest_proc(data);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int __init aest_register_gsi(u32 gsi, int trigger, void *data)
> +{
> +	int cpu, irq;
> +
> +	irq = acpi_register_gsi(NULL, gsi, trigger, ACPI_ACTIVE_HIGH);
> +
> +	if (irq == -EINVAL) {
> +		pr_err("failed to map AEST GSI %d\n", gsi);
> +		return -EINVAL;
> +	}
> +
> +	if (gsi < 16) {
> +		pr_err("invalid GSI %d\n", gsi);
> +		return -EINVAL;
> +	} else if (gsi < 32) {
> +		if (ppi_idx >= AEST_MAX_PPI) {
> +			pr_err("Unable to register PPI %d\n", gsi);
> +			return -EINVAL;
> +		}
> +		enable_percpu_irq(irq, IRQ_TYPE_NONE);
> +		for_each_possible_cpu(cpu) {
> +			memcpy(per_cpu_ptr(ppi_data[ppi_idx], cpu), data,
> +			       sizeof(struct aest_node_data));
> +		}
> +		if (request_percpu_irq(irq, aest_irq_func, "AEST",
> +				       ppi_data[ppi_idx++])) {
> +			pr_err("failed to register AEST IRQ %d\n", irq);
> +			return -EINVAL;
> +		}
> +	} else if (gsi < 1020) {
> +		if (request_irq(irq, aest_irq_func, IRQF_SHARED, "AEST",
> +				data)) {
> +			pr_err("failed to register AEST IRQ %d\n", irq);
> +			return -EINVAL;
> +		}
> +	} else {
> +		pr_err("invalid GSI %d\n", gsi);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __init aest_init_interrupts(struct aest_type_header *node,
> +				       struct aest_node_data *data)
> +{
> +	struct aest_interrupt *interrupt;
> +	int i, trigger, ret = 0;
> +
> +	interrupt = ACPI_ADD_PTR(struct aest_interrupt, node,
> +				 node->interrupt_offset);
> +
> +	for (i = 0; i < node->interrupt_size; i++, interrupt++) {
> +		trigger = (interrupt->flags & AEST_INTERRUPT_MODE) ?
> +			  ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
> +		if (aest_register_gsi(interrupt->gsiv, trigger, data))
> +			ret = -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static int __init aest_init_interface(struct aest_type_header *node,
> +				       struct aest_node_data *data)
> +{
> +	struct aest_interface *interface;
> +	struct resource *res;
> +	int size;
> +
> +	interface = ACPI_ADD_PTR(struct aest_interface, node,
> +				 node->interface_offset);
> +
> +	if (interface->type > AEST_MEMORY_MAPPED_INTERFACE) {
> +		pr_err("invalid interface type: %d\n", interface->type);
> +		return -EINVAL;
> +	}
> +
> +	data->interface.type = interface->type;
> +
> +	/*
> +	 * Currently SR based handling is done through the architected
> +	 * discovery exposed through SRs. That may change in the future
> +	 * if there is supplemental information in the AEST that is
> +	 * needed.
> +	 */
> +	if (interface->type == AEST_SYSTEM_REG_INTERFACE)
> +		return 0;
> +
> +	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
> +	if (!res)
> +		return -ENOMEM;
> +
> +	size = interface->num_records * sizeof(struct ras_ext_regs);
> +	res->name = "AEST";
> +	res->start = interface->address;
> +	res->end = res->start + size;
> +	res->flags = IORESOURCE_MEM;
> +	if (request_resource_conflict(&iomem_resource, res)) {
> +		pr_err("unable to request region starting at 0x%llx\n",
> +			res->start);
> +		kfree(res);
> +		return -EEXIST;
> +	}
> +
> +	data->interface.start = interface->start_index;
> +	data->interface.end = interface->start_index + interface->num_records;
> +
> +	data->interface.regs = ioremap(interface->address, size);
> +	if (data->interface.regs == NULL)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int __init aest_init_node(struct aest_type_header *node)
> +{
> +	struct aest_node_data *data;
> +	union aest_node_spec *node_spec;
> +	int ret;
> +
> +	data = kzalloc(sizeof(struct aest_node_data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->node_type = node->type;
> +
> +	node_spec = ACPI_ADD_PTR(union aest_node_spec, node, node->data_offset);
> +
> +	switch (node->type) {
> +	case AEST_NODE_TYPE_PROC:
> +		memcpy(&data->data, node_spec, sizeof(struct aest_proc_data));
> +		break;
> +	case AEST_NODE_TYPE_MEM:
> +		memcpy(&data->data, node_spec, sizeof(struct aest_mem_data));
> +		break;
> +	case AEST_NODE_TYPE_VENDOR:
> +		memcpy(&data->data, node_spec, sizeof(struct aest_vendor_data));
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	ret = aest_init_interface(node, data);
> +	if (ret) {
> +		kfree(data);
> +		return ret;
> +	}
> +
> +	return aest_init_interrupts(node, data);
> +}
> +
> +static void aest_count_ppi(struct aest_type_header *node)
> +{
> +	struct aest_interrupt *interrupt;
> +	int i;
> +
> +	interrupt = ACPI_ADD_PTR(struct aest_interrupt, node,
> +				 node->interrupt_offset);
> +
> +	for (i = 0; i < node->interrupt_size; i++, interrupt++) {
> +		if (interrupt->gsiv >= 16 && interrupt->gsiv < 32)
> +			num_ppi++;
> +	}
> +
> +}
> +
> +int __init acpi_aest_init(void)
> +{
> +	struct acpi_table_aest *aest;
> +	struct aest_type_header *aest_node, *aest_end;
> +	int i, ret = 0;
> +
> +	if (acpi_disabled)
> +		return 0;
> +
> +	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_AEST, 0, &aest_table)))
> +		return -EINVAL;
> +
> +	aest = (struct acpi_table_aest *)aest_table;
> +
> +	/* Get the first AEST node */
> +	aest_node = ACPI_ADD_PTR(struct aest_type_header, aest,
> +				 sizeof(struct acpi_table_aest));
> +	/* Pointer to the end of the AEST table */
> +	aest_end = ACPI_ADD_PTR(struct aest_type_header, aest,
> +				aest_table->length);
> +
> +	while (aest_node < aest_end) {
> +		if (((u64)aest_node + aest_node->length) > (u64)aest_end) {
> +			pr_err("AEST node pointer overflow, bad table\n");
> +			return -EINVAL;
> +		}
> +
> +		aest_count_ppi(aest_node);
> +
> +		aest_node = ACPI_ADD_PTR(struct aest_type_header, aest_node,
> +					 aest_node->length);
> +	}
> +
> +	if (num_ppi > AEST_MAX_PPI) {
> +		pr_err("Limiting PPI support to %d PPIs\n", AEST_MAX_PPI);
> +		num_ppi = AEST_MAX_PPI;
> +	}
> +
> +	ppi_data = kcalloc(num_ppi, sizeof(struct aest_node_data *),
> +			   GFP_KERNEL);
> +
> +	for (i = 0; i < num_ppi; i++) {
> +		ppi_data[i] = alloc_percpu(struct aest_node_data);
> +		if (!ppi_data[i]) {
> +			ret = -ENOMEM;
> +			break;
> +		}
> +	}
> +
> +	if (ret) {
> +		pr_err("Failed percpu allocation\n");
> +		for (i = 0; i < num_ppi; i++)
> +			free_percpu(ppi_data[i]);
> +		return ret;
> +	}
> +
> +	aest_node = ACPI_ADD_PTR(struct aest_type_header, aest,
> +				 sizeof(struct acpi_table_aest));
> +
> +	while (aest_node < aest_end) {
> +		ret = aest_init_node(aest_node);
> +		if (ret)
> +			pr_err("failed to init node: %d", ret);
> +
> +		aest_node = ACPI_ADD_PTR(struct aest_type_header, aest_node,
> +					 aest_node->length);
> +	}
> +
> +	return 0;
> +}
> +
> +early_initcall(acpi_aest_init);
> diff --git a/include/linux/acpi_aest.h b/include/linux/acpi_aest.h
> new file mode 100644
> index 0000000..376122b
> --- /dev/null
> +++ b/include/linux/acpi_aest.h
> @@ -0,0 +1,94 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef AEST_H
> +#define AEST_H
> +
> +#include <acpi/actbl.h>
> +
> +#define ACPI_SIG_AEST			"AEST"	/* ARM Error Source Table */
> +
> +#define AEST_NODE_TYPE_PROC		0
> +#define AEST_NODE_TYPE_MEM		1
> +#define AEST_NODE_TYPE_VENDOR		2
> +
> +#define AEST_SYSTEM_REG_INTERFACE	0x0
> +#define AEST_MEMORY_MAPPED_INTERFACE	0x1
> +
> +#define AEST_INTERRUPT_MODE		BIT(0)
> +
> +#define AEST_MAX_PPI			4
> +
> +#pragma pack(1)
> +
> +struct acpi_table_aest {
> +	struct acpi_table_header header;
> +};
> +
> +struct aest_type_header {
> +	u8 type;
> +	u16 length;
> +	u8 reserved;
> +	u32 revision;
> +	u32 data_offset;
> +	u32 interface_offset;
> +	u32 interface_size;
> +	u32 interrupt_offset;
> +	u32 interrupt_size;
> +	u64 timestamp_rate;
> +	u64 timestamp_start;
> +	u64 countdown_rate;
> +};
> +
> +struct aest_proc_data {
> +	u32 id;
> +	u32 level;
> +	u32 cache_type;
> +};
> +
> +struct aest_mem_data {
> +	u32 domain;
> +};
> +
> +struct aest_vendor_data {
> +	u32 id;
> +	u32 data;
> +};
> +
> +struct aest_interface {
> +	u8 type;
> +	u8 reserved[3];
> +	u32 flags;
> +	u64 address;
> +	u16 start_index;
> +	u16 num_records;
> +};
> +
> +struct aest_interrupt {
> +	u8 type;
> +	u16 reserved;
> +	u8 flags;
> +	u32 gsiv;
> +	u8 iort_id[20];
> +};
> +
> +#pragma pack()
> +
> +struct aest_interface_data {
> +	u8 type;
> +	u16 start;
> +	u16 end;
> +	struct ras_ext_regs *regs;
> +};
> +
> +union aest_node_spec {
> +	struct aest_proc_data proc;
> +	struct aest_mem_data mem;
> +	struct aest_vendor_data vendor;
> +};
> +
> +struct aest_node_data {
> +	u8 node_type;
> +	struct aest_interface_data interface;
> +	union aest_node_spec data;
> +};
> +
> +#endif /* AEST_H */
> -- 
> 1.8.3.1
>
Tyler Baicar July 3, 2019, 5:30 p.m. UTC | #2
Hello Andrew,

