On arm64, when kexec switches to the new kernel, the mmu is off. So the efi emulator should turn on the mmu to enable the identity mapping at the first stage. In fact, the kexec switching can run with mmu-on if it enters emulator, but that requires the re-arrangement of the relocate_kernel.S [1]. After that, this patch can be drop. But let us focus on emulator itself and keep things simple for the time being. [1]: https://lore.kernel.org/linux-arm-kernel/20240328115656.24090-1-piliu@xxxxxxxxxx/ Signed-off-by: Pingfan Liu <piliu@xxxxxxxxxx> Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> Cc: Jan Hendrik Farr <kernel@xxxxxxxx> Cc: Philipp Rudo <prudo@xxxxxxxxxx> Cc: Lennart Poettering <mzxreary@xxxxxxxxxxx> Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Dave Young <dyoung@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx To: kexec@xxxxxxxxxxxxxxxxxxx To: linux-efi@xxxxxxxxxxxxxxx --- drivers/firmware/efi/efi_emulator/Makefile | 2 +- .../firmware/efi/efi_emulator/arm64_proc.S | 172 ++++++++++++++++++ drivers/firmware/efi/efi_emulator/entry.c | 7 + 3 files changed, 180 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/efi/efi_emulator/arm64_proc.S diff --git a/drivers/firmware/efi/efi_emulator/Makefile b/drivers/firmware/efi/efi_emulator/Makefile index e37472004a2b5..b78a6241182fc 100644 --- a/drivers/firmware/efi/efi_emulator/Makefile +++ b/drivers/firmware/efi/efi_emulator/Makefile @@ -64,7 +64,7 @@ OBJECT_FILES_NON_STANDARD := y emulator-y := head.o entry.o \ core.o pe_loader.o misc.o memory.o memory_api.o runtime_service.o config_table.o \ lib.o printf.o \ - amba-pl011.o + amba-pl011.o arm64_proc.o obj-y := efi_emulator.o diff --git a/drivers/firmware/efi/efi_emulator/arm64_proc.S b/drivers/firmware/efi/efi_emulator/arm64_proc.S new file mode 100644 index 0000000000000..93618637e4935 --- /dev/null +++ b/drivers/firmware/efi/efi_emulator/arm64_proc.S @@ -0,0 +1,172 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Based on arch/arm/mm/proc.S + * + * Copyright (C) 2001 Deep Blue Solutions Ltd. + * Copyright (C) 2012 ARM Ltd. + * Author: Catalin Marinas <catalin.marinas@xxxxxxx> + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <linux/pgtable.h> +#include <linux/cfi_types.h> +#include <asm/assembler.h> +#include <asm/asm-offsets.h> +#include <asm/asm_pointer_auth.h> +#include <asm/hwcap.h> +#include <asm/kernel-pgtable.h> +#include <asm/pgtable-hwdef.h> +#include <asm/cpufeature.h> +#include <asm/alternative.h> +#include <asm/smp.h> +#include <asm/sysreg.h> + +#ifdef CONFIG_ARM64_64K_PAGES +#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K +#elif defined(CONFIG_ARM64_16K_PAGES) +#define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K +#else /* CONFIG_ARM64_4K_PAGES */ +#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K +#endif + +#ifdef CONFIG_RANDOMIZE_BASE +#define TCR_KASLR_FLAGS TCR_NFD1 +#else +#define TCR_KASLR_FLAGS 0 +#endif + +#define TCR_SMP_FLAGS TCR_SHARED + +/* PTWs cacheable, inner/outer WBWA */ +#define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA + +#ifdef CONFIG_KASAN_SW_TAGS +#define TCR_KASAN_SW_FLAGS TCR_TBI1 | TCR_TBID1 +#else +#define TCR_KASAN_SW_FLAGS 0 +#endif + +#ifdef CONFIG_KASAN_HW_TAGS +#define TCR_MTE_FLAGS TCR_TCMA1 | TCR_TBI1 | TCR_TBID1 +#elif defined(CONFIG_ARM64_MTE) +/* + * The mte_zero_clear_page_tags() implementation uses DC GZVA, which relies on + * TBI being enabled at EL1. + */ +#define TCR_MTE_FLAGS TCR_TBI1 | TCR_TBID1 +#else +#define TCR_MTE_FLAGS 0 +#endif + +/* + * Default MAIR_EL1. MT_NORMAL_TAGGED is initially mapped as Normal memory and + * changed during mte_cpu_setup to Normal Tagged if the system