Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm

Pull second set of ARM updates from Russell King:
 "This is the second set of ARM updates for this merge window.

  Contained within are changes to allow the kernel to boot in hypervisor
  mode on CPUs supporting virtualization, and cache flushing support to
  the point of inner sharable unification, which are used by the
  suspend/resume code to avoid having to do a full cache flush.

  Also included is one fix for VFP code identified by Michael Olbrich."

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernels
  ARM: 7549/1: HYP: fix boot on some ARM1136 cores
  ARM: 7542/1: mm: fix cache LoUIS API for xscale and feroceon
  ARM: mm: update __v7_setup() to the new LoUIS cache maintenance API
  ARM: kernel: update __cpu_disable to use cache LoUIS maintenance API
  ARM: kernel: update cpu_suspend code to use cache LoUIS operations
  ARM: mm: rename jump labels in v7_flush_dcache_all function
  ARM: mm: implement LoUIS API for cache maintenance ops
  ARM: virt: arch_timers: enable access to physical timers
  ARM: virt: Add CONFIG_ARM_VIRT_EXT option
  ARM: virt: Add boot-time diagnostics
  ARM: virt: Update documentation for hyp mode entry support
  ARM: zImage/virt: hyp mode entry support for the zImage loader
  ARM: virt: allow the kernel to be entered in HYP mode
  ARM: opcodes: add __ERET/__MSR_ELR_HYP instruction encoding

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.
 

arch/arm/boot/compressed/.gitignore

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

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)

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

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)
 
@@ -239,6 +240,34 @@
 	.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_I_BIT | PSR_F_BIT
+	bic	\reg , \reg , #MODE_MASK
+	orr	\reg , \reg , #SVC_MODE
+THUMB(	orr	\reg , \reg , #PSR_T_BIT	)
+	bne	1f
+	orr	\reg, \reg, #PSR_A_BIT
+	adr	lr, BSYM(2f)
+	msr	spsr_cxsf, \reg
+	__MSR_ELR_HYP(14)
+	__ERET
+1:	msr	cpsr_c, \reg
+2:
+.endm
+
 /*
  * STRT/LDRT access macros with ARM and Thumb-2 variants
  */

arch/arm/include/asm/cacheflush.h

@@ -49,6 +49,13 @@
  *
  *		Unconditionally clean and invalidate the entire cache.
  *
+ *     flush_kern_louis()
+ *
+ *             Flush data cache levels up to the level of unification
+ *             inner shareable and invalidate the I-cache.
+ *             Only needed from v7 onwards, falls back to flush_cache_all()
+ *             for all other processor versions.
+ *
  *	flush_user_all()
  *
  *		Clean and invalidate all user space cache entries
@@ -97,6 +104,7 @@
 struct cpu_cache_fns {
 	void (*flush_icache_all)(void);
 	void (*flush_kern_all)(void);
+	void (*flush_kern_louis)(void);
 	void (*flush_user_all)(void);
 	void (*flush_user_range)(unsigned long, unsigned long, unsigned int);
 
@@ -119,6 +127,7 @@ extern struct cpu_cache_fns cpu_cache;
 
 #define __cpuc_flush_icache_all		cpu_cache.flush_icache_all
 #define __cpuc_flush_kern_all		cpu_cache.flush_kern_all
+#define __cpuc_flush_kern_louis		cpu_cache.flush_kern_louis
 #define __cpuc_flush_user_all		cpu_cache.flush_user_all
 #define __cpuc_flush_user_range		cpu_cache.flush_user_range
 #define __cpuc_coherent_kern_range	cpu_cache.coherent_kern_range
@@ -139,6 +148,7 @@ extern struct cpu_cache_fns cpu_cache;
 
 extern void __cpuc_flush_icache_all(void);
 extern void __cpuc_flush_kern_all(void);
+extern void __cpuc_flush_kern_louis(void);
 extern void __cpuc_flush_user_all(void);
 extern void __cpuc_flush_user_range(unsigned long, unsigned long, unsigned int);
 extern void __cpuc_coherent_kern_range(unsigned long, unsigned long);
@@ -204,6 +214,11 @@ static inline void __flush_icache_all(void)
 	__flush_icache_preferred();
 }
 
+/*
+ * Flush caches up to Level of Unification Inner Shareable
+ */
+#define flush_cache_louis()		__cpuc_flush_kern_louis()
+
 #define flush_cache_all()		__cpuc_flush_kern_all()
 
 static inline void vivt_flush_cache_mm(struct mm_struct *mm)

arch/arm/include/asm/glue-cache.h

@@ -132,6 +132,7 @@
 #ifndef MULTI_CACHE
 #define __cpuc_flush_icache_all		__glue(_CACHE,_flush_icache_all)
 #define __cpuc_flush_kern_all		__glue(_CACHE,_flush_kern_cache_all)
+#define __cpuc_flush_kern_louis		__glue(_CACHE,_flush_kern_cache_louis)
 #define __cpuc_flush_user_all		__glue(_CACHE,_flush_user_cache_all)
 #define __cpuc_flush_user_range		__glue(_CACHE,_flush_user_cache_range)
 #define __cpuc_coherent_kern_range	__glue(_CACHE,_coherent_kern_range)

arch/arm/include/asm/opcodes-virt.h

@@ -26,4 +26,14 @@
 	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 */

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

arch/arm/include/asm/vfpmacros.h

@@ -28,7 +28,7 @@
 	ldr	\tmp, =elf_hwcap		    @ may not have MVFR regs
 	ldr	\tmp, [\tmp, #0]
 	tst	\tmp, #HWCAP_VFPv3D16
-	ldceq	p11, cr0, [\base],#32*4		    @ FLDMIAD \base!, {d16-d31}
+	ldceql	p11, cr0, [\base],#32*4		    @ FLDMIAD \base!, {d16-d31}
 	addne	\base, \base, #32*4		    @ step over unused register space
 #else
 	VFPFMRX	\tmp, MVFR0			    @ Media and VFP Feature Register 0
@@ -52,7 +52,7 @@
 	ldr	\tmp, =elf_hwcap		    @ may not have MVFR regs
 	ldr	\tmp, [\tmp, #0]
 	tst	\tmp, #HWCAP_VFPv3D16
-	stceq	p11, cr0, [\base],#32*4		    @ FSTMIAD \base!, {d16-d31}
+	stceql	p11, cr0, [\base],#32*4		    @ FSTMIAD \base!, {d16-d31}
 	addne	\base, \base, #32*4		    @ step over unused register space
 #else
 	VFPFMRX	\tmp, MVFR0			    @ Media and VFP Feature Register 0

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 */