diff options
Diffstat (limited to 'arch/arm64/kernel/hyp-stub.S')
| -rw-r--r-- | arch/arm64/kernel/hyp-stub.S | 217 |
1 files changed, 202 insertions, 15 deletions
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 73d46070b315..2ee18c860f2a 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -8,31 +8,55 @@ #include <linux/init.h> #include <linux/linkage.h> -#include <linux/irqchip/arm-gic-v3.h> #include <asm/assembler.h> +#include <asm/el2_setup.h> #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> #include <asm/ptrace.h> #include <asm/virt.h> +// Warning, hardcoded register allocation +// This will clobber x1 and x2, and expect x1 to contain +// the id register value as read from the HW +.macro __check_override idreg, fld, width, pass, fail + ubfx x1, x1, #\fld, #\width + cbz x1, \fail + + adr_l x1, \idreg\()_override + ldr x2, [x1, FTR_OVR_VAL_OFFSET] + ldr x1, [x1, FTR_OVR_MASK_OFFSET] + ubfx x2, x2, #\fld, #\width + ubfx x1, x1, #\fld, #\width + cmp x1, xzr + and x2, x2, x1 + csinv x2, x2, xzr, ne + cbnz x2, \pass + b \fail +.endm + +.macro check_override idreg, fld, pass, fail + mrs x1, \idreg\()_el1 + __check_override \idreg \fld 4 \pass \fail +.endm + .text .pushsection .hyp.text, "ax" .align 11 -ENTRY(__hyp_stub_vectors) +SYM_CODE_START(__hyp_stub_vectors) ventry el2_sync_invalid // Synchronous EL2t ventry el2_irq_invalid // IRQ EL2t ventry el2_fiq_invalid // FIQ EL2t ventry el2_error_invalid // Error EL2t - ventry el2_sync_invalid // Synchronous EL2h + ventry elx_sync // Synchronous EL2h ventry el2_irq_invalid // IRQ EL2h ventry el2_fiq_invalid // FIQ EL2h ventry el2_error_invalid // Error EL2h - ventry el1_sync // Synchronous 64-bit EL1 + ventry elx_sync // Synchronous 64-bit EL1 ventry el1_irq_invalid // IRQ 64-bit EL1 ventry el1_fiq_invalid // FIQ 64-bit EL1 ventry el1_error_invalid // Error 64-bit EL1 @@ -41,16 +65,19 @@ ENTRY(__hyp_stub_vectors) ventry el1_irq_invalid // IRQ 32-bit EL1 ventry el1_fiq_invalid // FIQ 32-bit EL1 ventry el1_error_invalid // Error 32-bit EL1 -ENDPROC(__hyp_stub_vectors) +SYM_CODE_END(__hyp_stub_vectors) .align 11 -el1_sync: +SYM_CODE_START_LOCAL(elx_sync) cmp x0, #HVC_SET_VECTORS - b.ne 2f + b.ne 1f msr vbar_el2, x1 b 9f +1: cmp x0, #HVC_FINALISE_EL2 + b.eq __finalise_el2 + 2: cmp x0, #HVC_SOFT_RESTART b.ne 3f mov x0, x2 @@ -63,17 +90,154 @@ el1_sync: beq 9f // Nothing to reset! /* Someone called kvm_call_hyp() against the hyp-stub... */ - ldr x0, =HVC_STUB_ERR + mov_q x0, HVC_STUB_ERR eret 9: mov x0, xzr eret -ENDPROC(el1_sync) +SYM_CODE_END(elx_sync) + +SYM_CODE_START_LOCAL(__finalise_el2) + check_override id_aa64pfr0 ID_AA64PFR0_EL1_SVE_SHIFT .Linit_sve .Lskip_sve + +.Linit_sve: /* SVE register access */ + mrs x0, cptr_el2 // Disable SVE traps + bic x0, x0, #CPTR_EL2_TZ + msr cptr_el2, x0 + isb + mov x1, #ZCR_ELx_LEN_MASK // SVE: Enable full vector + msr_s SYS_ZCR_EL2, x1 // length for EL1. + +.Lskip_sve: + check_override id_aa64pfr1 ID_AA64PFR1_EL1_SME_SHIFT .Linit_sme .Lskip_sme + +.Linit_sme: /* SME register access and priority mapping */ + mrs x0, cptr_el2 // Disable SME traps + bic x0, x0, #CPTR_EL2_TSM + msr cptr_el2, x0 + isb + + mrs x1, sctlr_el2 + orr x1, x1, #SCTLR_ELx_ENTP2 // Disable TPIDR2 traps + msr sctlr_el2, x1 + isb + + mov x0, #0 // SMCR controls + + // Full FP in SM? + mrs_s x1, SYS_ID_AA64SMFR0_EL1 + __check_override id_aa64smfr0 ID_AA64SMFR0_EL1_FA64_SHIFT 1 .Linit_sme_fa64 .Lskip_sme_fa64 + +.Linit_sme_fa64: + orr x0, x0, SMCR_ELx_FA64_MASK +.Lskip_sme_fa64: + + orr x0, x0, #SMCR_ELx_LEN_MASK // Enable full SME vector + msr_s