ghes_copy_tofrom_phys() uses a different fixmap slot depending on in_nmi(). This doesn't work when we have multiple NMI-like notifications, that can interrupt each other.
As with the locking, move the chosen fixmap_idx to the notification helper. This only matters for NMI-like notifications, anything calling ghes_proc() can use the IRQ fixmap slot as its already holding an irqsave spinlock. This lets us collapse the ghes_ioremap_pfn_*() helpers. Signed-off-by: James Morse <[email protected]> --- The fixmap-idx and vaddr are passed back to ghes_unmap() to allow ioremap() to be used in process context in the future. --- drivers/acpi/apei/ghes.c | 76 ++++++++++++++-------------------------- 1 file changed, 27 insertions(+), 49 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index ed8669a6c100..adf7fd402813 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -41,6 +41,7 @@ #include <linux/llist.h> #include <linux/genalloc.h> #include <linux/pci.h> +#include <linux/pfn.h> #include <linux/aer.h> #include <linux/nmi.h> #include <linux/sched/clock.h> @@ -129,38 +130,24 @@ static atomic_t ghes_estatus_cache_alloced; static int ghes_panic_timeout __read_mostly = 30; -static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn) +static void __iomem *ghes_map(u64 pfn, int fixmap_idx) { phys_addr_t paddr; pgprot_t prot; - paddr = pfn << PAGE_SHIFT; + paddr = PFN_PHYS(pfn); prot = arch_apei_get_mem_attribute(paddr); - __set_fixmap(FIX_APEI_GHES_NMI, paddr, prot); + __set_fixmap(fixmap_idx, paddr, prot); - return (void __iomem *) fix_to_virt(FIX_APEI_GHES_NMI); + return (void __iomem *) __fix_to_virt(fixmap_idx); } -static void __iomem *ghes_ioremap_pfn_irq(u64 pfn) +static void ghes_unmap(int fixmap_idx, void __iomem *vaddr) { - phys_addr_t paddr; - pgprot_t prot; - - paddr = pfn << PAGE_SHIFT; - prot = arch_apei_get_mem_attribute(paddr); - __set_fixmap(FIX_APEI_GHES_IRQ, paddr, prot); - - return (void __iomem *) fix_to_virt(FIX_APEI_GHES_IRQ); -} - -static void ghes_iounmap_nmi(void) -{ - clear_fixmap(FIX_APEI_GHES_NMI); -} + int _idx = virt_to_fix((unsigned long)vaddr); -static void ghes_iounmap_irq(void) -{ - clear_fixmap(FIX_APEI_GHES_IRQ); + WARN_ON_ONCE(fixmap_idx != _idx); + clear_fixmap(fixmap_idx); } static int ghes_estatus_pool_init(void) @@ -289,20 +276,15 @@ static inline int ghes_severity(int severity) } static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len, - int from_phys) + int from_phys, int fixmap_idx) { void __iomem *vaddr; - int in_nmi = in_nmi(); u64 offset; u32 trunk; while (len > 0) { offset = paddr - (paddr & PAGE_MASK); - if (in_nmi) { - vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT); - } else { - vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT); - } + vaddr = ghes_map(PHYS_PFN(paddr), fixmap_idx); trunk = PAGE_SIZE - offset; trunk = min(trunk, len); if (from_phys) @@ -312,15 +294,11 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len, len -= trunk; paddr += trunk; buffer += trunk; - if (in_nmi) { - ghes_iounmap_nmi(); - } else { - ghes_iounmap_irq(); - } + ghes_unmap(fixmap_idx, vaddr); } } -static int ghes_read_estatus(struct ghes *ghes, int silent) +static int