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authorCatalin Marinas <catalin.marinas@arm.com>2010-05-21 18:06:41 +0100
committerUwe Kleine-König <u.kleine-koenig@pengutronix.de>2013-04-17 21:38:10 +0200
commit55bdd694116597d2f16510b121463cd579ba78da (patch)
treec8a31f06f746700a1f9b8418602a43c3ea42627e
parent73a09d212ec65b7068a283e6034fa05649d3d075 (diff)
downloadlinux-linaro-stable-55bdd694116597d2f16510b121463cd579ba78da.tar.gz
ARM: Add base support for ARMv7-M
This patch adds the base support for the ARMv7-M architecture. It consists of the corresponding arch/arm/mm/ files and various #ifdef's around the kernel. Exception handling is implemented by a subsequent patch. [ukleinek: squash in some changes originating from commit b5717ba (Cortex-M3: Add support for the Microcontroller Prototyping System) from the v2.6.33-arm1 patch stack, port to post 3.6, drop zImage support, drop reorganisation of pt_regs, assert CONFIG_CPU_V7M doesn't leak into installed headers and a few cosmetic changes] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Jonathan Austin <jonathan.austin@arm.com> Tested-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
-rw-r--r--arch/arm/include/asm/assembler.h17
-rw-r--r--arch/arm/include/asm/cputype.h12
-rw-r--r--arch/arm/include/asm/glue-cache.h27
-rw-r--r--arch/arm/include/asm/glue-df.h8
-rw-r--r--arch/arm/include/asm/glue-proc.h9
-rw-r--r--arch/arm/include/asm/irqflags.h22
-rw-r--r--arch/arm/include/asm/ptrace.h4
-rw-r--r--arch/arm/include/asm/system_info.h1
-rw-r--r--arch/arm/include/asm/v7m.h44
-rw-r--r--arch/arm/include/uapi/asm/ptrace.h35
-rw-r--r--arch/arm/kernel/head-nommu.S10
-rw-r--r--arch/arm/kernel/setup.c17
-rw-r--r--arch/arm/kernel/traps.c8
-rw-r--r--arch/arm/mm/cache-nop.S50
-rw-r--r--arch/arm/mm/nommu.c7
-rw-r--r--arch/arm/mm/proc-v7m.S157
16 files changed, 407 insertions, 21 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 05ee9eebad6b..a5fef710af32 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -136,7 +136,11 @@
* assumes FIQs are enabled, and that the processor is in SVC mode.
*/
.macro save_and_disable_irqs, oldcpsr
+#ifdef CONFIG_CPU_V7M
+ mrs \oldcpsr, primask
+#else
mrs \oldcpsr, cpsr
+#endif
disable_irq
.endm
@@ -150,7 +154,11 @@
* guarantee that this will preserve the flags.
*/
.macro restore_irqs_notrace, oldcpsr
+#ifdef CONFIG_CPU_V7M
+ msr primask, \oldcpsr
+#else
msr cpsr_c, \oldcpsr
+#endif
.endm
.macro restore_irqs, oldcpsr
@@ -229,7 +237,14 @@
#endif
.endm
-#ifdef CONFIG_THUMB2_KERNEL
+#if defined(CONFIG_CPU_V7M)
+ /*
+ * setmode is used to assert to be in svc mode during boot. For v7-M
+ * this is done in __v7m_setup, so setmode can be empty here.
