[GIT pull] x86/misc for v5.15-rc1

[Thomas Gleixner <tglx@linutronix.de>]

Linus,

please pull the latest x86/misc branch from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-misc-2021-08-30

up to:  a729691b541f: x86/reboot: Limit Dell Optiplex 990 quirk to early BIOS versions


A set of updates for the 86 reboot code:

  - Limit the Dell Optiplex 990 quirk to early BIOS versions to avoid the
    full 'power cycle' alike reboot which is required for the buggy BIOSes.

  - Update documentation for the reboot=pci command line option and
    document how DMI platform quirks can be overridden.



Thanks,

	tglx

------------------>
Paul Gortmaker (3):
      x86/reboot: Document the "reboot=pci" option
      x86/reboot: Document how to override DMI platform quirks
      x86/reboot: Limit Dell Optiplex 990 quirk to early BIOS versions


 Documentation/admin-guide/kernel-parameters.txt |  2 +-
 Documentation/x86/x86_64/boot-options.rst       | 11 ++++++++++-
 arch/x86/kernel/reboot.c                        |  3 ++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index bdb22006f713..34c8dd54518e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4777,7 +4777,7 @@
 
 	reboot=		[KNL]
 			Format (x86 or x86_64):
-				[w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \
+				[w[arm] | c[old] | h[ard] | s[oft] | g[pio]] | d[efault] \
 				[[,]s[mp]#### \
 				[[,]b[ios] | a[cpi] | k[bd] | t[riple] | e[fi] | p[ci]] \
 				[[,]f[orce]
diff --git a/Documentation/x86/x86_64/boot-options.rst b/Documentation/x86/x86_64/boot-options.rst
index 5f62b3b86357..ccb7e86bf8d9 100644
--- a/Documentation/x86/x86_64/boot-options.rst
+++ b/Documentation/x86/x86_64/boot-options.rst
@@ -126,7 +126,7 @@ Idle loop
 Rebooting
 =========
 
-   reboot=b[ios] | t[riple] | k[bd] | a[cpi] | e[fi] [, [w]arm | [c]old]
+   reboot=b[ios] | t[riple] | k[bd] | a[cpi] | e[fi] | p[ci] [, [w]arm | [c]old]
       bios
         Use the CPU reboot vector for warm reset
       warm
@@ -145,6 +145,8 @@ Rebooting
         Use efi reset_system runtime service. If EFI is not configured or
         the EFI reset does not work, the reboot path attempts the reset using
         the keyboard controller.
+      pci
+        Use a write to the PCI config space register 0xcf9 to trigger reboot.
 
    Using warm reset will be much faster especially on big memory
    systems because the BIOS will not go through the memory check.
@@ -155,6 +157,13 @@ Rebooting
      Don't stop other CPUs on reboot. This can make reboot more reliable
      in some cases.
 
+   reboot=default
+     There are some built-in platform specific "quirks" - you may see:
+     "reboot: <name> series board detected. Selecting <type> for reboots."
+     In the case where you think the quirk is in error (e.g. you have
+     newer BIOS, or newer board) using this option will ignore the built-in
+     quirk table, and use the generic default reboot actions.
+
 Non Executable Mappings
 =======================
 
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index ebfb91108232..0a40df66a40d 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -388,10 +388,11 @@ static const struct dmi_system_id reboot_dmi_table[] __initconst = {
 	},
 	{	/* Handle problems with rebooting on the OptiPlex 990. */
 		.callback = set_pci_reboot,
-		.ident = "Dell OptiPlex 990",
+		.ident = "Dell OptiPlex 990 BIOS A0x",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
+			DMI_MATCH(DMI_BIOS_VERSION, "A0"),
 		},
 	},
 	{	/* Handle problems with rebooting on Dell 300's */