ghes_read_estatus(struct ghes *ghes, int silent, int fixmap_idx) { struct acpi_hest_generic *g = ghes->generic; u64 buf_paddr; @@ -339,7 +317,7 @@ static int ghes_read_estatus(struct ghes *ghes, int silent) return -ENOENT; ghes_copy_tofrom_phys(ghes->estatus, buf_paddr, - sizeof(*ghes->estatus), 1); + sizeof(*ghes->estatus), 1, fixmap_idx); if (!ghes->estatus->block_status) return -ENOENT; @@ -356,7 +334,7 @@ static int ghes_read_estatus(struct ghes *ghes, int silent) goto err_read_block; ghes_copy_tofrom_phys(ghes->estatus + 1, buf_paddr + sizeof(*ghes->estatus), - len - sizeof(*ghes->estatus), 1); + len - sizeof(*ghes->estatus), 1, fixmap_idx); if (cper_estatus_check(ghes->estatus)) goto err_read_block; rc = 0; @@ -368,13 +346,13 @@ static int ghes_read_estatus(struct ghes *ghes, int silent) return rc; } -static void ghes_clear_estatus(struct ghes *ghes) +static void ghes_clear_estatus(struct ghes *ghes, int fixmap_idx) { ghes->estatus->block_status = 0; if (!(ghes->flags & GHES_TO_CLEAR)) return; ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr, - sizeof(ghes->estatus->block_status), 0); + sizeof(ghes->estatus->block_status), 0, fixmap_idx); ghes->flags &= ~GHES_TO_CLEAR; } @@ -740,12 +718,12 @@ static void __process_error(struct ghes *ghes) llist_add(&estatus_node->llnode, &ghes_estatus_llist); } -static int _in_nmi_notify_one(struct ghes *ghes) +static int _in_nmi_notify_one(struct ghes *ghes, int fixmap_idx) { int sev; - if (ghes_read_estatus(ghes, 1)) { - ghes_clear_estatus(ghes); + if (ghes_read_estatus(ghes, 1, fixmap_idx)) { + ghes_clear_estatus(ghes, fixmap_idx); return -ENOENT; } @@ -759,19 +737,19 @@ static int _in_nmi_notify_one(struct ghes *ghes) return 0; __process_error(ghes); - ghes_clear_estatus(ghes); + ghes_clear_estatus(ghes, fixmap_idx); return 0; } -static int ghes_estatus_queue_notified(struct list_head *rcu_list) +static int ghes_estatus_queue_notified(struct list_head *rcu_list, int fixmap_idx) { int ret = -ENOENT; struct ghes *ghes; rcu_read_lock(); list_for_each_entry_rcu(ghes, rcu_list, list) { - if (!_in_nmi_notify_one(ghes)) + if (!_in_nmi_notify_one(ghes, fixmap_idx)) ret = 0; } rcu_read_unlock(); @@ -876,7 +854,7 @@ static int ghes_proc(struct ghes *ghes) { int rc; - rc = ghes_read_estatus(ghes, 0); + rc = ghes_read_estatus(ghes, 0, FIX_APEI_GHES_IRQ); if (rc) goto out; @@ -891,7 +869,7 @@ static int ghes_proc(struct ghes *ghes) ghes_do_proc(ghes, ghes->estatus); out: - ghes_clear_estatus(ghes); + ghes_clear_estatus(ghes, FIX_APEI_GHES_IRQ); if (rc == -ENOENT) return rc; @@ -984,7 +962,7 @@ int ghes_notify_sea(void) int rv; raw_spin_lock(&ghes_notify_lock_sea); - rv = ghes_estatus_queue_notified(&ghes_sea); + rv = ghes_estatus_queue_notified(&ghes_sea, FIX_APEI_GHES_NMI); raw_spin_unlock(&ghes_notify_lock_sea); return rv; @@ -1031,7 +1009,7 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) return ret; raw_spin_lock(&ghes_notify_lock_nmi); - if (!ghes_estatus_queue_notified(&ghes_nmi)) + if (!ghes_estatus_queue_notified(&ghes_nmi, FIX_APEI_GHES_NMI)) ret = NMI_HANDLED; raw_spin_unlock(&ghes_notify_lock_nmi); -- 2.19.0 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