Thank you for the feedback!

On Wed, Jul 3, 2019 at 5:26 AM Andrew Murray <andrew.murray@arm.com> wrote:
>
> On Tue, Jul 02, 2019 at 04:51:38PM +0000, Tyler Baicar OS wrote:
> > Add support for parsing the ARM Error Source Table and basic handling of
> > errors reported through both memory mapped and system register interfaces.
> >
> > Signed-off-by: Tyler Baicar <baicar@os.amperecomputing.com>
> > ---
> >  arch/arm64/include/asm/ras.h |  41 +++++
> >  arch/arm64/kernel/Makefile   |   2 +-
> >  arch/arm64/kernel/ras.c      |  67 ++++++++
> >  drivers/acpi/arm64/Kconfig   |   3 +
> >  drivers/acpi/arm64/Makefile  |   1 +
> >  drivers/acpi/arm64/aest.c    | 362 +++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/acpi_aest.h    |  94 +++++++++++
> >  7 files changed, 569 insertions(+), 1 deletion(-)
> >  create mode 100644 arch/arm64/include/asm/ras.h
> >  create mode 100644 arch/arm64/kernel/ras.c
> >  create mode 100644 drivers/acpi/arm64/aest.c
> >  create mode 100644 include/linux/acpi_aest.h
> >
> > diff --git a/arch/arm64/include/asm/ras.h b/arch/arm64/include/asm/ras.h
> > new file mode 100644
> > index 0000000..36bfff4
> > --- /dev/null
> > +++ b/arch/arm64/include/asm/ras.h
> > @@ -0,0 +1,41 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef __ASM_RAS_H
> > +#define __ASM_RAS_H
> > +
> > +#define ERR_STATUS_AV                BIT(31)
> > +#define ERR_STATUS_V         BIT(30)
> > +#define ERR_STATUS_UE                BIT(29)
> > +#define ERR_STATUS_ER                BIT(28)
> > +#define ERR_STATUS_OF                BIT(27)
> > +#define ERR_STATUS_MV                BIT(26)
> > +#define ERR_STATUS_CE_SHIFT  24
> > +#define ERR_STATUS_CE_MASK   0x3
> > +#define ERR_STATUS_DE                BIT(23)
> > +#define ERR_STATUS_PN                BIT(22)
> > +#define ERR_STATUS_UET_SHIFT 20
> > +#define ERR_STATUS_UET_MASK  0x3
> > +#define ERR_STATUS_IERR_SHIFT        8
> > +#define ERR_STATUS_IERR_MASK 0xff
> > +#define ERR_STATUS_SERR_SHIFT        0
> > +#define ERR_STATUS_SERR_MASK 0xff
>
> Some of these (_ER, _OF, _CE*, _PN, _UET*) are not used anywhere in the series,
> I'd suggest you drop the unused ones.

Yes, I'll remove them in the next version.

> There may be some merit in renaming these to match the register names in the
> spec, e.g. ERXSTATUS_EL1 instead of ERR_STATUS.

ERX* are the register names for the system registers, but these macros are used
for both system registers and memory mapped registers. The memory mapped
registers have prefix ERR<n>*. Also, the spec definition of the ERX* system
registers is "accesses ERR<n>* for the error record selected by
ERRSELR_EL1.SEL." So really, the registers being accessed in all cases are
ERR<n>*. Either way, if folks think these names should be changed I can change
them.

> > +
> > +#define ERR_FR_CEC_SHIFT     12
> > +#define ERR_FR_CEC_MASK              0x7
> > +
> > +#define ERR_FR_8B_CEC                BIT(1)
> > +#define ERR_FR_16B_CEC               BIT(2)
>
> All of these ERR_FR_ defines aren't used anywhere either.

Will remove.

> > +
> > +struct ras_ext_regs {
> > +     u64 err_fr;
> > +     u64 err_ctlr;
> > +     u64 err_status;
> > +     u64 err_addr;
> > +     u64 err_misc0;
> > +     u64 err_misc1;
> > +     u64 err_misc2;
> > +     u64 err_misc3;
> > +};
> > +
> > +void arch_arm_ras_report_error(void);
> > +
> > +#endif       /* __ASM_RAS_H */
> > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> > index 9e7dcb2..294f602 100644
> > --- a/arch/arm64/kernel/Makefile
> > +++ b/arch/arm64/kernel/Makefile
> > @@ -19,7 +19,7 @@ obj-y                       := debug-monitors.o entry.o irq.o fpsimd.o              \
> >                          return_address.o cpuinfo.o cpu_errata.o              \
> >                          cpufeature.o alternative.o cacheinfo.o               \
> >                          smp.o smp_spin_table.o topology.o smccc-call.o       \
> > -                        syscall.o
> > +                        syscall.o ras.o
>
> Given that arch_arm_ras_report_error depends on the ARM64_HAS_RAS_EXTN
> capability, which in turn depends on CONFIG_ARM64_RAS_EXTN - you should
> probably conditionally build ras.o only if CONFIG_ARM64_RAS_EXTN is defined
> (and provide a stub in the header for when it isn't defined).

Yes, I can do that.

> > 
> >  extra-$(CONFIG_EFI)                  := efi-entry.o
> > 
> > diff --git a/arch/arm64/kernel/ras.c b/arch/arm64/kernel/ras.c
> > new file mode 100644
> > index 0000000..ca47efa
> > --- /dev/null
> > +++ b/arch/arm64/kernel/ras.c
> > @@ -0,0 +1,67 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/cpu.h>
> > +#include <linux/smp.h>
> > +
> > +#include <asm/ras.h>
> > +
> > +void arch_arm_ras_report_error(void)
> > +{
> > +     u64 num_records;
> > +     unsigned int i, cpu_num;
> > +     bool fatal = false;
> > +     struct ras_ext_regs regs;
> > +
> > +     if (!this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
> > +             return;
> > +
> > +     cpu_num = get_cpu();
> > +     num_records = read_sysreg_s(SYS_ERRIDR_EL1);
>
> This value should be masked to exclude the reserved bits. This will
> also prevent you writing to reserved bits in ERRSELR.

True, I'll add that in the next version.

> > +
> > +     for (i = 0; i < num_records; i++) {
> > +             write_sysreg_s(i, SYS_ERRSELR_EL1);
>
> There should be an isb here, this will ensure the record selection has
> happened before reading the record.

