diff options
| -rw-r--r-- | Documentation/arm/Booting | 22 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/.gitignore | 1 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/Makefile | 9 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 71 | ||||
| -rw-r--r-- | arch/arm/include/asm/assembler.h | 28 | ||||
| -rw-r--r-- | arch/arm/include/asm/opcodes-virt.h | 39 | ||||
| -rw-r--r-- | arch/arm/include/asm/opcodes.h | 181 | ||||
| -rw-r--r-- | arch/arm/include/asm/ptrace.h | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/virt.h | 69 | ||||
| -rw-r--r-- | arch/arm/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/head.S | 14 | ||||
| -rw-r--r-- | arch/arm/kernel/hyp-stub.S | 223 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 20 | ||||
| -rw-r--r-- | arch/arm/kernel/smp.c | 3 | ||||
| -rw-r--r-- | arch/arm/mm/Kconfig | 17 |
15 files changed, 673 insertions, 27 deletions
diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting index a341d87d276e..0c1f475fdf36 100644 --- a/Documentation/arm/Booting +++ b/Documentation/arm/Booting @@ -154,13 +154,33 @@ In either case, the following conditions must be met: - CPU mode All forms of interrupts must be disabled (IRQs and FIQs) - The CPU must be in SVC mode. (A special exception exists for Angel) + + For CPUs which do not include the ARM virtualization extensions, the + CPU must be in SVC mode. (A special exception exists for Angel) + + CPUs which include support for the virtualization extensions can be + entered in HYP mode in order to enable the kernel to make full use of + these extensions. This is the recommended boot method for such CPUs, + unless the virtualisations are already in use by a pre-installed + hypervisor. + + If the kernel is not entered in HYP mode for any reason, it must be + entered in SVC mode. - Caches, MMUs The MMU must be off. Instruction cache may be on or off. Data cache must be off. + If the kernel is entered in HYP mode, the above requirements apply to + the HYP mode configuration in addition to the ordinary PL1 (privileged + kernel modes) configuration. In addition, all traps into the + hypervisor must be disabled, and PL1 access must be granted for all + peripherals and CPU resources for which this is architecturally + possible. Except for entering in HYP mode, the system configuration + should be such that a kernel which does not include support for the + virtualization extensions can boot correctly without extra help. + - The boot loader is expected to call the kernel image by jumping directly to the first instruction of the kernel image. diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore index d0d441c429ae..f79a08efe000 100644 --- a/arch/arm/boot/compressed/.gitignore +++ b/arch/arm/boot/compressed/.gitignore @@ -1,6 +1,7 @@ ashldi3.S font.c lib1funcs.S +hyp-stub.S piggy.gzip piggy.lzo piggy.lzma diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index bb267562e7ed..a517153a13ea 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -30,6 +30,10 @@ FONTC = $(srctree)/drivers/video/console/font_acorn_8x8.c OBJS += string.o CFLAGS_string.o := -Os +ifeq ($(CONFIG_ARM_VIRT_EXT),y) +OBJS += hyp-stub.o +endif + # # Architecture dependencies # @@ -126,7 +130,7 @@ KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS)) endif ccflags-y := -fpic -fno-builtin -I$(obj) -asflags-y := -Wa,-march=all +asflags-y := -Wa,-march=all -DZIMAGE # Supply kernel BSS size to the decompressor via a linker symbol. KBSS_SZ = $(shell $(CROSS_COMPILE)size $(obj)/../../../../vmlinux | \ @@ -198,3 +202,6 @@ $(obj)/font.c: $(FONTC) $(obj)/vmlinux.lds: $(obj)/vmlinux.lds.in arch/arm/boot/Makefile $(KCONFIG_CONFIG) @sed "$(SEDFLAGS)" < $< > $@ + +$(obj)/hyp-stub.S: $(srctree)/arch/$(SRCARCH)/kernel/hyp-stub.S + $(call cmd,shipped) diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index bc67cbff3944..90275f036cd1 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -9,6 +9,7 @@ * published by the Free Software Foundation. */ #include <linux/linkage.h> +#include <asm/assembler.h> /* * Debugging stuff @@ -132,7 +133,12 @@ start: .word start @ absolute load/run zImage address .word _edata @ zImage end address THUMB( .thumb ) -1: mov r7, r1 @ save architecture ID +1: + mrs r9, cpsr +#ifdef CONFIG_ARM_VIRT_EXT + bl __hyp_stub_install @ get into SVC mode, reversibly +#endif + mov r7, r1 @ save architecture ID mov r8, r2 @ save atags pointer #ifndef __ARM_ARCH_2__ @@ -148,9 +154,9 @@ start: ARM( swi 0x123456 ) @ angel_SWI_ARM THUMB( svc 0xab ) @ angel_SWI_THUMB not_angel: - mrs r2, cpsr @ turn off interrupts to - orr r2, r2, #0xc0 @ prevent angel from running - msr cpsr_c, r2 + safe_svcmode_maskall r0 + msr spsr_cxsf, r9 @ Save the CPU boot mode in + @ SPSR #else teqp pc, #0x0c000003 @ turn off interrupts #endif @@ -350,6 +356,20 @@ dtb_check_done: adr r5, restart bic r5, r5, #31 +/* Relocate the hyp vector base if necessary */ +#ifdef CONFIG_ARM_VIRT_EXT + mrs r0, spsr + and r0, r0, #MODE_MASK + cmp r0, #HYP_MODE + bne 1f + + bl __hyp_get_vectors + sub r0, r0, r5 + add r0, r0, r10 + bl __hyp_set_vectors +1: +#endif + sub r9, r6, r5 @ size to copy add r9, r9, #31 @ rounded up to a multiple bic r9, r9, #31 @ ... of 32 bytes @@ -458,11 +478,29 @@ not_relocated: mov r0, #0 bl decompress_kernel bl cache_clean_flush bl cache_off - mov r0, #0 @ must be zero mov r1, r7 @ restore architecture number mov r2, r8 @ restore atags pointer - ARM( mov pc, r4 ) @ call kernel - THUMB( bx r4 ) @ entry point is always ARM + +#ifdef CONFIG_ARM_VIRT_EXT + mrs r0, spsr @ Get saved CPU boot mode + and r0, r0, #MODE_MASK + cmp r0, #HYP_MODE @ if not booted in HYP mode... + bne __enter_kernel @ boot kernel directly + + adr r12, .L__hyp_reentry_vectors_offset + ldr r0, [r12] + add r0, r0, r12 + + bl __hyp_set_vectors + __HVC(0) @ otherwise bounce to hyp mode + + b . @ should never be reached + + .align 2 +.L__hyp_reentry_vectors_offset: .long __hyp_reentry_vectors - . +#else + b __enter_kernel +#endif .align 2 .type LC0, #object @@ -1196,6 +1234,25 @@ memdump: mov r12, r0 #endif .ltorg + +#ifdef CONFIG_ARM_VIRT_EXT +.align 5 +__hyp_reentry_vectors: + W(b) . @ reset + W(b) . @ undef + W(b) . @ svc + W(b) . @ pabort + W(b) . @ dabort + W(b) __enter_kernel @ hyp + W(b) . @ irq + W(b) . @ fiq +#endif /* CONFIG_ARM_VIRT_EXT */ + +__enter_kernel: + mov r0, #0 @ must be 0 + ARM( mov pc, r4 ) @ call kernel + THUMB( bx r4 ) @ entry point is always ARM + reloc_code_end: .align diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 5c8b3bf4d825..683a1e6b6020 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -22,6 +22,7 @@ #include <asm/ptrace.h> #include <asm/domain.h> +#include <asm/opcodes-virt.h> #define IOMEM(x) (x) @@ -240,6 +241,33 @@ #endif /* + * Helper macro to enter SVC mode cleanly and mask interrupts. reg is + * a scratch register for the macro to overwrite. + * + * This macro is intended for forcing the CPU into SVC mode at boot time. + * you cannot return to the original mode. + * + * Beware, it also clobers LR. + */ +.macro safe_svcmode_maskall reg:req + mrs \reg , cpsr + mov lr , \reg + and lr , lr , #MODE_MASK + cmp lr , #HYP_MODE + orr \reg , \reg , #PSR_A_BIT | PSR_I_BIT | PSR_F_BIT + bic \reg , \reg , #MODE_MASK + orr \reg , \reg , #SVC_MODE +THUMB( orr \reg , \reg , #PSR_T_BIT ) + msr spsr_cxsf, \reg + adr lr, BSYM(2f) + bne 1f + __MSR_ELR_HYP(14) + __ERET +1: movs pc, lr +2: +.endm + +/* * STRT/LDRT access macros with ARM and Thumb-2 variants */ #ifdef CONFIG_THUMB2_KERNEL diff --git a/arch/arm/include/asm/opcodes-virt.h b/arch/arm/include/asm/opcodes-virt.h new file mode 100644 index 000000000000..efcfdf92d9d5 --- /dev/null +++ b/arch/arm/include/asm/opcodes-virt.h @@ -0,0 +1,39 @@ +/* + * opcodes-virt.h: Opcode definitions for the ARM virtualization extensions + * Copyright (C) 2012 Linaro Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#ifndef __ASM_ARM_OPCODES_VIRT_H +#define __ASM_ARM_OPCODES_VIRT_H + +#include <asm/opcodes.h> + +#define __HVC(imm16) __inst_arm_thumb32( \ + 0xE1400070 | (((imm16) & 0xFFF0) << 4) | ((imm16) & 0x000F), \ + 0xF7E08000 | (((imm16) & 0xF000) << 4) | ((imm16) & 0x0FFF) \ +) + +#define __ERET __inst_arm_thumb32( \ + 0xE160006E, \ + 0xF3DE8F00 \ +) + +#define __MSR_ELR_HYP(regnum) __inst_arm_thumb32( \ + 0xE12EF300 | regnum, \ + 0xF3808E30 | (regnum << 16) \ +) + +#endif /* ! __ASM_ARM_OPCODES_VIRT_H */ diff --git a/arch/arm/include/asm/opcodes.h b/arch/arm/include/asm/opcodes.h index 19c48deda70f..74e211a6fb24 100644 --- a/arch/arm/include/asm/opcodes.h +++ b/arch/arm/include/asm/opcodes.h @@ -19,6 +19,33 @@ extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr); /* + * Assembler opcode byteswap helpers. + * These are only intended for use by this header: don't use them directly, + * because they will be suboptimal in most cases. + */ +#define ___asm_opcode_swab32(x) ( \ + (((x) << 24) & 0xFF000000) \ + | (((x) << 8) & 0x00FF0000) \ + | (((x) >> 8) & 0x0000FF00) \ + | (((x) >> 24) & 0x000000FF) \ +) +#define ___asm_opcode_swab16(x) ( \ + (((x) << 8) & 0xFF00) \ + | (((x) >> 8) & 0x00FF) \ +) +#define ___asm_opcode_swahb32(x) ( \ + (((x) << 8) & 0xFF00FF00) \ + | (((x) >> 8) & 0x00FF00FF) \ +) +#define ___asm_opcode_swahw32(x) ( \ + (((x) << 16) & 0xFFFF0000) \ + | (((x) >> 16) & 0x0000FFFF) \ +) +#define ___asm_opcode_identity32(x) ((x) & 0xFFFFFFFF) +#define ___asm_opcode_identity16(x) ((x) & 0xFFFF) + + +/* * Opcode byteswap helpers * * These macros help with converting instructions between a canonical integer @@ -41,39 +68,163 @@ extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr); * Note that values in the range 0x0000E800..0xE7FFFFFF intentionally do not * represent any valid Thumb-2 instruction. For this range, * __opcode_is_thumb32() and __opcode_is_thumb16() will both be false. + * + * The ___asm variants are intended only for use by this header, in situations + * involving inline assembler. For .S files, the normal __opcode_*() macros + * should do the right thing. */ +#ifdef __ASSEMBLY__ -#ifndef __ASSEMBLY__ +#define ___opcode_swab32(x) ___asm_opcode_swab32(x) +#define ___opcode_swab16(x) ___asm_opcode_swab16(x) +#define ___opcode_swahb32(x) ___asm_opcode_swahb32(x) +#define ___opcode_swahw32(x) ___asm_opcode_swahw32(x) +#define ___opcode_identity32(x) ___asm_opcode_identity32(x) +#define ___opcode_identity16(x) ___asm_opcode_identity16(x) + +#else /* ! __ASSEMBLY__ */ #include <linux/types.h> #include <linux/swab.h> +#define ___opcode_swab32(x) swab32(x) +#define ___opcode_swab16(x) swab16(x) +#define ___opcode_swahb32(x) swahb32(x) +#define ___opcode_swahw32(x) swahw32(x) +#define ___opcode_identity32(x) ((u32)(x)) +#define ___opcode_identity16(x) ((u16)(x)) + +#endif /* ! __ASSEMBLY__ */ + + #ifdef CONFIG_CPU_ENDIAN_BE8 -#define __opcode_to_mem_arm(x) swab32(x) -#define __opcode_to_mem_thumb16(x) swab16(x) -#define __opcode_to_mem_thumb32(x) swahb32(x) -#else -#define __opcode_to_mem_arm(x) ((u32)(x)) -#define __opcode_to_mem_thumb16(x) ((u16)(x)) -#define __opcode_to_mem_thumb32(x) swahw32(x) + +#define __opcode_to_mem_arm(x) ___opcode_swab32(x) +#define __opcode_to_mem_thumb16(x) ___opcode_swab16(x) +#define __opcode_to_mem_thumb32(x) ___opcode_swahb32(x) +#define ___asm_opcode_to_mem_arm(x) ___asm_opcode_swab32(x) +#define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_swab16(x) +#define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahb32(x) + +#else /* ! CONFIG_CPU_ENDIAN_BE8 */ + +#define __opcode_to_mem_arm(x) ___opcode_identity32(x) +#define __opcode_to_mem_thumb16(x) ___opcode_identity16(x) +#define ___asm_opcode_to_mem_arm(x) ___asm_opcode_identity32(x) +#define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_identity16(x) +#ifndef CONFIG_CPU_ENDIAN_BE32 +/* + * On BE32 systems, using 32-bit accesses to store Thumb instructions will not + * work in all cases, due to alignment constraints. For now, a correct + * version is not provided for BE32. + */ +#define __opcode_to_mem_thumb32(x) ___opcode_swahw32(x) +#define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahw32(x) #endif +#endif /* ! CONFIG_CPU_ENDIAN_BE8 */ + #define __mem_to_opcode_arm(x) __opcode_to_mem_arm(x) #define __mem_to_opcode_thumb16(x) __opcode_to_mem_thumb16(x) +#ifndef CONFIG_CPU_ENDIAN_BE32 #define __mem_to_opcode_thumb32(x) __opcode_to_mem_thumb32(x) +#endif /* Operations specific to Thumb opcodes */ /* Instruction size checks: */ -#define __opcode_is_thumb32(x) ((u32)(x) >= 0xE8000000UL) -#define __opcode_is_thumb16(x) ((u32)(x) < 0xE800UL) +#define __opcode_is_thumb32(x) ( \ + ((x) & 0xF8000000) == 0xE8000000 \ + || ((x) & 0xF0000000) == 0xF0000000 \ +) +#define __opcode_is_thumb16(x) ( \ + ((x) & 0xFFFF0000) == 0 \ + && !(((x) & 0xF800) == 0xE800 || ((x) & 0xF000) == 0xF000) \ +) /* Operations to construct or split 32-bit Thumb instructions: */ -#define __opcode_thumb32_first(x) ((u16)((x) >> 16)) -#define __opcode_thumb32_second(x) ((u16)(x)) -#define __opcode_thumb32_compose(first, second) \ - (((u32)(u16)(first) << 16) | (u32)(u16)(second)) +#define __opcode_thumb32_first(x) (___opcode_identity16((x) >> 16)) +#define __opcode_thumb32_second(x) (___opcode_identity16(x)) +#define __opcode_thumb32_compose(first, second) ( \ + (___opcode_identity32(___opcode_identity16(first)) << 16) \ + | ___opcode_identity32(___opcode_identity16(second)) \ +) +#define ___asm_opcode_thumb32_first(x) (___asm_opcode_identity16((x) >> 16)) +#define ___asm_opcode_thumb32_second(x) (___asm_opcode_identity16(x)) +#define ___asm_opcode_thumb32_compose(first, second) ( \ + (___asm_opcode_identity32(___asm_opcode_identity16(first)) << 16) \ + | ___asm_opcode_identity32(___asm_opcode_identity16(second)) \ +) -#endif /* __ASSEMBLY__ */ +/* + * Opcode injection helpers + * + * In rare cases it is necessary to assemble an opcode which the + * assembler does not support directly, or which would normally be + * rejected because of the CFLAGS or AFLAGS used to build the affected + * file. + * + * Before using these macros, consider carefully whether it is feasible + * instead to change the build flags for your file, or whether it really + * makes sense to support old assembler versions when building that + * particular kernel feature. + * + * The macros defined here should only be used where there is no viable + * alternative. + * + * + * __inst_arm(x): emit the specified ARM opcode + * __inst_thumb16(x): emit the specified 16-bit Thumb opcode + * __inst_thumb32(x): emit the specified 32-bit Thumb opcode + * + * __inst_arm_thumb16(arm, thumb): emit either the specified arm or + * 16-bit Thumb opcode, depending on whether an ARM or Thumb-2 + * kernel is being built + * + * __inst_arm_thumb32(arm, thumb): emit either the specified arm or + * 32-bit Thumb opcode, depending on whether an ARM or Thumb-2 + * kernel is being built + * + * + * Note that using these macros directly is poor practice. Instead, you + * should use them to define human-readable wrapper macros to encode the + * instructions that you care about. In code which might run on ARMv7 or + * above, you can usually use the __inst_arm_thumb{16,32} macros to + * specify the ARM and Thumb alternatives at the same time. This ensures + * that the correct opcode gets emitted depending on the instruction set + * used for the kernel build. + * + * Look at opcodes-virt.h for an example of how to use these macros. + */ +#include <linux/stringify.h> + +#define __inst_arm(x) ___inst_arm(___asm_opcode_to_mem_arm(x)) +#define __inst_thumb32(x) ___inst_thumb32( \ + ___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_first(x)), \ + ___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_second(x)) \ +) +#define __inst_thumb16(x) ___inst_thumb16(___asm_opcode_to_mem_thumb16(x)) + +#ifdef CONFIG_THUMB2_KERNEL +#define __inst_arm_thumb16(arm_opcode, thumb_opcode) \ + __inst_thumb16(thumb_opcode) +#define __inst_arm_thumb32(arm_opcode, thumb_opcode) \ + __inst_thumb32(thumb_opcode) +#else +#define __inst_arm_thumb16(arm_opcode, thumb_opcode) __inst_arm(arm_opcode) +#define __inst_arm_thumb32(arm_opcode, thumb_opcode) __inst_arm(arm_opcode) +#endif + +/* Helpers for the helpers. Don't use these directly. */ +#ifdef __ASSEMBLY__ +#define ___inst_arm(x) .long x +#define ___inst_thumb16(x) .short x +#define ___inst_thumb32(first, second) .short first, second +#else +#define ___inst_arm(x) ".long " __stringify(x) "\n\t" +#define ___inst_thumb16(x) ".short " __stringify(x) "\n\t" +#define ___inst_thumb32(first, second) \ + ".short " __stringify(first) ", " __stringify(second) "\n\t" +#endif #endif /* __ASM_ARM_OPCODES_H */ diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index 355ece523f41..91ef6c231c47 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -44,6 +44,7 @@ #define IRQ_MODE 0x00000012 #define SVC_MODE 0x00000013 #define ABT_MODE 0x00000017 +#define HYP_MODE 0x0000001a #define UND_MODE 0x0000001b #define SYSTEM_MODE 0x0000001f #define MODE32_BIT 0x00000010 diff --git a/arch/arm/include/asm/virt.h b/arch/arm/include/asm/virt.h new file mode 100644 index 000000000000..86164df86cb4 --- /dev/null +++ b/arch/arm/include/asm/virt.h @@ -0,0 +1,69 @@ +/* + * Copyright (c) 2012 Linaro Limited. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef VIRT_H +#define VIRT_H + +#include <asm/ptrace.h> + +/* + * Flag indicating that the kernel was not entered in the same mode on every + * CPU. The zImage loader stashes this value in an SPSR, so we need an + * architecturally defined flag bit here (the N flag, as it happens) + */ +#define BOOT_CPU_MODE_MISMATCH (1<<31) + +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_ARM_VIRT_EXT +/* + * __boot_cpu_mode records what mode the primary CPU was booted in. + * A correctly-implemented bootloader must start all CPUs in the same mode: + * if it fails to do this, the flag BOOT_CPU_MODE_MISMATCH is set to indicate + * that some CPU(s) were booted in a different mode. + * + * This allows the kernel to flag an error when the secondaries have come up. + */ +extern int __boot_cpu_mode; + +void __hyp_set_vectors(unsigned long phys_vector_base); +unsigned long __hyp_get_vectors(void); +#else +#define __boot_cpu_mode (SVC_MODE) +#endif + +#ifndef ZIMAGE +void hyp_mode_check(void); + +/* Reports the availability of HYP mode */ +static inline bool is_hyp_mode_available(void) +{ + return ((__boot_cpu_mode & MODE_MASK) == HYP_MODE && + !