sst-linux/arch/mips/kernel
Maciej W. Rozycki f0a6c68f69 MIPS: Fix CP0 counter erratum detection for R4k CPUs
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>
2022-04-29 15:52:00 +02:00
..
syscalls arch: syscalls: simplify uapi/kapi directory creation 2022-03-31 12:03:46 +09:00
.gitignore
access-helper.h
asm-offsets.c sched,arch: Remove unused TASK_STATE offsets 2021-06-18 11:43:09 +02:00
bmips_5xxx_init.S
bmips_vec.S
branch.c
cacheinfo.c drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION() 2021-09-01 10:29:10 +02:00
cevt-bcm1480.c
cevt-ds1287.c
cevt-gt641xx.c
cevt-r4k.c
cevt-sb1250.c
cevt-txx9.c
cmpxchg.c
cps-vec-ns16550.S
cps-vec.S
cpu-probe.c MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
cpu-r3k-probe.c MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
crash_dump.c
crash.c
csrc-bcm1480.c
csrc-ioasic.c
csrc-r4k.c
csrc-sb1250.c
early_printk_8250.c
early_printk.c
elf.c MIPS: Modernize READ_IMPLIES_EXEC 2022-02-23 13:08:30 +01:00
entry.S MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
fpu-probe.c
fpu-probe.h
ftrace.c
genex.S MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
gpio_txx9.c
head.S
i8253.c
idle.c MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
irq_txx9.c MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
irq-gt641xx.c
irq-msc01.c
irq.c MIPS: Only use current_stack_pointer on GCC 2022-03-14 15:02:53 +01:00
jump_label.c
kgdb.c
kprobes.c kprobes: treewide: Make it harder to refer kretprobe_trampoline directly 2021-09-30 21:24:06 -04:00
linux32.c
machine_kexec.c
Makefile MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
mcount.S
mips-cm.c mips: cm: Convert to bitfield API to fix out-of-bounds access 2021-11-02 10:53:52 +01:00
mips-cpc.c MIPS: CPC: Use bitfield helpers 2021-11-29 12:42:57 +01:00
mips-mt-fpaff.c MIPS: Replace deprecated CPU-hotplug functions. 2021-08-05 10:57:01 +02:00
mips-mt.c
mips-r2-to-r6-emul.c MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
module.c
octeon_switch.S
perf_event_mipsxx.c MIPS: Remove NETLOGIC support 2021-10-24 17:24:47 +02:00
perf_event.c
perf_regs.c
pm-cps.c
pm.c
probes-common.h
proc.c MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
process.c MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
prom.c MIPS: Remove redundant definitions of device_tree_init() 2022-03-14 15:09:02 +01:00
ptrace32.c
ptrace.c ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h 2022-03-10 13:35:08 -06:00
r4k_fpu.S MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
r4k_switch.S
r4k-bugs64.c MIPS: remove asm/war.h 2022-02-22 09:35:49 +01:00
r2300_fpu.S MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
r2300_switch.S
relocate_kernel.S MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
relocate.c kernel.h: split out panic and oops helpers 2021-07-01 11:06:04 -07:00
reset.c
rtlx-cmp.c
rtlx-mt.c
rtlx.c
scall32-o32.S MIPS: remove asm/war.h 2022-02-22 09:35:49 +01:00
scall64-n32.S MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
scall64-n64.S MIPS: remove asm/war.h 2022-02-22 09:35:49 +01:00
scall64-o32.S MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
segment.c
setup.c mips: setup: fix setnocoherentio() boolean setting 2022-02-22 09:35:02 +01:00
signal32.c
signal_n32.c MIPS: remove asm/war.h 2022-02-22 09:35:49 +01:00
signal_o32.c
signal-common.h
signal.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
smp-bmips.c MIPS: BMIPS: Remove use of irq_cpu_offline 2021-10-20 20:06:32 +01:00
smp-cmp.c
smp-cps.c
smp-mt.c
smp-up.c
smp.c MIPS: smp: fill in sibling and core maps earlier 2022-02-16 20:48:10 +01:00
spinlock_test.c
spram.c
stacktrace.c
sync-r4k.c
syscall.c MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
sysrq.c
time.c MIPS: Fix CP0 counter erratum detection for R4k CPUs 2022-04-29 15:52:00 +02:00
topology.c drivers/base/node: consolidate node device subsystem initialization in node_dev_init() 2022-03-22 15:57:10 -07:00
traps.c MIPS: fix fortify panic when copying asm exception handlers 2022-03-07 13:09:28 +01:00
unaligned.c MIPS: Handle address errors for accesses above CPU max virtual user address 2022-02-25 09:36:05 +01:00
uprobes.c MIPS: Fix fall-through warnings for Clang 2021-10-13 14:47:42 -05:00
vdso.c
vmlinux.lds.S
vpe-cmp.c
vpe-mt.c
vpe.c
watch.c