On 1/28/19 11:01 PM, Reza Arbab wrote:
In htab_convert_pte_flags(), _PAGE_CACHE_CTL is used to check for the
_PAGE_SAO flag:
else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
But, it isn't defined to include that flag:
#define _PAGE_CACHE_CTL (_PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT)
This happens to work, but only because of the flag values:
#define _PAGE_SAO 0x00010 /* Strong access order */
#define _PAGE_NON_IDEMPOTENT 0x00020 /* non idempotent memory */
#define _PAGE_TOLERANT 0x00030 /* tolerant memory, cache inhibited
*/
To prevent any issues if these particulars ever change, add _PAGE_SAO to
the mask.
Not sure what the fix is about. We set the related hash pte flags via
if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
rflags |= HPTE_R_I;
else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
rflags |= (HPTE_R_I | HPTE_R_G);
else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
else
/*
* Add memory coherence if cache inhibited is not set
*/
rflags |= HPTE_R_M;
Suggested-by: Charles Johns <crjo...@us.ibm.com>
Signed-off-by: Reza Arbab <ar...@linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h
b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 2e6ada2..1d97a28 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -811,7 +811,7 @@ static inline void __set_pte_at(struct mm_struct *mm,
unsigned long addr,
return hash__set_pte_at(mm, addr, ptep, pte, percpu);
}
-#define _PAGE_CACHE_CTL (_PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT)
+#define _PAGE_CACHE_CTL (_PAGE_SAO | _PAGE_NON_IDEMPOTENT |
_PAGE_TOLERANT)
#define pgprot_noncached pgprot_noncached
static inline pgprot_t pgprot_noncached(pgprot_t prot)
