Commit b484079b authored by James Morse's avatar James Morse Committed by Rafael J. Wysocki
Browse files

ACPI / APEI: Let the notification helper specify the fixmap slot 



ghes_copy_tofrom_phys() uses a different fixmap slot depending on in_nmi().
This doesn't work when there are multiple NMI-like notifications, that
could 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: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 3b880cbe

drivers/acpi/apei/ghes.c

+39 −53
Original line number Diff line number Diff line
@@ -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>
@@ -127,38 +128,24 @@ 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, enum fixed_addresses 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(void __iomem *vaddr, enum fixed_addresses fixmap_idx)

{

	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);

	int _idx = virt_to_fix((unsigned long)vaddr);



	return (void __iomem *) fix_to_virt(FIX_APEI_GHES_IRQ);

}



static void ghes_iounmap_nmi(void)

{

	clear_fixmap(FIX_APEI_GHES_NMI);

}



static void ghes_iounmap_irq(void)

{

	clear_fixmap(FIX_APEI_GHES_IRQ);

	WARN_ON_ONCE(fixmap_idx != _idx);

	clear_fixmap(fixmap_idx);

}



int ghes_estatus_pool_init(int num_ghes)
@@ -283,20 +270,16 @@ 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,

				  enum fixed_addresses 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)
@@ -306,15 +289,13 @@ 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(vaddr, fixmap_idx);

	}

}



static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr)

static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr,

			     enum fixed_addresses fixmap_idx)



{

	struct acpi_hest_generic *g = ghes->generic;

	u32 len;
@@ -332,7 +313,7 @@ static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr) 
		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) {

		*buf_paddr = 0;

		return -ENOENT;
@@ -348,7 +329,7 @@ static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr) 
		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;
@@ -361,7 +342,8 @@ err_read_block: 
	return rc;

}



static void ghes_clear_estatus(struct ghes *ghes, u64 buf_paddr)

static void ghes_clear_estatus(struct ghes *ghes, u64 buf_paddr,

			       enum fixed_addresses fixmap_idx)

{

	ghes->estatus->block_status = 0;
@@ -369,7 +351,8 @@ static void ghes_clear_estatus(struct ghes *ghes, u64 buf_paddr) 
		return;



	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,

			      sizeof(ghes->estatus->block_status), 0);

			      sizeof(ghes->estatus->block_status), 0,

			      fixmap_idx);



	/*

	 * GHESv2 type HEST entries introduce support for error acknowledgment,
@@ -668,11 +651,12 @@ static void ghes_estatus_cache_add( 
	rcu_read_unlock();

}



static void __ghes_panic(struct ghes *ghes, u64 buf_paddr)

static void __ghes_panic(struct ghes *ghes, u64 buf_paddr,

			 enum fixed_addresses fixmap_idx)

{

	__ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus);



	ghes_clear_estatus(ghes, buf_paddr);

	ghes_clear_estatus(ghes, buf_paddr, fixmap_idx);



	/* reboot to log the error! */

	if (!panic_timeout)
@@ -685,12 +669,12 @@ static int ghes_proc(struct ghes *ghes) 
	u64 buf_paddr;

	int rc;



	rc = ghes_read_estatus(ghes, &buf_paddr);

	rc = ghes_read_estatus(ghes, &buf_paddr, FIX_APEI_GHES_IRQ);

	if (rc)

		goto out;



	if (ghes_severity(ghes->estatus->error_severity) >= GHES_SEV_PANIC) {

		__ghes_panic(ghes, buf_paddr);

		__ghes_panic(ghes, buf_paddr, FIX_APEI_GHES_IRQ);

	}



	if (!ghes_estatus_cached(ghes->estatus)) {
@@ -700,7 +684,7 @@ static int ghes_proc(struct ghes *ghes) 
	ghes_do_proc(ghes, ghes->estatus);



out:

	ghes_clear_estatus(ghes, buf_paddr);

	ghes_clear_estatus(ghes, buf_paddr, FIX_APEI_GHES_IRQ);



	return rc;

}
@@ -866,36 +850,38 @@ static void __process_error(struct ghes *ghes) 
#endif

}



static int ghes_in_nmi_queue_one_entry(struct ghes *ghes)

static int ghes_in_nmi_queue_one_entry(struct ghes *ghes,

				       enum fixed_addresses fixmap_idx)

{

	u64 buf_paddr;

	int sev;



	if (ghes_read_estatus(ghes, &buf_paddr)) {

		ghes_clear_estatus(ghes, buf_paddr);

	if (ghes_read_estatus(ghes, &buf_paddr, fixmap_idx)) {

		ghes_clear_estatus(ghes, buf_paddr, fixmap_idx);

		return -ENOENT;

	}



	sev = ghes_severity(ghes->estatus->error_severity);

	if (sev >= GHES_SEV_PANIC) {

		ghes_print_queued_estatus();

		__ghes_panic(ghes, buf_paddr);

		__ghes_panic(ghes, buf_paddr, fixmap_idx);

	}



	__process_error(ghes);

	ghes_clear_estatus(ghes, buf_paddr);

	ghes_clear_estatus(ghes, buf_paddr, fixmap_idx);



	return 0;

}



static int ghes_in_nmi_spool_from_list(struct list_head *rcu_list)

static int ghes_in_nmi_spool_from_list(struct list_head *rcu_list,

				       enum fixed_addresses fixmap_idx)

{

	int ret = -ENOENT;

	struct ghes *ghes;



	rcu_read_lock();

	list_for_each_entry_rcu(ghes, rcu_list, list) {

		if (!ghes_in_nmi_queue_one_entry(ghes))

		if (!ghes_in_nmi_queue_one_entry(ghes, fixmap_idx))

			ret = 0;

	}

	rcu_read_unlock();
@@ -919,7 +905,7 @@ int ghes_notify_sea(void) 
	int rv;



	raw_spin_lock(&ghes_notify_lock_sea);

	rv = ghes_in_nmi_spool_from_list(&ghes_sea);

	rv = ghes_in_nmi_spool_from_list(&ghes_sea, FIX_APEI_GHES_NMI);

	raw_spin_unlock(&ghes_notify_lock_sea);



	return rv;
@@ -962,7 +948,7 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) 
		return ret;



	raw_spin_lock(&ghes_notify_lock_nmi);

	if (!ghes_in_nmi_spool_from_list(&ghes_nmi))

	if (!ghes_in_nmi_spool_from_list(&ghes_nmi, FIX_APEI_GHES_NMI))

		ret = NMI_HANDLED;

	raw_spin_unlock(&ghes_notify_lock_nmi);

CRA Git | Maintained and supported by SUSTech CRA and CCSE