Merge branch 'hyp-boot-mode-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into devel-stable

This commit is contained in:
Russell King 2012-09-30 09:03:44 +01:00
commit 648f3b6998
15 changed files with 673 additions and 27 deletions

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@ -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.

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@ -1,6 +1,7 @@
ashldi3.S
font.c
lib1funcs.S
hyp-stub.S
piggy.gzip
piggy.lzo
piggy.lzma

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@ -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)

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@ -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

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@ -22,6 +22,7 @@
#include <asm/ptrace.h>
#include <asm/domain.h>
#include <asm/opcodes-virt.h>
#define IOMEM(x) (x)
@ -239,6 +240,33 @@
.endm
#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
*/

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@ -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 */

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@ -18,6 +18,33 @@ extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
#define ARM_OPCODE_CONDTEST_UNCOND 2
/*
* 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
*
@ -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 */

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@ -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

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@ -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 */

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@ -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

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@ -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?

223
arch/arm/kernel/hyp-stub.S Normal file
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@ -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)

View File

@ -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();

View File

@ -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)

View File

@ -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