Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755342AbcDGAJu (ORCPT ); Wed, 6 Apr 2016 20:09:50 -0400 Received: from mail.kernel.org ([198.145.29.136]:55526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754627AbcDGAHA (ORCPT ); Wed, 6 Apr 2016 20:07:00 -0400 From: "Luis R. Rodriguez" To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, rusty@rustcorp.com.au Cc: x86@kernel.org, linux-kernel@vger.kernel.org, luto@amacapital.net, boris.ostrovsky@oracle.com, david.vrabel@citrix.com, konrad.wilk@oracle.com, xen-devel@lists.xensource.com, lguest@lists.ozlabs.org, andriy.shevchenko@linux.intel.com, jlee@suse.com, glin@suse.com, matt@codeblueprint.co.uk, andrew.cooper3@citrix.com, "Luis R. Rodriguez" Subject: [PATCH v4 04/14] x86/rtc: replace paravirt rtc check with platform legacy quirk Date: Wed, 6 Apr 2016 17:06:24 -0700 Message-Id: <1459987594-5434-5-git-send-email-mcgrof@kernel.org> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1459987594-5434-1-git-send-email-mcgrof@kernel.org> References: <1459987594-5434-1-git-send-email-mcgrof@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8731 Lines: 272 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 legacy quirk set early in boot through i386_start_kernel() and through x86_64_start_reservations(). This deals with the RTC quirks which we can rely on through the hardware subarch, the ACPI check can be dealt with separately. v2: split the subarch check from the ACPI check, clarify on the ACPI change commit log why ordering works Suggested-by: Ingo Molnar Signed-off-by: Luis R. Rodriguez --- arch/x86/Makefile | 1 + 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 | 13 +++++++++++++ arch/x86/kernel/Makefile | 6 +++++- arch/x86/kernel/head32.c | 2 ++ arch/x86/kernel/head64.c | 1 + arch/x86/kernel/platform-quirks.c | 18 ++++++++++++++++++ arch/x86/kernel/rtc.c | 7 ++----- arch/x86/lguest/boot.c | 1 - arch/x86/xen/enlighten.c | 3 --- 12 files changed, 42 insertions(+), 22 deletions(-) create mode 100644 arch/x86/kernel/platform-quirks.c diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 4086abca0b32..f9ed8a7ce2b6 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -209,6 +209,7 @@ endif head-y := arch/x86/kernel/head_$(BITS).o head-y += arch/x86/kernel/head$(BITS).o head-y += arch/x86/kernel/head.o +head-y += arch/x86/kernel/platform-quirks.o libs-y += arch/x86/lib/ diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 601f1b8f9961..6c7a4a192032 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -20,12 +20,6 @@ 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 e8c2326478c8..6acc1b26cf40 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 9264476f3d57..0c70c7daa6b8 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -474,7 +474,6 @@ 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..27d5c3fe5198 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -142,6 +142,15 @@ struct x86_cpuinit_ops { struct timespec; /** + * struct x86_legacy_features - legacy x86 features + * + * @rtc: this device has a CMOS real-time clock present + */ +struct x86_legacy_features { + int rtc; +}; + +/** * struct x86_platform_ops - platform specific runtime functions * @calibrate_tsc: calibrate TSC * @get_wallclock: get time from HW clock like RTC etc. @@ -152,6 +161,7 @@ struct timespec; * @save_sched_clock_state: save state for sched_clock() on suspend * @restore_sched_clock_state: restore state for sched_clock() on resume * @apic_post_init: adjust apic if neeeded + * @legacy: legacy features */ struct x86_platform_ops { unsigned long (*calibrate_tsc)(void); @@ -165,6 +175,7 @@ struct x86_platform_ops { void (*save_sched_clock_state)(void); void (*restore_sched_clock_state)(void); void (*apic_post_init)(void); + struct x86_legacy_features legacy; }; struct pci_dev; @@ -186,6 +197,8 @@ extern struct x86_cpuinit_ops x86_cpuinit; extern struct x86_platform_ops x86_platform; extern struct x86_msi_ops x86_msi; extern struct x86_io_apic_ops x86_io_apic_ops; + +extern void x86_early_init_platform_quirks(void); extern void x86_init_noop(void); extern void x86_init_uint_noop(unsigned int unused); diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 89f8ade0bc7c..7a9e44d935de 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -2,7 +2,11 @@ # Makefile for the linux kernel. # -extra-y := head_$(BITS).o head$(BITS).o head.o vmlinux.lds +extra-y := head_$(BITS).o +extra-y += head$(BITS).o +extra-y += head.o +extra-y += platform-quirks.o +extra-y += vmlinux.lds CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE) diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c index 2911ef3a9f1c..d784bb547a9d 100644 --- a/arch/x86/kernel/head32.c +++ b/arch/x86/kernel/head32.c @@ -34,6 +34,8 @@ asmlinkage __visible void __init i386_start_kernel(void) cr4_init_shadow(); sanitize_boot_params(&boot_params); + x86_early_init_platform_quirks(); + /* Call the subarch specific early setup function */ switch (boot_params.hdr.hardware_subarch) { case X86_SUBARCH_INTEL_MID: diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 1f4422d5c8d0..b72fb0b71dd1 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -182,6 +182,7 @@ void __init x86_64_start_reservations(char *real_mode_data) if (!boot_params.hdr.version) copy_bootdata(__va(real_mode_data)); + x86_early_init_platform_quirks(); reserve_ebda_region(); switch (boot_params.hdr.hardware_subarch) { diff --git a/arch/x86/kernel/platform-quirks.c b/arch/x86/kernel/platform-quirks.c new file mode 100644 index 000000000000..1b114ac5996f --- /dev/null +++ b/arch/x86/kernel/platform-quirks.c @@ -0,0 +1,18 @@ +#include +#include + +#include +#include + +void __init x86_early_init_platform_quirks(void) +{ + x86_platform.legacy.rtc = 1; + + switch (boot_params.hdr.hardware_subarch) { + case X86_SUBARCH_XEN: + case X86_SUBARCH_LGUEST: + case X86_SUBARCH_INTEL_MID: + x86_platform.legacy.rtc = 0; + break; + } +} diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c index 4af8d063fb36..62c48da3889d 100644 --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -14,6 +14,7 @@ #include #include #include +#include #ifdef CONFIG_X86_32 /* @@ -188,10 +189,6 @@ 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. */ @@ -200,7 +197,7 @@ static __init int add_rtc_cmos(void) } #endif - if (paravirt_enabled() && !paravirt_has(RTC)) + if (!x86_platform.legacy.rtc) return -ENODEV; platform_device_register(&rtc_device); diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index fd57d3ae7e16..f5497ee5fd2f 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 diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 40487f1ecb4c..7449f268d687 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", }; @@ -1525,8 +1524,6 @@ 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; -- 2.7.2