I'll add that in the next version.

> > +             regs.err_status = read_sysreg_s(SYS_ERXSTATUS_EL1);
> > +
> > +             if (!(regs.err_status & ERR_STATUS_V))
> > +                     continue;
> > +
> > +             pr_err("CPU%u: ERR%uSTATUS: 0x%llx\n", cpu_num, i,
> > +                    regs.err_status);
> > +
> > +             if (regs.err_status & ERR_STATUS_AV) {
> > +                     regs.err_addr = read_sysreg_s(SYS_ERXSTATUS_EL1);
>
> This should be SYS_ERXADDR_EL1 not SYS_ERXSTATUS_EL1!

Oops, good catch! I missed this in testing because none of the errors injected
resulted in valid address info in the system registers.

> > +                     pr_err("CPU%u: ERR%uADDR: 0x%llx\n", cpu_num, i,
> > +                            regs.err_addr);
> > +             } else
> > +                     regs.err_addr = 0;
>
> Or perhaps set "regs = { }" at the start of the function instead?

Yes, I could do that.

> > +
> > +             regs.err_fr = read_sysreg_s(SYS_ERXFR_EL1);
> > +             pr_err("CPU%u: ERR%uFR: 0x%llx\n", cpu_num, i, regs.err_fr);
> > +             regs.err_ctlr = read_sysreg_s(SYS_ERXCTLR_EL1);
> > +             pr_err("CPU%u: ERR%uCTLR: 0x%llx\n", cpu_num, i, regs.err_ctlr);
> > +
> > +             if (regs.err_status & ERR_STATUS_MV) {
> > +                     regs.err_misc0 = read_sysreg_s(SYS_ERXMISC0_EL1);
> > +                     pr_err("CPU%u: ERR%uMISC0: 0x%llx\n", cpu_num, i,
> > +                            regs.err_misc0);
> > +                     regs.err_misc1 = read_sysreg_s(SYS_ERXMISC1_EL1);
> > +                     pr_err("CPU%u: ERR%uMISC1: 0x%llx\n", cpu_num, i,
> > +                            regs.err_misc1);
> > +             }
> > +
> > +             /*
> > +              * In the future, we will treat UER conditions as potentially
> > +              * recoverable.
> > +              */
> > +             if (regs.err_status & ERR_STATUS_UE)
> > +                     fatal = true;
> > +
> > +             write_sysreg_s(regs.err_status, SYS_ERXSTATUS_EL1);
> > +     }
> > +
> > +     if (fatal)
> > +             panic("uncorrectable error encountered");
>
> On the do_serror path, we will already panic if arm64_is_fatal_ras_serror
> indicates uncorrectable errors. Is this here for the other paths?

This same function is called for the SEA path and also from AEST for errors
that are reported through the system register interface.

> > +
> > +     put_cpu();
> > +}
>
> Finally, should we clear the errors when we see them?

Each error is being cleared at the end of the loop above by writing the value
read from the status register back to the status register. The status register
bits are write 1 to clear and writing back the same value that was read
guarantees that a higher priority error that occurs between the read and write
isn't cleared.

> > diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> > index 6dba187..8d5cf99 100644
> > --- a/drivers/acpi/arm64/Kconfig
> > +++ b/drivers/acpi/arm64/Kconfig
> > @@ -8,3 +8,6 @@ config ACPI_IORT
> > 
> >  config ACPI_GTDT
> >       bool
> > +
> > +config ACPI_AEST
> > +     bool "ARM Error Source Table Support"
> > diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> > index 6ff50f4..ea1ba28 100644
> > --- a/drivers/acpi/arm64/Makefile
> > +++ b/drivers/acpi/arm64/Makefile
> > @@ -1,3 +1,4 @@
> >  # SPDX-License-Identifier: GPL-2.0-only
> >  obj-$(CONFIG_ACPI_IORT)      += iort.o
> >  obj-$(CONFIG_ACPI_GTDT)      += gtdt.o
> > +obj-$(CONFIG_ACPI_AEST)      += aest.o
> > diff --git a/drivers/acpi/arm64/aest.c b/drivers/acpi/arm64/aest.c
> > new file mode 100644
> > index 0000000..fd4f3b5
> > --- /dev/null
> > +++ b/drivers/acpi/arm64/aest.c
> > @@ -0,0 +1,362 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +/* ARM Error Source Table Support */
> > +
> > +#include <linux/acpi.h>
> > +#include <linux/acpi_aest.h>
> > +#include <linux/init.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/kernel.h>
> > +#include <linux/percpu.h>
> > +#include <linux/ratelimit.h>
> > +
> > +#include <asm/ras.h>
> > +
> > +#undef pr_fmt
> > +#define pr_fmt(fmt) "ACPI AEST: " fmt
> > +
> > +static struct acpi_table_header *aest_table;
> > +
> > +static struct aest_node_data __percpu **ppi_data;
> > +static u8 num_ppi;
> > +static u8 ppi_idx;
> > +
> > +static void aest_print(struct aest_node_data *data, struct ras_ext_regs regs,
> > +                    int index)
> > +{
> > +     /* No more than 2 corrected messages every 5 seconds */
> > +     static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
> > +
> > +     if (regs.err_status & ERR_STATUS_UE ||
> > +         regs.err_status & ERR_STATUS_DE ||
> > +         __ratelimit(&ratelimit_corrected)) {
> > +             switch (data->node_type) {
> > +             case AEST_NODE_TYPE_PROC:
> > +                     pr_err("error from processor 0x%x\n",
> > +                            data->data.proc.id);
> > +                     break;
> > +             case AEST_NODE_TYPE_MEM:
> > +                     pr_err("error from memory domain 0x%x\n",
> > +                            data->data.mem.domain);
> > +                     break;
> > +             case AEST_NODE_TYPE_VENDOR:
> > +                     pr_err("error from vendor specific source 0x%x\n",
> > +                            data->data.vendor.id);
> > +             }
> > +
> > +             pr_err("ERR%dSTATUS = 0x%llx\n", index, regs.err_status);
> > +             if (regs.err_status & ERR_STATUS_AV)
> > +                     pr_err("ERR%dADDR = 0x%llx\n", index, regs.err_addr);
> > +
> > +             pr_err("ERR%dFR = 0x%llx\n", index, regs.err_fr);
> > +             pr_err("ERR%dCTLR = 0x%llx\n", index, regs.err_ctlr);
> > +
> > +             if (regs.err_status & ERR_STATUS_MV) {
> > +                     pr_err("ERR%dMISC0 = 0x%llx\n", index, regs.err_misc0);
> > +                     pr_err("ERR%dMISC1 = 0x%llx\n", index, regs.err_misc1);
> > +             }
>
> Given that we have a ras_ext_regs struct, can't we use a single function to
> print the error - rather than have duplicate pr_err's here and in
> arch_arm_ras_report_error?

That was an option I had thought about, but I left it as is to get other
opinions. Right now the system register reporting prefixes everything with the
CPU number that the error occurred on...but now that I think about it more I
could just have the print function take a prefix as a parameter. I'll unify the
printing into a single function in the next version.

