4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 0f27cff8597d86f881ea8274b49b63b678c14a3c ]

The acpi_mask_gpe= kernel parameter documentation states that the range
of mask is 128 GPEs (0x00 to 0x7F).  The acpi_masked_gpes mask is a u64 so
only 64 GPEs (0x00 to 0x3F) can really be masked.

Use a bitmap of size 0xFF instead of a u64 for the GPE mask so 256
GPEs can be masked.

Fixes: 9c4aa1eecb48 (ACPI / sysfs: Provide quirk mechanism to prevent GPE 
flooding)
Signed-off-by: Prarit Bharava <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 Documentation/kernel-parameters.txt |  1 -
 drivers/acpi/sysfs.c                | 26 ++++++++------------------
 2 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/Documentation/kernel-parameters.txt 
b/Documentation/kernel-parameters.txt
index f9f67be8d3c3..c708a50b060e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -313,7 +313,6 @@ bytes respectively. Such letter suffixes can also be 
entirely omitted.
                        This facility can be used to prevent such uncontrolled
                        GPE floodings.
                        Format: <int>
-                       Support masking of GPEs numbered from 0x00 to 0x7f.
 
        acpi_no_auto_serialize  [HW,ACPI]
                        Disable auto-serialization of AML methods
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index cf05ae973381..a36d0739dbfe 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -724,14 +724,8 @@ end:
  * interface:
  *   echo unmask > /sys/firmware/acpi/interrupts/gpe00
  */
-
-/*
- * Currently, the GPE flooding prevention only supports to mask the GPEs
- * numbered from 00 to 7f.
- */
-#define ACPI_MASKABLE_GPE_MAX  0x80
-
-static u64 __initdata acpi_masked_gpes;
+#define ACPI_MASKABLE_GPE_MAX  0xFF
+static DECLARE_BITMAP(acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) __initdata;
 
 static int __init acpi_gpe_set_masked_gpes(char *val)
 {
@@ -739,7 +733,7 @@ static int __init acpi_gpe_set_masked_gpes(char *val)
 
        if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
                return -EINVAL;
-       acpi_masked_gpes |= ((u64)1<<gpe);
+       set_bit(gpe, acpi_masked_gpes_map);
 
        return 1;
 }
@@ -751,15 +745,11 @@ void __init acpi_gpe_apply_masked_gpes(void)
        acpi_status status;
        u8 gpe;
 
-       for (gpe = 0;
-            gpe < min_t(u8, ACPI_MASKABLE_GPE_MAX, acpi_current_gpe_count);
-            gpe++) {
-               if (acpi_masked_gpes & ((u64)1<<gpe)) {
-                       status = acpi_get_gpe_device(gpe, &handle);
-                       if (ACPI_SUCCESS(status)) {
-                               pr_info("Masking GPE 0x%x.\n", gpe);
-                               (void)acpi_mask_gpe(handle, gpe, TRUE);
-                       }
+       for_each_set_bit(gpe, acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) {
+               status = acpi_get_gpe_device(gpe, &handle);
+               if (ACPI_SUCCESS(status)) {
+                       pr_info("Masking GPE 0x%x.\n", gpe);
+                       (void)acpi_mask_gpe(handle, gpe, TRUE);
                }
        }
 }
-- 
2.17.1



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