From 37b8304642c7f91df54888955c373ae89b577fcc Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Sun, 19 Jun 2011 23:36:03 -0400 Subject: ARM: kuser: move interface documentation out of the source code Digging into some assembly file in order to get information about the kuser helpers is not that convivial. Let's move that information to a better formatted file in Documentation/arm/ and improve on it a bit. Thanks to Dave Martin for the initial cleanup and clarifications. Signed-off-by: Nicolas Pitre Acked-by: Dave Martin --- Documentation/arm/kernel_user_helpers.txt | 203 ++++++++++++++++++++++++++++++ 1 file changed, 203 insertions(+) create mode 100644 Documentation/arm/kernel_user_helpers.txt (limited to 'Documentation') diff --git a/Documentation/arm/kernel_user_helpers.txt b/Documentation/arm/kernel_user_helpers.txt new file mode 100644 index 000000000000..0c33f72d1873 --- /dev/null +++ b/Documentation/arm/kernel_user_helpers.txt @@ -0,0 +1,203 @@ +Kernel-provided User Helpers +============================ + +These are segment of kernel provided user code reachable from user space +at a fixed address in kernel memory. This is used to provide user space +with some operations which require kernel help because of unimplemented +native feature and/or instructions in many ARM CPUs. The idea is for this +code to be executed directly in user mode for best efficiency but which is +too intimate with the kernel counter part to be left to user libraries. +In fact this code might even differ from one CPU to another depending on +the available instruction set, or whether it is a SMP systems. In other +words, the kernel reserves the right to change this code as needed without +warning. Only the entry points and their results as documented here are +guaranteed to be stable. + +This is different from (but doesn't preclude) a full blown VDSO +implementation, however a VDSO would prevent some assembly tricks with +constants that allows for efficient branching to those code segments. And +since those code segments only use a few cycles before returning to user +code, the overhead of a VDSO indirect far call would add a measurable +overhead to such minimalistic operations. + +User space is expected to bypass those helpers and implement those things +inline (either in the code emitted directly by the compiler, or part of +the implementation of a library call) when optimizing for a recent enough +processor that has the necessary native support, but only if resulting +binaries are already to be incompatible with earlier ARM processors due to +useage of similar native instructions for other things. In other words +don't make binaries unable to run on earlier processors just for the sake +of not using these kernel helpers if your compiled code is not going to +use new instructions for other purpose. + +New helpers may be added over time, so an older kernel may be missing some +helpers present in a newer kernel. For this reason, programs must check +the value of __kuser_helper_version (see below) before assuming that it is +safe to call any particular helper. This check should ideally be +performed only once at process startup time, and execution aborted early +if the required helpers are not provided by the kernel version that +process is running on. + +kuser_helper_version +-------------------- + +Location: 0xffff0ffc + +Reference declaration: + + extern int32_t __kuser_helper_version; + +Definition: + + This field contains the number of helpers being implemented by the + running kernel. User space may read this to determine the availability + of a particular helper. + +Usage example: + +#define __kuser_helper_version (*(int32_t *)0xffff0ffc) + +void check_kuser_version(void) +{ + if (__kuser_helper_version < 2) { + fprintf(stderr, "can't do atomic operations, kernel too old\n"); + abort(); + } +} + +Notes: + + User space may assume that the value of this field never changes + during the lifetime of any single process. This means that this + field can be read once during the initialisation of a library or + startup phase of a program. + +kuser_get_tls +------------- + +Location: 0xffff0fe0 + +Reference prototype: + + void * __kuser_get_tls(void); + +Input: + + lr = return address + +Output: + + r0 = TLS value + +Clobbered registers: + + none + +Definition: + + Get the TLS value as previously set via the __ARM_NR_set_tls syscall. + +Usage example: + +typedef void * (__kuser_get_tls_t)(void); +#define __kuser_get_tls (*(__kuser_get_tls_t *)0xffff0fe0) + +void foo() +{ + void *tls = __kuser_get_tls(); + printf("TLS = %p\n", tls); +} + +Notes: + + - Valid only if __kuser_helper_version >= 1 (from kernel version 2.6.12). + +kuser_cmpxchg +------------- + +Location: 0xffff0fc0 + +Reference prototype: + + int __kuser_cmpxchg(int32_t oldval, int32_t newval, volatile int32_t *ptr); + +Input: + + r0 = oldval + r1 = newval + r2 = ptr + lr = return address + +Output: + + r0 = success code (zero or non-zero) + C flag = set if r0 == 0, clear if r0 != 0 + +Clobbered registers: + + r3, ip, flags + +Definition: + + Atomically store newval in *ptr only if *ptr is equal to oldval. + Return zero if *ptr