Thanks,
Tyler
Andrew Murray July 4, 2019, 9:05 a.m. UTC | #3
On Wed, Jul 03, 2019 at 05:30:53PM +0000, Tyler Baicar OS wrote:
> Hello Andrew,
> 
> Thank you for the feedback!
> 
> On Wed, Jul 3, 2019 at 5:26 AM Andrew Murray <andrew.murray@arm.com> wrote:
> >
> > On Tue, Jul 02, 2019 at 04:51:38PM +0000, Tyler Baicar OS wrote:
> > > Add support for parsing the ARM Error Source Table and basic handling of
> > > errors reported through both memory mapped and system register interfaces.
> > >
> > > Signed-off-by: Tyler Baicar <baicar@os.amperecomputing.com>
> > > ---
> > >  arch/arm64/include/asm/ras.h |  41 +++++
> > >  arch/arm64/kernel/Makefile   |   2 +-
> > >  arch/arm64/kernel/ras.c      |  67 ++++++++
> > >  drivers/acpi/arm64/Kconfig   |   3 +
> > >  drivers/acpi/arm64/Makefile  |   1 +
> > >  drivers/acpi/arm64/aest.c    | 362 +++++++++++++++++++++++++++++++++++++++++++
> > >  include/linux/acpi_aest.h    |  94 +++++++++++
> > >  7 files changed, 569 insertions(+), 1 deletion(-)
> > >  create mode 100644 arch/arm64/include/asm/ras.h
> > >  create mode 100644 arch/arm64/kernel/ras.c
> > >  create mode 100644 drivers/acpi/arm64/aest.c
> > >  create mode 100644 include/linux/acpi_aest.h
> > >
> > > diff --git a/arch/arm64/include/asm/ras.h b/arch/arm64/include/asm/ras.h
> > > new file mode 100644
> > > index 0000000..36bfff4
> > > --- /dev/null
> > > +++ b/arch/arm64/include/asm/ras.h
> > > @@ -0,0 +1,41 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +#ifndef __ASM_RAS_H
> > > +#define __ASM_RAS_H
> > > +
> > > +#define ERR_STATUS_AV                BIT(31)
> > > +#define ERR_STATUS_V         BIT(30)
> > > +#define ERR_STATUS_UE                BIT(29)
> > > +#define ERR_STATUS_ER                BIT(28)
> > > +#define ERR_STATUS_OF                BIT(27)
> > > +#define ERR_STATUS_MV                BIT(26)
> > > +#define ERR_STATUS_CE_SHIFT  24
> > > +#define ERR_STATUS_CE_MASK   0x3
> > > +#define ERR_STATUS_DE                BIT(23)
> > > +#define ERR_STATUS_PN                BIT(22)
> > > +#define ERR_STATUS_UET_SHIFT 20
> > > +#define ERR_STATUS_UET_MASK  0x3
> > > +#define ERR_STATUS_IERR_SHIFT        8
> > > +#define ERR_STATUS_IERR_MASK 0xff
> > > +#define ERR_STATUS_SERR_SHIFT        0
> > > +#define ERR_STATUS_SERR_MASK 0xff
> >
> > Some of these (_ER, _OF, _CE*, _PN, _UET*) are not used anywhere in the series,
> > I'd suggest you drop the unused ones.
> 
> Yes, I'll remove them in the next version.
> 
> > There may be some merit in renaming these to match the register names in the
> > spec, e.g. ERXSTATUS_EL1 instead of ERR_STATUS.
> 
> ERX* are the register names for the system registers, but these macros are used
> for both system registers and memory mapped registers. The memory mapped
> registers have prefix ERR<n>*. Also, the spec definition of the ERX* system
> registers is "accesses ERR<n>* for the error record selected by
> ERRSELR_EL1.SEL." So really, the registers being accessed in all cases are
> ERR<n>*. Either way, if folks think these names should be changed I can change
> them.

Sorry I hadn't considered the memory mapped registers. Your rationale seems
sound so no need to change them.

> 
> > > +
> > > +#define ERR_FR_CEC_SHIFT     12
> > > +#define ERR_FR_CEC_MASK              0x7
> > > +
> > > +#define ERR_FR_8B_CEC                BIT(1)
> > > +#define ERR_FR_16B_CEC               BIT(2)
> >
> > All of these ERR_FR_ defines aren't used anywhere either.
> 
> Will remove.
> 
> > > +
> > > +struct ras_ext_regs {
> > > +     u64 err_fr;
> > > +     u64 err_ctlr;
> > > +     u64 err_status;
> > > +     u64 err_addr;
> > > +     u64 err_misc0;
> > > +     u64 err_misc1;
> > > +     u64 err_misc2;
> > > +     u64 err_misc3;
> > > +};
> > > +
> > > +void arch_arm_ras_report_error(void);
> > > +
> > > +#endif       /* __ASM_RAS_H */
> > > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> > > index 9e7dcb2..294f602 100644
> > > --- a/arch/arm64/kernel/Makefile
> > > +++ b/arch/arm64/kernel/Makefile
> > > @@ -19,7 +19,7 @@ obj-y                       := debug-monitors.o entry.o irq.o fpsimd.o              \
> > >                          return_address.o cpuinfo.o cpu_errata.o              \
> > >                          cpufeature.o alternative.o cacheinfo.o               \
> > >                          smp.o smp_spin_table.o topology.o smccc-call.o       \
> > > -                        syscall.o
> > > +                        syscall.o ras.o
> >
> > Given that arch_arm_ras_report_error depends on the ARM64_HAS_RAS_EXTN
> > capability, which in turn depends on CONFIG_ARM64_RAS_EXTN - you should
> > probably conditionally build ras.o only if CONFIG_ARM64_RAS_EXTN is defined
> > (and provide a stub in the header for when it isn't defined).
> 
> Yes, I can do that.
> 
> > > 
> > >  extra-$(CONFIG_EFI)                  := efi-entry.o
> > > 
> > > diff --git a/arch/arm64/kernel/ras.c b/arch/arm64/kernel/ras.c
> > > new file mode 100644
> > > index 0000000..ca47efa
> > > --- /dev/null
> > > +++ b/arch/arm64/kernel/ras.c
> > > @@ -0,0 +1,67 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +#include <linux/kernel.h>
> > > +#include <linux/cpu.h>
> > > +#include <linux/smp.h>
> > > +
> > > +#include <asm/ras.h>
> > > +
> > > +void arch_arm_ras_report_error(void)
> > > +{
> > > +     u64 num_records;
> > > +     unsigned int i, cpu_num;
> > > +     bool fatal = false;
> > > +     struct ras_ext_regs regs;
> > > +
> > > +     if (!this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
> > > +             return;
> > > +
> > > +     cpu_num = get_cpu();
> > > +     num_records = read_sysreg_s(SYS_ERRIDR_EL1);
> >
> > This value should be masked to exclude the reserved bits. This will
> > also prevent you writing to reserved bits in ERRSELR.
> 
> True, I'll add that in the next version.
> 
> > > +
> > > +     for (i = 0; i < num_records; i++) {
> > > +             write_sysreg_s(i, SYS_ERRSELR_EL1);
> >
> > There should be an isb here, this will ensure the record selection has
> > happened before reading the record.
> 
> I'll add that in the next version.
> 
> > > +             regs.err_status = read_sysreg_s(SYS_ERXSTATUS_EL1);
> > > +
> > > +             if (!(regs.err_status & ERR_STATUS_V))
> > > +                     continue;
> > > +
> > > +             pr_err("CPU%u: ERR%uSTATUS: 0x%llx\n", cpu_num, i,
> > > +                    regs.err_status);
> > > +
> > > +             if (regs.err_status & ERR_STATUS_AV) {
> > > +                     regs.err_addr = read_sysreg_s(SYS_ERXSTATUS_EL1);
> >
> > This should be SYS_ERXADDR_EL1 not SYS_ERXSTATUS_EL1!
> 
> Oops, good catch! I missed this in testing because none of the errors injected
> resulted in valid address info in the system registers.
> 
> > > +                     pr_err("CPU%u: ERR%uADDR: 0x%llx\n", cpu_num, i,
> > > +                            regs.err_addr);
> > > +             } else
> > > +                     regs.err_addr = 0;
> >
> > Or perhaps set "regs = { }" at the start of the function instead?
> 
> Yes, I could do that.
> 
> > > +
> > > +             regs.err_fr = read_sysreg_s(SYS_ERXFR_EL1);
> > > +             pr_err("CPU%u: ERR%uFR: 0x%llx\n", cpu_num, i, regs.err_fr);
> > > +             regs.err_ctlr = read_sysreg_s(SYS_ERXCTLR_EL1);
> > > +             pr_err("CPU%u: ERR%uCTLR: 0x%llx\n", cpu_num, i, regs.err_ctlr);
> > > +
> > > +             if (regs.err_status & ERR_STATUS_MV) {
> > > +                     regs.err_misc0 = read_sysreg_s(SYS_ERXMISC0_EL1);
> > > +                     pr_err("CPU%u: ERR%uMISC0: 0x%llx\n", cpu_num, i,
> > > +                            regs.err_misc0);
> > > +                     regs.err_misc1 = read_sysreg_s(SYS_ERXMISC1_EL1);
> > > +                     pr_err("CPU%u: ERR%uMISC1: 0x%llx\n", cpu_num, i,
> > > +                            regs.err_misc1);
> > > +             }
> > > +
> > > +             /*
> > > +              * In the future, we will treat UER conditions as potentially
> > > +              * recoverable.
> > > +              */
> > > +             if (regs.err_status & ERR_STATUS_UE)
> > > +                     fatal = true;
> > > +
> > > +             write_sysreg_s(regs.err_status, SYS_ERXSTATUS_EL1);
> > > +     }
> > > +
> > > +     if (fatal)
> > > +             panic("uncorrectable error encountered");
> >
> > On the do_serror path, we will already panic if arm64_is_fatal_ras_serror
> > indicates uncorrectable errors. Is this here for the other paths?
> 
> This same function is called for the SEA path and also from AEST for errors
> that are reported through the system register interface.
> 
> > > +
> > > +     put_cpu();
> > > +}
> >
> > Finally, should we clear the errors when we see them?
> 
> Each error is being cleared at the end of the loop above by writing the value
> read from the status register back to the status register. The status register
> bits are write 1 to clear and writing back the same value that was read
> guarantees that a higher priority error that occurs between the read and write
> isn't cleared.

