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authorRussell King <rmk+kernel@arm.linux.org.uk>2012-09-30 09:03:44 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-09-30 09:03:44 +0100
commit648f3b69986b4d0ade57e59504a431b973ce2875 (patch)
tree6d0b6ccc6f243c1c582d52b88ab917eaffa022ba /arch/arm
parent8ee777fd915b0e36f35a430225729007a1df6441 (diff)
parent8ec58be9f3ff2ad4a4d7bde8f48b4a4c406768e7 (diff)
downloadop-kernel-dev-648f3b69986b4d0ade57e59504a431b973ce2875.zip
op-kernel-dev-648f3b69986b4d0ade57e59504a431b973ce2875.tar.gz
Merge branch 'hyp-boot-mode-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into devel-stable
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/boot/compressed/.gitignore1
-rw-r--r--arch/arm/boot/compressed/Makefile9
-rw-r--r--arch/arm/boot/compressed/head.S71
-rw-r--r--arch/arm/include/asm/assembler.h28
-rw-r--r--arch/arm/include/asm/opcodes-virt.h39
-rw-r--r--arch/arm/include/asm/opcodes.h181
-rw-r--r--arch/arm/include/asm/ptrace.h1
-rw-r--r--arch/arm/include/asm/virt.h69
-rw-r--r--arch/arm/kernel/Makefile2
-rw-r--r--arch/arm/kernel/head.S14
-rw-r--r--arch/arm/kernel/hyp-stub.S223
-rw-r--r--arch/arm/kernel/setup.c20
-rw-r--r--arch/arm/kernel/smp.c3
-rw-r--r--arch/arm/mm/Kconfig17
14 files changed, 652 insertions, 26 deletions
diff --git a/arch/arm/boot/compressed/.gitignore b/arch/arm/boot/compressed/.gitignore
index d0d441c..f79a08e 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 bb26756..a517153 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 bc67cbf..90275f0 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 5c8b3bf4..683a1e6 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 0000000..efcfdf9
--- /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 19c48de..74e211a 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 355ece5..91ef6c2 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 0000000..86164df
--- /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 7ad2d5c..49b61a3 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 3db960e..27093e4 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 0000000..65b2417
--- /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 a81dcec..04fd01f 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 199558b..f34514a 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 101b968..c9a4963 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
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