| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Wed, 18 Aug 2010 10:41:44 -0700
From: Alok Kataria <akataria@...are.com>
To: "H. Peter Anvin" <hpa@...or.com>,
the arch/x86 maintainers <x86@...nel.org>
Cc: LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH] x86, apic: Add apic calibration hook.
Add a new function pointer calibrate_apic to x86_platform_ops. On native this
does the usual apic calibration. On VMware's platform we override it with a
routine which gets that information from the hypervisor.
Signed-off-by: Alok N Kataria <akataria@...are.com>
Cc: H. Peter Anvin <hpa@...or.com>
Index: linux-x86-tree.git/arch/x86/include/asm/apic.h
===================================================================
--- linux-x86-tree.git.orig/arch/x86/include/asm/apic.h 2010-08-17 15:29:21.000000000 -0700
+++ linux-x86-tree.git/arch/x86/include/asm/apic.h 2010-08-17 15:32:11.000000000 -0700
@@ -238,6 +238,7 @@ extern void setup_boot_APIC_clock(void);
extern void setup_secondary_APIC_clock(void);
extern int APIC_init_uniprocessor(void);
extern void enable_NMI_through_LVT0(void);
+extern unsigned int native_calibrate_apic(void);
/*
* On 32bit this is mach-xxx local
Index: linux-x86-tree.git/arch/x86/include/asm/x86_init.h
===================================================================
--- linux-x86-tree.git.orig/arch/x86/include/asm/x86_init.h 2010-08-17 15:29:21.000000000 -0700
+++ linux-x86-tree.git/arch/x86/include/asm/x86_init.h 2010-08-18 10:20:21.000000000 -0700
@@ -143,6 +143,7 @@ struct x86_cpuinit_ops {
* @is_untracked_pat_range exclude from PAT logic
* @nmi_init enable NMI on cpus
* @i8042_detect pre-detect if i8042 controller exists
+ * @calibrate_apic: calibrate APIC bus freq
*/
struct x86_platform_ops {
unsigned long (*calibrate_tsc)(void);
@@ -152,6 +153,7 @@ struct x86_platform_ops {
bool (*is_untracked_pat_range)(u64 start, u64 end);
void (*nmi_init)(void);
int (*i8042_detect)(void);
+ unsigned int (*calibrate_apic)(void);
};
extern struct x86_init_ops x86_init;
Index: linux-x86-tree.git/arch/x86/kernel/apic/apic.c
===================================================================
--- linux-x86-tree.git.orig/arch/x86/kernel/apic/apic.c 2010-08-17 15:29:21.000000000 -0700
+++ linux-x86-tree.git/arch/x86/kernel/apic/apic.c 2010-08-18 10:20:55.000000000 -0700
@@ -176,7 +176,7 @@ static struct resource lapic_resource =
.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
};
-static unsigned int calibration_result;
+static unsigned int apic_calibration_res;
static int lapic_next_event(unsigned long delta,
struct clock_event_device *evt);
@@ -431,7 +431,7 @@ static void lapic_timer_setup(enum clock
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
case CLOCK_EVT_MODE_ONESHOT:
- __setup_APIC_LVTT(calibration_result,
+ __setup_APIC_LVTT(apic_calibration_res,
mode != CLOCK_EVT_MODE_PERIODIC, 1);
break;
case CLOCK_EVT_MODE_UNUSED:
@@ -590,13 +590,46 @@ calibrate_by_pmtimer(long deltapm, long
return 0;
}
+static void __init initialize_lapic_clkevt(long delta)
+{
+ /* Calculate the scaled math multiplication factor */
+ lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
+ lapic_clockevent.shift);
+ lapic_clockevent.max_delta_ns =
+ clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
+ lapic_clockevent.min_delta_ns =
+ clockevent_delta2ns(0xF, &lapic_clockevent);
+}
+
static int __init calibrate_APIC_clock(void)
{
+ apic_calibration_res = x86_platform.calibrate_apic();
+ if (apic_calibration_res) {
+ struct clock_event_device *levt = &__get_cpu_var(lapic_events);
+ long delta;
+
+ if (lapic_clockevent.mult)
