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Message-ID: <0f0e88a3-a617-408f-8f1a-3af7a0f99337@linux.alibaba.com>
Date: Thu, 21 Mar 2024 11:52:36 +0800
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MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v2 1/2] ACPI/AEST: Initial AEST driver
To: Ruidong Tian <tianruidong@linux.alibaba.com>, catalin.marinas@arm.com,
 will@kernel.org, lpieralisi@kernel.org, guohanjun@huawei.com,
 sudeep.holla@arm.com, xueshuai@linux.alibaba.com,
 linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, rafael@kernel.org, lenb@kernel.org,
 tony.luck@intel.com, bp@alien8.de, linux-edac@vger.kernel.org
Cc: tianruidond@linux.alibaba.com,
 Tyler Baicar <baicar@os.amperecomputing.com>
References: <20240321025317.114621-1-tianruidong@linux.alibaba.com>
 <20240321025317.114621-2-tianruidong@linux.alibaba.com>
From: Baolin Wang <baolin.wang@linux.alibaba.com>
In-Reply-To: <20240321025317.114621-2-tianruidong@linux.alibaba.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
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On 2024/3/21 10:53, Ruidong Tian wrote:
> From: Tyler Baicar <baicar@os.amperecomputing.com>
> 
> Add support for parsing the ARM Error Source Table and basic handling of
> errors reported through both memory mapped and system register interfaces.
> 
> Assume system register interfaces are only registered with private
> peripheral interrupts (PPIs); otherwise there is no guarantee the
> core handling the error is the core which took the error and has the
> syndrome info in its system registers.
> 
> In kernel-first mode, all configuration is controlled by kernel, include
> CE ce_threshold and interrupt enable/disable.
> 
> All detected errors will be processed as follow:
>    - CE, DE: use a workqueue to log this hardware errors.
>    - UER, UEO: log it and call memory_failure in workquee.
>    - UC, UEU: panic in irq context.
> 
> Signed-off-by: Tyler Baicar <baicar@os.amperecomputing.com>
> Signed-off-by: Ruidong Tian <tianruidong@linux.alibaba.com>
> ---
>   MAINTAINERS                  |  11 +
>   arch/arm64/include/asm/ras.h |  71 +++
>   drivers/acpi/arm64/Kconfig   |  10 +
>   drivers/acpi/arm64/Makefile  |   1 +
>   drivers/acpi/arm64/aest.c    | 834 +++++++++++++++++++++++++++++++++++
>   include/linux/acpi_aest.h    |  92 ++++
>   include/linux/cpuhotplug.h   |   1 +
>   7 files changed, 1020 insertions(+)
>   create mode 100644 arch/arm64/include/asm/ras.h
>   create mode 100644 drivers/acpi/arm64/aest.c
>   create mode 100644 include/linux/acpi_aest.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index dd5de540ec0b..34900d4bb677 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -330,6 +330,17 @@ L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
>   S:	Maintained
>   F:	drivers/acpi/arm64
>   
> +ACPI AEST
> +M:	Tyler Baicar <baicar@os.amperecomputing.com>
> +M:	Ruidong Tian <tianruidond@linux.alibaba.com>
> +L:	linux-acpi@vger.kernel.org
> +L:	linux-arm-kernel@lists.infradead.org
> +S:	Supported
> +F:	arch/arm64/include/asm/ras.h
> +F:	drivers/acpi/arm64/aest.c
> +F:	include/linux/acpi_aest.h
> +
> +
>   ACPI FOR RISC-V (ACPI/riscv)
>   M:	Sunil V L <sunilvl@ventanamicro.com>
>   L:	linux-acpi@vger.kernel.org
> diff --git a/arch/arm64/include/asm/ras.h b/arch/arm64/include/asm/ras.h
> new file mode 100644
> index 000000000000..04667f0de30f
> --- /dev/null
> +++ b/arch/arm64/include/asm/ras.h
> @@ -0,0 +1,71 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ASM_RAS_H
> +#define __ASM_RAS_H
> +
> +#include <linux/types.h>
> +#include <linux/bits.h>
> +
> +/* ERR<n>FR */
> +#define ERR_FR_RP                      BIT(15)
> +#define ERR_FR_CEC                     GENMASK_ULL(14, 12)
> +
> +#define ERR_FR_RP_SINGLE_COUNTER       0
> +#define ERR_FR_RP_DOUBLE_COUNTER       1
> +
> +#define ERR_FR_CEC_0B_COUNTER          0
> +#define ERR_FR_CEC_8B_COUNTER          BIT(1)
> +#define ERR_FR_CEC_16B_COUNTER         BIT(2)
> +
> +/* ERR<n>STATUS */
> +#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		(BIT(25) | BIT(24))
> +#define ERR_STATUS_DE		BIT(23)
> +#define ERR_STATUS_PN		BIT(22)
> +#define ERR_STATUS_UET		(BIT(21) | BIT(20))
> +#define ERR_STATUS_CI		BIT(19)
> +#define ERR_STATUS_IERR		GENMASK_ULL(15, 8)
> +#define ERR_STATUS_SERR		GENMASK_ULL(7, 0)
> +
> +/* These bit is write-one-to-clear */