was changed or non-zero if no exchange happened. + The C flag is also set if *ptr was changed to allow for assembly + optimization in the calling code. + +Usage example: + +typedef int (__kuser_cmpxchg_t)(int oldval, int newval, volatile int *ptr); +#define __kuser_cmpxchg (*(__kuser_cmpxchg_t *)0xffff0fc0) + +int atomic_add(volatile int *ptr, int val) +{ + int old, new; + + do { + old = *ptr; + new = old + val; + } while(__kuser_cmpxchg(old, new, ptr)); + + return new; +} + +Notes: + + - This routine already includes memory barriers as needed. + + - Valid only if __kuser_helper_version >= 2 (from kernel version 2.6.12). + +kuser_memory_barrier +-------------------- + +Location: 0xffff0fa0 + +Reference prototype: + + void __kuser_memory_barrier(void); + +Input: + + lr = return address + +Output: + + none + +Clobbered registers: + + none + +Definition: + + Apply any needed memory barrier to preserve consistency with data modified + manually and __kuser_cmpxchg usage. + +Usage example: + +typedef void (__kuser_dmb_t)(void); +#define __kuser_dmb (*(__kuser_dmb_t *)0xffff0fa0) + +Notes: + + - Valid only if __kuser_helper_version >= 3 (from kernel version 2.6.15). -- cgit v1.2.3 From 40fb79c8a88625504857d44de1bc89dc0341e618 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Sun, 19 Jun 2011 23:36:03 -0400 Subject: ARM: add a kuser_cmpxchg64 user space helper Some user space applications are designed around the ability to perform atomic operations on 64 bit values. Since this is natively possible only with ARMv6k and above, let's provide a new kuser helper to perform the operation with kernel supervision on pre ARMv6k hardware. Signed-off-by: Nicolas Pitre Tested-by: Dave Martin --- Documentation/arm/kernel_user_helpers.txt | 64 ++++++++++++++++++++ arch/arm/kernel/entry-armv.S | 99 ++++++++++++++++++++++++++++++- 2 files changed, 160 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/arm/kernel_user_helpers.txt b/Documentation/arm/kernel_user_helpers.txt index 0c33f72d1873..a17df9f91d16 100644 --- a/Documentation/arm/kernel_user_helpers.txt +++ b/Documentation/arm/kernel_user_helpers.txt @@ -201,3 +201,67 @@ typedef void (__kuser_dmb_t)(void); Notes: - Valid only if __kuser_helper_version >= 3 (from kernel version 2.6.15). + +kuser_cmpxchg64 +--------------- + +Location: 0xffff0f60 + +Reference prototype: + + int __kuser_cmpxchg64(const int64_t *oldval, + const int64_t *newval, + volatile int64_t *ptr); + +Input: + + r0 = pointer to oldval + r1 = pointer to newval + r2 = pointer to target value + lr = return address + +Output: + + r0 = success code (zero or non-zero) + C flag = set if r0 == 0, clear if r0 != 0 + +Clobbered registers: + + r3, lr, flags + +Definition: + + Atomically store the 64-bit value pointed by *newval in *ptr only if *ptr + is equal to the 64-bit value pointed by *oldval. Return zero if *ptr was + changed or non-zero if no exchange happened. + + The C flag is also set if *ptr was changed to allow for assembly + optimization in the calling code. + +Usage example: + +typedef int (__kuser_cmpxchg64_t)(const int64_t *oldval, + const int64_t *newval, + volatile int64_t *ptr); +#define __kuser_cmpxchg64 (*(__kuser_cmpxchg64_t *)0xffff0f60) + +int64_t atomic_add64(volatile int64_t *ptr, int64_t val) +{ + int64_t old, new; + + do { + old = *ptr; + new = old + val; + } while(__kuser_cmpxchg64(&old, &new, ptr)); + + return new; +} + +Notes: + + - This routine already includes memory barriers as needed. + + - Due to the length of this sequence, this spans 2 conventional kuser + "slots", therefore 0xffff0f80 is not used as a valid entry point. + + - Valid only if __kuser_helper_version >= 5 (from kernel version 3.1). diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 63f7907c4c3c..9be97deca215 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -383,7 +383,7 @@ ENDPROC(__pabt_svc) .endm .macro kuser_cmpxchg_check -#if __LINUX_ARM_ARCH__ < 6 && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG) +#if !defined(CONFIG_CPU_32v6K) && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG) #ifndef CONFIG_MMU #warning "NPTL on non MMU needs fixing" #else @@ -392,7 +392,7 @@ ENDPROC(__pabt_svc) @ perform a quick test inline since it should be false @ 99.9999% of the time. The rest is done out of line. cmp r2, #TASK_SIZE - blhs kuser_cmpxchg_fixup + blhs kuser_cmpxchg64_fixup #endif #endif .endm @@ -775,6 +775,99 @@ ENDPROC(__switch_to) .globl __kuser_helper_start __kuser_helper_start: +/* + * Due to the length of some sequences, __kuser_cmpxchg64 spans 2 regular + * kuser "slots", therefore 0xffff0f80 is not used as a valid entry point. + */ + +__kuser_cmpxchg64: @ 0xffff0f60 + +#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG) + + /* + * Poor you. No fast solution possible... + * The kernel itself must perform the operation. + * A special ghost syscall is used for that (see traps.c). + */ + stmfd sp!, {r7, lr} + ldr r7, 1f @ it's 20 bits + swi __ARM_NR_cmpxchg64 + ldmfd sp!, {r7, pc} +1: .word __ARM_NR_cmpxchg64 + +#elif defined(CONFIG_CPU_32v6K) + + stmfd sp!, {r4, r5, r6, r7} + ldrd r4, r5, [r0] @ load old val + ldrd r6, r7, [r1] @ load new val + smp_dmb arm +1: ldrexd r0, r1, [r2] @ load current val + eors r3, r0, r4 @ compare with oldval (1) + eoreqs r3, r1, r5 @ compare with oldval (2) + strexdeq r3, r6, r7, [r2] @ store newval if eq + teqeq r3, #1 @ success? + beq 1b @ if no then retry + smp_dmb arm + rsbs r0, r3, #0 @ set returned val and C flag + ldmfd sp!, {r4, r5, r6, r7} + bx lr + +#elif !defined(CONFIG_SMP) + +#ifdef CONFIG_MMU + + /* + * The only thing that can break atomicity in this cmpxchg64 + * implementation is either an IRQ or a data abort exception + * causing another process/thread to be scheduled in the middle of + * the critical sequence. The same strategy as for cmpxchg is used. + */ + stmfd sp!, {r4, r5, r6, lr} + ldmia r0, {r4, r5} @ load old val + ldmia r1, {r6, lr} @ load new val +1: ldmia r2, {r0, r1} @ load current val + eors r3, r0, r4 @ compare with oldval (1) + eoreqs r3, r1, r5 @ compare with oldval (2) +2: stmeqia r2, {r6, lr} @ store newval if eq + rsbs r0, r3, #0 @ set return val and C flag + ldmfd sp!, {r4, r5, r6, pc} + + .text +kuser_cmpxchg64_fixup: + @ Called from kuser_cmpxchg_fixup. + @ r2 = address of interrupted insn (must be preserved). + @ sp = saved regs. r7 and r8 are clobbered. + @ 1b = first critical insn, 2b = last critical insn. + @ If r2 >= 1b and r2 <= 2b then saved pc_usr is set to 1b. + mov r7, #0xffff0fff + sub r7, r7, #(0xffff0fff - (0xffff0f60 + (1b - __kuser_cmpxchg64))) + subs r8, r2, r7 + rsbcss r8, r8, #(2b - 1b) + strcs r7, [sp, #S_PC] +#if __LINUX_ARM_ARCH__ < 6 + bcc kuser_cmpxchg32_fixup +#endif + mov pc, lr + .previous + +#else +#warning "NPTL on non MMU needs fixing" + mov r0, #-1 + adds r0, r0, #0 + usr_ret lr +#endif + +#else +#error "incoherent kernel configuration" +#endif + + /* pad to next slot */ + .rept (16 - (. - __kuser_cmpxchg64)/4) + .word 0 + .endr + + .align 5 + __kuser_memory_barrier: @ 0xffff0fa0 smp_dmb arm usr_ret lr @@ -816,7 +909,7 @@ __kuser_cmpxchg: @ 0xffff0fc0 usr_ret lr .text -kuser_cmpxchg_fixup: +kuser_cmpxchg32_fixup: @ Called from kuser_cmpxchg_check macro. @ r2 = address of interrupted insn (must be preserved). @ sp = saved regs. r7 and r8 are clobbered. -- cgit v1.2.3 From 090ab3ff8ebb842c0f159d34d57d6e51bd94ace1 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Tue, 26 Apr 2011 06:29:53 +0100 Subject: ARM: 6886/1: mmc, Add zboot from eSD support for SuperH Mobile ARM This allows a ROM-able zImage to be written to eSD and for SuperH Mobile ARM to boot directly from the SDHI hardware block. This is achieved by the MaskROM loading the first portion of the image into MERAM and then jumping to it. This portion contains loader code which copies the entire image to SDRAM and jumps to it. From there the zImage boot code proceeds as normal, uncompressing the image into its final location and then jumping to it. Cc: Paul Mundt Acked-by: Magnus Damm Acked-by: Paul Mundt Signed-off-by: Simon Horman Signed-off-by: Russell King --- Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt | 42 ++ arch/arm/Kconfig | 33 +- arch/arm/boot/compressed/Makefile | 10 +- arch/arm/boot/compressed/head-shmobile.S | 12 +- arch/arm/boot/compressed/mmcif-sh7372.c | 2 +- arch/arm/boot/compressed/sdhi-sh7372.c | 95 +++++ arch/arm/boot/compressed/sdhi-shmobile.c | 449 ++++++++++++++++++++++ arch/arm/boot/compressed/sdhi-shmobile.h | 11 + arch/arm/mach-shmobile/include/mach/sdhi-sh7372.h | 21 + arch/arm/mach-shmobile/include/mach/sdhi.h | 16 + 10 files changed, 674 insertions(+), 17 deletions(-) create mode 100644 Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt create mode 100644 arch/arm/boot/compressed/sdhi-sh7372.c create mode 100644 arch/arm/boot/compressed/sdhi-shmobile.c create mode 100644 arch/arm/boot/compressed/sdhi-shmobile.h create mode 100644 arch/arm/mach-shmobile/include/mach/sdhi-sh7372.h create mode 100644 arch/arm/mach-shmobile/include/mach/sdhi.h (limited to 'Documentation') diff --git a/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt new file mode 100644 index 000000000000..441959846e1a --- /dev/null +++ b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt @@ -0,0 +1,42 @@ +ROM-able zImage boot from eSD +----------------------------- + +An ROM-able zImage compiled with ZBOOT_ROM_SDHI may be written to eSD and +SuperH Mobile ARM will to boot directly from the SDHI hardware block. + +This is achieved by the mask ROM loading the first portion of the image into +MERAM and then jumping to it. This portion contains loader code which +copies the entire image to SDRAM and jumps to it. From there the zImage +boot code proceeds as normal, uncompressing the image into its final +location and then jumping to it. + +This code has been tested on an mackerel board using the developer 1A eSD +boot mode which is configured using the following jumper settings. + + 8 7 6 5 4 3 2 1 + x|x|x|x| |x|x| +S4 -+-+-+-+-+-+-+- + | | | |x| | |x on + +The eSD card needs to be present in SDHI slot 1 (CN7). +As such S1 and S33 also need to be configured as per +the notes in arch/arm/mach-shmobile/board-mackerel.c. + +A partial zImage must be written to physical partition #1 (boot) +of the eSD at sector 0 in vrl4 format. A utility vrl4 is