Merge tag 'x86-misc-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git...

Pull misc x86 updates from Thomas Gleixner:
 "A set of updates for the x86 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"

* tag 'x86-misc-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/reboot: Limit Dell Optiplex 990 quirk to early BIOS versions
  x86/reboot: Document how to override DMI platform quirks
  x86/reboot: Document the "reboot=pci" option

diff --combined Documentation/admin-guide/kernel-parameters.txt
index b105db2,34c8dd5..56bd70e
--- 1/Documentation/admin-guide/kernel-parameters.txt
--- 2/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@@ -2421,23 -2421,6 +2421,23 @@@
                        feature (tagged TLBs) on capable Intel chips.
                        Default is 1 (enabled)
  
 +      l1d_flush=      [X86,INTEL]
 +                      Control mitigation for L1D based snooping vulnerability.
 +
 +                      Certain CPUs are vulnerable to an exploit against CPU
 +                      internal buffers which can forward information to a
 +                      disclosure gadget under certain conditions.
 +
 +                      In vulnerable processors, the speculatively
 +                      forwarded data can be used in a cache side channel
 +                      attack, to access data to which the attacker does
 +                      not have direct access.
 +
 +                      This parameter controls the mitigation. The
 +                      options are:
 +
 +                      on         - enable the interface for the mitigation
 +
        l1tf=           [X86] Control mitigation of the L1TF vulnerability on
                              affected CPUs
  
@@@ -4794,7 -4777,7 +4794,7 @@@
  
        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]