> +#define ERR_STATUS_W1TC		(ERR_STATUS_AV | ERR_STATUS_V | ERR_STATUS_UE | \
> +				ERR_STATUS_ER | ERR_STATUS_OF | ERR_STATUS_MV | \
> +				ERR_STATUS_CE | ERR_STATUS_DE | ERR_STATUS_PN | \
> +				ERR_STATUS_UET | ERR_STATUS_CI)
> +
> +#define ERR_STATUS_UET_UC	0
> +#define ERR_STATUS_UET_UEU	1
> +#define ERR_STATUS_UET_UER	2
> +#define ERR_STATUS_UET_UEO	3
> +
> +/* ERR<n>CTLR */
> +#define ERR_CTLR_FI		BIT(3)
> +#define ERR_CTLR_UI		BIT(2)
> +
> +/* ERR<n>ADDR */
> +#define ERR_ADDR_AI		BIT(61)
> +#define ERR_ADDR_PADDR		GENMASK_ULL(55, 0)
> +
> +/* ERR<n>MISC0 */
> +
> +/* ERR<n>FR.CEC == 0b010, ERR<n>FR.RP == 0  */
> +#define ERR_MISC0_8B_OF		BIT(39)
> +#define ERR_MISC0_8B_CEC	GENMASK_ULL(38, 32)
> +
> +/* ERR<n>FR.CEC == 0b100, ERR<n>FR.RP == 0  */
> +#define ERR_MISC0_16B_OF	BIT(47)
> +#define ERR_MISC0_16B_CEC	GENMASK_ULL(46, 32)
> +
> +struct ras_ext_regs {
> +	u64 err_fr;
> +	u64 err_ctlr;
> +	u64 err_status;
> +	u64 err_addr;
> +	u64 err_misc[4];
> +};
> +
> +#endif	/* __ASM_RAS_H */
> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> index b3ed6212244c..639db671c5cf 100644
> --- a/drivers/acpi/arm64/Kconfig
> +++ b/drivers/acpi/arm64/Kconfig
> @@ -21,3 +21,13 @@ config ACPI_AGDI
>   
>   config ACPI_APMT
>   	bool
> +
> +config ACPI_AEST
> +	bool "ARM Error Source Table Support"
> +
> +	help
> +	  The Arm Error Source Table (AEST) provides details on ACPI
> +	  extensions that enable kernel-first handling of errors in a
> +	  system that supports the Armv8 RAS extensions.
> +
> +	  If set, the kernel will report and log hardware errors.
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> index 143debc1ba4a..b5b740058c46 100644
> --- a/drivers/acpi/arm64/Makefile
> +++ b/drivers/acpi/arm64/Makefile
> @@ -5,3 +5,4 @@ obj-$(CONFIG_ACPI_GTDT) 	+= gtdt.o
>   obj-$(CONFIG_ACPI_APMT) 	+= apmt.o
>   obj-$(CONFIG_ARM_AMBA)		+= amba.o
>   obj-y				+= dma.o init.o
> +obj-$(CONFIG_ACPI_AEST) 	+= aest.o
> diff --git a/drivers/acpi/arm64/aest.c b/drivers/acpi/arm64/aest.c
> new file mode 100644
> index 000000000000..ab17aa5f5997
> --- /dev/null
> +++ b/drivers/acpi/arm64/aest.c
> @@ -0,0 +1,834 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ARM Error Source Table Support
> + *
> + * Copyright (c) 2021, Ampere Computing LLC
> + * Copyright (c) 2021-2024, Alibaba Group.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/acpi_aest.h>
> +#include <linux/cpuhotplug.h>
> +#include <linux/kernel.h>
> +#include <linux/genalloc.h>
> +#include <linux/llist.h>
> +#include <acpi/actbl.h>
> +#include <asm/ras.h>
> +
> +#undef pr_fmt
> +#define pr_fmt(fmt) "ACPI AEST: " fmt
> +
> +#define CASE_READ(res, x)						\
> +	case (x): {							\
> +		res = read_sysreg_s(SYS_##x##_EL1);			\
> +		break;							\
> +	}
> +
> +#define CASE_WRITE(val, x)						\
> +	case (x): {							\
> +		write_sysreg_s((val), SYS_##x##_EL1);			\
> +		break;							\
> +	}
> +
> +#define for_each_implemented_record(index, node)			\
> +		for ((index) = node->interface.record_start;		\
> +			(index) < node->interface.record_end;		\
> +			(index)++)
> +
> +#define AEST_LOG_PREFIX_BUFFER	64
> +
> +/*
> + * This memory pool is only to be used to save AEST node in AEST irq context.
> + * There can be 500 AEST node at most.
> + */
> +#define AEST_NODE_ALLOCED_MAX	500
> +
> +static struct acpi_table_header *aest_table;
> +
> +static struct aest_node __percpu **aest_ppi_data;
> +
> +static int *ppi_irqs;
> +static u8 num_ppi;
> +static u8 ppi_idx;
> +
> +static struct work_struct aest_work;
> +
> +static struct gen_pool *aest_node_pool;
> +static struct llist_head aest_node_llist;
> +
> +static u64 aest_sysreg_read(u64 __unused, u32 offset)
> +{
> +	u64 res;
> +
> +	switch (offset) {
> +	CASE_READ(res, ERXFR)
> +	CASE_READ(res, ERXCTLR)
> +	CASE_READ(res, ERXSTATUS)
> +	CASE_READ(res, ERXADDR)
> +	CASE_READ(res, ERXMISC0)
> +	CASE_READ(res, ERXMISC1)
> +	CASE_READ(res, ERXMISC2)
> +	CASE_READ(res, ERXMISC3)
> +	default :
> +		res = 0;
> +	}
> +	return res;
> +}
> +
> +static void aest_sysreg_write(u64 base, u32 offset, u64 val)
> +{
> +	switch (offset) {
> +	CASE_WRITE(val, ERXFR)
> +	CASE_WRITE(val, ERXCTLR)
> +	CASE_WRITE(val, ERXSTATUS)
> +	CASE_WRITE(val, ERXADDR)
> +	CASE_WRITE(val, ERXMISC0)
> +	CASE_WRITE(val, ERXMISC1)
> +	CASE_WRITE(val, ERXMISC2)
> +	CASE_WRITE(val, ERXMISC3)
> +	default :
> +		return;
> +	}
> +}
> +
> +static u64 aest_iomem_read(u64 base, u32 offset)
> +{
> +	return readq_relaxed((void *)(base + offset));
> +}
> +
> +static void aest_iomem_write(u64 base, u32 offset, u64 val)
> +{
> +	writeq_relaxed(val, (void *)(base + offset));
> +}
> +
> +static void aest_print(struct aest_node_llist *lnode)
> +{
> +	static atomic_t seqno = { 0 };
> +	unsigned int curr_seqno;
> +	char pfx_seq[AEST_LOG_PREFIX_BUFFER];
> +	int index;
> +	struct ras_ext_regs *regs;
> +
> +	curr_seqno = atomic_inc_return(&seqno);
> +	snprintf(pfx_seq, sizeof(pfx_seq), "{%u}" HW_ERR, curr_seqno);
> +	pr_info("%sHardware error from %s\n", pfx_seq, lnode->node_name);
> +
> +	switch (lnode->type) {
> +	case ACPI_AEST_PROCESSOR_ERROR_NODE:
> +		pr_err("%s Error from CPU%d\n", pfx_seq, lnode->id0);
> +		break;
> +	case ACPI_AEST_MEMORY_ERROR_NODE:
> +		pr_err("%s Error from memory at SRAT proximity domain 0x%x\n",
> +			pfx_seq, lnode->id0);
> +		break;
> +	case ACPI_AEST_SMMU_ERROR_NODE:
> +		pr_err("%s Error from SMMU IORT node 0x%x subcomponent 0x%x\n",
> +			pfx_seq, lnode->id0, lnode->id1);
> +		break;
> +	case ACPI_AEST_VENDOR_ERROR_NODE:
> +		pr_err("%s Error from vendor hid 0x%x uid 0x%x\n",
> +			pfx_seq, lnode->id0, lnode->id1);
> +		break;
> +	case ACPI_AEST_GIC_ERROR_NODE:
> +		pr_err("%s Error from GIC type 0x%x instance 0x%x\n",
> +			pfx_seq, lnode->id0, lnode->id1);
> +		break;
> +	default:
> +		pr_err("%s Unknown AEST node type\n", pfx_seq);
> +		return;
> +	}
> +
> +	index = lnode->index;
> +	regs = lnode->regs;
> +
> +	pr_err("%s  ERR%uFR: 0x%llx\n", pfx_seq, index, regs->err_fr);
> +	pr_err("%s  ERR%uCTRL: 0x%llx\n", pfx_seq, index, regs->err_ctlr);
> +	pr_err("%s  ERR%uSTATUS: 0x%llx\n", pfx_seq, index, regs->err_status);
> +	if (regs->err_status & ERR_STATUS_AV)
> +		pr_err("%s  ERR%uADDR: 0x%llx\n", pfx_seq, index, regs->err_addr);
> +
> +	if (regs->err_status & ERR_STATUS_MV) {
> +		pr_err("%s  ERR%uMISC0: 0x%llx\n", pfx_seq, index, regs->err_misc[0]);
> +		pr_err("%s  ERR%uMISC1: 0x%llx\n", pfx_seq, index, regs->err_misc[1]);
> +		pr_err("%s  ERR%uMISC2: 0x%llx\n", pfx_seq, index, regs->err_misc[2]);
> +		pr_err("%s  ERR%uMISC3: 0x%llx\n", pfx_seq, index, regs->err_misc[3]);
> +	}
> +}
> +
> +static void aest_handle_memory_failure(struct aest_node_llist *lnode)
> +{
> +	unsigned long pfn;
> +	u64 addr;
> +
> +	if (test_bit(lnode->index, &lnode->addressing_mode) ||
> +		(lnode->regs->err_addr & ERR_ADDR_AI))
> +		return;
> +
> +	addr = lnode->regs->err_addr & (1UL << CONFIG_ARM64_PA_BITS);
> +	pfn = PHYS_PFN(addr);
> +
> +	if (!pfn_valid(pfn)) {
> +		pr_warn(HW_ERR "Invalid physical address: %#llx\n", addr);
> +		return;
> +	}
> +
> +	memory_failure(pfn, 0);
> +}
> +
> +static void aest_node_pool_process(struct work_struct *__unused)
> +{
> +	struct llist_node *head;
> +	struct aest_node_llist *lnode, *tmp;
> +	u64 status;
> +
> +	head = llist_del_all(&aest_node_llist);
> +	if (!head)
> +		return;
> +
> +	head = llist_reverse_order(head);
> +	llist_for_each_entry_safe(lnode, tmp, head, llnode) {
> +		aest_print(lnode);
> +
> +		status = lnode->regs->err_status;
> +		if ((status & ERR_STATUS_UE) &&
> +			(status & ERR_STATUS_UET) > ERR_STATUS_UET_UEU)
> +			aest_handle_memory_failure(lnode);
> +		gen_pool_free(aest_node_pool, (unsigned long)lnode,
> +				sizeof(*lnode));
> +	}
> +}
> +
> +static int aest_node_gen_pool_add(struct aest_node *node, int index,
> +				struct ras_ext_regs *regs)
> +{
> +	struct aest_node_llist *list;
> +
> +	if (!aest_node_pool)
> +		return -EINVAL;
> +
> +	list = (void *)gen_pool_alloc(aest_node_pool, sizeof(*list));
> +	if (!list)
> +		return -ENOMEM;
> +
> +	list->type = node->type;
> +	list->node_name = node->name;
> +	switch (node->type) {
> +	case ACPI_AEST_PROCESSOR_ERROR_NODE:
> +		list->id0 = node->spec.processor.processor_id;
> +		if (node->spec.processor.flags & (ACPI_AEST_PROC_FLAG_SHARED |
> +						ACPI_AEST_PROC_FLAG_GLOBAL))
> +			list->id0 = smp_processor_id();
> +
> +		list->id1 = node->spec.processor.resource_type;
> +		break;
> +	case ACPI_AEST_MEMORY_ERROR_NODE:
> +		list->id0 = node->spec.memory.srat_proximity_domain;
> +		break;
> +	case ACPI_AEST_SMMU_ERROR_NODE:
> +		list->id0 = node->spec.smmu.iort_node_reference;
> +		list->id1 = node->spec.smmu.subcomponent_reference;
> +		break;
> +	case ACPI_AEST_VENDOR_ERROR_NODE:
> +		list->id0 = node->spec.vendor.acpi_hid;
