@@ -19,6 +19,7 @@
#ifndef __ASM_KERNEL_PGTABLE_H
#define __ASM_KERNEL_PGTABLE_H
+#include <asm/sparsemem.h>
/*
* The linear mapping and the start of memory are both 2M aligned (per
@@ -86,10 +87,24 @@
* (64k granule), or a multiple that can be mapped using contiguous bits
* in the page tables: 32 * PMD_SIZE (16k granule)
*/
-#ifdef CONFIG_ARM64_64K_PAGES
-#define ARM64_MEMSTART_ALIGN SZ_512M
+#if defined(CONFIG_ARM64_4K_PAGES)
+#define ARM64_MEMSTART_SHIFT PUD_SHIFT
+#elif defined(CONFIG_ARM64_16K_PAGES)
+#define ARM64_MEMSTART_SHIFT (PMD_SHIFT + 5)
#else
-#define ARM64_MEMSTART_ALIGN SZ_1G
+#define ARM64_MEMSTART_SHIFT PMD_SHIFT
+#endif
+
+/*
+ * sparsemem vmemmap imposes an additional requirement on the alignment of
+ * memstart_addr, due to the fact that the base of the vmemmap region
+ * has a direct correspondence, and needs to appear sufficiently aligned
+ * in the virtual address space.
+ */
+#if defined(CONFIG_SPARSEMEM_VMEMMAP) && ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS
+#define ARM64_MEMSTART_ALIGN (1UL << SECTION_SIZE_BITS)
+#else
+#define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT)
#endif
#endif /* __ASM_KERNEL_PGTABLE_H */
This redefines ARM64_MEMSTART_ALIGN in terms of the minimal alignment required by sparsemem vmemmap. This comes down to using 1 GB for all translation granules if CONFIG_SPARSEMEM_VMEMMAP is enabled. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/include/asm/kernel-pgtable.h | 21 +++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) -- 2.5.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel