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

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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: James Morse <james.morse@arm.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
James Morse 2019-01-29 18:48:52 +00:00 committed by Rafael J. Wysocki
parent 3b880cbe4d
commit b484079b9f
1 changed files with 39 additions and 53 deletions
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92
drivers/acpi/apei/ghes.c
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@ -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;
int _idx = virt_to_fix((unsigned long)vaddr);
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);
}
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);