> +		list->id1 = node->spec.vendor.acpi_uid;
> +		break;
> +	case ACPI_AEST_GIC_ERROR_NODE:
> +		list->id0 = node->spec.gic.interface_type;
> +		list->id1 = node->spec.gic.instance_id;
> +		break;
> +	default:
> +		list->id0 = 0;
> +		list->id1 = 0;
> +	}
> +
> +	list->regs =  regs;
> +	list->index = index;
> +	list->addressing_mode = node->interface.addressing_mode;
> +	llist_add(&list->llnode, &aest_node_llist);
> +
> +	return 0;
> +}
> +
> +static int aest_node_pool_init(void)
> +{
> +	unsigned long addr, size;
> +	int rc;
> +
> +	if (aest_node_pool)
> +		return 0;
> +
> +	size = ilog2(sizeof(struct aest_node_llist));
> +	aest_node_pool = gen_pool_create(size, -1);
> +	if (!aest_node_pool)
> +		return -ENOMEM;
> +
> +	addr = (unsigned long)vmalloc(PAGE_ALIGN(size * AEST_NODE_ALLOCED_MAX));
> +	if (!addr)
> +		goto err_pool_alloc;
> +
> +	rc = gen_pool_add(aest_node_pool, addr, size, -1);
> +	if (rc)
> +		goto err_pool_add;
> +
> +	return 0;
> +
> +err_pool_add:
> +	vfree((void *)addr);
> +
> +err_pool_alloc:
> +	gen_pool_destroy(aest_node_pool);
> +
> +	return -ENOMEM;
> +}
> +
> +static void aest_log(struct aest_node *node, int index, struct ras_ext_regs *regs)
> +{
> +	if (!aest_node_gen_pool_add(node, index, regs))
> +		schedule_work(&aest_work);
> +}
> +
> +/*
> + * Each PE may has multi error record, you must selects an error record to
> + * be accessed through the Error Record System registers.
> + */
> +static inline void aest_select_record(struct aest_node *node, int i)
> +{
> +	if (node->interface.type == ACPI_AEST_NODE_SYSTEM_REGISTER) {
> +		write_sysreg_s(i, SYS_ERRSELR_EL1);
> +		isb();
> +	}
> +}
> +
> +/* Ensure all writes has taken effect. */
> +static inline void aest_sync(struct aest_node *node)
> +{
> +	if (node->interface.type == ACPI_AEST_NODE_SYSTEM_REGISTER)
> +		isb();
> +}
> +
> +static int aest_proc(struct aest_node *node)
> +{
> +	struct ras_ext_regs regs = {0};
> +	struct aest_access *access;
> +	int i, count = 0;
> +	u64 regs_p;
> +
> +	for_each_implemented_record(i, node) {
> +
> +		/* 1b: Error record at i index is not implemented */
> +		if (test_bit(i, &node->interface.record_implemented))
> +			continue;
> +
> +		aest_select_record(node, i);
> +
> +		access = node->access;
> +		regs_p = (u64)&node->interface.regs[i];
> +
> +		regs.err_status = access->read(regs_p, ERXSTATUS);
> +		if (!(regs.err_status & ERR_STATUS_V))
> +			continue;
> +
> +		count++;
> +
> +		if (regs.err_status & ERR_STATUS_AV)
> +			regs.err_addr = access->read(regs_p, ERXADDR);
> +
> +		regs.err_fr = access->read(regs_p, ERXFR);
> +		regs.err_ctlr = access->read(regs_p, ERXCTLR);
> +
> +		if (regs.err_status & ERR_STATUS_MV) {
> +			regs.err_misc[0] = access->read(regs_p, ERXMISC0);
> +			regs.err_misc[1] = access->read(regs_p, ERXMISC1);
> +			regs.err_misc[2] = access->read(regs_p, ERXMISC2);
> +			regs.err_misc[3] = access->read(regs_p, ERXMISC3);
> +		}
> +
> +		if (node->interface.flags & ACPI_AEST_INTERFACE_CLEAR_MISC) {
> +			access->write(regs_p, ERXMISC0, 0);
> +			access->write(regs_p, ERXMISC1, 0);
> +			access->write(regs_p, ERXMISC2, 0);
> +			access->write(regs_p, ERXMISC3, 0);
> +		} else
> +			access->write(regs_p, ERXMISC0,
> +					node->interface.ce_threshold[i]);
> +
> +		aest_log(node, i, &regs);
> +
> +		/* panic if unrecoverable and uncontainable error encountered */
> +		if ((regs.err_status & ERR_STATUS_UE) &&
> +			(regs.err_status & ERR_STATUS_UET) < ERR_STATUS_UET_UER)
> +			panic("AEST: unrecoverable error encountered");
> +
> +		/* Write-one-to-clear the bits we've seen */
> +		regs.err_status &= ERR_STATUS_W1TC;
> +
> +		/* Multi bit filed need to write all-ones to clear. */
> +		if (regs.err_status & ERR_STATUS_CE)
> +			regs.err_status |= ERR_STATUS_CE;
> +
> +		/* Multi bit filed need to write all-ones to clear. */
> +		if (regs.err_status & ERR_STATUS_UET)
> +			regs.err_status |= ERR_STATUS_UET;
> +
> +		access->write(regs_p, ERXSTATUS, regs.err_status);
> +
> +		aest_sync(node);
> +	}
> +
> +	return count;
> +}
> +
> +static irqreturn_t aest_irq_func(int irq, void *input)
> +{
> +	struct aest_node *node = input;
> +
> +	if (aest_proc(node))
> +		return IRQ_HANDLED;
> +
> +	return IRQ_NONE;
> +}
> +
> +static int __init aest_register_gsi(u32 gsi, int trigger, void *data,
> +					irq_handler_t aest_irq_func)
> +{
> +	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;
> +	}

