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authorOliver O'Halloran <oohall@gmail.com>2019-07-11 01:05:17 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2019-07-12 01:02:09 +1000
commit33439620680be5225c1b8806579a291e0d761ca0 (patch)
tree5fe6deef47c4b804058fb5f7a3a8a2c3f4285048 /arch
parent73a2b047c81046a7f734a5759ab5fdedbb6968fd (diff)
powerpc/eeh: Handle hugepages in ioremap space
In commit 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap space") support for using hugepages in the vmalloc and ioremap areas was enabled for radix. Unfortunately this broke EEH MMIO error checking. Detection works by inserting a hook which checks the results of the ioreadXX() set of functions. When a read returns a 0xFFs response we need to check for an error which we do by mapping the (virtual) MMIO address back to a physical address, then mapping physical address to a PCI device via an interval tree. When translating virt -> phys we currently assume the ioremap space is only populated by PAGE_SIZE mappings. If a hugepage mapping is found we emit a WARN_ON(), but otherwise handles the check as though a normal page was found. In pathalogical cases such as copying a buffer containing a lot of 0xFFs from BAR memory this can result in the system not booting because it's too busy printing WARN_ON()s. There's no real reason to assume huge pages can't be present and we're prefectly capable of handling them, so do that. Fixes: 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap space") Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190710150517.27114-1-oohall@gmail.com
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/eeh.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 289c0b37d845..0dc1865c84ce 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -367,10 +367,19 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
ptep = find_init_mm_pte(token, &hugepage_shift);
if (!ptep)
return token;
- WARN_ON(hugepage_shift);
- pa = pte_pfn(*ptep) << PAGE_SHIFT;
- return pa | (token & (PAGE_SIZE-1));
+ pa = pte_pfn(*ptep);
+
+ /* On radix we can do hugepage mappings for io, so handle that */
+ if (hugepage_shift) {
+ pa <<= hugepage_shift;
+ pa |= token & ((1ul << hugepage_shift) - 1);
+ } else {
+ pa <<= PAGE_SHIFT;
+ pa |= token & (PAGE_SIZE - 1);
+ }
+
+ return pa;
}
/*