linux/arch/mips/kernel
Maciej W. Rozycki 326f02f172 MIPS: Fix CP0 counter erratum detection for R4k CPUs
commit f0a6c68f69 upstream.

Fix the discrepancy between the two places we check for the CP0 counter
erratum in along with the incorrect comparison of the R4400 revision
number against 0x30 which matches none and consistently consider all
R4000 and R4400 processors affected, as documented in processor errata
publications[1][2][3], following the mapping between CP0 PRId register
values and processor models:

  PRId   |  Processor Model
---------+--------------------
00000422 | R4000 Revision 2.2
00000430 | R4000 Revision 3.0
00000440 | R4400 Revision 1.0
00000450 | R4400 Revision 2.0
00000460 | R4400 Revision 3.0

No other revision of either processor has ever been spotted.

Contrary to what has been stated in commit ce202cbb9e ("[MIPS] Assume
R4000/R4400 newer than 3.0 don't have the mfc0 count bug") marking the
CP0 counter as buggy does not preclude it from being used as either a
clock event or a clock source device.  It just cannot be used as both at
a time, because in that case clock event interrupts will be occasionally
lost, and the use as a clock event device takes precedence.

Compare against 0x4ff in `can_use_mips_counter' so that a single machine
instruction is produced.

References:

[1] "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", MIPS
    Technologies Inc., May 10, 1994, Erratum 53, p.13

[2] "MIPS R4400PC/SC Errata, Processor Revision 1.0", MIPS Technologies
    Inc., February 9, 1994, Erratum 21, p.4

[3] "MIPS R4400PC/SC Errata, Processor Revision 2.0 & 3.0", MIPS
    Technologies Inc., January 24, 1995, Erratum 14, p.3