supplied to +accomplish this. + +e.g. + vrl4 < zImage | dd of=/dev/sdX bs=512 count=17 + +A full copy of _the same_ zImage should be written to physical partition #1 +(boot) of the eSD at sector 0. This should _not_ be in vrl4 format. + + vrl4 < zImage | dd of=/dev/sdX bs=512 + +Note: The commands above assume that the physical partition has been +switched. No such facility currently exists in the Linux Kernel. + +Physical partitions are described in the eSD specification. At the time of +writing they are not the same as partitions that are typically configured +using fdisk and visible through /proc/partitions diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index cc0dcbf1f6b5..cd8f520dd03d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1718,17 +1718,34 @@ config ZBOOT_ROM Say Y here if you intend to execute your compressed kernel image (zImage) directly from ROM or flash. If unsure, say N. +choice + prompt "Include SD/MMC loader in zImage (EXPERIMENTAL)" + depends on ZBOOT_ROM && ARCH_SH7372 && EXPERIMENTAL + default ZBOOT_ROM_NONE + help + Include experimental SD/MMC loading code in the ROM-able zImage. + With this enabled it is possible to write the the ROM-able zImage + kernel image to an MMC or SD card and boot the kernel straight + from the reset vector. At reset the processor Mask ROM will load + the first part of the the ROM-able zImage which in turn loads the + rest the kernel image to RAM. + +config ZBOOT_ROM_NONE + bool "No SD/MMC loader in zImage (EXPERIMENTAL)" + help + Do not load image from SD or MMC + config ZBOOT_ROM_MMCIF bool "Include MMCIF loader in zImage (EXPERIMENTAL)" - depends on ZBOOT_ROM && ARCH_SH7372 && EXPERIMENTAL help - Say Y here to include experimental MMCIF loading code in the - ROM-able zImage. With this enabled it is possible to write the - the ROM-able zImage kernel image to an MMC card and boot the - kernel straight from the reset vector. At reset the processor - Mask ROM will load the first part of the the ROM-able zImage - which in turn loads the rest the kernel image to RAM using the - MMCIF hardware block. + Load image from MMCIF hardware block. + +config ZBOOT_ROM_SH_MOBILE_SDHI + bool "Include SuperH Mobile SDHI loader in zImage (EXPERIMENTAL)" + help + Load image from SDHI hardware block + +endchoice config CMDLINE string "Default kernel command string" diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 23aad0722303..0c74a6fab952 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -6,13 +6,19 @@ OBJS = -# Ensure that mmcif loader code appears early in the image +# Ensure that MMCIF loader code appears early in the image # to minimise that number of bocks that have to be read in # order to load it. ifeq ($(CONFIG_ZBOOT_ROM_MMCIF),y) -ifeq ($(CONFIG_ARCH_SH7372),y) OBJS += mmcif-sh7372.o endif + +# Ensure that SDHI loader code appears early in the image +# to minimise that number of bocks that have to be read in +# order to load it. +ifeq ($(CONFIG_ZBOOT_ROM_SH_MOBILE_SDHI),y) +OBJS += sdhi-shmobile.o +OBJS += sdhi-sh7372.o endif AFLAGS_head.o += -DTEXT_OFFSET=$(TEXT_OFFSET) diff --git a/arch/arm/boot/compressed/head-shmobile.S b/arch/arm/boot/compressed/head-shmobile.S index c943d2e7da9d..fe3719b516fd 100644 --- a/arch/arm/boot/compressed/head-shmobile.S +++ b/arch/arm/boot/compressed/head-shmobile.S @@ -25,14 +25,14 @@ /* load board-specific initialization code */ #include -#ifdef CONFIG_ZBOOT_ROM_MMCIF - /* Load image from MMC */ - adr sp, __tmp_stack + 128 +#if defined(CONFIG_ZBOOT_ROM_MMCIF) || defined(CONFIG_ZBOOT_ROM_SH_MOBILE_SDHI) + /* Load image from MMC/SD */ + adr sp, __tmp_stack + 256 ldr r0, __image_start ldr r1, __image_end subs r1, r1, r0 ldr r0, __load_base - bl mmcif_loader + bl mmc_loader /* Jump to loaded code */ ldr r0, __loaded @@ -51,9 +51,9 @@ __loaded: .long __continue .align __tmp_stack: - .space 128 + .space 256 __continue: -#endif /* CONFIG_ZBOOT_ROM_MMCIF */ +#endif /* CONFIG_ZBOOT_ROM_MMC || CONFIG_ZBOOT_ROM_SH_MOBILE_SDHI */ b 1f __atags:@ tag #1 diff --git a/arch/arm/boot/compressed/mmcif-sh7372.c b/arch/arm/boot/compressed/mmcif-sh7372.c index 7453c8337b83..b6f61d9a5a1b 100644 --- a/arch/arm/boot/compressed/mmcif-sh7372.c +++ b/arch/arm/boot/compressed/mmcif-sh7372.c @@ -40,7 +40,7 @@ * to an MMC card * # dd if=vrl4.out of=/dev/sdx bs=512 seek=1 */ -asmlinkage void mmcif_loader(unsigned char *buf, unsigned long len) +asmlinkage void mmc_loader(unsigned char *buf, unsigned long len) { mmc_init_progress(); mmc_update_progress(MMC_PROGRESS_ENTER); diff --git a/arch/arm/boot/compressed/sdhi-sh7372.c b/arch/arm/boot/compressed/sdhi-sh7372.c new file mode 100644 index 000000000000..d403a8b24d7f --- /dev/null +++ b/arch/arm/boot/compressed/sdhi-sh7372.c @@ -0,0 +1,95 @@ +/* + * SuperH Mobile SDHI + * + * Copyright (C) 2010 Magnus Damm + * Copyright (C) 2010 Kuninori Morimoto + * Copyright (C) 2010 Simon Horman + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Parts inspired by u-boot + */ + +#include +#include +#include +#include + +#include "sdhi-shmobile.h" + +#define PORT179CR 0xe60520b3 +#define PORT180CR 0xe60520b4 +#define PORT181CR 0xe60520b5 +#define PORT182CR 0xe60520b6 +#define PORT183CR 0xe60520b7 +#define PORT184CR 0xe60520b8 + +#define SMSTPCR3 0xe615013c + +#define CR_INPUT_ENABLE 0x10 +#define CR_FUNCTION1 0x01 + +#define SDHI1_BASE (void __iomem *)0xe6860000 +#define SDHI_BASE SDHI1_BASE + +/* SuperH Mobile SDHI loader + * + * loads the zImage from an SD card starting from block 0 + * on physical partition 1 + * + * The image must be start with a vrl4 header and + * the zImage must start at offset 512 of the image. That is, + * at block 1 (=byte 512) of physical partition 1 + * + * Use the following line to write the vrl4 formated zImage + * to an SD card + * # dd if=vrl4.out of=/dev/sdx bs=512 + */ +asmlinkage void mmc_loader(unsigned short *buf, unsigned long len) +{ + int high_capacity; + + mmc_init_progress(); + + mmc_update_progress(MMC_PROGRESS_ENTER); + /* Initialise SDHI1 */ + /* PORT184CR: GPIO_FN_SDHICMD1 Control */ + __raw_writeb(CR_FUNCTION1, PORT184CR); + /* PORT179CR: GPIO_FN_SDHICLK1 Control */ + __raw_writeb(CR_INPUT_ENABLE|CR_FUNCTION1, PORT179CR); + /* PORT181CR: GPIO_FN_SDHID1_3 Control */ + __raw_writeb(CR_FUNCTION1, PORT183CR); + /* PORT182CR: GPIO_FN_SDHID1_2 Control */ + __raw_writeb(CR_FUNCTION1, PORT182CR); + /* PORT183CR: GPIO_FN_SDHID1_1 Control */ + __raw_writeb(CR_FUNCTION1, PORT181CR); + /* PORT180CR: GPIO_FN_SDHID1_0 Control */ + __raw_writeb(CR_FUNCTION1, PORT180CR); + + /* Enable clock to SDHI1 hardware block */ + __raw_writel(__raw_readl(SMSTPCR3) & ~(1 << 13), SMSTPCR3); + + /* setup SDHI hardware */ + mmc_update_progress(MMC_PROGRESS_INIT); + high_capacity = sdhi_boot_init(SDHI_BASE); + if (high_capacity < 0) + goto err; + + mmc_update_progress(MMC_PROGRESS_LOAD); + /* load kernel */ + if (sdhi_boot_do_read(SDHI_BASE, high_capacity, + 0, /* Kernel is at block 1 */ + (len + TMIO_BBS - 1) / TMIO_BBS, buf)) + goto err; + + /* Disable clock to SDHI1 hardware block */ + __raw_writel(__raw_readl(SMSTPCR3) & (1 << 13), SMSTPCR3); + + mmc_update_progress(MMC_PROGRESS_DONE); + + return; +err: + for(;;); +} diff --git a/arch/arm/boot/compressed/sdhi-shmobile.c b/arch/arm/boot/compressed/sdhi-shmobile.c new file mode 100644 index 000000000000..bd3d46980955 --- /dev/null +++ b/arch/arm/boot/compressed/sdhi-shmobile.c @@ -0,0 +1,449 @@ +/* + * SuperH Mobile SDHI + * + * Copyright (C) 2010 Magnus Damm + * Copyright (C) 2010 Kuninori Morimoto + * Copyright (C) 2010 Simon Horman + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Parts inspired by u-boot + */ + +#include +#include +#include +#include +#include +#include +#include + +#define OCR_FASTBOOT (1<<29) +#define OCR_HCS (1<<30) +#define OCR_BUSY (1<<31) + +#define RESP_CMD12 0x00000030 + +static inline u16 sd_ctrl_read16(void __iomem *base, int addr) +{ + return __raw_readw(base + addr); +} + +static inline u32 sd_ctrl_read32(void __iomem *base, int addr) +{ + return __raw_readw(base + addr) | + __raw_readw(base + addr + 2) << 16; +} + +static inline void sd_ctrl_write16(void __iomem *base, int addr, u16 val) +{ + __raw_writew(val, base + addr); +} + +static inline void sd_ctrl_write32(void __iomem *base, int addr, u32 val) +{ + __raw_writew(val, base + addr); + __raw_writew(val >> 16, base + addr + 2); +} + +#define ALL_ERROR (TMIO_STAT_CMD_IDX_ERR | TMIO_STAT_CRCFAIL | \ + TMIO_STAT_STOPBIT_ERR | TMIO_STAT_DATATIMEOUT | \ + TMIO_STAT_RXOVERFLOW | TMIO_STAT_TXUNDERRUN | \ + TMIO_STAT_CMDTIMEOUT | TMIO_STAT_ILL_ACCESS | \ + TMIO_STAT_ILL_FUNC) + +static int sdhi_intr(void __iomem *base) +{ + unsigned long state = sd_ctrl_read32(base, CTL_STATUS); + + if (state & ALL_ERROR) { + sd_ctrl_write32(base, CTL_STATUS, ~ALL_ERROR); + sd_ctrl_write32(base, CTL_IRQ_MASK, + ALL_ERROR | + sd_ctrl_read32(base, CTL_IRQ_MASK)); + return -EINVAL; + } + if (state & TMIO_STAT_CMDRESPEND) { + sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_CMDRESPEND); + sd_ctrl_write32(base, CTL_IRQ_MASK, + TMIO_STAT_CMDRESPEND | + sd_ctrl_read32(base, CTL_IRQ_MASK)); + return 0; + } + if (state & TMIO_STAT_RXRDY) { + sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_RXRDY); + sd_ctrl_write32(base, CTL_IRQ_MASK, + TMIO_STAT_RXRDY | TMIO_STAT_TXUNDERRUN | + sd_ctrl_read32(base, CTL_IRQ_MASK)); + return 0; + } + if (state & TMIO_STAT_DATAEND) { + sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_DATAEND); + sd_ctrl_write32(base, CTL_IRQ_MASK, + TMIO_STAT_DATAEND | + sd_ctrl_read32(base, CTL_IRQ_MASK)); + return 0; + } + + return -EAGAIN; +} + +static int sdhi_boot_wait_resp_end(void __iomem *base) +{ + int err = -EAGAIN, timeout = 10000000; + + while (timeout--) { + err = sdhi_intr(base); + if (err != -EAGAIN) + break; + udelay(1); + } + + return err; +} + +/* SDHI_CLK_CTRL */ +#define CLK_MMC_ENABLE (1 << 8) +#define CLK_MMC_INIT (1 << 6) /* clk / 256 */ + +static void sdhi_boot_mmc_clk_stop(void __iomem *base) +{ + sd_ctrl_write16(base, CTL_CLK_AND_WAIT_CTL, 0x0000); + msleep(10); + sd_ctrl_write16(base, CTL_SD_CARD_CLK_CTL, ~CLK_MMC_ENABLE & + sd_ctrl_read16(base, CTL_SD_CARD_CLK_CTL)); + msleep(10); +} + +static void sdhi_boot_mmc_clk_start(void __iomem *base) +{ + sd_ctrl_write16(base, CTL_SD_CARD_CLK_CTL, CLK_MMC_ENABLE | + sd_ctrl_read16(base, CTL_SD_CARD_CLK_CTL)); + msleep(10); + sd_ctrl_write16(base, CTL_CLK_AND_WAIT_CTL, CLK_MMC_ENABLE); + msleep(10); +} + +static void sdhi_boot_reset(void __iomem *base) +{ + sd_ctrl_write16(base, CTL_RESET_SD, 0x0000); + msleep(10); + sd_ctrl_write16(base, CTL_RESET_SD, 0x0001); + msleep(10); +} + +/* Set MMC clock / power. + * Note: This controller uses a simple divider scheme therefore it cannot + * run a MMC card at full speed (20MHz). The max clock is 24MHz on SD, but as + * MMC wont run that fast, it has to be clocked at 12MHz which is the next + * slowest setting. + */ +static int sdhi_boot_mmc_set_ios(void __iomem *base, struct mmc_ios *ios) +{ + if (sd_ctrl_read32(base, CTL_STATUS) & TMIO_STAT_CMD_BUSY) + return -EBUSY; + + if (ios->clock) + sd_ctrl_write16(base, CTL_SD_CARD_CLK_CTL, + ios->clock | CLK_MMC_ENABLE); + + /* Power sequence - OFF -> ON -> UP */ + switch (ios->power_mode) { + case MMC_POWER_OFF: /* power down SD bus */ + sdhi_boot_mmc_clk_stop(base); + break; + case MMC_POWER_ON: /* power up SD bus */ + break; + case MMC_POWER_UP: /* start bus clock */ + sdhi_boot_mmc_clk_start(base); + break; + } + + switch (ios->bus_width) { + case MMC_BUS_WIDTH_1: + sd_ctrl_write16(base, CTL_SD_MEM_CARD_OPT, 0x80e0); + break; + case MMC_BUS_WIDTH_4: + sd_ctrl_write16(base, CTL_SD_MEM_CARD_OPT, 0x00e0); + break; + } + + /* Let things settle. delay taken from winCE driver */ + udelay(140); + + return 0; +} + +/* These are the bitmasks the tmio chip requires to implement the MMC response + * types. Note that R1 and R6 are the same in this scheme. */ +#define RESP_NONE 0x0300 +#define RESP_R1 0x0400 +#define RESP_R1B 0x0500 +#define RESP_R2 0x0600 +#define RESP_R3 0x0700 +#define DATA_PRESENT 0x0800 +#define TRANSFER_READ 0x1000 + +static int sdhi_boot_request(void __iomem *base, struct mmc_command *cmd) +{ + int err, c = cmd->opcode; + + switch (mmc_resp_type(cmd)) { + case MMC_RSP_NONE: c |= RESP_NONE; break; + case MMC_RSP_R1: c |= RESP_R1; break; + case MMC_RSP_R1B: c |= RESP_R1B; break; + case MMC_RSP_R2: c |= RESP_R2; break; + case MMC_RSP_R3: c |= RESP_R3; break; + default: + return -EINVAL; + } + + /* No interrupts so this may not be cleared */ + sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_CMDRESPEND); + + sd_ctrl_write32(base, CTL_IRQ_MASK, TMIO_STAT_CMDRESPEND | + sd_ctrl_read32(base, CTL_IRQ_MASK)); + sd_ctrl_write32(base, CTL_ARG_REG, cmd->arg); + sd_ctrl_write16(base, CTL_SD_CMD, c); + + + sd_ctrl_write32(base, CTL_IRQ_MASK, + ~(TMIO_STAT_CMDRESPEND | ALL_ERROR) & + sd_ctrl_read32(base, CTL_IRQ_MASK)); + + err = sdhi_boot_wait_resp_end(base); + if (err) + return err; + + cmd->resp[0] = sd_ctrl_read32(base, CTL_RESPONSE); + + return 0; +} + +static int sdhi_boot_do_read_single(void __iomem *base, int high_capacity, + unsigned long block, unsigned short *buf) +{ + int err, i; + + /* CMD17 - Read */ + { + struct mmc_command cmd; + + cmd.opcode = MMC_READ_SINGLE_BLOCK | \ + TRANSFER_READ | DATA_PRESENT; + if (high_capacity) + cmd.arg = block; + else + cmd.arg = block * TMIO_BBS; + cmd.flags = MMC_RSP_R1; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + } + + sd_ctrl_write32(base, CTL_IRQ_MASK, + ~(TMIO_STAT_DATAEND | TMIO_STAT_RXRDY | + TMIO_STAT_TXUNDERRUN) & + sd_ctrl_read32(base, CTL_IRQ_MASK)); + err = sdhi_boot_wait_resp_end(base); + if (err) + return err; + + sd_ctrl_write16(base, CTL_SD_XFER_LEN, TMIO_BBS); + for (i = 0; i < TMIO_BBS / sizeof(*buf); i++) + *buf++ = sd_ctrl_read16(base, RESP_CMD12); + + err = sdhi_boot_wait_resp_end(base); + if (err) + return err; + + return 0; +} + +int sdhi_boot_do_read(void __iomem *base, int high_capacity, + unsigned long offset, unsigned short count, + unsigned short *buf) +{ + unsigned long i; + int err = 0; + + for (i = 0; i < count; i++) { + err = sdhi_boot_do_read_single(base, high_capacity, offset + i, + buf + (i * TMIO_BBS / + sizeof(*buf))); + if (err) + return err; + } + + return 0; +} + +#define VOLTAGES (MMC_VDD_32_33 | MMC_VDD_33_34) + +int sdhi_boot_init(void __iomem *base) +{ + bool sd_v2 = false, sd_v1_0 = false; + unsigned short cid; + int err, high_capacity = 0; + + sdhi_boot_mmc_clk_stop(base); + sdhi_boot_reset(base); + + /* mmc0: clock 400000Hz busmode 1 powermode 2 cs 0 Vdd 21 width 0 timing 0 */ + { + struct mmc_ios ios; + ios.power_mode = MMC_POWER_ON; + ios.bus_width = MMC_BUS_WIDTH_1; + ios.clock = CLK_MMC_INIT; + err = sdhi_boot_mmc_set_ios(base, &ios); + if (err) + return err; + } + + /* CMD0 */ + { + struct mmc_command cmd; + msleep(1); + cmd.opcode = MMC_GO_IDLE_STATE; + cmd.arg = 0; + cmd.flags = MMC_RSP_NONE; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + msleep(2); + } + + /* CMD8 - Test for SD version 2 */ + { + struct mmc_command cmd; + cmd.opcode = SD_SEND_IF_COND; + cmd.arg = (VOLTAGES != 0) << 8 | 0xaa; + cmd.flags = MMC_RSP_R1; + err = sdhi_boot_request(base, &cmd); /* Ignore error */ + if ((cmd.resp[0] & 0xff) == 0xaa) + sd_v2 = true; + } + + /* CMD55 - Get OCR (SD) */ + { + int timeout = 1000; + struct mmc_command cmd; + + cmd.arg = 0; + + do { + cmd.opcode = MMC_APP_CMD; + cmd.flags = MMC_RSP_R1; + cmd.arg = 0; + err = sdhi_boot_request(base, &cmd); + if (err) + break; + + cmd.opcode = SD_APP_OP_COND; + cmd.flags = MMC_RSP_R3; + cmd.arg = (VOLTAGES & 0xff8000); + if (sd_v2) + cmd.arg |= OCR_HCS; + cmd.arg |= OCR_FASTBOOT; + err = sdhi_boot_request(base, &cmd); + if (err) + break; + + msleep(1); + } while((!