ARM: LPAE: MMU setup for the 3-level page table format

This patch adds the MMU initialisation for the LPAE page table format.
The swapper_pg_dir size with LPAE is 5 rather than 4 pages. A new
proc-v7-3level.S file contains the TTB initialisation, context switch
and PTE setting code with the LPAE. The TTBRx split is based on the
PAGE_OFFSET with TTBR1 used for the kernel mappings. The 36-bit mappings
(supersections) and a few other memory types in mmu.c are conditionally
compiled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 150 insertions, 0 deletions

diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S
new file mode 100644
index 0000000..8de0f1d
--- /dev/null
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -0,0 +1,150 @@
+/*
+ * arch/arm/mm/proc-v7-3level.S
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2011 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ *   based on arch/arm/mm/proc-v7-2level.S
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#define TTB_IRGN_NC	(0 << 8)
+#define TTB_IRGN_WBWA	(1 << 8)
+#define TTB_IRGN_WT	(2 << 8)
+#define TTB_IRGN_WB	(3 << 8)
+#define TTB_RGN_NC	(0 << 10)
+#define TTB_RGN_OC_WBWA	(1 << 10)
+#define TTB_RGN_OC_WT	(2 << 10)
+#define TTB_RGN_OC_WB	(3 << 10)
+#define TTB_S		(3 << 12)
+#define TTB_EAE		(1 << 31)
+
+/* PTWs cacheable, inner WB not shareable, outer WB not shareable */
+#define TTB_FLAGS_UP	(TTB_IRGN_WB|TTB_RGN_OC_WB)
+#define PMD_FLAGS_UP	(PMD_SECT_WB)
+
+/* PTWs cacheable, inner WBWA shareable, outer WBWA not shareable */
+#define TTB_FLAGS_SMP	(TTB_IRGN_WBWA|TTB_S|TTB_RGN_OC_WBWA)
+#define PMD_FLAGS_SMP	(PMD_SECT_WBWA|PMD_SECT_S)
+
+/*
+ * cpu_v7_switch_mm(pgd_phys, tsk)
+ *
+ * Set the translation table base pointer to be pgd_phys (physical address of
+ * the new TTB).
+ */
+ENTRY(cpu_v7_switch_mm)
+#ifdef CONFIG_MMU
+	ldr	r1, [r1, #MM_CONTEXT_ID]	@ get mm->context.id
+	and	r3, r1, #0xff
+	mov	r3, r3, lsl #(48 - 32)		@ ASID
+	mcrr	p15, 0, r0, r3, c2		@ set TTB 0
+	isb
+#endif
+	mov	pc, lr
+ENDPROC(cpu_v7_switch_mm)
+
+/*
+ * cpu_v7_set_pte_ext(ptep, pte)
+ *
+ * Set a level 2 translation table entry.
+ * - ptep - pointer to level 3 translation table entry
+ * - pte - PTE value to store (64-bit in r2 and r3)
+ */
+ENTRY(cpu_v7_set_pte_ext)
+#ifdef CONFIG_MMU
+	tst	r2, #L_PTE_PRESENT
+	beq	1f
+	tst	r3, #1 << (55 - 32)		@ L_PTE_DIRTY
+	orreq	r2, #L_PTE_RDONLY
+1:	strd	r2, r3, [r0]
+	mcr	p15, 0, r0, c7, c10, 1		@ flush_pte
+#endif
+	mov	pc, lr
+ENDPROC(cpu_v7_set_pte_ext)
+
+	/*
+	 * Memory region attributes for LPAE (defined in pgtable-3level.h):
+	 *
+	 *   n = AttrIndx[2:0]
+	 *
+	 *			n	MAIR
+	 *   UNCACHED		000	00000000
+	 *   BUFFERABLE		001	01000100
+	 *   DEV_WC		001	01000100
+	 *   WRITETHROUGH	010	10101010
+	 *   WRITEBACK		011	11101110
+	 *   DEV_CACHED		011	11101110
+	 *   DEV_SHARED		100	00000100
+	 *   DEV_NONSHARED	100	00000100
+	 *   unused		101
+	 *   unused		110
+	 *   WRITEALLOC		111	11111111
+	 */
+.equ	PRRR,	0xeeaa4400			@ MAIR0
+.equ	NMRR,	0xff000004			@ MAIR1
+
+	/*
+	 * Macro for setting up the TTBRx and TTBCR registers.
+	 * - \ttbr1 updated.
+	 */
+	.macro	v7_ttb_setup, zero, ttbr0, ttbr1, tmp
+	ldr	\tmp, =swapper_pg_dir		@ swapper_pg_dir virtual address
+	cmp	\ttbr1, \tmp			@ PHYS_OFFSET > PAGE_OFFSET? (branch below)
+	mrc	p15, 0, \tmp, c2, c0, 2		@ TTB control register
+	orr	\tmp, \tmp, #TTB_EAE
+	ALT_SMP(orr	\tmp, \tmp, #TTB_FLAGS_SMP)
+	ALT_UP(orr	\tmp, \tmp, #TTB_FLAGS_UP)
+	ALT_SMP(orr	\tmp, \tmp, #TTB_FLAGS_SMP << 16)
+	ALT_UP(orr	\tmp, \tmp, #TTB_FLAGS_UP << 16)
+	/*
+	 * TTBR0/TTBR1 split (PAGE_OFFSET):
+	 *   0x40000000: T0SZ = 2, T1SZ = 0 (not used)
+	 *   0x80000000: T0SZ = 0, T1SZ = 1
+	 *   0xc0000000: T0SZ = 0, T1SZ = 2
+	 *
+	 * Only use this feature if PHYS_OFFSET <= PAGE_OFFSET, otherwise
+	 * booting secondary CPUs would end up using TTBR1 for the identity
+	 * mapping set up in TTBR0.
+	 */
+	bhi	9001f				@ PHYS_OFFSET > PAGE_OFFSET?
+	orr	\tmp, \tmp, #(((PAGE_OFFSET >> 30) - 1) << 16) @ TTBCR.T1SZ
+#if defined CONFIG_VMSPLIT_2G
+	/* PAGE_OFFSET == 0x80000000, T1SZ == 1 */
+	add	\ttbr1, \ttbr1, #1 << 4		@ skip two L1 entries
+#elif defined CONFIG_VMSPLIT_3G
+	/* PAGE_OFFSET == 0xc0000000, T1SZ == 2 */
+	add	\ttbr1, \ttbr1, #4096 * (1 + 3)	@ only L2 used, skip pgd+3*pmd
+#endif
+	/* CONFIG_VMSPLIT_1G does not need TTBR1 adjustment */
+9001:	mcr	p15, 0, \tmp, c2, c0, 2		@ TTB control register
+	mcrr	p15, 1, \ttbr1, \zero, c2	@ load TTBR1
+	.endm
+
+	__CPUINIT
+
+	/*
+	 *   AT
+	 *  TFR   EV X F   IHD LR    S
+	 * .EEE ..EE PUI. .TAT 4RVI ZWRS BLDP WCAM
+	 * rxxx rrxx xxx0 0101 xxxx xxxx x111 xxxx < forced
+	 *   11    0 110    1  0011 1100 .111 1101 < we want
+	 */
+	.align	2
+	.type	v7_crval, #object
+v7_crval:
+	crval	clear=0x0120c302, mmuset=0x30c23c7d, ucset=0x00c01c7c
+
+	.previous