320 строки
7.4 KiB
C
320 строки
7.4 KiB
C
/*
|
|
* Copyright (C) 2003, 2004, 2007 Maciej W. Rozycki
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/stddef.h>
|
|
|
|
#include <asm/bugs.h>
|
|
#include <asm/compiler.h>
|
|
#include <asm/cpu.h>
|
|
#include <asm/fpu.h>
|
|
#include <asm/mipsregs.h>
|
|
#include <asm/setup.h>
|
|
|
|
static char bug64hit[] __initdata =
|
|
"reliable operation impossible!\n%s";
|
|
static char nowar[] __initdata =
|
|
"Please report to <linux-mips@linux-mips.org>.";
|
|
static char r4kwar[] __initdata =
|
|
"Enable CPU_R4000_WORKAROUNDS to rectify.";
|
|
static char daddiwar[] __initdata =
|
|
"Enable CPU_DADDI_WORKAROUNDS to rectify.";
|
|
|
|
static inline void align_mod(const int align, const int mod)
|
|
{
|
|
asm volatile(
|
|
".set push\n\t"
|
|
".set noreorder\n\t"
|
|
".balign %0\n\t"
|
|
".rept %1\n\t"
|
|
"nop\n\t"
|
|
".endr\n\t"
|
|
".set pop"
|
|
:
|
|
: GCC_IMM_ASM() (align), GCC_IMM_ASM() (mod));
|
|
}
|
|
|
|
static inline void mult_sh_align_mod(long *v1, long *v2, long *w,
|
|
const int align, const int mod)
|
|
{
|
|
unsigned long flags;
|
|
int m1, m2;
|
|
long p, s, lv1, lv2, lw;
|
|
|
|
/*
|
|
* We want the multiply and the shift to be isolated from the
|
|
* rest of the code to disable gcc optimizations. Hence the
|
|
* asm statements that execute nothing, but make gcc not know
|
|
* what the values of m1, m2 and s are and what lv2 and p are
|
|
* used for.
|
|
*/
|
|
|
|
local_irq_save(flags);
|
|
/*
|
|
* The following code leads to a wrong result of the first
|
|
* dsll32 when executed on R4000 rev. 2.2 or 3.0 (PRId
|
|
* 00000422 or 00000430, respectively).
|
|
*
|
|
* See "MIPS R4000PC/SC Errata, Processor Revision 2.2 and
|
|
* 3.0" by MIPS Technologies, Inc., errata #16 and #28 for
|
|
* details. I got no permission to duplicate them here,
|
|
* sigh... --macro
|
|
*/
|
|
asm volatile(
|
|
""
|
|
: "=r" (m1), "=r" (m2), "=r" (s)
|
|
: "0" (5), "1" (8), "2" (5));
|
|
align_mod(align, mod);
|
|
/*
|
|
* The trailing nop is needed to fulfill the two-instruction
|
|
* requirement between reading hi/lo and staring a mult/div.
|
|
* Leaving it out may cause gas insert a nop itself breaking
|
|
* the desired alignment of the next chunk.
|
|
*/
|
|
asm volatile(
|
|
".set push\n\t"
|
|
".set noat\n\t"
|
|
".set noreorder\n\t"
|
|
".set nomacro\n\t"
|
|
"mult %2, %3\n\t"
|
|
"dsll32 %0, %4, %5\n\t"
|
|
"mflo $0\n\t"
|
|
"dsll32 %1, %4, %5\n\t"
|
|
"nop\n\t"
|
|
".set pop"
|
|
: "=&r" (lv1), "=r" (lw)
|
|
: "r" (m1), "r" (m2), "r" (s), "I" (0)
|
|
: "hi", "lo", GCC_REG_ACCUM);
|
|
/* We have to use single integers for m1 and m2 and a double
|
|
* one for p to be sure the mulsidi3 gcc's RTL multiplication
|
|
* instruction has the workaround applied. Older versions of
|
|
* gcc have correct umulsi3 and mulsi3, but other
|
|
* multiplication variants lack the workaround.
