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authorJarred White <jarredwhite@linux.microsoft.com>2024-04-09 08:23:09 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-05-02 17:35:30 +0300
commit5cfdf783323fa4f3990314509317d880982c5305 (patch)
treee596a717b12e233b5529fef62a47eb67e926f008
parent6cb6b12b78dcd8867a3fdbb1b6d0ed1df2b208d1 (diff)
downloadlinux-5cfdf783323fa4f3990314509317d880982c5305.tar.xz
ACPI: CPPC: Fix bit_offset shift in MASK_VAL() macro
commit 05d92ee782eeb7b939bdd0189e6efcab9195bf95 upstream. Commit 2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for system memory accesses") neglected to properly wrap the bit_offset shift when it comes to applying the mask. This may cause incorrect values to be read and may cause the cpufreq module not be loaded. [ 11.059751] cpu_capacity: CPU0 missing/invalid highest performance. [ 11.066005] cpu_capacity: partial information: fallback to 1024 for all CPUs Also, corrected the bitmask generation in GENMASK (extra bit being added). Fixes: 2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for system memory accesses") Signed-off-by: Jarred White <jarredwhite@linux.microsoft.com> Cc: 5.15+ <stable@vger.kernel.org> # 5.15+ Reviewed-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/acpi/cppc_acpi.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index b954ce3638a9..ed8cac40c096 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -170,8 +170,8 @@ show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time);
#define GET_BIT_WIDTH(reg) ((reg)->access_width ? (8 << ((reg)->access_width - 1)) : (reg)->bit_width)
/* Shift and apply the mask for CPC reads/writes */
-#define MASK_VAL(reg, val) ((val) >> ((reg)->bit_offset & \
- GENMASK(((reg)->bit_width), 0)))
+#define MASK_VAL(reg, val) (((val) >> (reg)->bit_offset) & \
+ GENMASK(((reg)->bit_width) - 1, 0))
static ssize_t show_feedback_ctrs(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)