FAILED: patch "[PATCH] ACPI: CPPC: Fix bit_offset shift in MASK_VAL() macro" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] ACPI: CPPC: Fix bit_offset shift in MASK_VAL() macro" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 05d92ee782eeb7b939bdd0189e6efcab9195bf95
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024042941-fleshed-collide-d77b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

05d92ee782ee ("ACPI: CPPC: Fix bit_offset shift in MASK_VAL() macro")
2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for system memory accesses")
0651ab90e4ad ("ACPI: CPPC: Check _OSC for flexible address space")
c42fa24b4475 ("ACPI: bus: Avoid using CPPC if not supported by firmware")
2ca8e6285250 ("Revert "ACPI: Pass the same capabilities to the _OSC regardless of the query flag"")
f684b1075128 ("ACPI: CPPC: Drop redundant local variable from cpc_read()")
5f51c7ce1dc3 ("ACPI: CPPC: Fix up I/O port access in cpc_read()")
a2c8f92bea5f ("ACPI: CPPC: Implement support for SystemIO registers")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 05d92ee782eeb7b939bdd0189e6efcab9195bf95 Mon Sep 17 00:00:00 2001
From: Jarred White <jarredwhite@linux.microsoft.com>
Date: Mon, 8 Apr 2024 22:23:09 -0700
Subject: [PATCH] ACPI: CPPC: Fix bit_offset shift in MASK_VAL() macro

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>

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)