(cmd.resp[0] & OCR_BUSY)) && --timeout); + + if (!err && timeout) { + if (!sd_v2) + sd_v1_0 = true; + high_capacity = (cmd.resp[0] & OCR_HCS) == OCR_HCS; + } + } + + /* CMD1 - Get OCR (MMC) */ + if (!sd_v2 && !sd_v1_0) { + int timeout = 1000; + struct mmc_command cmd; + + do { + cmd.opcode = MMC_SEND_OP_COND; + cmd.arg = VOLTAGES | OCR_HCS; + cmd.flags = MMC_RSP_R3; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + + msleep(1); + } while((!(cmd.resp[0] & OCR_BUSY)) && --timeout); + + if (!timeout) + return -EAGAIN; + + high_capacity = (cmd.resp[0] & OCR_HCS) == OCR_HCS; + } + + /* CMD2 - Get CID */ + { + struct mmc_command cmd; + cmd.opcode = MMC_ALL_SEND_CID; + cmd.arg = 0; + cmd.flags = MMC_RSP_R2; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + } + + /* CMD3 + * MMC: Set the relative address + * SD: Get the relative address + * Also puts the card into the standby state + */ + { + struct mmc_command cmd; + cmd.opcode = MMC_SET_RELATIVE_ADDR; + cmd.arg = 0; + cmd.flags = MMC_RSP_R1; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + cid = cmd.resp[0] >> 16; + } + + /* CMD9 - Get CSD */ + { + struct mmc_command cmd; + cmd.opcode = MMC_SEND_CSD; + cmd.arg = cid << 16; + cmd.flags = MMC_RSP_R2; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + } + + /* CMD7 - Select the card */ + { + struct mmc_command cmd; + cmd.opcode = MMC_SELECT_CARD; + //cmd.arg = rca << 16; + cmd.arg = cid << 16; + //cmd.flags = MMC_RSP_R1B; + cmd.flags = MMC_RSP_R1; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + } + + /* CMD16 - Set the block size */ + { + struct mmc_command cmd; + cmd.opcode = MMC_SET_BLOCKLEN; + cmd.arg = TMIO_BBS; + cmd.flags = MMC_RSP_R1; + err = sdhi_boot_request(base, &cmd); + if (err) + return err; + } + + return high_capacity; +} diff --git a/arch/arm/boot/compressed/sdhi-shmobile.h b/arch/arm/boot/compressed/sdhi-shmobile.h new file mode 100644 index 000000000000..92eaa09f985e --- /dev/null +++ b/arch/arm/boot/compressed/sdhi-shmobile.h @@ -0,0 +1,11 @@ +#ifndef SDHI_MOBILE_H +#define SDHI_MOBILE_H + +#include + +int sdhi_boot_do_read(void __iomem *base, int high_capacity, + unsigned long offset, unsigned short count, + unsigned short *buf); +int sdhi_boot_init(void __iomem *base); + +#endif diff --git a/arch/arm/mach-shmobile/include/mach/sdhi-sh7372.h b/arch/arm/mach-shmobile/include/mach/sdhi-sh7372.h new file mode 100644 index 000000000000..4a81b01f1e8f --- /dev/null +++ b/arch/arm/mach-shmobile/include/mach/sdhi-sh7372.h @@ -0,0 +1,21 @@ +#ifndef SDHI_SH7372_H +#define SDHI_SH7372_H + +#define SDGENCNTA 0xfe40009c + +/* The countdown of SDGENCNTA is controlled by + * ZB3D2CLK which runs at 149.5MHz. + * That is 149.5ticks/us. Approximate this as 150ticks/us. + */ +static void udelay(int us) +{ + __raw_writel(us * 150, SDGENCNTA); + while(__raw_readl(SDGENCNTA)) ; +} + +static void msleep(int ms) +{ + udelay(ms * 1000); +} + +#endif diff --git a/arch/arm/mach-shmobile/include/mach/sdhi.h b/arch/arm/mach-shmobile/include/mach/sdhi.h new file mode 100644 index 000000000000..0ec9e69f2c3b --- /dev/null +++ b/arch/arm/mach-shmobile/include/mach/sdhi.h @@ -0,0 +1,16 @@ +#ifndef SDHI_H +#define SDHI_H + +/************************************************** + * + * CPU specific settings + * + **************************************************/ + +#ifdef CONFIG_ARCH_SH7372 +#include "mach/sdhi-sh7372.h" +#else +#error "unsupported CPU." +#endif + +#endif /* SDHI_H */ -- cgit v1.2.3 From e73c34c3d522a60d9f7b38a7683076362bad98f5 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 22 Jun 2011 15:33:55 +0100 Subject: ARM: 6976/1: pmu: add OF probing support This is based on an earlier patch from Rob Herring > Add OF match table to enable OF style driver binding. The dts entry is like > this: > > pmu { > compatible = "arm,cortex-a9-pmu"; > interrupts = <100 101>; > }; > > The use of pdev->id as an index breaks with OF device binding, so set the type > based on the OF compatible string. This modification sets the PMU hardware type based on data embedded in the binding, allowing easy addition of new PMU types in future. Support for new PMU types not provided by devicetree can be added later using platform_device_id tables in a similar fashion. Signed-off-by: Mark Rutland Acked-by: Jamie Iles Acked-by: Rob Herring Cc: Will Deacon Signed-off-by: Russell King --- Documentation/devicetree/bindings/arm/pmu.txt | 21 +++++++++++++++++ arch/arm/kernel/pmu.c | 34 ++++++++++++++++++++++++++- 2 files changed, 54 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/bindings/arm/pmu.