arm64: MMU definitions

The virtual memory layout is described in
Documentation/arm64/memory.txt. This patch adds the MMU definitions for
the 4KB and 64KB translation table configurations. The SECTION_SIZE is
2MB with 4KB page and 512MB with 64KB page configuration.

PHYS_OFFSET is calculated at run-time and stored in a variable (no
run-time code patching at this stage).

On the current implementation, both user and kernel address spaces are
512G (39-bit) each with a maximum of 256G for the RAM linear mapping.
Linux uses 3 levels of translation tables with the 4K page configuration
and 2 levels with the 64K configuration. Extending the memory space
beyond 39-bit with the 4K pages or 42-bit with 64K pages requires an
additional level of translation tables.

The SPARSEMEM configuration is global to all AArch64 platforms and
allows for 1GB sections with SPARSEMEM_VMEMMAP enabled by default.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 94 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
new file mode 100644
index 000000000000..0f3b4581d925
--- /dev/null
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_PGTABLE_HWDEF_H
+#define __ASM_PGTABLE_HWDEF_H
+
+#ifdef CONFIG_ARM64_64K_PAGES
+#include <asm/pgtable-2level-hwdef.h>
+#else
+#include <asm/pgtable-3level-hwdef.h>
+#endif
+
+/*
+ * Hardware page table definitions.
+ *
+ * Level 2 descriptor (PMD).
+ */
+#define PMD_TYPE_MASK		(_AT(pmdval_t, 3) << 0)
+#define PMD_TYPE_FAULT		(_AT(pmdval_t, 0) << 0)
+#define PMD_TYPE_TABLE		(_AT(pmdval_t, 3) << 0)
+#define PMD_TYPE_SECT		(_AT(pmdval_t, 1) << 0)
+
+/*
+ * Section
+ */
+#define PMD_SECT_S		(_AT(pmdval_t, 3) << 8)
+#define PMD_SECT_AF		(_AT(pmdval_t, 1) << 10)
+#define PMD_SECT_NG		(_AT(pmdval_t, 1) << 11)
+#define PMD_SECT_XN		(_AT(pmdval_t, 1) << 54)
+
+/*
+ * AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
+ */
+#define PMD_ATTRINDX(t)		(_AT(pmdval_t, (t)) << 2)
+#define PMD_ATTRINDX_MASK	(_AT(pmdval_t, 7) << 2)
+
+/*
+ * Level 3 descriptor (PTE).
+ */
+#define PTE_TYPE_MASK		(_AT(pteval_t, 3) << 0)
+#define PTE_TYPE_FAULT		(_AT(pteval_t, 0) << 0)
+#define PTE_TYPE_PAGE		(_AT(pteval_t, 3) << 0)
+#define PTE_USER		(_AT(pteval_t, 1) << 6)		/* AP[1] */
+#define PTE_RDONLY		(_AT(pteval_t, 1) << 7)		/* AP[2] */
+#define PTE_SHARED		(_AT(pteval_t, 3) << 8)		/* SH[1:0], inner shareable */
+#define PTE_AF			(_AT(pteval_t, 1) << 10)	/* Access Flag */
+#define PTE_NG			(_AT(pteval_t, 1) << 11)	/* nG */
+#define PTE_XN			(_AT(pteval_t, 1) << 54)	/* XN */
+
+/*
+ * AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
+ */
+#define PTE_ATTRINDX(t)		(_AT(pteval_t, (t)) << 2)
+#define PTE_ATTRINDX_MASK	(_AT(pteval_t, 7) << 2)
+
+/*
+ * 40-bit physical address supported.
+ */
+#define PHYS_MASK_SHIFT		(40)
+#define PHYS_MASK		((UL(1) << PHYS_MASK_SHIFT) - 1)
+
+/*
+ * TCR flags.
+ */
+#define TCR_TxSZ(x)		(((UL(64) - (x)) << 16) | ((UL(64) - (x)) << 0))
+#define TCR_IRGN_NC		((UL(0) << 8) | (UL(0) << 24))
+#define TCR_IRGN_WBWA		((UL(1) << 8) | (UL(1) << 24))
+#define TCR_IRGN_WT		((UL(2) << 8) | (UL(2) << 24))
+#define TCR_IRGN_WBnWA		((UL(3) << 8) | (UL(3) << 24))
+#define TCR_IRGN_MASK		((UL(3) << 8) | (UL(3) << 24))
+#define TCR_ORGN_NC		((UL(0) << 10) | (UL(0) << 26))
+#define TCR_ORGN_WBWA		((UL(1) << 10) | (UL(1) << 26))
+#define TCR_ORGN_WT		((UL(2) << 10) | (UL(2) << 26))
+#define TCR_ORGN_WBnWA		((UL(3) << 10) | (UL(3) << 26))
+#define TCR_ORGN_MASK		((UL(3) << 10) | (UL(3) << 26))
+#define TCR_SHARED		((UL(3) << 12) | (UL(3) << 28))
+#define TCR_TG0_64K		(UL(1) << 14)
+#define TCR_TG1_64K		(UL(1) << 30)
+#define TCR_IPS_40BIT		(UL(2) << 32)
+#define TCR_ASID16		(UL(1) << 36)
+
+#endif