Ah, I missed that.

When you write back the status to clear the bits, I think you ought to mask
off the bottom 16 bits (SERR, IERR) and arguably the top 32 bits to prevent
writing to res0 or fields that are not error write-1-to-clear bits.

Also the manual states "Software must also write ones to the { ER, PN, UET,
CI } fields when clearing these [valid bits] fields" - we achieve this
implicitly by writing back the value of status... however UET and CE take up
2 bits each and include this comment "Writing a value other than all-zeros or
all-ones sets this field to an UNKNOWN value". Thus we probably should do
the following (or similar) to be inline with the spec:

/* Write-one-to-clear the bits we've seen */
regs.err_status &= ~ERR_STATUS_ERR_MASK;

/* Correctly clear double bit fields */
if (regs.err_status & ERR_STATUS_CE_MASK)
    regs.err_status |= ERR_STATUS_CE_MASK;
if (regs.err_status & ERR_STATUS_UET_MASK)
    regs.err_status |= ERR_STATUS_UET_MASK

write_sysreg_s(regs.err_status, SYS_ERXSTATUS_EL1);
isb();

The isb may not be necessary but ensures we've cleared the errors before
leaving the function.

> 
> > > diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> > > index 6dba187..8d5cf99 100644
> > > --- a/drivers/acpi/arm64/Kconfig
> > > +++ b/drivers/acpi/arm64/Kconfig
> > > @@ -8,3 +8,6 @@ config ACPI_IORT
> > > 
> > >  config ACPI_GTDT
> > >       bool
> > > +
> > > +config ACPI_AEST
> > > +     bool "ARM Error Source Table Support"
> > > diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> > > index 6ff50f4..ea1ba28 100644
> > > --- a/drivers/acpi/arm64/Makefile
> > > +++ b/drivers/acpi/arm64/Makefile
> > > @@ -1,3 +1,4 @@
> > >  # SPDX-License-Identifier: GPL-2.0-only
> > >  obj-$(CONFIG_ACPI_IORT)      += iort.o
> > >  obj-$(CONFIG_ACPI_GTDT)      += gtdt.o
> > > +obj-$(CONFIG_ACPI_AEST)      += aest.o
> > > diff --git a/drivers/acpi/arm64/aest.c b/drivers/acpi/arm64/aest.c
> > > new file mode 100644
> > > index 0000000..fd4f3b5
> > > --- /dev/null
> > > +++ b/drivers/acpi/arm64/aest.c
> > > @@ -0,0 +1,362 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +/* ARM Error Source Table Support */
> > > +
> > > +#include <linux/acpi.h>
> > > +#include <linux/acpi_aest.h>
> > > +#include <linux/init.h>
> > > +#include <linux/interrupt.h>
> > > +#include <linux/io.h>
> > > +#include <linux/irq.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/percpu.h>
> > > +#include <linux/ratelimit.h>
> > > +
> > > +#include <asm/ras.h>
> > > +
> > > +#undef pr_fmt
> > > +#define pr_fmt(fmt) "ACPI AEST: " fmt
> > > +
> > > +static struct acpi_table_header *aest_table;
> > > +
> > > +static struct aest_node_data __percpu **ppi_data;
> > > +static u8 num_ppi;
> > > +static u8 ppi_idx;
> > > +
> > > +static void aest_print(struct aest_node_data *data, struct ras_ext_regs regs,
> > > +                    int index)
> > > +{
> > > +     /* No more than 2 corrected messages every 5 seconds */
> > > +     static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
> > > +
> > > +     if (regs.err_status & ERR_STATUS_UE ||
> > > +         regs.err_status & ERR_STATUS_DE ||
> > > +         __ratelimit(&ratelimit_corrected)) {
> > > +             switch (data->node_type) {
> > > +             case AEST_NODE_TYPE_PROC:
> > > +                     pr_err("error from processor 0x%x\n",
> > > +                            data->data.proc.id);
> > > +                     break;
> > > +             case AEST_NODE_TYPE_MEM:
> > > +                     pr_err("error from memory domain 0x%x\n",
> > > +                            data->data.mem.domain);
> > > +                     break;
> > > +             case AEST_NODE_TYPE_VENDOR:
> > > +                     pr_err("error from vendor specific source 0x%x\n",
> > > +                            data->data.vendor.id);
> > > +             }
> > > +
> > > +             pr_err("ERR%dSTATUS = 0x%llx\n", index, regs.err_status);
> > > +             if (regs.err_status & ERR_STATUS_AV)
> > > +                     pr_err("ERR%dADDR = 0x%llx\n", index, regs.err_addr);
> > > +
> > > +             pr_err("ERR%dFR = 0x%llx\n", index, regs.err_fr);
> > > +             pr_err("ERR%dCTLR = 0x%llx\n", index, regs.err_ctlr);
> > > +
> > > +             if (regs.err_status & ERR_STATUS_MV) {
> > > +                     pr_err("ERR%dMISC0 = 0x%llx\n", index, regs.err_misc0);
> > > +                     pr_err("ERR%dMISC1 = 0x%llx\n", index, regs.err_misc1);
> > > +             }
> >
> > Given that we have a ras_ext_regs struct, can't we use a single function to
> > print the error - rather than have duplicate pr_err's here and in
> > arch_arm_ras_report_error?
> 
> That was an option I had thought about, but I left it as is to get other
> opinions. Right now the system register reporting prefixes everything with the
> CPU number that the error occurred on...but now that I think about it more I
> could just have the print function take a prefix as a parameter. I'll unify the
> printing into a single function in the next version.

This is also helpful for times when you want to clear the error without
printing it. (E.g. to catch guest non-fatal errors and prevent a bad guest from
spaming the log buffer).

Thanks,

Andrew Murray

> 
> Thanks,
> Tyler
Shiju Jose July 4, 2019, 4:02 p.m. UTC | #4
Hi Tyler,

>-----Original Message-----
>From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi-
>owner@vger.kernel.org] On Behalf Of Tyler Baicar OS
>Sent: 02 July 2019 17:52
>To: Open Source Submission <patches@amperecomputing.com>; linux-arm-
>kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
>acpi@vger.kernel.org; linux-edac@vger.kernel.org; james.morse@arm.com;
>catalin.marinas@arm.com; will@kernel.org; lorenzo.pieralisi@arm.com;
>Guohanjun (Hanjun Guo) <guohanjun@huawei.com>; sudeep.holla@arm.com;
>rjw@rjwysocki.net; lenb@kernel.org; mark.rutland@arm.com;
>tony.luck@intel.com; bp@alien8.de; Matteo.Carlini@arm.com;
>Andrew.Murray@arm.com
>Cc: Tyler Baicar OS <baicar@os.amperecomputing.com>
>Subject: [PATCH RFC 1/4] ACPI/AEST: Initial AEST driver
>
>Add support for parsing the ARM Error Source Table and basic handling of
>errors reported through both memory mapped and system register interfaces.
>
>Signed-off-by: Tyler Baicar <baicar@os.amperecomputing.com>
>---
> arch/arm64/include/asm/ras.h |  41 +++++
> arch/arm64/kernel/Makefile   |   2 +-
> arch/arm64/kernel/ras.c      |  67 ++++++++
> drivers/acpi/arm64/Kconfig   |   3 +
> drivers/acpi/arm64/Makefile  |   1 +
> drivers/acpi/arm64/aest.c    | 362
>+++++++++++++++++++++++++++++++++++++++++++
> include/linux/acpi_aest.h    |  94 +++++++++++
> 7 files changed, 569 insertions(+), 1 deletion(-)  create mode 100644
>arch/arm64/include/asm/ras.h  create mode 100644 arch/arm64/kernel/ras.c
>create mode 100644 drivers/acpi/arm64/aest.c  create mode 100644
>include/linux/acpi_aest.h
>
>diff --git a/arch/arm64/include/asm/ras.h b/arch/arm64/include/asm/ras.h
>new file mode 100644 index 0000000..36bfff4
>--- /dev/null
>+++ b/arch/arm64/include/asm/ras.h
>@@ -0,0 +1,41 @@
>+/* SPDX-License-Identifier: GPL-2.0 */
>+#ifndef __ASM_RAS_H
>+#define __ASM_RAS_H
>+
>+#define ERR_STATUS_AV		BIT(31)
>+#define ERR_STATUS_V		BIT(30)
>+#define ERR_STATUS_UE		BIT(29)
>+#define ERR_STATUS_ER		BIT(28)
>+#define ERR_STATUS_OF		BIT(27)
>+#define ERR_STATUS_MV		BIT(26)
>+#define ERR_STATUS_CE_SHIFT	24
>+#define ERR_STATUS_CE_MASK	0x3
>+#define ERR_STATUS_DE		BIT(23)
>+#define ERR_STATUS_PN		BIT(22)
>+#define ERR_STATUS_UET_SHIFT	20
>+#define ERR_STATUS_UET_MASK	0x3
>+#define ERR_STATUS_IERR_SHIFT	8
>+#define ERR_STATUS_IERR_MASK	0xff
>+#define ERR_STATUS_SERR_SHIFT	0
>+#define ERR_STATUS_SERR_MASK	0xff
>+
>+#define ERR_FR_CEC_SHIFT	12
>+#define ERR_FR_CEC_MASK		0x7
>+
>+#define ERR_FR_8B_CEC		BIT(1)
>+#define ERR_FR_16B_CEC		BIT(2)
>+
>+struct ras_ext_regs {
>+	u64 err_fr;
>+	u64 err_ctlr;
>+	u64 err_status;
>+	u64 err_addr;
>+	u64 err_misc0;
>+	u64 err_misc1;
>+	u64 err_misc2;
>+	u64 err_misc3;
err_misc2 and err_misc3 are not used. Are they for the future purpose?