+ */
+ .macro setmode, mode, reg
+ .endm
+#elif defined(CONFIG_THUMB2_KERNEL)
.macro setmode, mode, reg
mov \reg, #\mode
msr cpsr_c, \reg
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index 7652712d1d14..4eb94a3add3c 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -106,7 +106,17 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void)
return read_cpuid(CPUID_ID);
}
-#else /* ifdef CONFIG_CPU_CP15 */
+#elif defined(CONFIG_CPU_V7M)
+
+#include <asm/io.h>
+#include <asm/v7m.h>
+
+static inline unsigned int __attribute_const__ read_cpuid_id(void)
+{
+ return readl(BASEADDR_V7M_SCB + V7M_SCB_CPUID);
+}
+
+#else /* ifdef CONFIG_CPU_CP15 / elif defined(CONFIG_CPU_V7M) */
static inline unsigned int __attribute_const__ read_cpuid_id(void)
{
diff --git a/arch/arm/include/asm/glue-cache.h b/arch/arm/include/asm/glue-cache.h
index cca9f15704ed..65c9faf7a34a 100644
--- a/arch/arm/include/asm/glue-cache.h
+++ b/arch/arm/include/asm/glue-cache.h
@@ -125,10 +125,37 @@
# endif
#endif
+#if defined(CONFIG_CPU_V7M)
+# ifdef _CACHE
+# define MULTI_CACHE 1
+# else
+# define _CACHE nop
+# endif
+#endif
+
#if !defined(_CACHE) && !defined(MULTI_CACHE)
#error Unknown cache maintenance model
#endif
+#ifndef __ASSEMBLER__
+extern inline void nop_flush_icache_all(void) { }
+extern inline void nop_flush_kern_cache_all(void) { }
+extern inline void nop_flush_kern_cache_louis(void) { }
+extern inline void nop_flush_user_cache_all(void) { }
+extern inline void nop_flush_user_cache_range(unsigned long a,
+ unsigned long b, unsigned int c) { }
+
+extern inline void nop_coherent_kern_range(unsigned long a, unsigned long b) { }
+extern inline int nop_coherent_user_range(unsigned long a,
+ unsigned long b) { return 0; }
+extern inline void nop_flush_kern_dcache_area(void *a, size_t s) { }
+
+extern inline void nop_dma_flush_range(const void *a, const void *b) { }
+
+extern inline void nop_dma_map_area(const void *s, size_t l, int f) { }
+extern inline void nop_dma_unmap_area(const void *s, size_t l, int f) { }
+#endif
+
#ifndef MULTI_CACHE
#define __cpuc_flush_icache_all __glue(_CACHE,_flush_icache_all)
#define __cpuc_flush_kern_all __glue(_CACHE,_flush_kern_cache_all)
diff --git a/arch/arm/include/asm/glue-df.h b/arch/arm/include/asm/glue-df.h
index b6e9f2c108b5..6b70f1b46a6e 100644
--- a/arch/arm/include/asm/glue-df.h
+++ b/arch/arm/include/asm/glue-df.h
@@ -95,6 +95,14 @@
# endif
#endif
+#ifdef CONFIG_CPU_ABRT_NOMMU
+# ifdef CPU_DABORT_HANDLER
+# define MULTI_DABORT 1
+# else
+# define CPU_DABORT_HANDLER nommu_early_abort
+# endif
+#endif
+
#ifndef CPU_DABORT_HANDLER
#error Unknown data abort handler type
#endif
diff --git a/arch/arm/include/asm/glue-proc.h b/arch/arm/include/asm/glue-proc.h
index ac1dd54724b6..f2f39bcf7945 100644
--- a/arch/arm/include/asm/glue-proc.h
+++ b/arch/arm/include/asm/glue-proc.h
@@ -230,6 +230,15 @@
# endif
#endif
+#ifdef CONFIG_CPU_V7M
+# ifdef CPU_NAME
+# undef MULTI_CPU
+# define MULTI_CPU
+# else
+# define CPU_NAME cpu_v7m
+# endif
+#endif
+
#ifndef MULTI_CPU
#define cpu_proc_init __glue(CPU_NAME,_proc_init)
#define cpu_proc_fin __glue(CPU_NAME,_proc_fin)
diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h
index 1e6cca55c750..3b763d6652a0 100644
--- a/arch/arm/include/asm/irqflags.h
+++ b/arch/arm/include/asm/irqflags.h
@@ -8,6 +8,16 @@
/*
* CPU interrupt mask handling.
