From feb2d38013ddfc8ea4b53134d194582dc1e4de2c Mon Sep 17 00:00:00 2001 From: Shuai Xue Date: Mon, 12 Jan 2026 11:22:38 +0800 Subject: [PATCH] ACPI: APEI: GHES: Extract helper functions for error status handling Refactors the GHES driver by extracting common functionality into reusable helper functions: 1. ghes_has_active_errors() - Checks if any error sources in a given list have active errors 2. ghes_map_error_status() - Maps error status address to virtual address 3. ghes_unmap_error_status() - Unmaps error status virtual address 4. Use `guard(rcu)()` instead of explicit `rcu_read_lock()`/`rcu_read_unlock()`. These helpers eliminate code duplication in the NMI path and prepare for similar usage in the SEA path in a subsequent patch. No functional change intended. Tested-by: Tony Luck Reviewed-by: Tony Luck Signed-off-by: Shuai Xue Reviewed-by: Breno Leitao Reviewed-by: Hanjun Guo Link: https://patch.msgid.link/20260112032239.30023-3-xueshuai@linux.alibaba.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/apei/ghes.c | 89 ++++++++++++++++++++++++++++++---------- 1 file changed, 68 insertions(+), 21 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 8796013b51667..067a58dbcc01a 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -1434,6 +1434,71 @@ static int ghes_in_nmi_spool_from_list(struct list_head *rcu_list, return ret; } +/** + * ghes_has_active_errors - Check if there are active errors in error sources + * @ghes_list: List of GHES entries to check for active errors + * + * This function iterates through all GHES entries in the given list and + * checks if any of them has active error status by reading the error + * status register. + * + * Return: true if at least one source has active error, false otherwise. + */ +static bool __maybe_unused ghes_has_active_errors(struct list_head *ghes_list) +{ + struct ghes *ghes; + + guard(rcu)(); + list_for_each_entry_rcu(ghes, ghes_list, list) { + if (ghes->error_status_vaddr && + readl(ghes->error_status_vaddr)) + return true; + } + + return false; +} + +/** + * ghes_map_error_status - Map error status address to virtual address + * @ghes: pointer to GHES structure + * + * Reads the error status address from ACPI HEST table and maps it to a virtual + * address that can be accessed by the kernel. + * + * Return: 0 on success, error code on failure. + */ +static int __maybe_unused ghes_map_error_status(struct ghes *ghes) +{ + struct acpi_hest_generic *g = ghes->generic; + u64 paddr; + int rc; + + rc = apei_read(&paddr, &g->error_status_address); + if (rc) + return rc; + + ghes->error_status_vaddr = + acpi_os_ioremap(paddr, sizeof(ghes->estatus->block_status)); + if (!ghes->error_status_vaddr) + return -EINVAL; + + return 0; +} + +/** + * ghes_unmap_error_status - Unmap error status virtual address + * @ghes: pointer to GHES structure + * + * Unmaps the error status address if it was previously mapped. + */ +static void __maybe_unused ghes_unmap_error_status(struct ghes *ghes) +{ + if (ghes->error_status_vaddr) { + iounmap(ghes->error_status_vaddr); + ghes->error_status_vaddr = NULL; + } +} + #ifdef CONFIG_ACPI_APEI_SEA static LIST_HEAD(ghes_sea); @@ -1484,20 +1549,9 @@ static LIST_HEAD(ghes_nmi); static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) { static DEFINE_RAW_SPINLOCK(ghes_notify_lock_nmi); - bool active_error = false; int ret = NMI_DONE; - struct ghes *ghes; - rcu_read_lock(); - list_for_each_entry_rcu(ghes, &ghes_nmi, list) { - if (ghes->error_status_vaddr && readl(ghes->error_status_vaddr)) { - active_error = true; - break; - } - } - rcu_read_unlock(); - - if (!active_error) + if (!ghes_has_active_errors(&ghes_nmi)) return ret; if (!atomic_add_unless(&ghes_in_nmi, 1, 1)) @@ -1514,18 +1568,12 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) static int ghes_nmi_add(struct ghes *ghes) { - struct acpi_hest_generic *g = ghes->generic; - u64 paddr; int rc; - rc = apei_read(&paddr, &g->error_status_address); + rc = ghes_map_error_status(ghes); if (rc) return rc; - ghes->error_status_vaddr = acpi_os_ioremap(paddr, sizeof(ghes->estatus->block_status)); - if (!ghes->error_status_vaddr) - return -EINVAL; - mutex_lock(&ghes_list_mutex); if (list_empty(&ghes_nmi)) register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes"); @@ -1543,8 +1591,7 @@ static void ghes_nmi_remove(struct ghes *ghes) unregister_nmi_handler(NMI_LOCAL, "ghes"); mutex_unlock(&ghes_list_mutex); - if (ghes->error_status_vaddr) - iounmap(ghes->error_status_vaddr); + ghes_unmap_error_status(ghes); /* * To synchronize with NMI handler, ghes can only be -- 2.47.3