IMO, should be:
if (irq < 0) {
	pr_err("failed to map AEST GSI %d\n", gsi);
	return irq;
}

> +
> +	if (irq_is_percpu_devid(irq)) {
> +		ppi_irqs[ppi_idx] = irq;
> +		for_each_possible_cpu(cpu) {
> +			memcpy(per_cpu_ptr(aest_ppi_data[ppi_idx], cpu), data,
> +			       sizeof(struct aest_node));
> +		}
> +		if (request_percpu_irq(irq, aest_irq_func, "AEST",
> +				       aest_ppi_data[ppi_idx++])) {
> +			pr_err("failed to register AEST IRQ %d\n", irq);
> +			return -EINVAL;

Do not override the error number.

> +		}
> +	} else {
> +		if (request_irq(irq, aest_irq_func, IRQF_SHARED, "AEST",
> +				data)) {
> +			pr_err("failed to register AEST IRQ %d\n", irq);
> +			return -EINVAL;

ditto.

> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int __init aest_init_interrupts(struct acpi_aest_hdr *hdr,
> +				       struct aest_node *node)
> +{
> +	struct acpi_aest_node_interrupt *interrupt;
> +	int i, trigger, ret = 0, err_ctlr, regs_p;
> +
> +	interrupt = ACPI_ADD_PTR(struct acpi_aest_node_interrupt, hdr,
> +				 hdr->node_interrupt_offset);
> +
> +	for (i = 0; i < hdr->node_interrupt_count; i++, interrupt++) {
> +		trigger = (interrupt->flags & AEST_INTERRUPT_MODE) ?
> +			  ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
> +		if (aest_register_gsi(interrupt->gsiv, trigger, node,
> +					aest_irq_func))
> +			ret = -EINVAL;

Do not override the error number.

> +	}
> +
> +	/* Ensure RAS interrupt is enabled */
> +	for_each_implemented_record(i, node) {
> +		/* 1b: Error record at i index is not implemented */
> +		if (test_bit(i, &node->interface.record_implemented))
> +			continue;
> +
> +		aest_select_record(node, i);
> +
> +		regs_p = (u64)&node->interface.regs[i];
> +
> +		err_ctlr = node->access->read(regs_p, ERXCTLR);
> +
> +		if (interrupt->type == ACPI_AEST_NODE_FAULT_HANDLING)
> +			err_ctlr |= ERR_CTLR_FI;
> +		if (interrupt->type == ACPI_AEST_NODE_ERROR_RECOVERY)
> +			err_ctlr |= ERR_CTLR_UI;
> +
> +		node->access->write(regs_p, ERXCTLR, err_ctlr);
> +
> +		aest_sync(node);
> +	}
> +
> +	return ret;
> +}
> +
> +static void __init set_aest_node_name(struct aest_node *node)
> +{
> +	switch (node->type) {
> +	case ACPI_AEST_PROCESSOR_ERROR_NODE:
> +		node->name = kasprintf(GFP_KERNEL, "AEST-CPU%d",
> +			node->spec.processor.processor_id);
> +		break;
> +	case ACPI_AEST_MEMORY_ERROR_NODE:
> +	case ACPI_AEST_SMMU_ERROR_NODE:
> +	case ACPI_AEST_VENDOR_ERROR_NODE:
> +	case ACPI_AEST_GIC_ERROR_NODE:
> +		node->name = kasprintf(GFP_KERNEL, "AEST-%llx",
> +			node->interface.phy_addr);
> +		break;
> +	default:
> +		node->name = kasprintf(GFP_KERNEL, "AEST-Unkown-Node");

IMO, better to check the return value for memory allocation.

