powerpc/mm: Cleanup initialization of hugepages on powerpc
This patch simplifies the logic used to initialize hugepages on
powerpc. The somewhat oddly named set_huge_psize() is renamed to
add_huge_page_size() and now does all necessary verification of
whether it's given a valid hugepage sizes (instead of just some) and
instantiates the generic hstate structure (but no more).
hugetlbpage_init() now steps through the available pagesizes, checks
if they're valid for hugepages by calling add_huge_page_size() and
initializes the kmem_caches for the hugepage pagetables. This means
we can now eliminate the mmu_huge_psizes array, since we no longer
need to pass the sizing information for the pagetable caches from
set_huge_psize() into hugetlbpage_init()
Determination of the default huge page size is also moved from the
hash code into the general hugepage code.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 95220a5..a7161c0 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -37,27 +37,17 @@
static unsigned long gpage_freearray[MAX_NUMBER_GPAGES];
static unsigned nr_gpages;
-/* Array of valid huge page sizes - non-zero value(hugepte_shift) is
- * stored for the huge page sizes that are valid.
- */
-static unsigned int mmu_huge_psizes[MMU_PAGE_COUNT] = { }; /* initialize all to 0 */
-
/* Flag to mark huge PD pointers. This means pmd_bad() and pud_bad()
* will choke on pointers to hugepte tables, which is handy for
* catching screwups early. */
static inline int shift_to_mmu_psize(unsigned int shift)
{
- switch (shift) {
-#ifndef CONFIG_PPC_64K_PAGES
- case PAGE_SHIFT_64K:
- return MMU_PAGE_64K;
-#endif
- case PAGE_SHIFT_16M:
- return MMU_PAGE_16M;
- case PAGE_SHIFT_16G:
- return MMU_PAGE_16G;
- }
+ int psize;
+
+ for (psize = 0; psize < MMU_PAGE_COUNT; ++psize)
+ if (mmu_psize_defs[psize].shift == shift)
+ return psize;
return -1;
}
@@ -502,8 +492,6 @@
struct hstate *hstate = hstate_file(file);
int mmu_psize = shift_to_mmu_psize(huge_page_shift(hstate));
- if (!mmu_huge_psizes[mmu_psize])
- return -EINVAL;
return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1, 0);
}
@@ -666,47 +654,46 @@
return err;
}
-static void __init set_huge_psize(int psize)
+static int __init add_huge_page_size(unsigned long long size)
{
- unsigned pdshift;
+ int shift = __ffs(size);
+ int mmu_psize;
/* Check that it is a page size supported by the hardware and
- * that it fits within pagetable limits. */
- if (mmu_psize_defs[psize].shift &&
- mmu_psize_defs[psize].shift < SID_SHIFT_1T &&
- (mmu_psize_defs[psize].shift > MIN_HUGEPTE_SHIFT ||
- mmu_psize_defs[psize].shift == PAGE_SHIFT_64K ||
- mmu_psize_defs[psize].shift == PAGE_SHIFT_16G)) {
- /* Return if huge page size has already been setup or is the
- * same as the base page size. */
- if (mmu_huge_psizes[psize] ||
- mmu_psize_defs[psize].shift == PAGE_SHIFT)
- return;
- hugetlb_add_hstate(mmu_psize_defs[psize].shift - PAGE_SHIFT);
+ * that it fits within pagetable and slice limits. */
+ if (!is_power_of_2(size)
+ || (shift > SLICE_HIGH_SHIFT) || (shift <= PAGE_SHIFT))
+ return -EINVAL;
- if (mmu_psize_defs[psize].shift < PMD_SHIFT)
- pdshift = PMD_SHIFT;
- else if (mmu_psize_defs[psize].shift < PUD_SHIFT)
- pdshift = PUD_SHIFT;
- else
- pdshift = PGDIR_SHIFT;
- mmu_huge_psizes[psize] = pdshift - mmu_psize_defs[psize].shift;
- }
+ if ((mmu_psize = shift_to_mmu_psize(shift)) < 0)
+ return -EINVAL;
+
+#ifdef CONFIG_SPU_FS_64K_LS
+ /* Disable support for 64K huge pages when 64K SPU local store
+ * support is enabled as the current implementation conflicts.
+ */
+ if (shift == PAGE_SHIFT_64K)
+ return -EINVAL;
+#endif /* CONFIG_SPU_FS_64K_LS */
+
+ BUG_ON(mmu_psize_defs[mmu_psize].shift != shift);
+
+ /* Return if huge page size has already been setup */
+ if (size_to_hstate(size))
+ return 0;
+
+ hugetlb_add_hstate(shift - PAGE_SHIFT);
+
+ return 0;
}
static int __init hugepage_setup_sz(char *str)
{
unsigned long long size;
- int mmu_psize;
- int shift;
size = memparse(str, &str);
- shift = __ffs(size);
- mmu_psize = shift_to_mmu_psize(shift);
- if (mmu_psize >= 0 && mmu_psize_defs[mmu_psize].shift)
- set_huge_psize(mmu_psize);
- else
+ if (add_huge_page_size(size) != 0)
printk(KERN_WARNING "Invalid huge page size specified(%llu)\n", size);
return 1;
@@ -720,30 +707,39 @@
if (!cpu_has_feature(CPU_FTR_16M_PAGE))
return -ENODEV;
- /* Add supported huge page sizes. Need to change
- * HUGE_MAX_HSTATE if the number of supported huge page sizes
- * changes.
- */
- set_huge_psize(MMU_PAGE_16M);
- set_huge_psize(MMU_PAGE_16G);
-
- /* Temporarily disable support for 64K huge pages when 64K SPU local
- * store support is enabled as the current implementation conflicts.
- */
-#ifndef CONFIG_SPU_FS_64K_LS
- set_huge_psize(MMU_PAGE_64K);
-#endif
-
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
- if (mmu_huge_psizes[psize]) {
- pgtable_cache_add(mmu_huge_psizes[psize], NULL);
- if (!PGT_CACHE(mmu_huge_psizes[psize]))
- panic("hugetlbpage_init(): could not create "
- "pgtable cache for %d bit pagesize\n",
- mmu_psize_to_shift(psize));
- }
+ unsigned shift;
+ unsigned pdshift;
+
+ if (!mmu_psize_defs[psize].shift)
+ continue;
+
+ shift = mmu_psize_to_shift(psize);
+
+ if (add_huge_page_size(1ULL << shift) < 0)
+ continue;
+
+ if (shift < PMD_SHIFT)
+ pdshift = PMD_SHIFT;
+ else if (shift < PUD_SHIFT)
+ pdshift = PUD_SHIFT;
+ else
+ pdshift = PGDIR_SHIFT;
+
+ pgtable_cache_add(pdshift - shift, NULL);
+ if (!PGT_CACHE(pdshift - shift))
+ panic("hugetlbpage_init(): could not create "
+ "pgtable cache for %d bit pagesize\n", shift);
}
+ /* Set default large page size. Currently, we pick 16M or 1M
+ * depending on what is available
+ */
+ if (mmu_psize_defs[MMU_PAGE_16M].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_16M].shift;
+ else if (mmu_psize_defs[MMU_PAGE_1M].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_1M].shift;
+
return 0;
}