[PATCH v2 02/12] x86: Control warm reset setup via legacy feature flag

Jan Kiszka
2017-11-27T08:12:13Z

From: Jan Kiszka <jan.kiszka@siemens.com>

Allow to turn off the setup of BIOS-managed warm reset via a new flag in
x86_legacy_features. Besides the UV1, we will soon add another platform
that needs this switched off.

Signed-off-by: Jan Kiszka <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 aa4747569e23..fc2f082ac635 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 e1b8e8bf6b3c..6de35fc8fb3a 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 39a59299bfa0..235fe6008ac8 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 3d01df7d7cf6..21995490fc5e 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -947,7 +947,7 @@ 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");

@@ -1019,7 +1019,7 @@ 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...
*/
--
2.12.3