Commit c33c4054 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'x86-microcode-for-linus' of...

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

Pull x86 microcode changes from Ingo Molnar:
 "A microcode-debugging boot flag plus related refactoring"

* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, microcode: Add a disable chicken bit
  x86, boot: Carve out early cmdline parsing function
parents e30c631b 65cef131
#ifndef _ASM_X86_CMDLINE_H
#define _ASM_X86_CMDLINE_H
int cmdline_find_option_bool(const char *cmdline_ptr, const char *option);
#endif /* _ASM_X86_CMDLINE_H */
......@@ -25,6 +25,7 @@ struct cpu_signature {
struct device;
enum ucode_state { UCODE_ERROR, UCODE_OK, UCODE_NFOUND };
extern bool dis_ucode_ldr;
struct microcode_ops {
enum ucode_state (*request_microcode_user) (int cpu,
......
......@@ -97,6 +97,9 @@ MODULE_LICENSE("GPL");
static struct microcode_ops *microcode_ops;
bool dis_ucode_ldr;
module_param(dis_ucode_ldr, bool, 0);
/*
* Synchronization.
*
......@@ -546,6 +549,9 @@ static int __init microcode_init(void)
struct cpuinfo_x86 *c = &cpu_data(0);
int error;
if (dis_ucode_ldr)
return 0;
if (c->x86_vendor == X86_VENDOR_INTEL)
microcode_ops = init_intel_microcode();
else if (c->x86_vendor == X86_VENDOR_AMD)
......
......@@ -17,9 +17,11 @@
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <asm/microcode.h>
#include <asm/microcode_intel.h>
#include <asm/microcode_amd.h>
#include <asm/processor.h>
#include <asm/cmdline.h>
#define QCHAR(a, b, c, d) ((a) + ((b) << 8) + ((c) << 16) + ((d) << 24))
#define CPUID_INTEL1 QCHAR('G', 'e', 'n', 'u')
......@@ -72,10 +74,33 @@ static int x86_family(void)
return x86;
}
static bool __init check_loader_disabled_bsp(void)
{
#ifdef CONFIG_X86_32
const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
const char *opt = "dis_ucode_ldr";
const char *option = (const char *)__pa_nodebug(opt);
bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
#else /* CONFIG_X86_64 */
const char *cmdline = boot_command_line;
const char *option = "dis_ucode_ldr";
bool *res = &dis_ucode_ldr;
#endif
if (cmdline_find_option_bool(cmdline, option))
*res = true;
return *res;
}
void __init load_ucode_bsp(void)
{
int vendor, x86;
if (check_loader_disabled_bsp())
return;
if (!have_cpuid_p())
return;
......@@ -96,10 +121,22 @@ void __init load_ucode_bsp(void)
}
}
static bool check_loader_disabled_ap(void)
{
#ifdef CONFIG_X86_32
return __pa_nodebug(dis_ucode_ldr);
#else
return dis_ucode_ldr;
#endif
}
void load_ucode_ap(void)
{
int vendor, x86;
if (check_loader_disabled_ap())
return;
if (!have_cpuid_p())
return;
......
......@@ -16,7 +16,7 @@ clean-files := inat-tables.c
obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
lib-y := delay.o misc.o
lib-y := delay.o misc.o cmdline.o
lib-y += thunk_$(BITS).o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
......
/*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
*
* Misc librarized functions for cmdline poking.
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <asm/setup.h>
static inline int myisspace(u8 c)
{
return c <= ' '; /* Close enough approximation */
}
/**
* Find a boolean option (like quiet,noapic,nosmp....)
*
* @cmdline: the cmdline string
* @option: option string to look for
*
* Returns the position of that @option (starts counting with 1)
* or 0 on not found.
*/
int cmdline_find_option_bool(const char *cmdline, const char *option)
{
char c;
int len, pos = 0, wstart = 0;
const char *opptr = NULL;
enum {
st_wordstart = 0, /* Start of word/after whitespace */
st_wordcmp, /* Comparing this word */
st_wordskip, /* Miscompare, skip */
} state = st_wordstart;
if (!cmdline)
return -1; /* No command line */
len = min_t(int, strlen(cmdline), COMMAND_LINE_SIZE);
if (!len)
return 0;
while (len--) {
c = *(char *)cmdline++;
pos++;
switch (state) {
case st_wordstart:
if (!c)
return 0;
else if (myisspace(c))
break;
state = st_wordcmp;
opptr = option;
wstart = pos;
/* fall through */
case st_wordcmp:
if (!*opptr)
if (!c || myisspace(c))
return wstart;
else
state = st_wordskip;
else if (!c)
return 0;
else if (c != *opptr++)
state = st_wordskip;
else if (!len) /* last word and is matching */
return wstart;
break;
case st_wordskip:
if (!c)
return 0;
else if (myisspace(c))
state = st_wordstart;
break;
}
}
return 0; /* Buffer overrun */
}
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