parisc architecture fix for v6.10-rc4

Hi Linus,

Please pull one fix for the parisc architecture for 6.10-rc4.

On parisc we have suffered since years from random segfaults which seem to have been triggered due to cache inconsistencies. Those segfaults happened more often on machines with PA8800 and PA8900 CPUs, which have much bigger caches than the earlier machines.

Dave Anglin has worked over the last few weeks to fix this bug. His patch has been successfully tested by various people on various machines and with various kernels (6.6, 6.8 and 6.9), and the debian buildd servers haven't shown a single random segfault with this patch.

Since the cache handling has been reworked, the patch is slightly bigger than I would like in this stage, but the greatly improved stability IMHO justifies the inclusion now.

Please pull.

Thanks!
Helge

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The following changes since commit 83a7eefedc9b56fe7bfeff13b6c7356688ffa670:

Linux 6.10-rc3 (2024-06-09 14:19:43 -0700)

are available in the Git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git tags/parisc-for-6.10-rc4

for you to fetch changes up to 72d95924ee35c8cd16ef52f912483ee938a34d49:

parisc: Try to fix random segmentation faults in package builds (2024-06-12 01:57:05 +0200)

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parisc architecture fix for kernel v6.10-rc4:

One patch from John David Anglin which reworks the parisc cache flushing routines with the aim to fix the random segmentation faults on machines with PA8800 and PA8900 processors. We have faced those segfaults since many years, but with this patch no single segfault could be triggered any longer. The patch was tested by 3 people on 5 different machines with various stable kernels (6.6, 6.8 and 6.9).

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John David Anglin (1):
parisc: Try to fix random segmentation faults in package builds

 arch/parisc/include/asm/cacheflush.h |  15 +-
 arch/parisc/include/asm/pgtable.h    |  27 +--
 arch/parisc/kernel/cache.c           | 413 ++++++++++++++++++++++-------------
 3 files changed, 275 insertions(+), 180 deletions(-)