(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH)); +} + +/* Check if the bootloader has booted CPUs in different modes */ +static inline bool is_hyp_mode_mismatched(void) +{ + return !!(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH); +} +#endif + +#endif /* __ASSEMBLY__ */ + +#endif /* ! VIRT_H */ diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 7ad2d5cf7008..49b61a3f5b29 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -82,4 +82,6 @@ head-y := head$(MMUEXT).o obj-$(CONFIG_DEBUG_LL) += debug.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o +obj-$(CONFIG_ARM_VIRT_EXT) += hyp-stub.o + extra-y := $(head-y) vmlinux.lds diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 3db960e20cb8..27093e4feef8 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -83,8 +83,12 @@ ENTRY(stext) THUMB( .thumb ) @ switch to Thumb now. THUMB(1: ) - setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode - @ and irqs disabled +#ifdef CONFIG_ARM_VIRT_EXT + bl __hyp_stub_install +#endif + @ ensure svc mode and all interrupts masked + safe_svcmode_maskall r9 + mrc p15, 0, r9, c0, c0 @ get processor id bl __lookup_processor_type @ r5=procinfo r9=cpuid movs r10, r5 @ invalid processor (r5=0)? @@ -326,7 +330,11 @@ ENTRY(secondary_startup) * the processor type - there is no need to check the machine type * as it has already been validated by the primary processor. */ - setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 +#ifdef CONFIG_ARM_VIRT_EXT + bl __hyp_stub_install +#endif + safe_svcmode_maskall r9 + mrc p15, 0, r9, c0, c0 @ get processor id bl __lookup_processor_type movs r10, r5 @ invalid processor? diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S new file mode 100644 index 000000000000..65b2417aebce --- /dev/null +++ b/arch/arm/kernel/hyp-stub.S @@ -0,0 +1,223 @@ +/* + * Copyright (c) 2012 Linaro Limited. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/virt.h> + +#ifndef ZIMAGE +/* + * For the kernel proper, we need to find out the CPU boot mode long after + * boot, so we need to store it in a writable variable. + * + * This is not in .bss, because we set it sufficiently early that the boot-time + * zeroing of .bss would clobber it. + */ +.data +ENTRY(__boot_cpu_mode) + .long 0 +.text + + /* + * Save the primary CPU boot mode. Requires 3 scratch registers. + */ + .macro store_primary_cpu_mode reg1, reg2, reg3 + mrs \reg1, cpsr + and \reg1, \reg1, #MODE_MASK + adr \reg2, .L__boot_cpu_mode_offset + ldr \reg3, [\reg2] + str \reg1, [\reg2, \reg3] + .endm + + /* + * Compare the current mode with the one saved on the primary CPU. + * If they don't match, record that fact. The Z bit indicates + * if there's a match or not. + * Requires 3 additionnal scratch registers. + */ + .