SYS_SMCR_EL2, x0 // length for EL1. + + mrs_s x1, SYS_SMIDR_EL1 // Priority mapping supported? + ubfx x1, x1, #SMIDR_EL1_SMPS_SHIFT, #1 + cbz x1, .Lskip_sme + + msr_s SYS_SMPRIMAP_EL2, xzr // Make all priorities equal + + mrs x1, id_aa64mmfr1_el1 // HCRX_EL2 present? + ubfx x1, x1, #ID_AA64MMFR1_EL1_HCX_SHIFT, #4 + cbz x1, .Lskip_sme + + mrs_s x1, SYS_HCRX_EL2 + orr x1, x1, #HCRX_EL2_SMPME_MASK // Enable priority mapping + msr_s SYS_HCRX_EL2, x1 + +.Lskip_sme: + + // nVHE? No way! Give me the real thing! + // Sanity check: MMU *must* be off + mrs x1, sctlr_el2 + tbnz x1, #0, 1f + + // Needs to be VHE capable, obviously + check_override id_aa64mmfr1 ID_AA64MMFR1_EL1_VH_SHIFT 2f 1f + +1: mov_q x0, HVC_STUB_ERR + eret +2: + // Engage the VHE magic! + mov_q x0, HCR_HOST_VHE_FLAGS + msr hcr_el2, x0 + isb + + // Use the EL1 allocated stack, per-cpu offset + mrs x0, sp_el1 + mov sp, x0 + mrs x0, tpidr_el1 + msr tpidr_el2, x0 + + // FP configuration, vectors + mrs_s x0, SYS_CPACR_EL12 + msr cpacr_el1, x0 + mrs_s x0, SYS_VBAR_EL12 + msr vbar_el1, x0 + + // Use EL2 translations for SPE & TRBE and disable access from EL1 + mrs x0, mdcr_el2 + bic x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT) + bic x0, x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT) + msr mdcr_el2, x0 + + // Transfer the MM state from EL1 to EL2 + mrs_s x0, SYS_TCR_EL12 + msr tcr_el1, x0 + mrs_s x0, SYS_TTBR0_EL12 + msr ttbr0_el1, x0 + mrs_s x0, SYS_TTBR1_EL12 + msr ttbr1_el1, x0 + mrs_s x0, SYS_MAIR_EL12 + msr mair_el1, x0 + isb + + // Hack the exception return to stay at EL2 + mrs x0, spsr_el1 + and x0, x0, #~PSR_MODE_MASK + mov x1, #PSR_MODE_EL2h + orr x0, x0, x1 + msr spsr_el1, x0 + + b enter_vhe +SYM_CODE_END(__finalise_el2) + + // At the point where we reach enter_vhe(), we run with + // the MMU off (which is enforced by __finalise_el2()). + // We thus need to be in the idmap, or everything will + // explode when enabling the MMU. + + .pushsection .idmap.text, "ax" + +SYM_CODE_START_LOCAL(enter_vhe) + // Invalidate TLBs before enabling the MMU + tlbi vmalle1 + dsb nsh + isb + + // Enable the EL2 S1 MMU, as set up from EL1 + mrs_s x0, SYS_SCTLR_EL12 + set_sctlr_el1 x0 + + // Disable the EL1 S1 MMU for a good measure + mov_q x0, INIT_SCTLR_EL1_MMU_OFF + msr_s SYS_SCTLR_EL12, x0 + + mov x0, xzr + + eret +SYM_CODE_END(enter_vhe) + + .popsection .macro invalid_vector label -\label: +SYM_CODE_START_LOCAL(\label) b \label -ENDPROC(\label) +SYM_CODE_END(\label) .endm invalid_vector el2_sync_invalid @@ -85,6 +249,8 @@ ENDPROC(\label) invalid_vector el1_fiq_invalid invalid_vector el1_error_invalid + .popsection + /* * __hyp_set_vectors: Call this after boot to set the initial hypervisor * vectors as part of hypervisor installation. On an SMP system, this should @@ -106,15 +272,36 @@ ENDPROC(\label) * initialisation entry point. */ -ENTRY(__hyp_set_vectors) +SYM_FUNC_START(__hyp_set_vectors) mov x1, x0 mov x0, #HVC_SET_VECTORS hvc #0 ret -ENDPROC(__hyp_set_vectors) +SYM_FUNC_END(__hyp_set_vectors) -ENTRY(__hyp_reset_vectors) +SYM_FUNC_START(__hyp_reset_vectors) mov x0, #HVC_RESET_VECTORS hvc #0 ret -ENDPROC(__hyp_reset_vectors) +SYM_FUNC_END(__hyp_reset_vectors) + +/* + * Entry point to finalise EL2 and switch to VHE if deemed capable + * + * w0: boot mode, as returned by init_kernel_el() + */ +SYM_FUNC_START(finalise_el2) + // Need to have booted at EL2 + cmp w0, #BOOT_CPU_MODE_EL2 + b.ne 1f + + // and still be at EL1 + mrs x0, CurrentEL + cmp x0, #CurrentEL_EL1 + b.ne 1f + + mov x0, #HVC_FINALISE_EL2 + hvc #0 +1: + ret +SYM_FUNC_END(finalise_el2) |