> +	}
> +}
> +
> +/* access type is decided by AEST interface type. */
> +static struct aest_access aest_access[] = {
> +	[ACPI_AEST_NODE_SYSTEM_REGISTER] = {
> +		.read = aest_sysreg_read,
> +		.write = aest_sysreg_write,
> +	},
> +
> +	[ACPI_AEST_NODE_MEMORY_MAPPED] = {
> +		.read = aest_iomem_read,
> +		.write = aest_iomem_write,
> +	},
> +	{ }
> +};
> +
> +/* In kernel-first mode, kernel will report every CE by default. */
> +static void __init aest_set_ce_threshold(struct aest_node *node)
> +{
> +	u64 regs_p, err_fr, err_fr_cec, err_fr_rp, err_misc0, ce_threshold;
> +	int i;
> +
> +	for_each_implemented_record(i, node) {
> +		/* 1b: Error record at i index is not implemented */
> +		if (test_bit(i, &node->interface.record_implemented))
> +			continue;
> +
> +		aest_select_record(node, i);
> +		regs_p = (u64)&node->interface.regs[i];
> +
> +		err_fr = node->access->read(regs_p, ERXFR);
> +		err_fr_cec = FIELD_GET(ERR_FR_CEC, err_fr);
> +		err_fr_rp = FIELD_GET(ERR_FR_RP, err_fr);
> +		err_misc0 = node->access->read(regs_p, ERXMISC0);
> +
> +		if (err_fr_cec == ERR_FR_CEC_0B_COUNTER)
> +			pr_debug("%s-%d do not support CE threshold!\n",
> +					node->name, i);
> +		else if (err_fr_cec == ERR_FR_CEC_8B_COUNTER &&
> +				err_fr_rp == ERR_FR_RP_SINGLE_COUNTER) {
> +			pr_debug("%s-%d support 8 bit CE threshold!\n",
> +					node->name, i);
> +			ce_threshold = err_misc0 | ERR_MISC0_8B_CEC;
> +		} else if (err_fr_cec == ERR_FR_CEC_16B_COUNTER &&
> +				err_fr_rp == ERR_FR_RP_SINGLE_COUNTER) {
> +			pr_debug("%s-%d support 16 bit CE threshold!\n",
> +					node->name, i);
> +			ce_threshold = err_misc0 | ERR_MISC0_16B_CEC;
> +		} else
> +			pr_debug("%s-%d do not support double counter yet!\n",
> +					node->name, i);

Change to 'switch' statement will be more readable.

> +
> +		node->access->write(regs_p, ERXMISC0, ce_threshold);
> +		node->interface.ce_threshold[i] = ce_threshold;
> +
> +		aest_sync(node);
> +	}
> +}
> +
> +static int __init aest_init_interface(struct acpi_aest_hdr *hdr,
> +				       struct aest_node *node)
> +{
> +	struct acpi_aest_node_interface *interface;
> +	struct resource *res;
> +	int size;
> +
> +	interface = ACPI_ADD_PTR(struct acpi_aest_node_interface, hdr,
> +				 hdr->node_interface_offset);
> +
> +	if (interface->type >= ACPI_AEST_XFACE_RESERVED) {
> +		pr_err("invalid interface type: %d\n", interface->type);
> +		return -EINVAL;
> +	}
> +
> +	node->interface.type = interface->type;
> +	node->interface.phy_addr = interface->address;
> +	node->interface.record_start = interface->error_record_index;
> +	node->interface.record_end = interface->error_record_index +
> +					interface->error_record_count;
> +	node->interface.flags = interface->flags;
> +	node->interface.record_implemented = interface->error_record_implemented;
> +	node->interface.status_reporting = interface->error_status_reporting;
> +	node->interface.addressing_mode = interface->addressing_mode;
> +	node->access = &aest_access[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 == ACPI_AEST_NODE_SYSTEM_REGISTER)
> +		return 0;
> +
> +	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
> +	if (!res)
> +		return -ENOMEM;
> +
> +	size = interface->error_record_count * sizeof(struct ras_ext_regs);
> +	res->name = "AEST";
> +	res->start = interface->address;
> +	res->end = res->start + size;
> +	res->flags = IORESOURCE_MEM;
> +
> +	if (insert_resource(&iomem_resource, res)) {
> +		pr_notice("request region conflict with %s\n",
> +			res->name);
> +	}
> +
> +	node->interface.regs = ioremap(res->start, size);
> +	if (!node->interface.regs) {
> +		pr_err("Ioremap for %s failed!\n", node->name);
> +		kfree(res);
> +		return -EINVAL;

return -ENOMEM;

> +	}
> +
> +	node->interface.ce_threshold = kzalloc(sizeof(u64) *
> +				interface->error_record_count, GFP_KERNEL);
> +	if (!node->interface.ce_threshold)

kfree(res) and iounmap()

> +		return -ENOMEM;
> +
> +	aest_set_ce_threshold(node);
> +
> +	return 0;
> +}
> +
> +static int __init aest_init_common(struct acpi_aest_hdr *hdr,
> +						struct aest_node *node)
> +{
> +	int ret;
> +
> +	set_aest_node_name(node);
> +
> +	ret = aest_init_interface(hdr, node);
> +	if (ret) {
> +		pr_err("failed to init interface\n");
> +		return ret;

I did not see you free the node->name before returning an error.

