--- /dev/null
+/*
+ * Based on arch/arm/mm/proc.S
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * 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/>.
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+#include <asm/hwcap.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/pgtable.h>
+
+#include "proc-macros.S"
+
+#ifdef CONFIG_ARM64_64K_PAGES
+#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K
+#else
+#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K
+#endif
+
+#ifdef CONFIG_SMP
+#define TCR_SMP_FLAGS TCR_SHARED
+#else
+#define TCR_SMP_FLAGS 0
+#endif
+
+/* PTWs cacheable, inner/outer WBWA */
+#define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA
+
+#define MAIR(attr, mt) ((attr) << ((mt) * 8))
+
+/*
+ * cpu_cache_off()
+ *
+ * Turn the CPU D-cache off.
+ */
+ENTRY(cpu_cache_off)
+ mrs x0, sctlr_el1
+ bic x0, x0, #1 << 2 // clear SCTLR.C
+ msr sctlr_el1, x0
+ isb
+ ret
+ENDPROC(cpu_cache_off)
+
+/*
+ * cpu_reset(loc)
+ *
+ * Perform a soft reset of the system. Put the CPU into the same state
+ * as it would be if it had been reset, and branch to what would be the
+ * reset vector. It must be executed with the flat identity mapping.
+ *
+ * - loc - location to jump to for soft reset
+ */
+ .align 5
+ENTRY(cpu_reset)
+ mrs x1, sctlr_el1
+ bic x1, x1, #1
+ msr sctlr_el1, x1 // disable the MMU
+ isb
+ ret x0
+ENDPROC(cpu_reset)
+
+ENTRY(cpu_soft_restart)
+ /* Save address of cpu_reset() and reset address */
+ mov x19, x0
+ mov x20, x1
+
+ /* Turn D-cache off */
+ bl cpu_cache_off
+
+ /* Push out all dirty data, and ensure cache is empty */
+ bl flush_cache_all
+
+ mov x0, x20
+ ret x19
+ENDPROC(cpu_soft_restart)
+
+/*
+ * cpu_do_idle()
+ *
+ * Idle the processor (wait for interrupt).
+ */
+ENTRY(cpu_do_idle)
+ dsb sy // WFI may enter a low-power mode
+ wfi
+ ret
+ENDPROC(cpu_do_idle)
+
+#ifdef CONFIG_CPU_PM
+/**
+ * cpu_do_suspend - save CPU registers context
+ *
+ * x0: virtual address of context pointer
+ */
+ENTRY(cpu_do_suspend)
+ mrs x2, tpidr_el0
+ mrs x3, tpidrro_el0
+ mrs x4, contextidr_el1
+ mrs x5, mair_el1
+ mrs x6, cpacr_el1
+ mrs x7, ttbr1_el1
+ mrs x8, tcr_el1
+ mrs x9, vbar_el1
+ mrs x10, mdscr_el1
+ mrs x11, oslsr_el1
+ mrs x12, sctlr_el1
+ stp x2, x3, [x0]
+ stp x4, x5, [x0, #16]
+ stp x6, x7, [x0, #32]
+ stp x8, x9, [x0, #48]
+ stp x10, x11, [x0, #64]
+ str x12, [x0, #80]
+ ret
+ENDPROC(cpu_do_suspend)
+
+/**
+ * cpu_do_resume - restore CPU register context
+ *
+ * x0: Physical address of context pointer
+ * x1: ttbr0_el1 to be restored
+ *
+ * Returns:
+ * sctlr_el1 value in x0
+ */
+ENTRY(cpu_do_resume)
+ /*
+ * Invalidate local tlb entries before turning on MMU
+ */
+ tlbi vmalle1
+ ldp x2, x3, [x0]
+ ldp x4, x5, [x0, #16]
+ ldp x6, x7, [x0, #32]
+ ldp x8, x9, [x0, #48]
+ ldp x10, x11, [x0, #64]
+ ldr x12, [x0, #80]
+ msr tpidr_el0, x2
+ msr tpidrro_el0, x3
+ msr contextidr_el1, x4
+ msr mair_el1, x5
+ msr cpacr_el1, x6
+ msr ttbr0_el1, x1
+ msr ttbr1_el1, x7
+ tcr_set_idmap_t0sz x8, x7
+ msr tcr_el1, x8
+ msr vbar_el1, x9
+ msr mdscr_el1, x10
+ /*
+ * Restore oslsr_el1 by writing oslar_el1
+ */
+ ubfx x11, x11, #1, #1
+ msr oslar_el1, x11
+ mov x0, x12
+ dsb nsh // Make sure local tlb invalidation completed
+ isb
+ ret
+ENDPROC(cpu_do_resume)
+#endif
+
+/*
+ * cpu_do_switch_mm(pgd_phys, tsk)
+ *
+ * Set the translation table base pointer to be pgd_phys.
