summaryrefslogtreecommitdiff
path: root/arch/arm64/kvm/hyp-init.S
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm64/kvm/hyp-init.S
Initial import
Diffstat (limited to 'arch/arm64/kvm/hyp-init.S')
-rw-r--r--arch/arm64/kvm/hyp-init.S145
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
new file mode 100644
index 000000000..178ba2248
--- /dev/null
+++ b/arch/arm64/kvm/hyp-init.S
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2012,2013 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@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/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+#include <asm/pgtable-hwdef.h>
+
+ .text
+ .pushsection .hyp.idmap.text, "ax"
+
+ .align 11
+
+ENTRY(__kvm_hyp_init)
+ ventry __invalid // Synchronous EL2t
+ ventry __invalid // IRQ EL2t
+ ventry __invalid // FIQ EL2t
+ ventry __invalid // Error EL2t
+
+ ventry __invalid // Synchronous EL2h
+ ventry __invalid // IRQ EL2h
+ ventry __invalid // FIQ EL2h
+ ventry __invalid // Error EL2h
+
+ ventry __do_hyp_init // Synchronous 64-bit EL1
+ ventry __invalid // IRQ 64-bit EL1
+ ventry __invalid // FIQ 64-bit EL1
+ ventry __invalid // Error 64-bit EL1
+
+ ventry __invalid // Synchronous 32-bit EL1
+ ventry __invalid // IRQ 32-bit EL1
+ ventry __invalid // FIQ 32-bit EL1
+ ventry __invalid // Error 32-bit EL1
+
+__invalid:
+ b .
+
+ /*
+ * x0: HYP boot pgd
+ * x1: HYP pgd
+ * x2: HYP stack
+ * x3: HYP vectors
+ */
+__do_hyp_init:
+
+ msr ttbr0_el2, x0
+
+ mrs x4, tcr_el1
+ ldr x5, =TCR_EL2_MASK
+ and x4, x4, x5
+ ldr x5, =TCR_EL2_FLAGS
+ orr x4, x4, x5
+
+#ifndef CONFIG_ARM64_VA_BITS_48
+ /*
+ * If we are running with VA_BITS < 48, we may be running with an extra
+ * level of translation in the ID map. This is only the case if system
+ * RAM is out of range for the currently configured page size and number
+ * of translation levels, in which case we will also need the extra
+ * level for the HYP ID map, or we won't be able to enable the EL2 MMU.
+ *
+ * However, at EL2, there is only one TTBR register, and we can't switch
+ * between translation tables *and* update TCR_EL2.T0SZ at the same
+ * time. Bottom line: we need the extra level in *both* our translation
+ * tables.
+ *
+ * So use the same T0SZ value we use for the ID map.
+ */
+ ldr_l x5, idmap_t0sz
+ bfi x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
+#endif
+ msr tcr_el2, x4
+
+ ldr x4, =VTCR_EL2_FLAGS
+ /*
+ * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in
+ * VTCR_EL2.
+ */
+ mrs x5, ID_AA64MMFR0_EL1
+ bfi x4, x5, #16, #3
+ msr vtcr_el2, x4
+
+ mrs x4, mair_el1
+ msr mair_el2, x4
+ isb
+
+ /* Invalidate the stale TLBs from Bootloader */
+ tlbi alle2
+ dsb sy
+
+ mrs x4, sctlr_el2
+ and x4, x4, #SCTLR_EL2_EE // preserve endianness of EL2
+ ldr x5, =SCTLR_EL2_FLAGS
+ orr x4, x4, x5
+ msr sctlr_el2, x4
+ isb
+
+ /* Skip the trampoline dance if we merged the boot and runtime PGDs */
+ cmp x0, x1
+ b.eq merged
+
+ /* MMU is now enabled. Get ready for the trampoline dance */
+ ldr x4, =TRAMPOLINE_VA
+ adr x5, target
+ bfi x4, x5, #0, #PAGE_SHIFT
+ br x4
+
+target: /* We're now in the trampoline code, switch page tables */
+ msr ttbr0_el2, x1
+ isb
+
+ /* Invalidate the old TLBs */
+ tlbi alle2
+ dsb sy
+
+merged:
+ /* Set the stack and new vectors */
+ kern_hyp_va x2
+ mov sp, x2
+ kern_hyp_va x3
+ msr vbar_el2, x3
+
+ /* Hello, World! */
+ eret
+ENDPROC(__kvm_hyp_init)
+
+ .ltorg
+
+ .popsection