powerpc: New hugepage directory format
Change the hugepage directory format so that we can have leaf ptes directly
at page directory avoiding the allocation of hugepage directory.
With the new table format we have 3 cases for pgds and pmds:
(1) invalid (all zeroes)
(2) pointer to next table, as normal; bottom 6 bits == 0
(4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table
Instead of storing shift value in hugepd pointer we use mmu_psize_def index
so that we can fit all the supported hugepage size in 4 bits
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index f072e97..652719c 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -249,6 +249,7 @@
#define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
#endif
+#ifndef CONFIG_PPC_BOOK3S_64
/*
* Use the top bit of the higher-level page table entries to indicate whether
* the entries we point to contain hugepages. This works because we know that
@@ -260,6 +261,7 @@
#else
#define PD_HUGE 0x80000000
#endif
+#endif /* CONFIG_PPC_BOOK3S_64 */
/*
* Some number of bits at the level of the page table that points to
@@ -354,10 +356,21 @@
typedef struct { signed long pd; } hugepd_t;
#ifdef CONFIG_HUGETLB_PAGE
+#ifdef CONFIG_PPC_BOOK3S_64
+static inline int hugepd_ok(hugepd_t hpd)
+{
+ /*
+ * hugepd pointer, bottom two bits == 00 and next 4 bits
+ * indicate size of table
+ */
+ return (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
+}
+#else
static inline int hugepd_ok(hugepd_t hpd)
{
return (hpd.pd > 0);
}
+#endif
#define is_hugepd(pdep) (hugepd_ok(*((hugepd_t *)(pdep))))
#else /* CONFIG_HUGETLB_PAGE */