Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cleanups from Ingo Molnar:
 "Various cleanups and simplifications, none of them really stands out,
  they are all over the place"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/uaccess: Remove unused __addr_ok() macro
  x86/smpboot: Remove unused phys_id variable
  x86/mm/dump_pagetables: Remove the unused prev_pud variable
  x86/fpu: Move init_xstate_size() to __init section
  x86/cpu_entry_area: Move percpu_setup_debug_store() to __init section
  x86/mtrr: Remove unused variable
  x86/boot/compressed/64: Explain paging_prepare()'s return value
  x86/resctrl: Remove duplicate MSR_MISC_FEATURE_CONTROL definition
  x86/asm/suspend: Drop ENTRY from local data
  x86/hw_breakpoints, kprobes: Remove kprobes ifdeffery
  x86/boot: Save several bytes in decompressor
  x86/trap: Remove useless declaration
  x86/mm/tlb: Remove unused cpu variable
  x86/events: Mark expected switch-case fall-throughs
  x86/asm-prototypes: Remove duplicate include <asm/page.h>
  x86/kernel: Mark expected switch-case fall-throughs
  x86/insn-eval: Mark expected switch-case fall-through
  x86/platform/UV: Replace kmalloc() and memset() with k[cz]alloc() calls
  x86/e820: Replace kmalloc() + memcpy() with kmemdup()

1 files changed, 6 insertions, 5 deletions

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index f62e347862cc..fafb75c6c592 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -358,8 +358,11 @@ ENTRY(startup_64)
 	 * paging_prepare() sets up the trampoline and checks if we need to
 	 * enable 5-level paging.
 	 *
-	 * Address of the trampoline is returned in RAX.
-	 * Non zero RDX on return means we need to enable 5-level paging.
+	 * paging_prepare() returns a two-quadword structure which lands
+	 * into RDX:RAX:
+	 *   - Address of the trampoline is returned in RAX.
+	 *   - Non zero RDX means trampoline needs to enable 5-level
+	 *     paging.
 	 *
 	 * RSI holds real mode data and needs to be preserved across
 	 * this function call.
@@ -565,7 +568,7 @@ adjust_got:
  *
  * RDI contains the return address (might be above 4G).
  * ECX contains the base address of the trampoline memory.
- * Non zero RDX on return means we need to enable 5-level paging.
+ * Non zero RDX means trampoline needs to enable 5-level paging.
  */
 ENTRY(trampoline_32bit_src)
 	/* Set up data and stack segments */
@@ -655,8 +658,6 @@ no_longmode:
 	.data
 gdt64:
 	.word	gdt_end - gdt
-	.long	0
-	.word	0
 	.quad   0
 gdt:
 	.word	gdt_end - gdt