>+};
>+
>+void arch_arm_ras_report_error(void);
>+
>+#endif	/* __ASM_RAS_H */
[...]
>+
>+int __init acpi_aest_init(void)
>+{
>+	struct acpi_table_aest *aest;
>+	struct aest_type_header *aest_node, *aest_end;
>+	int i, ret = 0;
>+
>+	if (acpi_disabled)
>+		return 0;
>+
>+	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_AEST, 0, &aest_table)))
>+		return -EINVAL;
>+
>+	aest = (struct acpi_table_aest *)aest_table;
>+
>+	/* Get the first AEST node */
>+	aest_node = ACPI_ADD_PTR(struct aest_type_header, aest,
>+				 sizeof(struct acpi_table_aest));
>+	/* Pointer to the end of the AEST table */
>+	aest_end = ACPI_ADD_PTR(struct aest_type_header, aest,
>+				aest_table->length);
>+
>+	while (aest_node < aest_end) {
>+		if (((u64)aest_node + aest_node->length) > (u64)aest_end) {
>+			pr_err("AEST node pointer overflow, bad table\n");
>+			return -EINVAL;
>+		}
>+
>+		aest_count_ppi(aest_node);
>+
>+		aest_node = ACPI_ADD_PTR(struct aest_type_header,
>aest_node,
>+					 aest_node->length);
>+	}
>+
>+	if (num_ppi > AEST_MAX_PPI) {
>+		pr_err("Limiting PPI support to %d PPIs\n", AEST_MAX_PPI);
>+		num_ppi = AEST_MAX_PPI;
>+	}
>+
>+	ppi_data = kcalloc(num_ppi, sizeof(struct aest_node_data *),
>+			   GFP_KERNEL);
>+
>+	for (i = 0; i < num_ppi; i++) {
>+		ppi_data[i] = alloc_percpu(struct aest_node_data);
>+		if (!ppi_data[i]) {
>+			ret = -ENOMEM;
>+			break;
>+		}
>+	}
>+
>+	if (ret) {
>+		pr_err("Failed percpu allocation\n");
>+		for (i = 0; i < num_ppi; i++)
>+			free_percpu(ppi_data[i]);
I think 'ppi_data' to be freed here?

>+		return ret;
[...]
>+
>+#endif /* AEST_H */
>--
>1.8.3.1

Thanks,
Shiju
Tyler Baicar July 10, 2019, 12:49 a.m. UTC | #5
Hello Shiju,

Thank you for the feedback!

On Thu, Jul 4, 2019 at 12:03 PM Shiju Jose <shiju.jose@huawei.com> wrote:
> >+struct ras_ext_regs {
> >+      u64 err_fr;
> >+      u64 err_ctlr;
> >+      u64 err_status;
> >+      u64 err_addr;
> >+      u64 err_misc0;
> >+      u64 err_misc1;
> >+      u64 err_misc2;
> >+      u64 err_misc3;
> err_misc2 and err_misc3 are not used. Are they for the future purpose?

Yes, these will be for future purpose once ARMv8.4 support is added. I'd like
to keep them in this structure define since that makes iterating through the
memory mapped error records easier. Regardless of ARMv8.2 or ARMv8.4 support,
each error record in memory mapped nodes are 64 bytes apart. Having these in
the structure make the structure 64 bytes long making it possible for me to
increment through error records with the increment ++ operation.

If folks don't agree with that, I can change this structure to just have a
reserved field at the end such as:

+ u64 res0[2];

or

+ u8 res0[8];


> >+      ppi_data = kcalloc(num_ppi, sizeof(struct aest_node_data *),
> >+                         GFP_KERNEL);
> >+
> >+      for (i = 0; i < num_ppi; i++) {
> >+              ppi_data[i] = alloc_percpu(struct aest_node_data);
> >+              if (!ppi_data[i]) {
> >+                      ret = -ENOMEM;
> >+                      break;
> >+              }
> >+      }
> >+
> >+      if (ret) {
> >+              pr_err("Failed percpu allocation\n");
> >+              for (i = 0; i < num_ppi; i++)
> >+                      free_percpu(ppi_data[i]);
> I think 'ppi_data' to be freed here?

Yes it should be! I'll add that in the next version.

Thanks,
Tyler
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/ras.h b/arch/arm64/include/asm/ras.h
new file mode 100644
index 0000000..36bfff4
--- /dev/null
+++ b/arch/arm64/include/asm/ras.h
@@ -0,0 +1,41 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_RAS_H
+#define __ASM_RAS_H
+
+#define ERR_STATUS_AV		BIT(31)
+#define ERR_STATUS_V		BIT(30)
+#define ERR_STATUS_UE		BIT(29)
+#define ERR_STATUS_ER		BIT(28)
+#define ERR_STATUS_OF		BIT(27)
+#define ERR_STATUS_MV		BIT(26)
+#define ERR_STATUS_CE_SHIFT	24
+#define ERR_STATUS_CE_MASK	0x3
+#define ERR_STATUS_DE		BIT(23)
+#define ERR_STATUS_PN		BIT(22)
+#define ERR_STATUS_UET_SHIFT	20
+#define ERR_STATUS_UET_MASK	0x3
+#define ERR_STATUS_IERR_SHIFT	8
+#define ERR_STATUS_IERR_MASK	0xff
+#define ERR_STATUS_SERR_SHIFT	0
+#define ERR_STATUS_SERR_MASK	0xff
+
+#define ERR_FR_CEC_SHIFT	12
+#define ERR_FR_CEC_MASK		0x7
+
+#define ERR_FR_8B_CEC		BIT(1)
+#define ERR_FR_16B_CEC		BIT(2)
+
+struct ras_ext_regs {
+	u64 err_fr;
+	u64 err_ctlr;
+	u64 err_status;
+	u64 err_addr;
+	u64 err_misc0;
+	u64 err_misc1;
+	u64 err_misc2;
+	u64 err_misc3;
+};
+
+void arch_arm_ras_report_error(void);
+
+#endif	/* __ASM_RAS_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 9e7dcb2..294f602 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -19,7 +19,7 @@  obj-y			:= debug-monitors.o entry.o irq.o fpsimd.o		\
 			   return_address.o cpuinfo.o cpu_errata.o		\
 			   cpufeature.o alternative.o cacheinfo.o		\
 			   smp.o smp_spin_table.o topology.o smccc-call.o	\
-			   syscall.o
+			   syscall.o ras.o
 
