[PATCH v3 10/11] x86/rtc: replace paravirt rtc check with x86 specific solution
From: Luis R. Rodriguez
Date: Tue Feb 23 2016 - 02:24:48 EST
We have 4 types of x86 platforms that disable RTC:
* Intel MID
* Lguest - uses paravirt
* Xen dom-U - uses paravirt
* x86 on legacy systems annotated with an ACPI legacy flag
We can consolidate all of these into a platform specific solution.
Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
---
arch/x86/include/asm/paravirt.h | 6 ------
arch/x86/include/asm/paravirt_types.h | 5 -----
arch/x86/include/asm/processor.h | 1 -
arch/x86/include/asm/x86_init.h | 12 ++++++++++++
arch/x86/kernel/acpi/boot.c | 4 ++++
arch/x86/kernel/rtc.c | 15 ++-------------
arch/x86/lguest/boot.c | 2 +-
arch/x86/platform/intel-mid/intel-mid.c | 3 +++
arch/x86/xen/enlighten.c | 3 ---
arch/x86/xen/time.c | 4 +++-
10 files changed, 25 insertions(+), 30 deletions(-)
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index f6192502149e..c261402340e3 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -19,12 +19,6 @@ static inline int paravirt_enabled(void)
return pv_info.paravirt_enabled;
}
-static inline int paravirt_has_feature(unsigned int feature)
-{
- WARN_ON_ONCE(!pv_info.paravirt_enabled);
- return (pv_info.features & feature);
-}
-
static inline void load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
{
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 77db5616a473..2489d6a08e89 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -70,14 +70,9 @@ struct pv_info {
#endif
int paravirt_enabled;
- unsigned int features; /* valid only if paravirt_enabled is set */
const char *name;
};
-#define paravirt_has(x) paravirt_has_feature(PV_SUPPORTED_##x)
-/* Supported features */
-#define PV_SUPPORTED_RTC (1<<0)
-
struct pv_init_ops {
/*
* Patch may replace one of the defined code sequences with
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 20c11d1aa4cc..10f3614265c1 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -472,7 +472,6 @@ static inline unsigned long current_top_of_stack(void)
#else
#define __cpuid native_cpuid
#define paravirt_enabled() 0
-#define paravirt_has(x) 0
static inline void load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 1ae89a2721d6..0ef697e46f6e 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -1,6 +1,7 @@
#ifndef _ASM_X86_PLATFORM_H
#define _ASM_X86_PLATFORM_H
+#include <linux/bitops.h>
#include <asm/bootparam.h>
struct mpc_bus;
@@ -116,6 +117,7 @@ struct x86_init_pci {
/**
* struct x86_init_ops - functions for platform specific setup
*
+ * @platform_flags: bitmask of enum x86_platform_flags.
*/
struct x86_init_ops {
struct x86_init_resources resources;
@@ -126,6 +128,7 @@ struct x86_init_ops {
struct x86_init_timers timers;
struct x86_init_iommu iommu;
struct x86_init_pci pci;
+ u64 platform_flags;
};
/**
@@ -142,6 +145,15 @@ struct x86_cpuinit_ops {
struct timespec;
/**
+ * enum x86_platform_flags - x86 platform flags
+ *
+ * X86_PLATFORM_NO_RTC: set when platform has no CMOS real-time clock present
+ */
+enum x86_platform_flags {
+ X86_PLATFORM_NO_RTC = BIT(0),
+};
+
+/**
* struct x86_platform_ops - platform specific runtime functions
* @calibrate_tsc: calibrate TSC
* @get_wallclock: get time from HW clock like RTC etc.