|
|
*/
|
|
asm volatile(
|
|
""
|
|
: "=r" (m1), "=r" (m2), "=r" (s)
|
|
: "0" (m1), "1" (m2), "2" (s));
|
|
align_mod(align, mod);
|
|
p = m1 * m2;
|
|
lv2 = s << 32;
|
|
asm volatile(
|
|
""
|
|
: "=r" (lv2)
|
|
: "0" (lv2), "r" (p));
|
|
local_irq_restore(flags);
|
|
|
|
*v1 = lv1;
|
|
*v2 = lv2;
|
|
*w = lw;
|
|
}
|
|
|
|
static inline void check_mult_sh(void)
|
|
{
|
|
long v1[8], v2[8], w[8];
|
|
int bug, fix, i;
|
|
|
|
printk("Checking for the multiply/shift bug... ");
|
|
|
|
/*
|
|
* Testing discovered false negatives for certain code offsets
|
|
* into cache lines. Hence we test all possible offsets for
|
|
* the worst assumption of an R4000 I-cache line width of 32
|
|
* bytes.
|
|
*
|
|
* We can't use a loop as alignment directives need to be
|
|
* immediates.
|
|
*/
|
|
mult_sh_align_mod(&v1[0], &v2[0], &w[0], 32, 0);
|
|
mult_sh_align_mod(&v1[1], &v2[1], &w[1], 32, 1);
|
|
mult_sh_align_mod(&v1[2], &v2[2], &w[2], 32, 2);
|
|
mult_sh_align_mod(&v1[3], &v2[3], &w[3], 32, 3);
|
|
mult_sh_align_mod(&v1[4], &v2[4], &w[4], 32, 4);
|
|
mult_sh_align_mod(&v1[5], &v2[5], &w[5], 32, 5);
|
|
mult_sh_align_mod(&v1[6], &v2[6], &w[6], 32, 6);
|
|
mult_sh_align_mod(&v1[7], &v2[7], &w[7], 32, 7);
|
|
|
|
bug = 0;
|
|
for (i = 0; i < 8; i++)
|
|
if (v1[i] != w[i])
|
|
bug = 1;
|
|
|
|
if (bug == 0) {
|
|
printk("no.\n");
|
|
return;
|
|
}
|
|
|
|
printk("yes, workaround... ");
|
|
|
|
fix = 1;
|
|
for (i = 0; i < 8; i++)
|
|
if (v2[i] != w[i])
|
|
fix = 0;
|
|
|
|
if (fix == 1) {
|
|
printk("yes.\n");
|
|
return;
|
|
}
|
|
|
|
printk("no.\n");
|
|
panic(bug64hit, !R4000_WAR ? r4kwar : nowar);
|
|
}
|
|
|
|
static volatile int daddi_ov __cpuinitdata;
|
|
|
|
asmlinkage void __init do_daddi_ov(struct pt_regs *regs)
|
|
{
|
|
daddi_ov = 1;
|
|
regs->cp0_epc += 4;
|
|
}
|
|
|
|
static inline void check_daddi(void)
|
|
{
|
|
extern asmlinkage void handle_daddi_ov(void);
|
|
unsigned long flags;
|
|
void *handler;
|
|
long v, tmp;
|
|
|
|
printk("Checking for the daddi bug... ");
|
|
|
|
local_irq_save(flags);
|
|
handler = set_except_vector(12, handle_daddi_ov);
|
|
/*
|
|
* The following code fails to trigger an overflow exception
|
|
* when executed on R4000 rev. 2.2 or 3.0 (PRId 00000422 or
|
|
* 00000430, respectively).
|
|
*
|
|
* See "MIPS R4000PC/SC Errata, Processor Revision 2.2 and
|
|
* 3.0" by MIPS Technologies, Inc., erratum #23 for details.