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: ce202cbb9e ("[MIPS] Assume R4000/R4400 newer than 3.0 don't have the mfc0 count bug")
Cc: stable@vger.kernel.org # v2.6.24+
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-12 12:25:29 +02:00
..
syscalls mm/madvise: introduce process_madvise() syscall: an external memory hinting API 2020-10-18 09:27:10 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
asm-offsets.c
binfmt_elfn32.c MIPS: Fix malformed NT_FILE and NT_SIGINFO in 32bit coredumps 2021-01-19 18:27:20 +01:00
binfmt_elfo32.c MIPS: Fix malformed NT_FILE and NT_SIGINFO in 32bit coredumps 2021-01-19 18:27:20 +01:00
bmips_5xxx_init.S
bmips_vec.S
branch.c MIPS: kernel: include probes-common.h header in branch.c 2020-09-21 22:14:24 +02:00
cacheinfo.c drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION() 2021-09-26 14:08:59 +02:00
cevt-bcm1480.c MIPS: Replace setup_irq() by request_irq() 2020-03-05 16:47:35 +01:00
cevt-ds1287.c MIPS: Replace setup_irq() by request_irq() 2020-03-05 16:47:35 +01:00
cevt-gt641xx.c MIPS: Replace setup_irq() by request_irq() 2020-03-05 16:47:35 +01:00
cevt-r4k.c mips: cevt-r4k: Update the r4k-clockevent frequency in sync with CPU 2020-05-22 09:14:32 +02:00
cevt-sb1250.c MIPS: Replace setup_irq() by request_irq() 2020-03-05 16:47:35 +01:00
cevt-txx9.c MIPS: Replace setup_irq() by request_irq() 2020-03-05 16:47:35 +01:00
cmpxchg.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cps-vec-ns16550.S mips: Add CPS_NS16550_WIDTH config 2020-05-22 09:12:52 +02:00
cps-vec.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cpu-probe.c MIPS: loongson64: fix FTLB configuration 2021-12-01 09:19:07 +01:00
cpu-r3k-probe.c MIPS: cpu-probe: introduce exclusive R3k CPU probe 2020-10-12 12:05:16 +02:00
crash_dump.c
crash.c
csrc-bcm1480.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
csrc-ioasic.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
csrc-r4k.c mips: csrc-r4k: Mark R4K timer as unstable if CPU freq changes 2020-05-22 09:14:06 +02:00
csrc-sb1250.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
early_printk_8250.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1 2019-05-21 11:28:39 +02:00
early_printk.c
elf.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
entry.S mips: Add MIPS Release 5 support 2020-05-22 09:09:01 +02:00
fpu-probe.c MIPS: cpu-probe: move fpu probing/handling into its own file 2020-10-12 12:04:50 +02:00
fpu-probe.h MIPS: cpu-probe: move fpu probing/handling into its own file 2020-10-12 12:04:50 +02:00
ftrace.c MIPS: ftrace: Remove redundant #ifdef CONFIG_DYNAMIC_FTRACE 2020-08-17 13:00:24 +02:00
genex.S MIPS: handle Loongson-specific GSExc exception 2020-07-31 17:52:47 +02:00
gpio_txx9.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
head.S MIPS: Loongson-3: Enable COP2 usage in kernel 2020-09-21 22:15:03 +02:00
i8253.c MIPS: Replace setup_irq() by request_irq() 2020-03-05 16:47:35 +01:00
idle.c sched/idle: Fix arch_cpu_idle() vs tracing 2020-11-24 16:47:35 +01:00
irq_txx9.c
irq-gt641xx.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1 2019-05-21 11:28:39 +02:00
irq-msc01.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
irq-rm7000.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
irq.c
jump_label.c
kgdb.c
kprobes.c mips: kprobes: Use generic kretprobe trampoline handler 2020-09-08 11:52:33 +02:00
linux32.c
machine_kexec.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230 2019-06-19 17:09:06 +02:00
Makefile MIPS: cpu-probe: introduce exclusive R3k CPU probe 2020-10-12 12:05:16 +02:00
mcount.S
mips-cm.c mips: cm: Convert to bitfield API to fix out-of-bounds access 2021-11-18 14:04:21 +01:00
mips-cpc.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
mips-mt-fpaff.c MIPS: Use rcu to lookup a task in mipsmt_sys_sched_setaffinity() 2020-09-03 10:13:43 +02:00
mips-mt.c
mips-r2-to-r6-emul.c MIPS: Use fallthrough for arch/mips 2020-05-07 11:55:47 +02:00
module.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
octeon_switch.S
perf_event_mipsxx.c MIPS: perf: Fix wrong check condition of Loongson event IDs 2020-09-01 13:52:33 +02:00
perf_event.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pm-cps.c MIPS: barrier: Add __SYNC() infrastructure 2019-10-07 09:42:17 -07:00
pm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
probes-common.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
proc.c mips: Add MIPS Release 5 support 2020-05-22 09:09:01 +02:00
process.c MIPS: process: include exec.h header in process.c 2020-09-30 21:53:00 +02:00
prom.c MIPS: replace add_memory_region with memblock 2020-10-12 12:01:36 +02:00
ptrace.c mips: switch to ->regset_get() 2020-07-27 14:31:08 -04:00
ptrace32.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
r4k_fpu.S mips: Add MIPS Release 5 support 2020-05-22 09:09:01 +02:00
r4k_switch.S
r4k-bugs64.c MIPS: r4k-bugs64: Drop CONFIG_CPU_MIPSR6 checks 2019-10-07 09:38:54 -07:00
r2300_fpu.S signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT 2021-11-18 14:03:47 +01:00
r2300_switch.S
relocate_kernel.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230 2019-06-19 17:09:06 +02:00
relocate.c MIPS: relocatable: fix possible boot hangup with KASLR enabled 2021-01-19 18:27:20 +01:00
reset.c
rtlx-cmp.c
rtlx-mt.c MIPS: Replace setup_irq() by request_irq() 2020-03-05 16:47:35 +01:00
rtlx.c
scall32-o32.S mips: remove nargs from __SYSCALL 2019-07-30 10:50:30 -07:00
scall64-n32.S mips: remove nargs from __SYSCALL 2019-07-30 10:50:30 -07:00
scall64-n64.S mips: remove nargs from __SYSCALL 2019-07-30 10:50:30 -07:00
scall64-o32.S MIPS: asm: Rename some macros to avoid build errors 2020-05-07 13:20:05 +02:00
segment.c
setup.c MIPS: Don't round up kernel sections size for memblock_add() 2020-12-30 11:53:34 +01:00
signal_n32.c Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2019-07-08 21:48:15 -07:00
signal_o32.c signal: Remove task parameter from force_sig 2019-05-27 09:36:28 -05:00
signal-common.h
signal.c tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume() 2020-10-17 15:04:36 -06:00
signal32.c
smp-bmips.c MIPS: BMIPS: Also call bmips_cpu_setup() for secondary cores 2020-08-21 09:29:09 +02:00
smp-cmp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 182 2019-05-30 11:29:20 -07:00
smp-cps.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
smp-mt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 182 2019-05-30 11:29:20 -07:00
smp-up.c
smp.c MIPS: smp: fill in sibling and core maps earlier 2022-03-19 13:44:44 +01:00
spinlock_test.c
spram.c mips: Add CONFIG/CONFIG6/Cause reg fields macro 2020-05-22 09:12:22 +02:00
stacktrace.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
sync-r4k.c MIPS: sync-r4k: do slave counter synchronization with disabled HW interrupts 2020-01-22 10:16:18 -08:00
syscall.c signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT 2021-11-18 14:03:47 +01:00
sysrq.c MIPS: constify sysrq_key_op 2020-05-15 14:53:19 +02:00
time.c MIPS: Fix CP0 counter erratum detection for R4k CPUs 2022-05-12 12:25:29 +02:00
topology.c MIPS: CPU#0 is not hotpluggable 2020-07-26 10:18:35 +02:00
traps.c MIPS: fix fortify panic when copying asm exception handlers 2022-04-13 21:00:59 +02:00
unaligned.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
uprobes.c MIPS: uprobes: remove set but not used variable 'epc' 2019-05-29 13:20:30 -07:00
vdso.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
vmlinux.lds.S MIPS: properly stop .eh_frame generation 2021-03-04 11:37:41 +01:00
vpe-cmp.c
vpe-mt.c
vpe.c MIPS: VPE: Fix a double free and a memory leak in 'release_vpe()' 2020-02-15 12:44:03 -08:00
watch.c MIPS: Use fallthrough for arch/mips 2020-05-07 11:55:47 +02:00