+ *
+ * - pgd_phys - physical address of new TTB
+ */
+ENTRY(cpu_do_switch_mm)
+ mmid w1, x1 // get mm->context.id
+ bfi x0, x1, #48, #16 // set the ASID
+ msr ttbr0_el1, x0 // set TTBR0
+ isb
+ ret
+ENDPROC(cpu_do_switch_mm)
+
+ .section ".text.init", #alloc, #execinstr
+
+/*
+ * __cpu_setup
+ *
+ * Initialise the processor for turning the MMU on. Return in x0 the
+ * value of the SCTLR_EL1 register.
+ */
+ENTRY(__cpu_setup)
+ ic iallu // I+BTB cache invalidate
+ tlbi vmalle1is // invalidate I + D TLBs
+ dsb ish
+
+ mov x0, #3 << 20
+ msr cpacr_el1, x0 // Enable FP/ASIMD
+ msr mdscr_el1, xzr // Reset mdscr_el1
+ /*
+ * Memory region attributes for LPAE:
+ *
+ * n = AttrIndx[2:0]
+ * n MAIR
+ * DEVICE_nGnRnE 000 00000000
+ * DEVICE_nGnRE 001 00000100
+ * DEVICE_GRE 010 00001100
+ * NORMAL_NC 011 01000100
+ * NORMAL 100 11111111
+ */
+ ldr x5, =MAIR(0x00, MT_DEVICE_nGnRnE) | \
+ MAIR(0x04, MT_DEVICE_nGnRE) | \
+ MAIR(0x0c, MT_DEVICE_GRE) | \
+ MAIR(0x44, MT_NORMAL_NC) | \
+ MAIR(0xff, MT_NORMAL)
+ msr mair_el1, x5
+ /*
+ * Prepare SCTLR
+ */
+ adr x5, crval
+ ldp w5, w6, [x5]
+ mrs x0, sctlr_el1
+ bic x0, x0, x5 // clear bits
+ orr x0, x0, x6 // set bits
+ /*
+ * Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for
+ * both user and kernel.
+ */
+ ldr x10, =TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \
+ TCR_TG_FLAGS | TCR_ASID16 | TCR_TBI0
+ tcr_set_idmap_t0sz x10, x9
+
+ /*
+ * Read the PARange bits from ID_AA64MMFR0_EL1 and set the IPS bits in
+ * TCR_EL1.
+ */
+ mrs x9, ID_AA64MMFR0_EL1
+ bfi x10, x9, #32, #3
+ msr tcr_el1, x10
+ ret // return to head.S
+ENDPROC(__cpu_setup)
+
+ /*
+ * We set the desired value explicitly, including those of the
+ * reserved bits. The values of bits EE & E0E were set early in
+ * el2_setup, which are left untouched below.
+ *
+ * n n T
+ * U E WT T UD US IHBS
+ * CE0 XWHW CZ ME TEEA S
+ * .... .IEE .... NEAI TE.I ..AD DEN0 ACAM
+ * 0011 0... 1101 ..0. ..0. 10.. .0.. .... < hardware reserved
+ * .... .1.. .... 01.1 11.1 ..01 0.01 1101 < software settings
+ */
+ .type crval, #object
+crval:
+ .word 0xfcffffff // clear
+ .word 0x34d5d91d // set
Code Review / kvmfornfv.git / blobdiff