*/
+#ifdef CONFIG_CPU_V7M
+#define IRQMASK_REG_NAME_R "primask"
+#define IRQMASK_REG_NAME_W "primask"
+#define IRQMASK_I_BIT 1
+#else
+#define IRQMASK_REG_NAME_R "cpsr"
+#define IRQMASK_REG_NAME_W "cpsr_c"
+#define IRQMASK_I_BIT PSR_I_BIT
+#endif
+
#if __LINUX_ARM_ARCH__ >= 6
static inline unsigned long arch_local_irq_save(void)
@@ -15,7 +25,7 @@ static inline unsigned long arch_local_irq_save(void)
unsigned long flags;
asm volatile(
- " mrs %0, cpsr @ arch_local_irq_save\n"
+ " mrs %0, " IRQMASK_REG_NAME_R " @ arch_local_irq_save\n"
" cpsid i"
: "=r" (flags) : : "memory", "cc");
return flags;
@@ -129,7 +139,7 @@ static inline unsigned long arch_local_save_flags(void)
{
unsigned long flags;
asm volatile(
- " mrs %0, cpsr @ local_save_flags"
+ " mrs %0, " IRQMASK_REG_NAME_R " @ local_save_flags"
: "=r" (flags) : : "memory", "cc");
return flags;
}
@@ -140,7 +150,7 @@ static inline unsigned long arch_local_save_flags(void)
static inline void arch_local_irq_restore(unsigned long flags)
{
asm volatile(
- " msr cpsr_c, %0 @ local_irq_restore"
+ " msr " IRQMASK_REG_NAME_W ", %0 @ local_irq_restore"
:
: "r" (flags)
: "memory", "cc");
@@ -148,8 +158,8 @@ static inline void arch_local_irq_restore(unsigned long flags)
static inline int arch_irqs_disabled_flags(unsigned long flags)
{
- return flags & PSR_I_BIT;
+ return flags & IRQMASK_I_BIT;
}
-#endif
-#endif
+#endif /* ifdef __KERNEL__ */
+#endif /* ifndef __ASM_ARM_IRQFLAGS_H */
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index 3d52ee1bfb31..04c99f36ff7f 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -45,6 +45,7 @@ struct pt_regs {
*/
static inline int valid_user_regs(struct pt_regs *regs)
{
+#ifndef CONFIG_CPU_V7M
unsigned long mode = regs->ARM_cpsr & MODE_MASK;
/*
@@ -67,6 +68,9 @@ static inline int valid_user_regs(struct pt_regs *regs)
regs->ARM_cpsr |= USR_MODE;
return 0;
+#else /* ifndef CONFIG_CPU_V7M */
+ return 1;
+#endif
}
static inline long regs_return_value(struct pt_regs *regs)
diff --git a/arch/arm/include/asm/system_info.h b/arch/arm/include/asm/system_info.h
index dfd386d0c022..720ea0320a6d 100644
--- a/arch/arm/include/asm/system_info.h
+++ b/arch/arm/include/asm/system_info.h
@@ -11,6 +11,7 @@
#define CPU_ARCH_ARMv5TEJ 7
#define CPU_ARCH_ARMv6 8
#define CPU_ARCH_ARMv7 9
+#define CPU_ARCH_ARMv7M 10
#ifndef __ASSEMBLY__
diff --git a/arch/arm/include/asm/v7m.h b/arch/arm/include/asm/v7m.h
new file mode 100644
index 000000000000..fa88d09fa3d9
--- /dev/null
+++ b/arch/arm/include/asm/v7m.h
@@ -0,0 +1,44 @@
+/*
+ * Common defines for v7m cpus
+ */
+#define V7M_SCS_ICTR IOMEM(0xe000e004)
+#define V7M_SCS_ICTR_INTLINESNUM_MASK 0x0000000f
+
+#define BASEADDR_V7M_SCB IOMEM(0xe000ed00)
+
+#define V7M_SCB_CPUID 0x00
+
+#define V7M_SCB_ICSR 0x04
+#define V7M_SCB_ICSR_PENDSVSET (1 << 28)
+#define V7M_SCB_ICSR_PENDSVCLR (1 << 27)
+#define V7M_SCB_ICSR_RETTOBASE (1 << 11)
+
+#define V7M_SCB_VTOR 0x08
+
+#define V7M_SCB_SCR 0x10
+#define V7M_SCB_SCR_SLEEPDEEP (1 << 2)
+
+#define V7M_SCB_CCR 0x14
+#define V7M_SCB_CCR_STKALIGN (1 << 9)
+
+#define V7M_SCB_SHPR2 0x1c
+#define V7M_SCB_SHPR3 0x20
+
+#define V7M_SCB_SHCSR 0x24
+#define V7M_SCB_SHCSR_USGFAULTENA (1 << 18)
+#define V7M_SCB_SHCSR_BUSFAULTENA (1 << 17)
+#define V7M_SCB_SHCSR_MEMFAULTENA (1 << 16)
+
+#define V7M_xPSR_FRAMEPTRALIGN 0x00000200
+#define V7M_xPSR_EXCEPTIONNO 0x000001ff
+
+/*
+ * When branching to an address that has bits [31:28] == 0xf an exception return
+ * occurs. Bits [27:5] are reserved (SBOP). If the processor implements the FP
+ * extension Bit [4] defines if the exception frame has space allocated for FP
+ * state information, SBOP otherwise. Bit [3] defines the mode that is returned
+ * to (0 -> handler mode; 1 -> thread mode). Bit [2] defines which sp is used
+ * (0 -> msp; 1 -> psp). Bits [1:0] are fixed to 0b01.