|
|
* I got no permission to duplicate it here, sigh... --macro
|
|
*/
|
|
asm volatile(
|
|
".set push\n\t"
|
|
".set noat\n\t"
|
|
".set noreorder\n\t"
|
|
".set nomacro\n\t"
|
|
"addiu %1, $0, %2\n\t"
|
|
"dsrl %1, %1, 1\n\t"
|
|
#ifdef HAVE_AS_SET_DADDI
|
|
".set daddi\n\t"
|
|
#endif
|
|
"daddi %0, %1, %3\n\t"
|
|
".set pop"
|
|
: "=r" (v), "=&r" (tmp)
|
|
: "I" (0xffffffffffffdb9aUL), "I" (0x1234));
|
|
set_except_vector(12, handler);
|
|
local_irq_restore(flags);
|
|
|
|
if (daddi_ov) {
|
|
printk("no.\n");
|
|
return;
|
|
}
|
|
|
|
printk("yes, workaround... ");
|
|
|
|
local_irq_save(flags);
|
|
handler = set_except_vector(12, handle_daddi_ov);
|
|
asm volatile(
|
|
"addiu %1, $0, %2\n\t"
|
|
"dsrl %1, %1, 1\n\t"
|
|
"daddi %0, %1, %3"
|
|
: "=r" (v), "=&r" (tmp)
|
|
: "I" (0xffffffffffffdb9aUL), "I" (0x1234));
|
|
set_except_vector(12, handler);
|
|
local_irq_restore(flags);
|
|
|
|
if (daddi_ov) {
|
|
printk("yes.\n");
|
|
return;
|
|
}
|
|
|
|
printk("no.\n");
|
|
panic(bug64hit, !DADDI_WAR ? daddiwar : nowar);
|
|
}
|
|
|
|
int daddiu_bug = -1;
|
|
|
|
static inline void check_daddiu(void)
|
|
{
|
|
long v, w, tmp;
|
|
|
|
printk("Checking for the daddiu bug... ");
|
|
|
|
/*
|
|
* The following code leads to a wrong result of daddiu when
|
|
* executed on R4400 rev. 1.0 (PRId 00000440).
|
|
*
|
|
* See "MIPS R4400PC/SC Errata, Processor Revision 1.0" by
|
|
* MIPS Technologies, Inc., erratum #7 for details.
|
|
*
|
|
* According to "MIPS R4000PC/SC Errata, Processor Revision
|
|
* 2.2 and 3.0" by MIPS Technologies, Inc., erratum #41 this
|
|
* problem affects R4000 rev. 2.2 and 3.0 (PRId 00000422 and
|
|
* 00000430, respectively), too. Testing failed to trigger it
|
|
* so far.
|
|
*
|
|
* I got no permission to duplicate the errata here, sigh...
|
|
* --macro
|
|
*/
|
|
asm volatile(
|
|
".set push\n\t"
|
|
".set noat\n\t"
|
|
".set noreorder\n\t"
|
|
".set nomacro\n\t"
|
|
"addiu %2, $0, %3\n\t"
|
|
"dsrl %2, %2, 1\n\t"
|
|
#ifdef HAVE_AS_SET_DADDI
|
|
".set daddi\n\t"
|
|
#endif
|
|
"daddiu %0, %2, %4\n\t"
|
|
"addiu %1, $0, %4\n\t"
|
|
"daddu %1, %2\n\t"
|
|
".set pop"
|
|
: "=&r" (v), "=&r" (w), "=&r" (tmp)
|
|
: "I" (0xffffffffffffdb9aUL), "I" (0x1234));
|
|
|
|
daddiu_bug = v != w;
|
|
|
|
if (!daddiu_bug) {
|
|
printk("no.\n");
|
|
return;
|
|
}
|
|
|
|
printk("yes, workaround... ");
|
|
|
|
asm volatile(
|
|
"addiu %2, $0, %3\n\t"
|
|
"dsrl %2, %2, 1\n\t"
|
|
"daddiu %0, %2, %4\n\t"
|
|
"addiu %1, $0, %4\n\t"
|
|
"daddu %1, %2"
|
|
: "=&r" (v), "=&r" (w), "=&r" (tmp)
|
|
: "I" (0xffffffffffffdb9aUL), "I" (0x1234));
|
|
|
|
if (v == w) {
|
|
printk("yes.\n");
|
|
return;
|
|
}
|
|
|
|
printk("no.\n");
|
|
panic(bug64hit, !DADDI_WAR ? daddiwar : nowar);
|
|
}
|
|
|
|
void __init check_bugs64_early(void)
|
|
{
|
|
check_mult_sh();
|
|
check_daddiu();
|
|
}
|
|
|
|
void __init check_bugs64(void)
|
|
{
|
|
check_daddi();
|
|
}
|