x86/boot: Obsolete the MCA sys_desc_table

The kernel does not support the MCA bus anymroe, so mark sys_desc_table
as obsolete: remove any reference from the code together with the remaining
of MCA logic.

bloat-o-meter output:

  add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-55 (-55)
  function                                     old     new   delta
  i386_start_kernel                            128     119      -9
  setup_arch                                  1421    1375     -46

Signed-off-by: Paolo Pisati <p.pisati@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437409430-8491-1-git-send-email-p.pisati@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

5 files changed, 1 insertions, 49 deletions

diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index 57bbf2fb21f6..0d553e54171b 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -23,7 +23,7 @@ targets		+= fdimage fdimage144 fdimage288 image.iso mtools.conf
 subdir-		:= compressed
 
 setup-y		+= a20.o bioscall.o cmdline.o copy.o cpu.o cpuflags.o cpucheck.o
-setup-y		+= early_serial_console.o edd.o header.o main.o mca.o memory.o
+setup-y		+= early_serial_console.o edd.o header.o main.o memory.o
 setup-y		+= pm.o pmjump.o printf.o regs.o string.o tty.o video.o
 setup-y		+= video-mode.o version.o
 setup-$(CONFIG_X86_APM_BOOT) += apm.o
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index bd49ec61255c..0033e96c3f09 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -307,9 +307,6 @@ void query_edd(void);
 /* header.S */
 void __attribute__((noreturn)) die(void);
 
-/* mca.c */
-int query_mca(void);
-
 /* memory.c */
 int detect_memory(void);
 
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 2c82bd150d43..e140bccf9cf3 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -1041,7 +1041,6 @@ void setup_graphics(struct boot_params *boot_params)
 struct boot_params *make_boot_params(struct efi_config *c)
 {
 	struct boot_params *boot_params;
-	struct sys_desc_table *sdt;
 	struct apm_bios_info *bi;
 	struct setup_header *hdr;
 	struct efi_info *efi;
@@ -1089,7 +1088,6 @@ struct boot_params *make_boot_params(struct efi_config *c)
 	hdr = &boot_params->hdr;
 	efi = &boot_params->efi_info;
 	bi = &boot_params->apm_bios_info;
-	sdt = &boot_params->sys_desc_table;
 
 	/* Copy the second sector to boot_params */
 	memcpy(&hdr->jump, image->image_base + 512, 512);
@@ -1118,8 +1116,6 @@ struct boot_params *make_boot_params(struct efi_config *c)
 	/* Clear APM BIOS info */
 	memset(bi, 0, sizeof(*bi));
 
-	memset(sdt, 0, sizeof(*sdt));
-
 	status = efi_parse_options(cmdline_ptr);
 	if (status != EFI_SUCCESS)
 		goto fail2;
diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c
index fd6c9f236996..9bcea386db65 100644
--- a/arch/x86/boot/main.c
+++ b/arch/x86/boot/main.c
@@ -161,9 +161,6 @@ void main(void)
 	/* Set keyboard repeat rate (why?) and query the lock flags */
 	keyboard_init();
 
-	/* Query MCA information */
-	query_mca();
-
 	/* Query Intel SpeedStep (IST) information */
 	query_ist();
 
diff --git a/arch/x86/boot/mca.c b/arch/x86/boot/mca.c
deleted file mode 100644
index a95a531148ef..000000000000
--- a/arch/x86/boot/mca.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* -*- linux-c -*- ------------------------------------------------------- *
- *
- *   Copyright (C) 1991, 1992 Linus Torvalds
- *   Copyright 2007 rPath, Inc. - All Rights Reserved
- *   Copyright 2009 Intel Corporation; author H. Peter Anvin
- *
- *   This file is part of the Linux kernel, and is made available under
- *   the terms of the GNU General Public License version 2.
- *
- * ----------------------------------------------------------------------- */
-
-/*
- * Get the MCA system description table
- */
-
-#include "boot.h"
-
-int query_mca(void)
-{
-	struct biosregs ireg, oreg;
-	u16 len;
-
-	initregs(&ireg);
-	ireg.ah = 0xc0;
-	intcall(0x15, &ireg, &oreg);
-
-	if (oreg.eflags & X86_EFLAGS_CF)
-		return -1;	/* No MCA present */
-
-	set_fs(oreg.es);
-	len = rdfs16(oreg.bx);
-
-	if (len > sizeof(boot_params.sys_desc_table))
-		len = sizeof(boot_params.sys_desc_table);
-
-	copy_from_fs(&boot_params.sys_desc_table, oreg.bx, len);
-	return 0;
-}