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index e75907601a41..d156f6cd2be3 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -913,6 +913,10 @@ late_initcall(hpet_insert_resource);
static int __init acpi_parse_fadt(struct acpi_table_header *table)
{
+ if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC) {
+ pr_debug("ACPI: not registering RTC platform device\n");
+ x86_init.platform_flags |= X86_PLATFORM_NO_RTC;
+ }
#ifdef CONFIG_X86_PM_TIMER
/* detect the location of the ACPI PM Timer */
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 4af8d063fb36..5f95e42ecc68 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -14,6 +14,7 @@
#include <asm/time.h>
#include <asm/intel-mid.h>
#include <asm/rtc.h>
+#include <asm/setup.h>
#ifdef CONFIG_X86_32
/*
@@ -188,19 +189,7 @@ static __init int add_rtc_cmos(void)
if (of_have_populated_dt())
return 0;
- /* Intel MID platforms don't have ioport rtc */
- if (intel_mid_identify_cpu())
- return -ENODEV;
-
-#ifdef CONFIG_ACPI
- if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC) {
- /* This warning can likely go away again in a year or two. */
- pr_info("ACPI: not registering RTC platform device\n");
- return -ENODEV;
- }
-#endif
-
- if (paravirt_enabled() && !paravirt_has(RTC))
+ if (x86_init.platform_flags & X86_PLATFORM_NO_RTC)
return -ENODEV;
platform_device_register(&rtc_device);
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 4ba229ac3f4f..a85add6ce776 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -1414,7 +1414,6 @@ __init void lguest_init(void)
pv_info.kernel_rpl = 1;
/* Everyone except Xen runs with this set. */
pv_info.shared_kernel_pmd = 1;
- pv_info.features = 0;
/*
* We set up all the lguest overrides for sensitive operations. These
@@ -1482,6 +1481,7 @@ __init void lguest_init(void)
x86_init.resources.memory_setup = lguest_memory_setup;
x86_init.irqs.intr_init = lguest_init_IRQ;
x86_init.timers.timer_init = lguest_time_init;
+ x86_init.platform_flags |= X86_PLATFORM_NO_RTC;
x86_platform.calibrate_tsc = lguest_tsc_khz;
x86_platform.get_wallclock = lguest_get_wallclock;
diff --git a/arch/x86/platform/intel-mid/intel-mid.c b/arch/x86/platform/intel-mid/intel-mid.c
index 90bb997ed0a2..17953abcea52 100644
--- a/arch/x86/platform/intel-mid/intel-mid.c
+++ b/arch/x86/platform/intel-mid/intel-mid.c
@@ -175,6 +175,9 @@ void __init x86_intel_mid_early_setup(void)
x86_init.timers.timer_init = intel_mid_time_init;
x86_init.timers.setup_percpu_clockev = x86_init_noop;
+ /* Intel MID platforms don't have ioport rtc */
+ x86_init.platform_flags |= X86_PLATFORM_NO_RTC;
+
x86_init.irqs.pre_vector_init = x86_init_noop;
x86_init.oem.arch_setup = intel_mid_arch_setup;
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 5b3f1c763806..5c06169bce27 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1192,7 +1192,6 @@ static const struct pv_info xen_info __initconst = {
#ifdef CONFIG_X86_64
.extra_user_64bit_cs = FLAT_USER_CS64,
#endif
- .features = 0,
.name = "Xen",
};
@@ -1526,8 +1525,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
/* Install Xen paravirt ops */
pv_info = xen_info;
- if (xen_initial_domain())
- pv_info.features |= PV_SUPPORTED_RTC;
pv_init_ops = xen_init_ops;
if (!xen_pvh_domain()) {
pv_cpu_ops = xen_cpu_ops;
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index a0a4e554c6f1..fbfcb01015f0 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -446,8 +446,10 @@ void __init xen_init_time_ops(void)
x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
/* Dom0 uses the native method to set the hardware RTC. */
- if (!xen_initial_domain())
+ if (!xen_initial_domain()) {
+ x86_init.platform_flags |= X86_PLATFORM_NO_RTC;
x86_platform.set_wallclock = xen_set_wallclock;
+ }
}
#ifdef CONFIG_XEN_PVHVM
--
2.7.0