 extra-$(CONFIG_EFI)			:= efi-entry.o
 
diff --git a/arch/arm64/kernel/ras.c b/arch/arm64/kernel/ras.c
new file mode 100644
index 0000000..ca47efa
--- /dev/null
+++ b/arch/arm64/kernel/ras.c
@@ -0,0 +1,67 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+
+#include <asm/ras.h>
+
+void arch_arm_ras_report_error(void)
+{
+	u64 num_records;
+	unsigned int i, cpu_num;
+	bool fatal = false;
+	struct ras_ext_regs regs;
+
+	if (!this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
+		return;
+
+	cpu_num = get_cpu();
+	num_records = read_sysreg_s(SYS_ERRIDR_EL1);
+
+	for (i = 0; i < num_records; i++) {
+		write_sysreg_s(i, SYS_ERRSELR_EL1);
+		regs.err_status = read_sysreg_s(SYS_ERXSTATUS_EL1);
+
+		if (!(regs.err_status & ERR_STATUS_V))
+			continue;
+
+		pr_err("CPU%u: ERR%uSTATUS: 0x%llx\n", cpu_num, i,
+		       regs.err_status);
+
+		if (regs.err_status & ERR_STATUS_AV) {
+			regs.err_addr = read_sysreg_s(SYS_ERXSTATUS_EL1);
+			pr_err("CPU%u: ERR%uADDR: 0x%llx\n", cpu_num, i,
+			       regs.err_addr);
+		} else
+			regs.err_addr = 0;
+
+		regs.err_fr = read_sysreg_s(SYS_ERXFR_EL1);
+		pr_err("CPU%u: ERR%uFR: 0x%llx\n", cpu_num, i, regs.err_fr);
+		regs.err_ctlr = read_sysreg_s(SYS_ERXCTLR_EL1);
+		pr_err("CPU%u: ERR%uCTLR: 0x%llx\n", cpu_num, i, regs.err_ctlr);
+
+		if (regs.err_status & ERR_STATUS_MV) {
+			regs.err_misc0 = read_sysreg_s(SYS_ERXMISC0_EL1);
+			pr_err("CPU%u: ERR%uMISC0: 0x%llx\n", cpu_num, i,
+			       regs.err_misc0);
+			regs.err_misc1 = read_sysreg_s(SYS_ERXMISC1_EL1);
+			pr_err("CPU%u: ERR%uMISC1: 0x%llx\n", cpu_num, i,
+			       regs.err_misc1);
+		}
+
+		/*
+		 * In the future, we will treat UER conditions as potentially
+		 * recoverable.
+		 */
+		if (regs.err_status & ERR_STATUS_UE)
+			fatal = true;
+
+		write_sysreg_s(regs.err_status, SYS_ERXSTATUS_EL1);
+	}
+
+	if (fatal)
+		panic("uncorrectable error encountered");
+
+	put_cpu();
+}
diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
index 6dba187..8d5cf99 100644
--- a/drivers/acpi/arm64/Kconfig
+++ b/drivers/acpi/arm64/Kconfig
@@ -8,3 +8,6 @@  config ACPI_IORT
 