supports MTE. + */ +#define MAIR_EL1_SET \ + (MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRnE, MT_DEVICE_nGnRnE) | \ + MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) | \ + MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) | \ + MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) | \ + MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL_TAGGED)) + + +SYM_FUNC_START(__cpu_setup) + tlbi vmalle1 // Invalidate local TLB + dsb nsh + + msr cpacr_el1, xzr // Reset cpacr_el1 + mov x1, #1 << 12 // Reset mdscr_el1 and disable + msr mdscr_el1, x1 // access to the DCC from EL0 + reset_pmuserenr_el0 x1 // Disable PMU access from EL0 + reset_amuserenr_el0 x1 // Disable AMU access from EL0 + + /* + * Default values for VMSA control registers. These will be adjusted + * below depending on detected CPU features. + */ + mair .req x17 + tcr .req x16 + mov_q mair, MAIR_EL1_SET + mov_q tcr, TCR_T0SZ(IDMAP_VA_BITS) | TCR_T1SZ(VA_BITS_MIN) | TCR_CACHE_FLAGS | \ + TCR_SMP_FLAGS | TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \ + TCR_TBI0 | TCR_A1 | TCR_KASAN_SW_FLAGS | TCR_MTE_FLAGS + + tcr_clear_errata_bits tcr, x9, x5 + +#ifdef CONFIG_ARM64_VA_BITS_52 + mov x9, #64 - VA_BITS +alternative_if ARM64_HAS_VA52 + tcr_set_t1sz tcr, x9 +#ifdef CONFIG_ARM64_LPA2 + orr tcr, tcr, #TCR_DS +#endif +alternative_else_nop_endif +#endif + + /* + * Set the IPS bits in TCR_EL1. + */ + tcr_compute_pa_size tcr, #TCR_IPS_SHIFT, x5, x6 +#ifdef CONFIG_ARM64_HW_AFDBM + /* + * Enable hardware update of the Access Flags bit. + * Hardware dirty bit management is enabled later, + * via capabilities. + */ + mrs x9, ID_AA64MMFR1_EL1 + and x9, x9, ID_AA64MMFR1_EL1_HAFDBS_MASK + cbz x9, 1f + orr tcr, tcr, #TCR_HA // hardware Access flag update +1: +#endif /* CONFIG_ARM64_HW_AFDBM */ + msr mair_el1, mair + msr tcr_el1, tcr + + mrs_s x1, SYS_ID_AA64MMFR3_EL1 + ubfx x1, x1, #ID_AA64MMFR3_EL1_S1PIE_SHIFT, #4 + cbz x1, .Lskip_indirection + + /* + * The PROT_* macros describing the various memory types may resolve to + * C expressions if they include the PTE_MAYBE_* macros, and so they + * can only be used from C code. The PIE_E* constants below are also + * defined in terms of those macros, but will mask out those + * PTE_MAYBE_* constants, whether they are set or not. So #define them + * as 0x0 here so we can evaluate the PIE_E* constants in asm context. + */ + +#define PTE_MAYBE_NG 0 +#define PTE_MAYBE_SHARED 0 + + mov_q x0, PIE_E0 + msr REG_PIRE0_EL1, x0 + mov_q x0, PIE_E1 + msr REG_PIR_EL1, x0 + +#undef PTE_MAYBE_NG +#undef PTE_MAYBE_SHARED + + mov x0, TCR2_EL1x_PIE + msr REG_TCR2_EL1, x0 + +.Lskip_indirection: + + /* + * Prepare SCTLR + */ + mov_q x0, INIT_SCTLR_EL1_MMU_ON + ret // return to head.S + + .unreq mair + .unreq tcr +SYM_FUNC_END(__cpu_setup) + +SYM_FUNC_START(enable_sctlr_el1) + stp x29, x30, [sp, #-16]! + bl __cpu_setup + set_sctlr_el1 x0 + ldp x29, x30, [sp], #16 + ret +SYM_FUNC_END(enable_sctlr_el1) + diff --git a/drivers/firmware/efi/efi_emulator/entry.c b/drivers/firmware/efi/efi_emulator/entry.c index c851a9acafa77..a72a746805666 100644 --- a/drivers/firmware/efi/efi_emulator/entry.c +++ b/drivers/firmware/efi/efi_emulator/entry.c @@ -13,6 +13,13 @@ extern void enable_sctlr_el1(unsigned long scratch_reg); static void arch_handle_mmu(struct efi_emulator_param *param) { if (!param->mmu_on && param->pgd_root) { + unsigned long scratch_reg = 0; + // in fact, we need SYM_FUNC_START(__cpu_setup), later, set SCTLR_EL1 + // At present, the mmu is not ON + write_sysreg(param->pgd_root, ttbr0_el1); + isb(); + /* scratch_reg asks the C compiler to save x0 */ + enable_sctlr_el1(scratch_reg); } } -- 2.41.0