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3 + adr \reg2, .L__boot_cpu_mode_offset + ldr \reg3, [\reg2] + ldr \reg1, [\reg2, \reg3] + cmp \mode, \reg1 @ matches primary CPU boot mode? + orrne r7, r7, #BOOT_CPU_MODE_MISMATCH + strne r7, [r5, r6] @ record what happened and give up + .endm + +#else /* ZIMAGE */ + + .macro store_primary_cpu_mode reg1:req, reg2:req, reg3:req + .endm + +/* + * The zImage loader only runs on one CPU, so we don't bother with mult-CPU + * consistency checking: + */ + .macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3 + cmp \mode, \mode + .endm + +#endif /* ZIMAGE */ + +/* + * Hypervisor stub installation functions. + * + * These must be called with the MMU and D-cache off. + * They are not ABI compliant and are only intended to be called from the kernel + * entry points in head.S. + */ +@ Call this from the primary CPU +ENTRY(__hyp_stub_install) + store_primary_cpu_mode r4, r5, r6 +ENDPROC(__hyp_stub_install) + + @ fall through... + +@ Secondary CPUs should call here +ENTRY(__hyp_stub_install_secondary) + mrs r4, cpsr + and r4, r4, #MODE_MASK + + /* + * If the secondary has booted with a different mode, give up + * immediately. + */ + compare_cpu_mode_with_primary r4, r5, r6, r7 + bxne lr + + /* + * Once we have given up on one CPU, we do not try to install the + * stub hypervisor on the remaining ones: because the saved boot mode + * is modified, it can't compare equal to the CPSR mode field any + * more. + * + * Otherwise... + */ + + cmp r4, #HYP_MODE + bxne lr @ give up if the CPU is not in HYP mode + +/* + * Configure HSCTLR to set correct exception endianness/instruction set + * state etc. + * Turn off all traps + * Eventually, CPU-specific code might be needed -- assume not for now + * + * This code relies on the "eret" instruction to synchronize the + * various coprocessor accesses. + */ + @ Now install the hypervisor stub: + adr r7, __hyp_stub_vectors + mcr p15, 4, r7, c12, c0, 0 @ set hypervisor vector base (HVBAR) + + @ Disable all traps, so we don't get any nasty surprise + mov r7, #0 + mcr p15, 4, r7, c1, c1, 0 @ HCR + mcr p15, 4, r7, c1, c1, 2 @ HCPTR + mcr p15, 4, r7, c1, c1, 3 @ HSTR + +THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE +#ifdef CONFIG_CPU_BIG_ENDIAN + orr r7, #(1 << 9) @ HSCTLR.EE +#endif + mcr p15, 4, r7, c1, c0, 0 @ HSCTLR + + mrc p15, 4, r7, c1, c1, 1 @ HDCR + and r7, #0x1f @ Preserve HPMN + mcr p15, 4, r7, c1, c1, 1 @ HDCR + +#if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER) + @ make CNTP_* and CNTPCT accessible from PL1 + mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1 + lsr r7, #16 + and r7, #0xf + cmp r7, #1 + bne 1f + mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL + orr r7, r7, #3 @ PL1PCEN | PL1PCTEN + mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL +1: +#endif + + bic r7, r4, #MODE_MASK + orr r7, r7, #SVC_MODE +THUMB( orr r7, r7, #PSR_T_BIT ) + msr spsr_cxsf, r7 @ This is SPSR_hyp. + + __MSR_ELR_HYP(14) @ msr elr_hyp, lr + __ERET @ return, switching to SVC mode + @ The boot CPU mode is left in r4. +ENDPROC(__hyp_stub_install_secondary) + +__hyp_stub_do_trap: + cmp r0, #-1 + mrceq p15, 4, r0, c12, c0, 0 @ get HVBAR + mcrne p15, 4, r0, c12, c0, 0 @ set HVBAR + __ERET +ENDPROC(__hyp_stub_do_trap) + +/* + * __hyp_set_vectors: Call this after boot to set the initial hypervisor + * vectors as part of hypervisor installation. On an SMP system, this should + * be called on each CPU. + * + * r0 must be the physical address of the new vector table (which must lie in + * the bottom 4GB of physical address space. + * + * r0 must be 32-byte aligned. + * + * Before calling this, you must check that the stub hypervisor is installed + * everywhere, by waiting for any secondary CPUs to be brought up and then + * checking that BOOT_CPU_MODE_HAVE_HYP(__boot_cpu_mode) is true. + * + * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or + * something else went wrong... in such cases, trying to install a new + * hypervisor is unlikely to work as desired. + * + * When you call into your shiny new hypervisor, sp_hyp will contain junk, + * so you will need to set that to something sensible at the new hypervisor's + * initialisation entry point. + */ +ENTRY(__hyp_get_vectors) + mov r0, #-1 +ENDPROC(__hyp_get_vectors) + @ fall through +ENTRY(__hyp_set_vectors) + __HVC(0) + bx lr +ENDPROC(__hyp_set_vectors) + +#ifndef ZIMAGE +.align 2 +.L__boot_cpu_mode_offset: + .long __boot_cpu_mode - . +#endif + +.align 5 +__hyp_stub_vectors: +__hyp_stub_reset: W(b) . +__hyp_stub_und: W(b) . +__hyp_stub_svc: W(b) . +__hyp_stub_pabort: W(b) . +__hyp_stub_dabort: W(b) . +__hyp_stub_trap: W(b) __hyp_stub_do_trap +__hyp_stub_irq: W(b) . +__hyp_stub_fiq: W(b) . +ENDPROC(__hyp_stub_vectors) + diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index a81dcecc7343..04fd01feea86 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -55,6 +55,7 @@ #include <asm/traps.h> #include <asm/unwind.h> #include <asm/memblock.h> +#include <asm/virt.h> #if defined(CONFIG_DEPRECATED_PARAM_STRUCT) #include "compat.h" @@ -937,6 +938,21 @@ static int __init meminfo_cmp(const void *_a, const void *_b) return cmp < 0 ? -1 : cmp > 0 ? 1 : 0; } +void __init hyp_mode_check(void) +{ +#ifdef CONFIG_ARM_VIRT_EXT + if (is_hyp_mode_available()) { + pr_info("CPU: All CPU(s) started in HYP mode.\n"); + pr_info("CPU: Virtualization extensions available.\n"); + } else if (is_hyp_mode_mismatched()) { + pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n", + __boot_cpu_mode & MODE_MASK); + pr_warn("CPU: This may indicate a broken bootloader or firmware.\n"); + } else + pr_info("CPU: All CPU(s) started in SVC mode.\n"); +#endif +} + void __init setup_arch(char **cmdline_p) { struct machine_desc *mdesc; @@ -980,6 +996,10 @@ void __init setup_arch(char **cmdline_p) if (is_smp()) smp_init_cpus(); #endif + + if (!is_smp()) + hyp_mode_check(); + reserve_crashkernel(); tcm_init(); diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 199558b9462e..f34514a0834e 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -42,6 +42,7 @@ #include <asm/ptrace.h> #include <asm/localtimer.h> #include <asm/smp_plat.h> +#include <asm/virt.h> /* * as from 2.5, kernels no longer have an init_tasks structure @@ -290,6 +291,8 @@ void __init smp_cpus_done(unsigned int max_cpus) num_online_cpus(), bogosum / (500000/HZ), (bogosum / (5000/HZ)) % 100); + + hyp_mode_check(); } void __init smp_prepare_boot_cpu(void) diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 101b9681c08c..c9a4963b5c3d 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -624,6 +624,23 @@ config ARM_THUMBEE Say Y here if you have a CPU with the ThumbEE extension and code to make use of it. Say N for code that can run on CPUs without ThumbEE. +config ARM_VIRT_EXT + bool "Native support for the ARM Virtualization Extensions" + depends on MMU && CPU_V7 + help + Enable the kernel to make use of the ARM Virtualization + Extensions to install hypervisors without run-time firmware + assistance. + + A compliant bootloader is required in order to make maximum + use of this feature. Refer to Documentation/arm/Booting for + details. + + It is safe to enable this option even if the kernel may not be + booted in HYP mode, may not have support for the + virtualization extensions, or may be booted with a + non-compliant bootloader. + config SWP_EMULATE bool "Emulate SWP/SWPB instructions" depends on !CPU_USE_DOMAINS && CPU_V7 |