[tip:x86/platform] x86/platform: Control warm reset setup via legacy feature flag

tip-bot for Jan Kiszka
2018-01-14T20:35:39Z

Commit-ID: e348caef8b4a161cc27bec8f7500b7e100370ef1
Gitweb: https://git.kernel.org/tip/e348caef8b4a161cc27bec8f7500b7e100370ef1
Author: Jan Kiszka <jan.kiszka@siemens.com>
AuthorDate: Mon, 27 Nov 2017 09:11:44 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 14 Jan 2018 21:11:53 +0100

x86/platform: Control warm reset setup via legacy feature flag

Allow to turn off the setup of BIOS-managed warm reset via a new flag in
x86_legacy_features. Besides the UV1, the upcoming jailhose guest support
needs this switched off.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/44376558129d70a2c1527959811371ef4b82e829.1511770314.git.jan.kiszka@siemens.com

---
arch/x86/include/asm/x86_init.h | 1 +
arch/x86/kernel/apic/x2apic_uv_x.c | 1 +
arch/x86/kernel/platform-quirks.c | 1 +
arch/x86/kernel/smpboot.c | 4 ++--
4 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index aa47475..fc2f082 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -212,6 +212,7 @@ 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 e1b8e8b..6de35fc 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -316,6 +316,7 @@ 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/platform-quirks.c b/arch/x86/kernel/platform-quirks.c
index 39a5929..235fe60 100644
--- a/arch/x86/kernel/platform-quirks.c
+++ b/arch/x86/kernel/platform-quirks.c
@@ -9,6 +9,7 @@ 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 ed556d5..9adcae1 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -934,7 +934,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
* the targeted processor.
*/

- if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
+ if (x86_platform.legacy.warm_reset) {

pr_debug("Setting warm reset code and vector.\n");

@@ -1006,7 +1006,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
/* mark "stuck" area as not stuck */
*trampoline_status = 0;

- if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
+ if (x86_platform.legacy.warm_reset) {
/*
* Cleanup possible dangling ends...
*/