+ return 0;
+
+ delta = (apic_calibration_res * LAPIC_CAL_LOOPS) / APIC_DIVISOR;
+ initialize_lapic_clkevt(delta);
+ levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
+ return 0;
+ } else {
+ pr_warning("Unable to calibrate APIC frequency, "
+ "disabling apic timer\n");
+ return -1;
+ }
+}
+
+unsigned int __init native_calibrate_apic(void)
+{
struct clock_event_device *levt = &__get_cpu_var(lapic_events);
void (*real_handler)(struct clock_event_device *dev);
unsigned long deltaj;
long delta, deltatsc;
int pm_referenced = 0;
+ unsigned int calibration_result;
local_irq_disable();
@@ -631,14 +664,7 @@ static int __init calibrate_APIC_clock(v
pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
&delta, &deltatsc);
- /* Calculate the scaled math multiplication factor */
- lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
- lapic_clockevent.shift);
- lapic_clockevent.max_delta_ns =
- clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
- lapic_clockevent.min_delta_ns =
- clockevent_delta2ns(0xF, &lapic_clockevent);
-
+ initialize_lapic_clkevt(delta);
calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
@@ -664,7 +690,7 @@ static int __init calibrate_APIC_clock(v
if (calibration_result < (1000000 / HZ)) {
local_irq_enable();
pr_warning("APIC frequency too slow, disabling apic timer\n");
- return -1;
+ return 0;
}
levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
@@ -706,10 +732,10 @@ static int __init calibrate_APIC_clock(v
if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
pr_warning("APIC timer disabled due to verification failure\n");
- return -1;
+ return 0;
}
- return 0;
+ return calibration_result;
}
/*
Index: linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c
===================================================================
--- linux-x86-tree.git.orig/arch/x86/kernel/cpu/vmware.c 2010-08-17 15:29:21.000000000 -0700
+++ linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c 2010-08-18 10:20:21.000000000 -0700
@@ -72,17 +72,33 @@ static unsigned long vmware_get_tsc_khz(
return tsc_hz;
}
+static unsigned int vmware_calibrate_apic(void)
+{
+ unsigned int calibration_result;
+ uint32_t eax, ebx, ecx, edx;
+
+ VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
+ BUG_ON(!ecx);
+ calibration_result = ecx / HZ;
+
+ printk(KERN_INFO "APIC bus freq read from hypervisor : %u.%03u MHz\n",
+ calibration_result / (1000000 / HZ),
+ calibration_result % (1000000 / HZ));
+ return calibration_result;
+}
+
static void __init vmware_platform_setup(void)
{
uint32_t eax, ebx, ecx, edx;
VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
- if (ebx != UINT_MAX)
+ if (ebx != UINT_MAX) {
x86_platform.calibrate_tsc = vmware_get_tsc_khz;
- else
+ x86_platform.calibrate_apic = vmware_calibrate_apic;
+ } else
printk(KERN_WARNING
- "Failed to get TSC freq from the hypervisor\n");
+ "Failed to setup VMware hypervisor platform\n");
}
/*
Index: linux-x86-tree.git/arch/x86/kernel/x86_init.c
===================================================================
--- linux-x86-tree.git.orig/arch/x86/kernel/x86_init.c 2010-08-17 15:29:21.000000000 -0700
+++ linux-x86-tree.git/arch/x86/kernel/x86_init.c 2010-08-17 16:44:20.000000000 -0700
@@ -95,7 +95,8 @@ struct x86_platform_ops x86_platform = {
.iommu_shutdown = iommu_shutdown_noop,
.is_untracked_pat_range = is_ISA_range,
.nmi_init = default_nmi_init,
- .i8042_detect = default_i8042_detect
+ .i8042_detect = default_i8042_detect,
+ .calibrate_apic = native_calibrate_apic
};
EXPORT_SYMBOL_GPL(x86_platform);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists