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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/x86/kernel/acpi/cppc_msr.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/kernel/acpi/cppc_msr.c')
-rw-r--r--arch/x86/kernel/acpi/cppc_msr.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/cppc_msr.c b/arch/x86/kernel/acpi/cppc_msr.c
new file mode 100644
index 000000000..6fb478bf8
--- /dev/null
+++ b/arch/x86/kernel/acpi/cppc_msr.c
@@ -0,0 +1,58 @@
+/*
+ * cppc_msr.c: MSR Interface for CPPC
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <acpi/cppc_acpi.h>
+#include <asm/msr.h>
+
+/* Refer to drivers/acpi/cppc_acpi.c for the description of functions */
+
+bool cpc_ffh_supported(void)
+{
+ return true;
+}
+
+int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
+{
+ int err;
+
+ err = rdmsrl_safe_on_cpu(cpunum, reg->address, val);
+ if (!err) {
+ u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1,
+ reg->bit_offset);
+
+ *val &= mask;
+ *val >>= reg->bit_offset;
+ }
+ return err;
+}
+
+int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
+{
+ u64 rd_val;
+ int err;
+
+ err = rdmsrl_safe_on_cpu(cpunum, reg->address, &rd_val);
+ if (!err) {
+ u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1,
+ reg->bit_offset);
+
+ val <<= reg->bit_offset;
+ val &= mask;
+ rd_val &= ~mask;
+ rd_val |= val;
+ err = wrmsrl_safe_on_cpu(cpunum, reg->address, rd_val);
+ }
+ return err;
+}