On Tue, Mar 31, 2020 at 6:44 PM Andrew Cooper <andrew.coop...@citrix.com> wrote: > > On 31/03/2020 23:23, Brian Gerst wrote: > > On Tue, Mar 31, 2020 at 1:59 PM Andrew Cooper <andrew.coop...@citrix.com> > > wrote: > >> Linux has an implementation of the Universal Start-up Algorithm (MP spec, > >> Appendix B.4, Application Processor Startup), which includes > >> unconditionally > >> writing to the Bios Data Area and CMOS registers. > >> > >> The warm reset vector is only necessary in the non-integrated Local APIC > >> case. > >> UV and Jailhouse already have an opt-out for this behaviour, but blindly > >> using > >> the BDA and CMOS on a UEFI or other reduced hardware system isn't clever. > >> > >> We could make this conditional on the integrated-ness of the Local APIC, > >> but > >> 486-era SMP isn't supported. Drop the logic completely, tidying up the > >> includ > >> list and header files as appropriate. > >> > >> CC: Thomas Gleixner <t...@linutronix.de> > >> CC: Ingo Molnar <mi...@redhat.com> > >> CC: Borislav Petkov <b...@alien8.de> > >> CC: "H. Peter Anvin" <h...@zytor.com> > >> CC: x...@kernel.org > >> CC: Jan Kiszka <jan.kis...@siemens.com> > >> CC: James Morris <jmor...@namei.org> > >> CC: David Howells <dhowe...@redhat.com> > >> CC: Andrew Cooper <andrew.coop...@citrix.com> > >> CC: Matthew Garrett <mj...@google.com> > >> CC: Josh Boyer <jwbo...@redhat.com> > >> CC: Steve Wahl <steve.w...@hpe.com> > >> CC: Mike Travis <mike.tra...@hpe.com> > >> CC: Dimitri Sivanich <dimitri.sivan...@hpe.com> > >> CC: Arnd Bergmann <a...@arndb.de> > >> CC: "Peter Zijlstra (Intel)" <pet...@infradead.org> > >> CC: Giovanni Gherdovich <ggherdov...@suse.cz> > >> CC: "Rafael J. Wysocki" <rafael.j.wyso...@intel.com> > >> CC: Len Brown <len.br...@intel.com> > >> CC: Kees Cook <keesc...@chromium.org> > >> CC: Martin Molnar <martin.molnar.programm...@gmail.com> > >> CC: Pingfan Liu <kernelf...@gmail.com> > >> CC: linux-ker...@vger.kernel.org > >> CC: jailhouse-dev@googlegroups.com > >> Suggested-by: "H. Peter Anvin" <h...@zytor.com> > >> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com> > >> --- > >> v2: > >> * Drop logic entirely, rather than retaining support in 32bit builds. > >> --- > >> arch/x86/include/asm/apic.h | 6 ----- > >> arch/x86/include/asm/x86_init.h | 1 - > >> arch/x86/kernel/apic/x2apic_uv_x.c | 1 - > >> arch/x86/kernel/jailhouse.c | 1 - > >> arch/x86/kernel/platform-quirks.c | 1 - > >> arch/x86/kernel/smpboot.c | 50 > >> -------------------------------------- > >> 6 files changed, 60 deletions(-) > >> > >> diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h > >> index 19e94af9cc5d..5c33f9374b28 100644 > >> --- a/arch/x86/include/asm/apic.h > >> +++ b/arch/x86/include/asm/apic.h > >> @@ -472,12 +472,6 @@ static inline unsigned default_get_apic_id(unsigned > >> long x) > >> return (x >> 24) & 0x0F; > >> } > >> > >> -/* > >> - * Warm reset vector position: > >> - */ > >> -#define TRAMPOLINE_PHYS_LOW 0x467 > >> -#define TRAMPOLINE_PHYS_HIGH 0x469 > >> - > >> extern void generic_bigsmp_probe(void); > >> > >> #ifdef CONFIG_X86_LOCAL_APIC > >> diff --git a/arch/x86/include/asm/x86_init.h > >> b/arch/x86/include/asm/x86_init.h > >> index 96d9cd208610..006a5d7fd7eb 100644 > >> --- a/arch/x86/include/asm/x86_init.h > >> +++ b/arch/x86/include/asm/x86_init.h > >> @@ -229,7 +229,6 @@ enum x86_legacy_i8042_state { > >> struct x86_legacy_features { > >> enum x86_legacy_i8042_state i8042; > >> int rtc; > >> - int warm_reset; > >> int no_vga; > >> int reserve_bios_regions; > >> struct x86_legacy_devices devices; > >> diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c > >> b/arch/x86/kernel/apic/x2apic_uv_x.c > >> index ad53b2abc859..5afcfd193592 100644 > >> --- a/arch/x86/kernel/apic/x2apic_uv_x.c > >> +++ b/arch/x86/kernel/apic/x2apic_uv_x.c > >> @@ -343,7 +343,6 @@ static int __init uv_acpi_madt_oem_check(char > >> *_oem_id, char *_oem_table_id) > >> } else if (!strcmp(oem_table_id, "UVH")) { > >> /* Only UV1 systems: */ > >> uv_system_type = UV_NON_UNIQUE_APIC; > >> - x86_platform.legacy.warm_reset = 0; > >> __this_cpu_write(x2apic_extra_bits, pnodeid << > >> uvh_apicid.s.pnode_shift); > >> uv_set_apicid_hibit(); > >> uv_apic = 1; > >> diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c > >> index 6eb8b50ea07e..d628fe92d6af 100644 > >> --- a/arch/x86/kernel/jailhouse.c > >> +++ b/arch/x86/kernel/jailhouse.c > >> @@ -210,7 +210,6 @@ static void __init jailhouse_init_platform(void) > >> x86_platform.calibrate_tsc = jailhouse_get_tsc; > >> x86_platform.get_wallclock = jailhouse_get_wallclock; > >> x86_platform.legacy.rtc = 0; > >> - x86_platform.legacy.warm_reset = 0; > >> x86_platform.legacy.i8042 = X86_LEGACY_I8042_PLATFORM_ABSENT; > >> > >> legacy_pic = &null_legacy_pic; > >> diff --git a/arch/x86/kernel/platform-quirks.c > >> b/arch/x86/kernel/platform-quirks.c > >> index b348a672f71d..d922c5e0c678 100644 > >> --- a/arch/x86/kernel/platform-quirks.c > >> +++ b/arch/x86/kernel/platform-quirks.c > >> @@ -9,7 +9,6 @@ void __init x86_early_init_platform_quirks(void) > >> { > >> x86_platform.legacy.i8042 = X86_LEGACY_I8042_EXPECTED_PRESENT; > >> x86_platform.legacy.rtc = 1; > >> - x86_platform.legacy.warm_reset = 1; > >> x86_platform.legacy.reserve_bios_regions = 0; > >> x86_platform.legacy.devices.pnpbios = 1; > >> > >> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c > >> index fe3ab9632f3b..a9f5b511d0b4 100644 > >> --- a/arch/x86/kernel/smpboot.c > >> +++ b/arch/x86/kernel/smpboot.c > >> @@ -72,7 +72,6 @@ > >> #include <asm/fpu/internal.h> > >> #include <asm/setup.h> > >> #include <asm/uv/uv.h> > >> -#include <linux/mc146818rtc.h> > >> #include <asm/i8259.h> > >> #include <asm/misc.h> > >> #include <asm/qspinlock.h> > >> @@ -119,34 +118,6 @@ int arch_update_cpu_topology(void) > >> return retval; > >> } > >> > >> -static inline void smpboot_setup_warm_reset_vector(unsigned long > >> start_eip) > >> -{ > >> - unsigned long flags; > >> - > >> - spin_lock_irqsave(&rtc_lock, flags); > >> - CMOS_WRITE(0xa, 0xf); > >> - spin_unlock_irqrestore(&rtc_lock, flags); > >> - *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = > >> - start_eip >> 4; > >> - *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = > >> - start_eip & 0xf; > >> -} > >> - > >> -static inline void smpboot_restore_warm_reset_vector(void) > >> -{ > >> - unsigned long flags; > >> - > >> - /* > >> - * Paranoid: Set warm reset code and vector here back > >> - * to default values. > >> - */ > >> - spin_lock_irqsave(&rtc_lock, flags); > >> - CMOS_WRITE(0, 0xf); > >> - spin_unlock_irqrestore(&rtc_lock, flags); > >> - > >> - *((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0; > >> -} > >> - > >> static void init_freq_invariance(void); > >> > >> /* > >> @@ -1049,20 +1020,6 @@ static int do_boot_cpu(int apicid, int cpu, struct > >> task_struct *idle, > >> * the targeted processor. > >> */ > >> > >> - if (x86_platform.legacy.warm_reset) { > >> - > >> - pr_debug("Setting warm reset code and vector.\n"); > >> - > >> - smpboot_setup_warm_reset_vector(start_ip); > >> - /* > >> - * Be paranoid about clearing APIC errors. > >> - */ > >> - if (APIC_INTEGRATED(boot_cpu_apic_version)) { > >> - apic_write(APIC_ESR, 0); > >> - apic_read(APIC_ESR); > >> - } > >> - } > >> - > >> /* > >> * AP might wait on cpu_callout_mask in cpu_init() with > >> * cpu_initialized_mask set if previous attempt to online > >> @@ -1118,13 +1075,6 @@ static int do_boot_cpu(int apicid, int cpu, struct > >> task_struct *idle, > >> } > >> } > >> > >> - if (x86_platform.legacy.warm_reset) { > >> - /* > >> - * Cleanup possible dangling ends... > >> - */ > >> - smpboot_restore_warm_reset_vector(); > >> - } > >> - > >> return boot_error; > >> } > > You removed x86_platform.legacy.warm_reset in the original patch, but > > that is missing in V2. > > Second hunk? Or are you referring to something different?
Removing the warm_reset field from struct x86_legacy_features. -- Brian Gerst -- You received this message because you are subscribed to the Google Groups "Jailhouse" group. To unsubscribe from this group and stop receiving emails from it, send an email to jailhouse-dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/jailhouse-dev/CAMzpN2gdkmYYbQatFk66QMpiuZSfnUQUVtJ30VYF7nsX_%2BXVgA%40mail.gmail.com.