> +	}
> +
> +	return aest_init_interrupts(hdr, node);
> +}
> +
> +static int __init aest_init_node_default(struct acpi_aest_hdr *hdr)
> +{
> +	struct aest_node *node;
> +	union aest_node_spec *node_spec;
> +	int ret;
> +
> +	node = kzalloc(sizeof(struct aest_node), GFP_KERNEL);
> +	if (!node)
> +		return -ENOMEM;
> +
> +	node->type = hdr->type;
> +	node_spec = ACPI_ADD_PTR(union aest_node_spec, hdr,
> +					hdr->node_specific_offset);
> +
> +	memcpy(&node->spec, node_spec,
> +			hdr->node_interface_offset - hdr->node_specific_offset);
> +
> +	ret = aest_init_common(hdr, node);
> +	if (ret)
> +		kfree(node);
> +
> +	return ret;
> +}
> +
> +static int __init aest_init_processor_node(struct acpi_aest_hdr *hdr)
> +{
> +	struct aest_node *node;
> +	union aest_node_spec *node_spec;
> +	union aest_node_processor *proc;
> +	int ret;
> +
> +	node = kzalloc(sizeof(struct aest_node), GFP_KERNEL);
> +	if (!node)
> +		return -ENOMEM;
> +
> +	node->type = hdr->type;
> +	node_spec = ACPI_ADD_PTR(union aest_node_spec, hdr,
> +					hdr->node_specific_offset);
> +
> +	memcpy(&node->spec, node_spec,
> +			hdr->node_interface_offset - hdr->node_specific_offset);
> +
> +	proc = ACPI_ADD_PTR(union aest_node_processor, node_spec,
> +					sizeof(acpi_aest_processor));
> +
> +	switch (node->spec.processor.resource_type) {
> +	case ACPI_AEST_CACHE_RESOURCE:
> +		memcpy(&node->proc, proc,
> +				sizeof(struct acpi_aest_processor_cache));
> +		break;
> +	case ACPI_AEST_TLB_RESOURCE:
> +		memcpy(&node->proc, proc,
> +				sizeof(struct acpi_aest_processor_tlb));
> +		break;
> +	case ACPI_AEST_GENERIC_RESOURCE:
> +		memcpy(&node->proc, proc,
> +				sizeof(struct acpi_aest_processor_generic));
> +		break;
> +	}
> +
> +	ret = aest_init_common(hdr, node);
> +	if (ret)
> +		kfree(node);
> +
> +	return ret;
> +}
> +
> +static int __init aest_init_node(struct acpi_aest_hdr *node)
> +{
> +	switch (node->type) {
> +	case ACPI_AEST_PROCESSOR_ERROR_NODE:
> +		return aest_init_processor_node(node);
> +	case ACPI_AEST_MEMORY_ERROR_NODE:
> +	case ACPI_AEST_VENDOR_ERROR_NODE:
> +	case ACPI_AEST_SMMU_ERROR_NODE:
> +	case ACPI_AEST_GIC_ERROR_NODE:
> +		return aest_init_node_default(node);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static void __init aest_count_ppi(struct acpi_aest_hdr *header)
> +{
> +	struct acpi_aest_node_interrupt *interrupt;
> +	int i;
> +
> +	interrupt = ACPI_ADD_PTR(struct acpi_aest_node_interrupt, header,
> +				 header->node_interrupt_offset);
> +
> +	for (i = 0; i < header->node_interrupt_count; i++, interrupt++) {
> +		if (interrupt->gsiv >= 16 && interrupt->gsiv < 32)
> +			num_ppi++;
> +	}
> +}
> +
> +static int aest_starting_cpu(unsigned int cpu)
> +{
> +	int i;
> +
> +	for (i = 0; i < num_ppi; i++)
> +		enable_percpu_irq(ppi_irqs[i], IRQ_TYPE_NONE);
> +
> +	return 0;
> +}
> +
> +static int aest_dying_cpu(unsigned int cpu)
> +{
> +	int i;
> +
> +	for (i = 0; i < num_ppi; i++)
> +		disable_percpu_irq(ppi_irqs[i]);
> +
> +	return 0;
> +}
> +
> +int __init acpi_aest_init(void)

Should be 'static'.

> +{
> +	struct acpi_aest_hdr *aest_node, *aest_end;
> +	struct acpi_table_aest *aest;
> +	int i, ret = 0;
> +
> +	if (acpi_disabled)
> +		return 0;
> +
> +	if (!IS_ENABLED(CONFIG_ARM64_RAS_EXTN))
> +		return 0;

I think you can move this into Kconfig file, that makes ACPI_AEST 
dependent on this CONFIG_ARM64_RAS_EXTN?

> +
> +	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_AEST, 0, &aest_table)))
> +		return -EINVAL;
> +
> +	ret = aest_node_pool_init();
> +	if (ret) {
> +		pr_err("Failed init aest node pool.\n");
> +		goto fail;

Just return ret;

> +	}
> +
> +	INIT_WORK(&aest_work, aest_node_pool_process);
> +
> +	aest = (struct acpi_table_aest *)aest_table;
> +
> +	/* Get the first AEST node */
> +	aest_node = ACPI_ADD_PTR(struct acpi_aest_hdr, aest,
> +				 sizeof(struct acpi_table_header));
> +	/* Pointer to the end of the AEST table */
> +	aest_end = ACPI_ADD_PTR(struct acpi_aest_hdr, 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;

You should destroy the node pool before returning errors.

