/* * 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> #include <asm/sysreg.h> #include <asm/virt.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 pgd * x1: HYP stack * x2: HYP vectors */ __do_hyp_init: /* Check for a stub HVC call */ cmp x0, #HVC_STUB_HCALL_NR b.lo __kvm_handle_stub_hvc phys_to_ttbr x4, x0 msr ttbr0_el2, x4 mrs x4, tcr_el1 ldr x5, =TCR_EL2_MASK and x4, x4, x5 mov x5, #TCR_EL2_RES1 orr x4, x4, x5 /* * The ID map may be configured to use an extended virtual address * range. This is only the case if system RAM is out of range for the * currently configured page size and VA_BITS, in which case we will * also need the extended virtual range 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 to use the extended range with *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 /* * Set the PS bits in TCR_EL2. */ tcr_compute_pa_size x4, #TCR_EL2_PS_SHIFT, x5, x6 msr tcr_el2, x4 mrs x4, mair_el1 msr mair_el2, x4 isb /* Invalidate the stale TLBs from Bootloader */ tlbi alle2 dsb sy /* * Preserve all the RES1 bits while setting the default flags, * as well as the EE bit on BE. Drop the A flag since the compiler * is allowed to generate unaligned accesses. */ ldr x4, =(SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) CPU_BE( orr x4, x4, #SCTLR_ELx_EE) msr sctlr_el2, x4 isb /* Set the stack and new vectors */ kern_hyp_va x1 mov sp, x1 kern_hyp_va x2 msr vbar_el2, x2 /* copy tpidr_el1 into tpidr_el2 for use by HYP */ mrs x1, tpidr_el1 msr tpidr_el2, x1 /* Hello, World! */ eret ENDPROC(__kvm_hyp_init) ENTRY(__kvm_handle_stub_hvc) cmp x0, #HVC_SOFT_RESTART b.ne 1f /* This is where we're about to jump, staying at EL2 */ msr elr_el2, x1 mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h) msr spsr_el2, x0 /* Shuffle the arguments, and don't come back */ mov x0, x2 mov x1, x3 mov x2, x4 b reset 1: cmp x0, #HVC_RESET_VECTORS b.ne 1f reset: /* * Reset kvm back to the hyp stub. Do not clobber x0-x4 in * case we coming via HVC_SOFT_RESTART. */ mrs x5, sctlr_el2 ldr x6, =SCTLR_ELx_FLAGS bic x5, x5, x6 // Clear SCTL_M and etc pre_disable_mmu_workaround msr sctlr_el2, x5 isb /* Install stub vectors */ adr_l x5, __hyp_stub_vectors msr vbar_el2, x5 mov x0, xzr eret 1: /* Bad stub call */ ldr x0, =HVC_STUB_ERR eret ENDPROC(__kvm_handle_stub_hvc) .ltorg .popsection