OpenCloudOS-Kernel/arch/mips/kernel/r4k-bugs64.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2003, 2004, 2007 Maciej W. Rozycki
*/
#include <linux/context_tracking.h>
#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>
[MIPS] R4000/R4400 errata workarounds This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-23 19:43:11 +08:00
static char bug64hit[] __initdata =
"reliable operation impossible!\n%s";
static char nowar[] __initdata =
"Please report to <linux-mips@vger.kernel.org>.";
[MIPS] R4000/R4400 errata workarounds This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-23 19:43:11 +08:00
static char r4kwar[] __initdata =
"Enable CPU_R4000_WORKAROUNDS to rectify.";
static char daddiwar[] __initdata =
"Enable CPU_DADDI_WORKAROUNDS to rectify.";
static __always_inline __init
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"
:
: "n"(align), "n"(mod));
}
static __always_inline __init
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", "$0");
/* 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 __always_inline __init 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) {
pr_cont("no.\n");
return;
}
pr_cont("yes, workaround... ");
fix = 1;
for (i = 0; i < 8; i++)
if (v2[i] != w[i])
fix = 0;
if (fix == 1) {
pr_cont("yes.\n");
return;
}
pr_cont("no.\n");
panic(bug64hit,
IS_ENABLED(CONFIG_CPU_R4000_WORKAROUNDS) ? nowar : r4kwar);
}
MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code commit 3747069b25e419f6b51395f48127e9812abc3596 upstream. The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. Here, we remove all the MIPS __cpuinit from C code and __CPUINIT from asm files. MIPS is interesting in this respect, because there are also uasm users hiding behind their own renamed versions of the __cpuinit macros. [1] https://lkml.org/lkml/2013/5/20/589 [ralf@linux-mips.org: Folded in Paul's followup fix.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5494/ Patchwork: https://patchwork.linux-mips.org/patch/5495/ Patchwork: https://patchwork.linux-mips.org/patch/5509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-18 21:38:59 +08:00
static volatile int daddi_ov;
asmlinkage void __init do_daddi_ov(struct pt_regs *regs)
{
enum ctx_state prev_state;
prev_state = exception_enter();
daddi_ov = 1;
regs->cp0_epc += 4;
exception_exit(prev_state);
}
static __init 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(EXCCODE_OV, 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(EXCCODE_OV, handler);
local_irq_restore(flags);
if (daddi_ov) {
pr_cont("no.\n");
return;
}
pr_cont("yes, workaround... ");
local_irq_save(flags);
handler = set_except_vector(EXCCODE_OV, 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(EXCCODE_OV, handler);
local_irq_restore(flags);
if (daddi_ov) {
pr_cont("yes.\n");
return;
}
pr_cont("no.\n");
panic(bug64hit,
IS_ENABLED(CONFIG_CPU_DADDI_WORKAROUNDS) ? nowar : daddiwar);
}
int daddiu_bug = -1;
[MIPS] R4000/R4400 errata workarounds This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-23 19:43:11 +08:00
static __init 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));
[MIPS] R4000/R4400 errata workarounds This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-23 19:43:11 +08:00
daddiu_bug = v != w;
if (!daddiu_bug) {
pr_cont("no.\n");
return;
}
pr_cont("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) {
pr_cont("yes.\n");
return;
}
pr_cont("no.\n");
panic(bug64hit,
IS_ENABLED(CONFIG_CPU_DADDI_WORKAROUNDS) ? nowar : daddiwar);
}
[MIPS] R4000/R4400 errata workarounds This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-23 19:43:11 +08:00
void __init check_bugs64_early(void)
{
check_mult_sh();
check_daddiu();
}
[MIPS] R4000/R4400 errata workarounds This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-23 19:43:11 +08:00
void __init check_bugs64(void)
{
check_daddi();
[MIPS] R4000/R4400 errata workarounds This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-23 19:43:11 +08:00
}