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@xxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
---
The fixmap-idx and vaddr are passed back to ghes_unmap()
to allow ioremap() to be used in process context in the
future. This will let us send tlbi-ipi for notifications
that don't mask irqs.
---
drivers/acpi/apei/ghes.c | 79 +++++++++++++++-------------------------
1 file changed, 30 insertions(+), 49 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 30490eff7704..b5c31f65a1c0 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>
@@ -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, 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);
+ 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)
@@ -268,20 +255,15 @@ 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)
@@ -291,15 +273,12 @@ 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, u64 *buf_paddr)
+static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr, int fixmap_idx)
+
{
struct acpi_hest_generic *g = ghes->generic;
u32 len;
@@ -317,7 +296,7 @@ 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;
@@ -333,7 +312,7 @@ 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;
@@ -346,12 +325,13 @@ static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr)
return rc;
}
-static void ghes_clear_estatus(struct ghes *ghes, u64 buf_paddr)
+static void ghes_clear_estatus(struct ghes *ghes, u64 buf_paddr, int fixmap_idx)
{
ghes->estatus->block_status = 0;
if (buf_paddr)
ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
- sizeof(ghes->estatus->block_status), 0);
+ sizeof(ghes->estatus->block_status), 0,
+ fixmap_idx);
}
static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int sev)
@@ -673,7 +653,7 @@ 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;
@@ -688,7 +668,7 @@ 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);
if (rc == -ENOENT)
return rc;
@@ -864,13 +844,13 @@ static void __process_error(struct ghes *ghes)
#endif
}
-static int _in_nmi_notify_one(struct ghes *ghes)
+static int _in_nmi_notify_one(struct ghes *ghes, int 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;
}
@@ -881,7 +861,7 @@ static int _in_nmi_notify_one(struct ghes *ghes)
}
__process_error(ghes);
- ghes_clear_estatus(ghes, buf_paddr);
+ ghes_clear_estatus(ghes, buf_paddr, fixmap_idx);
if (is_hest_type_generic_v2(ghes) && ghes_ack_error(ghes->generic_v2))
pr_warn_ratelimited(FW_WARN GHES_PFX
@@ -890,14 +870,15 @@ static int _in_nmi_notify_one(struct ghes *ghes)
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();
@@ -921,7 +902,7 @@ 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;
@@ -964,7 +945,7 @@ 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);
--
2.19.2
