[tip:x86/autoprobe] x86, intel-idle: convert to x86_cpu_id auto probing

From: tip-bot for Andi Kleen
Date: Mon Dec 19 2011 - 20:27:28 EST


Commit-ID: 2023bae21ec13d12cdaf877809a17ee75190649b
Gitweb: http://git.kernel.org/tip/2023bae21ec13d12cdaf877809a17ee75190649b
Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
AuthorDate: Mon, 19 Dec 2011 15:46:29 -0800
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Mon, 19 Dec 2011 15:49:38 -0800

x86, intel-idle: convert to x86_cpu_id auto probing

With this it should be automatically loaded on suitable systems by
udev.

The old switch () is replaced with a table based approach, this
also cleans up the code.

Cc: lenb@xxxxxxxxxx
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1324338394-4670-4-git-send-email-andi@xxxxxxxxxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
drivers/idle/intel_idle.c | 114 +++++++++++++++++++++++++-------------------
1 files changed, 65 insertions(+), 49 deletions(-)

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 5d2f8e1..a0b292a 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -62,6 +62,7 @@
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/module.h>
+#include <asm/cpu_device_id.h>
#include <asm/mwait.h>
#include <asm/msr.h>

@@ -81,6 +82,17 @@ static unsigned int mwait_substates;
/* Reliable LAPIC Timer States, bit 1 for C1 etc. */
static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */

+struct idle_cpu {
+ struct cpuidle_state *state_table;
+
+ /*
+ * Hardware C-state auto-demotion may not always be optimal.
+ * Indicate which enable bits to clear here.
+ */
+ unsigned long auto_demotion_disable_flags;
+};
+
+static const struct idle_cpu *icpu;
static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
static int intel_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index);
@@ -88,12 +100,6 @@ static int intel_idle(struct cpuidle_device *dev,
static struct cpuidle_state *cpuidle_state_table;

/*
- * Hardware C-state auto-demotion may not always be optimal.
- * Indicate which enable bits to clear here.
- */
-static unsigned long long auto_demotion_disable_flags;
-
-/*
* Set this flag for states where the HW flushes the TLB for us
* and so we don't need cross-calls to keep it consistent.
* If this flag is set, SW flushes the TLB, so even if the
@@ -320,27 +326,72 @@ static void auto_demotion_disable(void *dummy)
unsigned long long msr_bits;

rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
- msr_bits &= ~auto_demotion_disable_flags;
+ msr_bits &= ~(icpu->auto_demotion_disable_flags);
wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
}

+static const struct idle_cpu idle_cpu_nehalem = {
+ .state_table = nehalem_cstates,
+};
+
+static const struct idle_cpu idle_cpu_westmere = {
+ .state_table = nehalem_cstates,
+ .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
+};
+
+static const struct idle_cpu idle_cpu_atom = {
+ .state_table = atom_cstates,
+};
+
+static const struct idle_cpu idle_cpu_lincroft = {
+ .state_table = atom_cstates,
+ .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
+};
+
+static const struct idle_cpu idle_cpu_snb = {
+ .state_table = snb_cstates,
+};
+
+#define ICPU(model, cpu) \
+ { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
+
+static const struct x86_cpu_id intel_idle_ids[] = {
+ ICPU(0x1a, idle_cpu_nehalem),
+ ICPU(0x1e, idle_cpu_nehalem),
+ ICPU(0x1f, idle_cpu_nehalem),
+ ICPU(0x25, idle_cpu_westmere),
+ ICPU(0x2c, idle_cpu_westmere),
+ ICPU(0x2f, idle_cpu_westmere),
+ ICPU(0x1c, idle_cpu_atom),
+ ICPU(0x26, idle_cpu_lincroft),
+ ICPU(0x2f, idle_cpu_westmere),
+ ICPU(0x2a, idle_cpu_snb),
+ ICPU(0x2d, idle_cpu_snb),
+ {}
+};
+MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
+
/*
* intel_idle_probe()
*/
static int intel_idle_probe(void)
{
unsigned int eax, ebx, ecx;
+ const struct x86_cpu_id *id;

if (max_cstate == 0) {
pr_debug(PREFIX "disabled\n");
return -EPERM;
}

- if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
- return -ENODEV;
-
- if (!boot_cpu_has(X86_FEATURE_MWAIT))
+ id = x86_match_cpu(intel_idle_ids);
+ if (!id) {
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ boot_cpu_data.x86 == 6)
+ pr_debug(PREFIX "does not run on family %d model %d\n",
+ boot_cpu_data.x86, boot_cpu_data.x86_model);
return -ENODEV;
+ }

if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
return -ENODEV;
@@ -353,43 +404,8 @@ static int intel_idle_probe(void)

pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);

-
- if (boot_cpu_data.x86 != 6) /* family 6 */
- return -ENODEV;
-
- switch (boot_cpu_data.x86_model) {
-
- case 0x1A: /* Core i7, Xeon 5500 series */
- case 0x1E: /* Core i7 and i5 Processor - Lynnfield Jasper Forest */
- case 0x1F: /* Core i7 and i5 Processor - Nehalem */
- case 0x2E: /* Nehalem-EX Xeon */
- case 0x2F: /* Westmere-EX Xeon */
- case 0x25: /* Westmere */
- case 0x2C: /* Westmere */
- cpuidle_state_table = nehalem_cstates;
- auto_demotion_disable_flags =
- (NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE);
- break;
-
- case 0x1C: /* 28 - Atom Processor */
- cpuidle_state_table = atom_cstates;
- break;
-
- case 0x26: /* 38 - Lincroft Atom Processor */
- cpuidle_state_table = atom_cstates;
- auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE;
- break;
-
- case 0x2A: /* SNB */
- case 0x2D: /* SNB Xeon */
- cpuidle_state_table = snb_cstates;
- break;
-
- default:
- pr_debug(PREFIX "does not run on family %d model %d\n",
- boot_cpu_data.x86, boot_cpu_data.x86_model);
- return -ENODEV;
- }
+ icpu = (const struct idle_cpu *)id->driver_data;
+ cpuidle_state_table = icpu->state_table;

if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
@@ -470,7 +486,7 @@ static int intel_idle_cpuidle_driver_init(void)
drv->state_count += 1;
}

- if (auto_demotion_disable_flags)
+ if (icpu->auto_demotion_disable_flags)
smp_call_function(auto_demotion_disable, NULL, 1);

return 0;
--
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