linux_dsm_epyc7002/arch/parisc/kernel
Helge Deller 527a1d1ede parisc: Fix crash due alternative coding for NP iopdir_fdc bit
According to the found documentation, data cache flushes and sync
instructions are needed on the PCX-U+ (PA8200, e.g. C200/C240)
platforms, while PCX-W (PA8500, e.g. C360) platforms aparently don't
need those flushes when changing the IO PDIR data structures.

We have no documentation for PCX-W+ (PA8600) and PCX-W2 (PA8700) CPUs,
but Carlo Pisani reported that his C3600 machine (PA8600, PCX-W+) fails
when the fdc instructions were removed. His firmware didn't set the NIOP
bit, so one may assume it's a firmware bug since other C3750 machines
had the bit set.

Even if documentation (as mentioned above) states that PCX-W (PA8500,
e.g.  J5000) does not need fdc flushes, Sven could show that an Adaptec
29320A PCI-X SCSI controller reliably failed on a dd command during the
first five minutes in his J5000 when fdc flushes were missing.

Going forward, we will now NOT replace the fdc and sync assembler
instructions by NOPS if:
a) the NP iopdir_fdc bit was set by firmware, or
b) we find a CPU up to and including a PCX-W+ (PA8600).

This fixes the HPMC crashes on a C240 and C36XX machines. For other
machines we rely on the firmware to set the bit when needed.

In case one finds HPMC issues, people could try to boot their machines
with the "no-alternatives" kernel option to turn off any alternative
patching.

Reported-by: Sven Schnelle <svens@stackframe.org>
Reported-by: Carlo Pisani <carlojpisani@gmail.com>
Tested-by: Sven Schnelle <svens@stackframe.org>
Fixes: 3847dab774 ("parisc: Add alternative coding infrastructure")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 5.0+
2019-06-06 14:25:22 +02:00
..
syscalls uapi: Wire up the mount API syscalls on non-x86 arches [ver #2] 2019-05-16 12:23:45 -04:00
.gitignore
alternative.c parisc: Fix crash due alternative coding for NP iopdir_fdc bit 2019-06-06 14:25:22 +02:00
asm-offsets.c
audit.c
cache.c parisc: Use __ro_after_init in cache.c 2019-05-10 21:00:44 +02:00
compat_audit.c
drivers.c parisc: Use __ro_after_init in drivers.c 2019-05-10 21:00:44 +02:00
entry.S parisc: Use per-pagetable spinlock 2019-05-03 23:47:41 +02:00
firmware.c parisc: Use __ro_after_init in firmware.c 2019-05-10 21:00:44 +02:00
ftrace.c function_graph: Place ftrace_graph_entry_stub() prototype in include/linux/ftrace.h 2019-04-29 17:17:22 -04:00
hardware.c
head.S parisc: Use __ro_after_init in head.S 2019-05-10 21:00:44 +02:00
hpmc.S
inventory.c parisc: Use __ro_after_init in inventory.c 2019-05-10 21:00:44 +02:00
irq.c parisc: Improve initial IRQ to CPU assignment 2019-02-21 20:37:11 +01:00
jump_label.c parisc: Add static branch and JUMP_LABEL feature 2019-05-06 00:10:03 +02:00
kgdb.c parisc: add KGDB support 2019-05-03 23:47:38 +02:00
kprobes.c parisc: Implement kretprobes 2019-05-03 23:47:39 +02:00
Makefile parisc: Add static branch and JUMP_LABEL feature 2019-05-06 00:10:03 +02:00
module.c
pa7300lc.c
pacache.S parisc: Remove lock code to serialize TLB operations in pacache.S 2019-05-03 23:47:40 +02:00
parisc_ksyms.c parisc: Switch from DISCONTIGMEM to SPARSEMEM 2019-05-03 23:47:40 +02:00
patch.c parisc: remove unused flags parameter in __patch_text() 2019-05-03 23:47:39 +02:00
pci-dma.c
pci.c parisc: Use __ro_after_init in pci.c 2019-05-10 21:00:44 +02:00
pdc_chassis.c
pdc_cons.c
pdt.c
perf_asm.S
perf_images.h parisc: Use __ro_after_init in perf_images.h 2019-05-10 21:00:44 +02:00
perf.c
process.c parisc: Use __ro_after_init in process.c 2019-05-10 21:00:45 +02:00
processor.c parisc: Use __ro_after_init in processor.c 2019-05-10 21:00:45 +02:00
ptrace.c parisc: add functions required by KPROBE_EVENTS 2019-05-03 23:47:39 +02:00
real2.S
setup.c parisc: Use per-pagetable spinlock 2019-05-03 23:47:41 +02:00
signal32.c
signal32.h
signal.c
smp.c parisc: Count IPI function call interrupts 2019-02-21 20:37:11 +01:00
stacktrace.c parisc/stacktrace: Remove the pointless ULONG_MAX marker 2019-04-14 19:58:29 +02:00
sys_parisc32.c
sys_parisc.c parisc: Consider stack randomization for mmap base only when necessary 2019-05-03 23:47:38 +02:00
syscall.S parisc: Drop LDCW barrier in CAS code when running UP 2019-05-10 21:00:24 +02:00
time.c parisc: Use __ro_after_init in time.c 2019-05-10 21:00:45 +02:00
topology.c
traps.c parisc: Implement kprobes 2019-05-03 23:47:39 +02:00
unaligned.c
unwind.c parisc: Use __ro_after_init in unwind.c 2019-05-10 21:00:45 +02:00
vmlinux.lds.S parisc: Allow building 64-bit kernel without -mlong-calls compiler option 2019-05-20 10:51:39 +02:00