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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm64/kvm/hyp/nvhe/hyp-init.S
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/hyp-init.S')
-rw-r--r--arch/arm64/kvm/hyp/nvhe/hyp-init.S190
1 files changed, 190 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
new file mode 100644
index 000000000..b11a9d7db
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
@@ -0,0 +1,190 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012,2013 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/linkage.h>
+
+#include <asm/alternative.h>
+#include <asm/assembler.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.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
+
+SYM_CODE_START(__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: SMCCC function ID
+ * x1: HYP pgd
+ * x2: per-CPU offset
+ * x3: HYP stack
+ * x4: HYP vectors
+ */
+__do_hyp_init:
+ /* Check for a stub HVC call */
+ cmp x0, #HVC_STUB_HCALL_NR
+ b.lo __kvm_handle_stub_hvc
+
+ // We only actively check bits [24:31], and everything
+ // else has to be zero, which we check at build time.
+#if (KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) & 0xFFFFFFFF00FFFFFF)
+#error Unexpected __KVM_HOST_SMCCC_FUNC___kvm_hyp_init value
+#endif
+
+ ror x0, x0, #24
+ eor x0, x0, #((KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) >> 24) & 0xF)
+ ror x0, x0, #4
+ eor x0, x0, #((KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) >> 28) & 0xF)
+ cbz x0, 1f
+ mov x0, #SMCCC_RET_NOT_SUPPORTED
+ eret
+
+1:
+ /* Set tpidr_el2 for use by HYP to free a register */
+ msr tpidr_el2, x2
+
+ phys_to_ttbr x0, x1
+alternative_if ARM64_HAS_CNP
+ orr x0, x0, #TTBR_CNP_BIT
+alternative_else_nop_endif
+ msr ttbr0_el2, x0
+
+ mrs x0, tcr_el1
+ mov_q x1, TCR_EL2_MASK
+ and x0, x0, x1
+ mov x1, #TCR_EL2_RES1
+ orr x0, x0, x1
+
+ /*
+ * 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 x1, idmap_t0sz
+ bfi x0, x1, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
+
+ /*
+ * Set the PS bits in TCR_EL2.
+ */
+ tcr_compute_pa_size x0, #TCR_EL2_PS_SHIFT, x1, x2
+
+ msr tcr_el2, x0
+
+ mrs x0, mair_el1
+ msr mair_el2, x0
+ 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.
+ */
+ mov_q x0, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A))
+CPU_BE( orr x0, x0, #SCTLR_ELx_EE)
+alternative_if ARM64_HAS_ADDRESS_AUTH
+ mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \
+ SCTLR_ELx_ENDA | SCTLR_ELx_ENDB)
+ orr x0, x0, x1
+alternative_else_nop_endif
+ msr sctlr_el2, x0
+ isb
+
+ /* Set the stack and new vectors */
+ mov sp, x3
+ msr vbar_el2, x4
+
+ /* Hello, World! */
+ mov x0, #SMCCC_RET_SUCCESS
+ eret
+SYM_CODE_END(__kvm_hyp_init)
+
+SYM_CODE_START(__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
+
+ /*
+ * Set the HVC_RESET_VECTORS return code before entering the common
+ * path so that we do not clobber x0-x2 in case we are coming via
+ * HVC_SOFT_RESTART.
+ */
+ mov x0, xzr
+reset:
+ /* Reset kvm back to the hyp stub. */
+ mrs x5, sctlr_el2
+ mov_q 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
+ eret
+
+1: /* Bad stub call */
+ mov_q x0, HVC_STUB_ERR
+ eret
+
+SYM_CODE_END(__kvm_handle_stub_hvc)
+
+ .popsection