+ */
+#define EXC_RET_STACK_MASK 0x00000004
+#define EXC_RET_THREADMODE_PROCESSSTACK 0xfffffffd
diff --git a/arch/arm/include/uapi/asm/ptrace.h b/arch/arm/include/uapi/asm/ptrace.h
index 96ee0929790f..5af0ed1b825a 100644
--- a/arch/arm/include/uapi/asm/ptrace.h
+++ b/arch/arm/include/uapi/asm/ptrace.h
@@ -34,28 +34,47 @@
/*
* PSR bits
+ * Note on V7M there is no mode contained in the PSR
*/
#define USR26_MODE 0x00000000
#define FIQ26_MODE 0x00000001
#define IRQ26_MODE 0x00000002
#define SVC26_MODE 0x00000003
+#if defined(__KERNEL__) && defined(CONFIG_CPU_V7M)
+/*
+ * Use 0 here to get code right that creates a userspace
+ * or kernel space thread.
+ */
+#define USR_MODE 0x00000000
+#define SVC_MODE 0x00000000
+#else
#define USR_MODE 0x00000010
+#define SVC_MODE 0x00000013
+#endif
#define FIQ_MODE 0x00000011
#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
#define MODE_MASK 0x0000001f
-#define PSR_T_BIT 0x00000020
-#define PSR_F_BIT 0x00000040
-#define PSR_I_BIT 0x00000080
-#define PSR_A_BIT 0x00000100
-#define PSR_E_BIT 0x00000200
-#define PSR_J_BIT 0x01000000
-#define PSR_Q_BIT 0x08000000
+
+#define V4_PSR_T_BIT 0x00000020 /* >= V4T, but not V7M */
+#define V7M_PSR_T_BIT 0x01000000
+#if defined(__KERNEL__) && defined(CONFIG_CPU_V7M)
+#define PSR_T_BIT V7M_PSR_T_BIT
+#else
+/* for compatibility */
+#define PSR_T_BIT V4_PSR_T_BIT
+#endif
+
+#define PSR_F_BIT 0x00000040 /* >= V4, but not V7M */
+#define PSR_I_BIT 0x00000080 /* >= V4, but not V7M */
+#define PSR_A_BIT 0x00000100 /* >= V6, but not V7M */
+#define PSR_E_BIT 0x00000200 /* >= V6, but not V7M */
+#define PSR_J_BIT 0x01000000 /* >= V5J, but not V7M */
+#define PSR_Q_BIT 0x08000000 /* >= V5E, including V7M */
#define PSR_V_BIT 0x10000000
#define PSR_C_BIT 0x20000000
#define PSR_Z_BIT 0x40000000
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 6a2e09c952c7..8812ce88f7a1 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -19,6 +19,7 @@
#include <asm/asm-offsets.h>
#include <asm/cp15.h>
#include <asm/thread_info.h>
+#include <asm/v7m.h>
/*
* Kernel startup entry point.
@@ -50,10 +51,13 @@ ENTRY(stext)
setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
@ and irqs disabled
-#ifndef CONFIG_CPU_CP15
- ldr r9, =CONFIG_PROCESSOR_ID
-#else
+#if defined(CONFIG_CPU_CP15)
mrc p15, 0, r9, c0, c0 @ get processor id
+#elif defined(CONFIG_CPU_V7M)
+ ldr r9, =BASEADDR_V7M_SCB
+ ldr r9, [r9, V7M_SCB_CPUID]
+#else
+ ldr r9, =CONFIG_PROCESSOR_ID
#endif
bl __lookup_processor_type @ r5=procinfo r9=cpuid
movs r10, r5 @ invalid processor (r5=0)?