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/arm/pmu.txt b/Documentation/devicetree/bindings/arm/pmu.txt new file mode 100644 index 000000000000..1c044eb320cc --- /dev/null +++ b/Documentation/devicetree/bindings/arm/pmu.txt @@ -0,0 +1,21 @@ +* ARM Performance Monitor Units + +ARM cores often have a PMU for counting cpu and cache events like cache misses +and hits. The interface to the PMU is part of the ARM ARM. The ARM PMU +representation in the device tree should be done as under:- + +Required properties: + +- compatible : should be one of + "arm,cortex-a9-pmu" + "arm,cortex-a8-pmu" + "arm,arm1176-pmu" + "arm,arm1136-pmu" +- interrupts : 1 combined interrupt or 1 per core. + +Example: + +pmu { + compatible = "arm,cortex-a9-pmu"; + interrupts = <100 101>; +}; diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c index de6b1b0860c2..2ce00be697ea 100644 --- a/arch/arm/kernel/pmu.c +++ b/arch/arm/kernel/pmu.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -45,14 +46,45 @@ static int __devinit pmu_register(struct platform_device *pdev, return 0; } +#define OF_MATCH_PMU(_name, _type) { \ + .compatible = _name, \ + .data = (void *)_type, \ +} + +#define OF_MATCH_CPU(name) OF_MATCH_PMU(name, ARM_PMU_DEVICE_CPU) + +static struct of_device_id armpmu_of_device_ids[] = { + OF_MATCH_CPU("arm,cortex-a9-pmu"), + OF_MATCH_CPU("arm,cortex-a8-pmu"), + OF_MATCH_CPU("arm,arm1136-pmu"), + OF_MATCH_CPU("arm,arm1176-pmu"), + {}, +}; + +enum arm_pmu_type armpmu_device_type(struct platform_device *pdev) +{ + const struct of_device_id *of_id; + + /* provided by of_device_id table */ + if (pdev->dev.of_node) { + of_id = of_match_device(armpmu_of_device_ids, &pdev->dev); + BUG_ON(!of_id); + return (enum arm_pmu_type)of_id->data; + } + + /* Provided by a 'legacy' platform_device */ + return ARM_PMU_DEVICE_CPU; +} + static int __devinit armpmu_device_probe(struct platform_device *pdev) { - return pmu_register(pdev, ARM_PMU_DEVICE_CPU); + return pmu_register(pdev, armpmu_device_type(pdev)); } static struct platform_driver armpmu_driver = { .driver = { .name = "arm-pmu", + .of_match_table = armpmu_of_device_ids, }, .probe = armpmu_device_probe, }; -- cgit v1.2.3 From 540b573875bd26dfe39aa18d22dc195f275fc0df Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Wed, 13 Jul 2011 15:53:30 +0100 Subject: ARM: 6999/1: head, zImage: Always Enter the kernel in ARM state Currently, the documented kernel entry requirements are not explicit about whether the kernel should be entered in ARM or Thumb, leading to an ambiguitity about how to enter Thumb-2 kernels. As a result, the kernel is reliant on the zImage decompressor to enter the kernel proper in the correct instruction set state. This patch changes the boot entry protocol for head.S and Image to be the same as for zImage: in all cases, the kernel is now entered in ARM. Documentation/arm/Booting is updated to reflect this new policy. A different rule will be needed for Cortex-M class CPUs as and when support for those lands in mainline, since these CPUs don't support the ARM instruction set at all: a note is added to the effect that the kernel must be entered in Thumb on such systems. Signed-off-by: Dave Martin Acked-by: Nicolas Pitre Signed-off-by: Russell King --- Documentation/arm/Booting | 5 +++++ arch/arm/boot/compressed/head.S | 3 ++- arch/arm/kernel/head-nommu.S | 8 ++++++++ arch/arm/kernel/head.S | 8 ++++++++ 4 files changed, 23 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting index 4e686a2ed91e..a341d87d276e 100644 --- a/Documentation/arm/Booting +++ b/Documentation/arm/Booting @@ -164,3 +164,8 @@ In either case, the following conditions must be met: - The boot loader is expected to call the kernel image by jumping directly to the first instruction of the kernel image. + On CPUs supporting the ARM instruction set, the entry must be + made in ARM state, even for a Thumb-2 kernel. + + On CPUs supporting only the Thumb instruction set such as + Cortex-M class CPUs, the entry must be made in Thumb state. diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index f9da41921c52..51af7091d84d 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -353,7 +353,8 @@ not_relocated: mov r0, #0 mov r0, #0 @ must be zero mov r1, r7 @ restore architecture number mov r2, r8 @ restore atags pointer - mov pc, r4 @ call kernel + ARM( mov pc, r4 ) @ call kernel + THUMB( bx r4 ) @ entry point is always ARM .align 2 .type LC0, #object diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index 6b1e0ad9ec3b..d46f25968bec 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -32,8 +32,16 @@ * numbers for r1. * */ + .arm + __HEAD ENTRY(stext) + + THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. + THUMB( bx r9 ) @ If this is a Thumb-2 kernel, + THUMB( .thumb ) @ switch to Thumb now. + THUMB(1: ) + setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode @ and irqs disabled #ifndef CONFIG_CPU_CP15 diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 278c1b0ebb2e..742b6108a001 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -71,8 +71,16 @@ * crap here - that's what the boot loader (or in extreme, well justified * circumstances, zImage) is for. */ + .arm + __HEAD ENTRY(stext) + + THUMB( adr r9, BSYM(1f) ) @ Kernel is always entered in ARM. + THUMB( bx r9 ) @ If this is a Thumb-2 kernel, + THUMB( .thumb ) @ switch to Thumb now. + THUMB(1: ) + setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode @ and irqs disabled mrc p15, 0, r9, c0, c0 @ get processor id -- cgit v1.2.3