| Message ID | 20240409052310.3162495-1-jarredwhite@linux.microsoft.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | ACPI: CPPC: Fix bit_offset shift in MASK_VAL macro | expand |
On 4/8/2024 10:23 PM, Jarred White wrote: > 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: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> > CC: stable@vger.kernel.org #5.15+ > --- > drivers/acpi/cppc_acpi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > index 4bfbe55553f4..00a30ca35e78 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) Hi Vanshi, Could you review please? Thanks, Jarred
Looks good to me. Reviewed-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> On Mon, Apr 08, 2024 at 10:23:09PM -0700, Jarred White wrote: >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: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> >CC: stable@vger.kernel.org #5.15+ >--- > drivers/acpi/cppc_acpi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > >diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c >index 4bfbe55553f4..00a30ca35e78 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) >-- >2.33.8 >
On Wed, Apr 17, 2024 at 7:37 PM Vanshidhar Konda <vanshikonda@os.amperecomputing.com> wrote: > > Looks good to me. > > Reviewed-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> > > On Mon, Apr 08, 2024 at 10:23:09PM -0700, Jarred White wrote: > >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: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> > >CC: stable@vger.kernel.org #5.15+ > >--- > > drivers/acpi/cppc_acpi.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > >diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > >index 4bfbe55553f4..00a30ca35e78 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) > >-- Applied as 6.9-rc material, thanks!
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 4bfbe55553f4..00a30ca35e78 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)
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: Vanshidhar Konda <vanshikonda@os.amperecomputing.com> CC: stable@vger.kernel.org #5.15+ --- drivers/acpi/cppc_acpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)