[PATCH v7 104/120] x86/cpu: cpuinfo: Use parsed CPUID(0x80000007)

For /proc/cpuinfo "power management" line, use parsed CPUID(0x80000007)
instead of poking at cpuinfo_x86::x86_power.  The latter is backed by a
direct CPUID query and will be later removed.

Remove the x86_power_flags[] strings table as it has no more users.

Signed-off-by: Ahmed S. Darwish <[email protected]>
---
 arch/x86/include/asm/cpufeature.h |  1 -
 arch/x86/kernel/cpu/Makefile      |  2 +-
 arch/x86/kernel/cpu/powerflags.c  | 24 ------------
 arch/x86/kernel/cpu/proc.c        | 61 ++++++++++++++++++++++++-------
 4 files changed, 49 insertions(+), 39 deletions(-)
 delete mode 100644 arch/x86/kernel/cpu/powerflags.c

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 3ddc1d33399b..520949560138 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -39,7 +39,6 @@ enum cpuid_leafs
 };
 
 extern const char * const x86_cap_flags[NCAPINTS*32];
-extern const char * const x86_power_flags[32];
 
 /*
  * In order to save room, we index into this array by doing
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index d62e2d60a965..5c091d9fc9ee 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -27,7 +27,7 @@ obj-y			+= bugs.o
 obj-y			+= aperfmperf.o
 obj-y			+= cpuid-deps.o cpuid_0x2_table.o
 obj-y			+= umwait.o
-obj-y 			+= capflags.o powerflags.o
+obj-y 			+= capflags.o
 
 obj-$(CONFIG_X86_LOCAL_APIC)		+= topology.o
 
diff --git a/arch/x86/kernel/cpu/powerflags.c b/arch/x86/kernel/cpu/powerflags.c
deleted file mode 100644
index fd6ec2aa0303..000000000000
--- a/arch/x86/kernel/cpu/powerflags.c
+++ /dev/null
@@ -1,24 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Strings for the various x86 power flags
- *
- * This file must not contain any executable code.
- */
-
-#include <asm/cpufeature.h>
-
-const char *const x86_power_flags[32] = {
-	"ts",	/* temperature sensor */
-	"fid",  /* frequency id control */
-	"vid",  /* voltage id control */
-	"ttp",  /* thermal trip */
-	"tm",	/* hardware thermal control */
-	"stc",	/* software thermal control */
-	"100mhzsteps", /* 100 MHz multiplier control */
-	"hwpstate", /* hardware P-state control */
-	"",	/* tsc invariant mapped to constant_tsc */
-	"cpb",  /* core performance boost */
-	"eff_freq_ro", /* Readonly aperf/mperf */
-	"proc_feedback", /* processor feedback interface */
-	"acc_power", /* accumulated power mechanism */
-};
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 6571d432cbe3..89471bcfcc32 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -4,9 +4,11 @@
 #include <linux/string.h>
 #include <linux/seq_file.h>
 #include <linux/cpufreq.h>
-#include <asm/prctl.h>
 #include <linux/proc_fs.h>
 
+#include <asm/cpuid/api.h>
+#include <asm/prctl.h>
+
 #include "cpu.h"
 
 #ifdef CONFIG_X86_VMX_FEATURE_NAMES
@@ -60,6 +62,50 @@ static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
 }
 #endif
 
+static void show_cpuinfo_power(struct cpuinfo_x86 *c, struct seq_file *m)
+{
+	const struct cpuid_regs *el7_regs = cpuid_leaf_raw(c, 0x80000007);
+	const struct leaf_0x80000007_0 *el7 = cpuid_leaf(c, 0x80000007);
+
+	seq_puts(m, "power management:");
+
+	if (!el7_regs || !el7)
+		return;
+
+	if (el7->digital_temp)
+		seq_puts(m, " ts");
+	if (el7->powernow_freq_id)
+		seq_puts(m, " fid");
+	if (el7->powernow_volt_id)
+		seq_puts(m, " vid");
+	if (el7->thermal_trip)
+		seq_puts(m, " ttp");
+	if (el7->hw_thermal_control)
+		seq_puts(m, " tm");
+	if (el7->sw_thermal_control)
+		seq_puts(m, " stc");
+	if (el7->_100mhz_steps)
+		seq_puts(m, " 100mhzsteps");
+	if (el7->hw_pstate)
+		seq_puts(m, " hwpstate");
+
+	/* Keep constant_tsc off the power management line */
+
+	if (el7->core_perf_boost)
+		seq_puts(m, " cpb");
+	if (el7->eff_freq_ro)
+		seq_puts(m, " eff_freq_ro");
+	if (el7->proc_feedback)
+		seq_puts(m, " proc_feedback");
+	if (el7->proc_power_reporting)
+		seq_puts(m, " acc_power");
+
+	/* Afterwards, just output the offsets of set bits */
+	for (int i = 13; i < 32; i++)
+		if (el7_regs->edx & BIT(i))
+			seq_printf(m, " [%d]", i);
+}
+
 static int show_cpuinfo(struct seq_file *m, void *v)
 {
 	struct cpuinfo_x86 *c = v;
@@ -138,18 +184,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 	seq_printf(m, "address sizes\t: %u bits physical, %u bits virtual\n",
 		   c->x86_phys_bits, c->x86_virt_bits);
 
-	seq_puts(m, "power management:");
-	for (i = 0; i < 32; i++) {
-		if (c->x86_power & (1 << i)) {
-			if (i < ARRAY_SIZE(x86_power_flags) &&
-			    x86_power_flags[i])
-				seq_printf(m, "%s%s",
-					   x86_power_flags[i][0] ? " " : "",
-					   x86_power_flags[i]);
-			else
-				seq_printf(m, " [%d]", i);
-		}
-	}
+	show_cpuinfo_power(c, m);
 
 	seq_puts(m, "\n\n");
 
-- 
2.54.0