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| author | Jarred White <jarredwhite@linux.microsoft.com> | 2024-04-09 08:23:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-05-02 17:29:29 +0300 |
| commit | 0f708a7e0abdceaaa35dc1844020e12a1153de53 (patch) | |
| tree | 22d8c3efad7cca3f6f31f71995fd884da883a8fd | |
| parent | 01fc53be672acae37e611c80cc0b4f3939584de3 (diff) | |
| download | linux-0f708a7e0abdceaaa35dc1844020e12a1153de53.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.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index c123fdbca693..f153f7d3e6b7 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -167,8 +167,8 @@ 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) |