If we changed base page size of the segment, either via sub_page_protect
or via remap_4k_pfn, we do a demote_segment which doesn't flush the hash
table entries. We do that when inserting a new hash pte by checking the
_PAGE_COMBO flag. We missed to do that when inserting hash for a new 16MB
page. Add the same. This patch mark the 4k base page size 16MB hugepage
via _PAGE_COMBO.
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
arch/powerpc/mm/hugepage-hash64.c | 66 +++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/arch/powerpc/mm/hugepage-hash64.c
b/arch/powerpc/mm/hugepage-hash64.c
index 826893fcb3a7..28d1b8b93674 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -18,6 +18,56 @@
#include <linux/mm.h>
#include <asm/machdep.h>
+static void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
+ pmd_t *pmdp, unsigned int psize, int ssize)
+{
+ int i, max_hpte_count, valid;
+ unsigned long s_addr = addr;
+ unsigned char *hpte_slot_array;
+ unsigned long hidx, shift, vpn, hash, slot;
+
+ hpte_slot_array = get_hpte_slot_array(pmdp);
+ /*
+ * IF we try to do a HUGE PTE update after a withdraw is done.
+ * we will find the below NULL. This happens when we do
+ * split_huge_page_pmd
+ */
+ if (!hpte_slot_array)
+ return;
+
+ if (ppc_md.hugepage_invalidate)
+ return ppc_md.hugepage_invalidate(vsid, addr, hpte_slot_array,
+ psize, ssize);
+ /*
+ * No bluk hpte removal support, invalidate each entry
+ */
+ shift = mmu_psize_defs[psize].shift;
+ max_hpte_count = HPAGE_PMD_SIZE >> shift;
+ for (i = 0; i < max_hpte_count; i++) {
+ /*
+ * 8 bits per each hpte entries
+ * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
+ */
+ valid = hpte_valid(hpte_slot_array, i);
+ if (!valid)
+ continue;
+ hidx = hpte_hash_index(hpte_slot_array, i);
+
+ /* get the vpn */
+ addr = s_addr + (i * (1ul << shift));
+ vpn = hpt_vpn(addr, vsid, ssize);
+ hash = hpt_hash(vpn, shift, ssize);
+ if (hidx & _PTEIDX_SECONDARY)
+ hash = ~hash;
+
+ slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+ slot += hidx & _PTEIDX_GROUP_IX;
+ ppc_md.hpte_invalidate(slot, vpn, psize,
+ MMU_PAGE_16M, ssize, 0);
+ }
+}
+
+
int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
pmd_t *pmdp, unsigned long trap, int local, int ssize,
unsigned int psize)
@@ -85,6 +135,15 @@ int __hash_page_thp(unsigned long ea, unsigned long access,
unsigned long vsid,
vpn = hpt_vpn(ea, vsid, ssize);
hash = hpt_hash(vpn, shift, ssize);
hpte_slot_array = get_hpte_slot_array(pmdp);
+ if (psize == MMU_PAGE_4K) {
+ /*
+ * invalidate the old hpte entry if we have that mapped via 64K
+ * base page size. This is because demote_segment won't flush
+ * hash page table entries.
+ */
+ if (!(old_pmd & _PAGE_COMBO))
+ flush_hash_hugepage(vsid, ea, pmdp, MMU_PAGE_64K,
ssize);
+ }
valid = hpte_valid(hpte_slot_array, index);
if (valid) {
@@ -172,6 +231,13 @@ repeat:
mark_hpte_slot_valid(hpte_slot_array, index, slot);
}
/*
+ * Mark the pte with _PAGE_COMBO, if we are trying to hash it with
+ * base page size 4k.
+ */
+ if (psize == MMU_PAGE_4K)
+ new_pmd |= _PAGE_COMBO;
+
+ /*
* No need to use ldarx/stdcx here
*/
*pmdp = __pmd(new_pmd & ~_PAGE_BUSY);
--
1.9.1
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