> +		}
> +
> +		aest_count_ppi(aest_node);
> +
> +		aest_node = ACPI_ADD_PTR(struct acpi_aest_hdr, aest_node,
> +					 aest_node->length);
> +	}
> +
> +	aest_ppi_data = kcalloc(num_ppi, sizeof(struct aest_node_data *),
> +				GFP_KERNEL);
> +	if (!aest_ppi_data) {
> +		ret = -ENOMEM;
> +		goto fail;
> +	}
> +
> +	ppi_irqs = kcalloc(num_ppi, sizeof(int), GFP_KERNEL);
> +	if (!ppi_irqs) {
> +		ret = -ENOMEM;
> +		goto fail;
> +	}
> +
> +	for (i = 0; i < num_ppi; i++) {
> +		aest_ppi_data[i] = alloc_percpu(struct aest_node);
> +		if (!aest_ppi_data[i]) {
> +			pr_err("Failed percpu allocation.\n");
> +			ret = -ENOMEM;
> +			goto fail;
> +		}
> +	}
> +
> +	aest_node = ACPI_ADD_PTR(struct acpi_aest_hdr, aest,
> +				 sizeof(struct acpi_table_header));
> +
> +	while (aest_node < aest_end) {
> +		ret = aest_init_node(aest_node);
> +		if (ret) {
> +			pr_err("failed to init node: %d", ret);
> +			goto fail;
> +		}
> +
> +		aest_node = ACPI_ADD_PTR(struct acpi_aest_hdr, aest_node,
> +					 aest_node->length);
> +	}
> +
> +
> +
> +	return cpuhp_setup_state(CPUHP_AP_ARM_AEST_STARTING,
> +			  "drivers/acpi/arm64/aest:starting",
> +			  aest_starting_cpu, aest_dying_cpu);

Need free the resources you requested if an error occurs.

> +
> +fail:
> +	for (i = 0; i < num_ppi; i++)
> +		free_percpu(aest_ppi_data[i]);
> +	kfree(aest_ppi_data);
> +	return ret;
> +}
> +subsys_initcall(acpi_aest_init);
> diff --git a/include/linux/acpi_aest.h b/include/linux/acpi_aest.h
> new file mode 100644
> index 000000000000..679187505dc6
> --- /dev/null
> +++ b/include/linux/acpi_aest.h
> @@ -0,0 +1,92 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef AEST_H
> +#define AEST_H
> +
> +#include <acpi/actbl.h>
> +#include <asm/ras.h>
> +
> +#define AEST_INTERRUPT_MODE		BIT(0)
> +
> +#define ACPI_AEST_PROC_FLAG_GLOBAL	(1<<0)
> +#define ACPI_AEST_PROC_FLAG_SHARED	(1<<1)
> +
> +#define ACPI_AEST_INTERFACE_CLEAR_MISC	(1<<0)
> +
> +#define ERXFR			0x0
> +#define ERXCTLR			0x8
> +#define ERXSTATUS		0x10
> +#define ERXADDR			0x18
> +#define ERXMISC0		0x20
> +#define ERXMISC1		0x28
> +#define ERXMISC2		0x30
> +#define ERXMISC3		0x38
> +
> +struct aest_node_interface {
> +	u8 type;
> +	u64 phy_addr;
> +	u16 record_start;
> +	u16 record_end;
> +	u32 flags;
> +	unsigned long record_implemented;
> +	unsigned long status_reporting;
> +	unsigned long addressing_mode;
> +	struct ras_ext_regs *regs;
> +	u64 *ce_threshold;
> +};
> +
> +union aest_node_processor {
> +	struct acpi_aest_processor_cache cache_data;
> +	struct acpi_aest_processor_tlb tlb_data;
> +	struct acpi_aest_processor_generic generic_data;
> +};
> +
> +union aest_node_spec {
> +	struct acpi_aest_processor processor;
> +	struct acpi_aest_memory memory;
> +	struct acpi_aest_smmu smmu;
> +	struct acpi_aest_vendor vendor;
> +	struct acpi_aest_gic gic;
> +};
> +
> +struct aest_access {
> +	u64 (*read)(u64 base, u32 offset);
> +	void (*write)(u64 base, u32 offset, u64 val);
> +};
> +
> +struct aest_node {
> +	char *name;
> +	u8 type;
> +	struct aest_node_interface interface;
> +	union aest_node_spec spec;
> +	union aest_node_processor proc;
> +	struct aest_access *access;
> +};
> +
> +struct aest_node_llist {
> +	struct llist_node llnode;
> +	char *node_name;
> +	int type;
> +	/*
> +	 * Different nodes have different meanings:
> +	 *   - Processor node	: processor number.
> +	 *   - Memory node	: SRAT proximity domain.
> +	 *   - SMMU node	: IORT proximity domain.
> +	 *   - Vendor node	: hardware ID.
> +	 *   - GIC node		: interface type.
> +	 */
> +	u32 id0;
> +	/*
> +	 * Different nodes have different meanings:
> +	 *   - Processor node	: processor resource type.
> +	 *   - Memory node	: Non.
> +	 *   - SMMU node	: subcomponent reference.
> +	 *   - Vendor node	: Unique ID.
> +	 *   - GIC node		: instance identifier.
> +	 */
> +	u32 id1;
> +	int index;
> +	unsigned long addressing_mode;
> +	struct ras_ext_regs *regs;
> +};

These are only aest-related structures? If so, I think they should be in 
aest.c file.

> +
> +#endif /* AEST_H */
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index 624d4a38c358..f0dda08dbad2 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -186,6 +186,7 @@ enum cpuhp_state {
>   	CPUHP_AP_CSKY_TIMER_STARTING,
>   	CPUHP_AP_TI_GP_TIMER_STARTING,
>   	CPUHP_AP_HYPERV_TIMER_STARTING,
> +	CPUHP_AP_ARM_AEST_STARTING,
>   	/* Must be the last timer callback */
>   	CPUHP_AP_DUMMY_TIMER_STARTING,
>   	CPUHP_AP_ARM_XEN_STARTING,