 config ACPI_GTDT
 	bool
+
+config ACPI_AEST
+	bool "ARM Error Source Table Support"
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
index 6ff50f4..ea1ba28 100644
--- a/drivers/acpi/arm64/Makefile
+++ b/drivers/acpi/arm64/Makefile
@@ -1,3 +1,4 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_ACPI_IORT) 	+= iort.o
 obj-$(CONFIG_ACPI_GTDT) 	+= gtdt.o
+obj-$(CONFIG_ACPI_AEST) 	+= aest.o
diff --git a/drivers/acpi/arm64/aest.c b/drivers/acpi/arm64/aest.c
new file mode 100644
index 0000000..fd4f3b5
--- /dev/null
+++ b/drivers/acpi/arm64/aest.c
@@ -0,0 +1,362 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/* ARM Error Source Table Support */
+
+#include <linux/acpi.h>
+#include <linux/acpi_aest.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/percpu.h>
+#include <linux/ratelimit.h>
+
+#include <asm/ras.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "ACPI AEST: " fmt
+
+static struct acpi_table_header *aest_table;
+
+static struct aest_node_data __percpu **ppi_data;
+static u8 num_ppi;
+static u8 ppi_idx;
+
+static void aest_print(struct aest_node_data *data, struct ras_ext_regs regs,
+		       int index)
+{
+	/* No more than 2 corrected messages every 5 seconds */
+	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
+
+	if (regs.err_status & ERR_STATUS_UE ||
+	    regs.err_status & ERR_STATUS_DE ||
+	    __ratelimit(&ratelimit_corrected)) {
+		switch (data->node_type) {
+		case AEST_NODE_TYPE_PROC:
+			pr_err("error from processor 0x%x\n",
+			       data->data.proc.id);
+			break;
+		case AEST_NODE_TYPE_MEM:
+			pr_err("error from memory domain 0x%x\n",
+			       data->data.mem.domain);
+			break;
+		case AEST_NODE_TYPE_VENDOR:
+			pr_err("error from vendor specific source 0x%x\n",
+			       data->data.vendor.id);
+		}
+
+		pr_err("ERR%dSTATUS = 0x%llx\n", index, regs.err_status);
+		if (regs.err_status & ERR_STATUS_AV)
+			pr_err("ERR%dADDR = 0x%llx\n", index, regs.err_addr);
+
+		pr_err("ERR%dFR = 0x%llx\n", index, regs.err_fr);
+		pr_err("ERR%dCTLR = 0x%llx\n", index, regs.err_ctlr);
+
+		if (regs.err_status & ERR_STATUS_MV) {
+			pr_err("ERR%dMISC0 = 0x%llx\n", index, regs.err_misc0);
+			pr_err("ERR%dMISC1 = 0x%llx\n", index, regs.err_misc1);
+		}
+	}
+}
+
+static void aest_proc(struct aest_node_data *data)
+{
+	struct ras_ext_regs *regs_p, regs;
+	int i;
+	bool fatal = false;
+
+	/*
+	 * Currently SR based handling is done through the architected
+	 * discovery exposed through SRs. That may change in the future
+	 * if there is supplemental information in the AEST that is
+	 * needed.
+	 */
+	if (data->interface.type == AEST_SYSTEM_REG_INTERFACE) {
+		arch_arm_ras_report_error();
+		return;
+	}
+
+	regs_p = data->interface.regs;
+
+	for (i = data->interface.start; i < data->interface.end; i++) {
+		regs.err_status = readq(&regs_p[i].err_status);
+		if (!(regs.err_status & ERR_STATUS_V))
+			continue;
+
+		if (regs.err_status & ERR_STATUS_AV)
+			regs.err_addr = readq(&regs_p[i].err_addr);
+		else
+			regs.err_addr = 0;
+
+		regs.err_fr = readq(&regs_p[i].err_fr);
+		regs.err_ctlr = readq(&regs_p[i].err_ctlr);
+
+		if (regs.err_status & ERR_STATUS_MV) {
+			regs.err_misc0 = readq(&regs_p[i].err_misc0);
+			regs.err_misc1 = readq(&regs_p[i].err_misc1);
+		} else {
+			regs.err_misc0 = 0;
+			regs.err_misc1 = 0;
+		}
+
+		aest_print(data, regs, i);
+
+		if (regs.err_status & ERR_STATUS_UE)
+			fatal = true;
+
+		writeq(regs.err_status, &regs_p[i].err_status);
+	}
+
+	if (fatal)
+		panic("AEST: uncorrectable error encountered");
+
+}
+
+static irqreturn_t aest_irq_func(int irq, void *input)
+{
+	struct aest_node_data *data = input;
+
+	aest_proc(data);
+
+	return IRQ_HANDLED;
+}
+
+static int __init aest_register_gsi(u32 gsi, int trigger, void *data)
+{
+	int cpu, irq;
+
+	irq = acpi_register_gsi(NULL, gsi, trigger, ACPI_ACTIVE_HIGH);
+
+	if (irq == -EINVAL) {
+		pr_err("failed to map AEST GSI %d\n", gsi);
+		return -EINVAL;
+	}
+
+	if (gsi < 16) {
+		pr_err("invalid GSI %d\n", gsi);
+		return -EINVAL;
+	} else if (gsi < 32) {
+		if (ppi_idx >= AEST_MAX_PPI) {
+			pr_err("Unable to register PPI %d\n", gsi);
+			return -EINVAL;
+		}
+		enable_percpu_irq(irq, IRQ_TYPE_NONE);
+		for_each_possible_cpu(cpu) {
+			memcpy(per_cpu_ptr(ppi_data[ppi_idx], cpu), data,
+			       sizeof(struct aest_node_data));
+		}
+		if (request_percpu_irq(irq, aest_irq_func, "AEST",
+				       ppi_data[ppi_idx++])) {
+			pr_err("failed to register AEST IRQ %d\n", irq);
+			return -EINVAL;
+		}
+	} else if (gsi < 1020) {
+		if (request_irq(irq, aest_irq_func, IRQF_SHARED, "AEST",
+				data)) {
+			pr_err("failed to register AEST IRQ %d\n", irq);
+			return -EINVAL;
+		}
+	} else {
+		pr_err("invalid GSI %d\n", gsi);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __init aest_init_interrupts(struct aest_type_header *node,
+				       struct aest_node_data *data)
+{
+	struct aest_interrupt *interrupt;
+	int i, trigger, ret = 0;
+
+	interrupt = ACPI_ADD_PTR(struct aest_interrupt, node,
+				 node->interrupt_offset);
+
+	for (i = 0; i < node->interrupt_size; i++, interrupt++) {
+		trigger = (interrupt->flags & AEST_INTERRUPT_MODE) ?
+			  ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
+		if (aest_register_gsi(interrupt->gsiv, trigger, data))
+			ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int __init aest_init_interface(struct aest_type_header *node,
+				       struct aest_node_data *data)
+{
+	struct aest_interface *interface;
+	struct resource *res;
+	int size;
+
+	interface = ACPI_ADD_PTR(struct aest_interface, node,
+				 node->interface_offset);
+
+	if (interface->type > AEST_MEMORY_MAPPED_INTERFACE) {
+		pr_err("invalid interface type: %d\n", interface->type);
+		return -EINVAL;
+	}
+
+	data->interface.type = interface->type;
+
+	/*
+	 * Currently SR based handling is done through the architected
+	 * discovery exposed through SRs. That may change in the future
+	 * if there is supplemental information in the AEST that is
+	 * needed.
+	 */
+	if (interface->type == AEST_SYSTEM_REG_INTERFACE)
+		return 0;
+
+	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
+	if (!res)
+		return -ENOMEM;
+
+	size = interface->num_records * sizeof(struct ras_ext_regs);
+	res->name = "AEST";
+	res->start = interface->address;
+	res->end = res->start + size;
+	res->flags = IORESOURCE_MEM;
+	if (request_resource_conflict(&iomem_resource, res)) {
+		pr_err("unable to request region starting at 0x%llx\n",
+			res->start);
+		kfree(res);
+		return -EEXIST;
+	}
+
+	data->interface.start = interface->start_index;
+	data->interface.end = interface->start_index + interface->num_records;
+
+	data->interface.regs = ioremap(interface->address, size);
+	if (data->interface.regs == NULL)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int __init aest_init_node(struct aest_type_header *node)
+{
+	struct aest_node_data *data;
+	union aest_node_spec *node_spec;
+	int ret;
+
+	data = kzalloc(sizeof(struct aest_node_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->node_type = node->type;
+
+	node_spec = ACPI_ADD_PTR(union aest_node_spec, node, node->data_offset);
+
+	switch (node->type) {
+	case AEST_NODE_TYPE_PROC:
+		memcpy(&data->data, node_spec, sizeof(struct aest_proc_data));
+		break;
+	case AEST_NODE_TYPE_MEM:
+		memcpy(&data->data, node_spec, sizeof(struct aest_mem_data));
+		break;
+	case AEST_NODE_TYPE_VENDOR:
+		memcpy(&data->data, node_spec, sizeof(struct aest_vendor_data));
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = aest_init_interface(node, data);
+	if (ret) {
+		kfree(data);
+		return ret;
+	}
+
+	return aest_init_interrupts(node, data);
+}
+
+static void aest_count_ppi(struct aest_type_header *node)
+{
+	struct aest_interrupt *interrupt;
+	int i;
+
+	interrupt = ACPI_ADD_PTR(struct aest_interrupt, node,
+				 node->interrupt_offset);
+
+	for (i = 0; i < node->interrupt_size; i++, interrupt++) {
+		if (interrupt->gsiv >= 16 && interrupt->gsiv < 32)
+			num_ppi++;
+	}
+
+}
+
+int __init acpi_aest_init(void)
+{
+	struct acpi_table_aest *aest;
+	struct aest_type_header *aest_node, *aest_end;
+	int i, ret = 0;
+
+	if (acpi_disabled)
+		return 0;
+
+	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_AEST, 0, &aest_table)))
+		return -EINVAL;
+
+	aest = (struct acpi_table_aest *)aest_table;
+
+	/* Get the first AEST node */
+	aest_node = ACPI_ADD_PTR(struct aest_type_header, aest,
+				 sizeof(struct acpi_table_aest));
+	/* Pointer to the end of the AEST table */
+	aest_end = ACPI_ADD_PTR(struct aest_type_header, aest,
+				aest_table->length);
+
+	while (aest_node < aest_end) {
+		if (((u64)aest_node + aest_node->length) > (u64)aest_end) {
+			pr_err("AEST node pointer overflow, bad table\n");
+			return -EINVAL;
+		}
+
+		aest_count_ppi(aest_node);
+
+		aest_node = ACPI_ADD_PTR(struct aest_type_header, aest_node,
+					 aest_node->length);
+	}
+
+	if (num_ppi > AEST_MAX_PPI) {
+		pr_err("Limiting PPI support to %d PPIs\n", AEST_MAX_PPI);
+		num_ppi = AEST_MAX_PPI;
+	}
+
+	ppi_data = kcalloc(num_ppi, sizeof(struct aest_node_data *),
+			   GFP_KERNEL);
+
+	for (i = 0; i < num_ppi; i++) {
+		ppi_data[i] = alloc_percpu(struct aest_node_data);
+		if (!ppi_data[i]) {
+			ret = -ENOMEM;
+			break;
+		}
+	}
+
+	if (ret) {
+		pr_err("Failed percpu allocation\n");
+		for (i = 0; i < num_ppi; i++)
+			free_percpu(ppi_data[i]);
+		return ret;
+	}
+
+	aest_node = ACPI_ADD_PTR(struct aest_type_header, aest,
+				 sizeof(struct acpi_table_aest));
+
+	while (aest_node < aest_end) {
+		ret = aest_init_node(aest_node);
+		if (ret)
+			pr_err("failed to init node: %d", ret);
+
+		aest_node = ACPI_ADD_PTR(struct aest_type_header, aest_node,
+					 aest_node->length);
+	}
+
+	return 0;
+}
+
+early_initcall(acpi_aest_init);
diff --git a/include/linux/acpi_aest.h b/include/linux/acpi_aest.h
new file mode 100644
index 0000000..376122b
--- /dev/null
+++ b/include/linux/acpi_aest.h
@@ -0,0 +1,94 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef AEST_H
+#define AEST_H
+
+#include <acpi/actbl.h>
+
+#define ACPI_SIG_AEST			"AEST"	/* ARM Error Source Table */
+
+#define AEST_NODE_TYPE_PROC		0
+#define AEST_NODE_TYPE_MEM		1
+#define AEST_NODE_TYPE_VENDOR		2
+
+#define AEST_SYSTEM_REG_INTERFACE	0x0
+#define AEST_MEMORY_MAPPED_INTERFACE	0x1
+
+#define AEST_INTERRUPT_MODE		BIT(0)
+
+#define AEST_MAX_PPI			4
+
+#pragma pack(1)
+
+struct acpi_table_aest {
+	struct acpi_table_header header;
+};
+
+struct aest_type_header {
+	u8 type;
+	u16 length;
+	u8 reserved;
+	u32 revision;
+	u32 data_offset;
+	u32 interface_offset;
+	u32 interface_size;
+	u32 interrupt_offset;
+	u32 interrupt_size;
+	u64 timestamp_rate;
+	u64 timestamp_start;
+	u64 countdown_rate;
+};
+
+struct aest_proc_data {
+	u32 id;
+	u32 level;
+	u32 cache_type;
+};
+
+struct aest_mem_data {
+	u32 domain;
+};
+
+struct aest_vendor_data {
+	u32 id;
+	u32 data;
+};
+
+struct aest_interface {
+	u8 type;
+	u8 reserved[3];
+	u32 flags;
+	u64 address;
+	u16 start_index;
+	u16 num_records;
+};
+
+struct aest_interrupt {
+	u8 type;
+	u16 reserved;
+	u8 flags;
+	u32 gsiv;
+	u8 iort_id[20];
+};
+
+#pragma pack()
+
+struct aest_interface_data {
+	u8 type;
+	u16 start;
+	u16 end;
+	struct ras_ext_regs *regs;
+};
+
+union aest_node_spec {
+	struct aest_proc_data proc;
+	struct aest_mem_data mem;
+	struct aest_vendor_data vendor;
+};
+
+struct aest_node_data {
+	u8 node_type;
+	struct aest_interface_data interface;
+	union aest_node_spec data;
+};
+
+#endif /* AEST_H */