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 1cc9e1796415..829124590e4c 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -128,7 +128,9 @@ struct stack {
u32 und[3];
} ____cacheline_aligned;
+#ifndef CONFIG_CPU_V7M
static struct stack stacks[NR_CPUS];
+#endif
char elf_platform[ELF_PLATFORM_SIZE];
EXPORT_SYMBOL(elf_platform);
@@ -207,7 +209,7 @@ static const char *proc_arch[] = {
"5TEJ",
"6TEJ",
"7",
- "?(11)",
+ "7M",
"?(12)",
"?(13)",
"?(14)",
@@ -216,6 +218,12 @@ static const char *proc_arch[] = {
"?(17)",
};
+#ifdef CONFIG_CPU_V7M
+static int __get_cpu_architecture(void)
+{
+ return CPU_ARCH_ARMv7M;
+}
+#else
static int __get_cpu_architecture(void)
{
int cpu_arch;
@@ -248,6 +256,7 @@ static int __get_cpu_architecture(void)
return cpu_arch;
}
+#endif
int __pure cpu_architecture(void)
{
@@ -293,7 +302,9 @@ static void __init cacheid_init(void)
{
unsigned int arch = cpu_architecture();
- if (arch >= CPU_ARCH_ARMv6) {
+ if (arch == CPU_ARCH_ARMv7M) {
+ cacheid = 0;
+ } else if (arch >= CPU_ARCH_ARMv6) {
unsigned int cachetype = read_cpuid_cachetype();
if ((cachetype & (7 << 29)) == 4 << 29) {
/* ARMv7 register format */
@@ -375,6 +386,7 @@ static void __init feat_v6_fixup(void)
*/
void cpu_init(void)
{
+#ifndef CONFIG_CPU_V7M
unsigned int cpu = smp_processor_id();
struct stack *stk = &stacks[cpu];
@@ -425,6 +437,7 @@ void cpu_init(void)
"I" (offsetof(struct stack, und[0])),
PLC (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
: "r14");
+#endif
}
int __cpu_logical_map[NR_CPUS];
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 1c089119b2d7..ec64571462d2 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -819,6 +819,7 @@ static void __init kuser_get_tls_init(unsigned long vectors)
void __init early_trap_init(void *vectors_base)
{
+#ifndef CONFIG_CPU_V7M
unsigned long vectors = (unsigned long)vectors_base;
extern char __stubs_start[], __stubs_end[];
extern char __vectors_start[], __vectors_end[];
@@ -850,4 +851,11 @@ void __init early_trap_init(void *vectors_base)
flush_icache_range(vectors, vectors + PAGE_SIZE);
modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
+#else /* ifndef CONFIG_CPU_V7M */
+ /*
+ * on V7-M there is no need to copy the vector table to a dedicated
+ * memory area. The address is configurable and so a table in the kernel
+ * image can be used.
+ */
+#endif
}
diff --git a/arch/arm/mm/cache-nop.S b/arch/arm/mm/cache-nop.S
new file mode 100644
index 000000000000..8e12ddca0031
--- /dev/null
+++ b/arch/arm/mm/cache-nop.S
@@ -0,0 +1,50 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+#include "proc-macros.S"
+
+ENTRY(nop_flush_icache_all)
+ mov pc, lr
+ENDPROC(nop_flush_icache_all)
+
+ .globl nop_flush_kern_cache_all
+ .equ nop_flush_kern_cache_all, nop_flush_icache_all
+
+ .globl nop_flush_kern_cache_louis
+ .equ nop_flush_kern_cache_louis, nop_flush_icache_all
+
+ .globl nop_flush_user_cache_all
+ .equ nop_flush_user_cache_all, nop_flush_icache_all
+
+ .globl nop_flush_user_cache_range
+ .equ nop_flush_user_cache_range, nop_flush_icache_all
+
+ .globl nop_coherent_kern_range
+ .equ nop_coherent_kern_range, nop_flush_icache_all
+
+ENTRY(nop_coherent_user_range)
+ mov r0, 0
+ mov pc, lr
+ENDPROC(nop_coherent_user_range)
+
+ .globl nop_flush_kern_dcache_area
+ .equ nop_flush_kern_dcache_area, nop_flush_icache_all
+
+ .globl nop_dma_flush_range
+ .equ nop_dma_flush_range, nop_flush_icache_all
+
+ .globl nop_dma_map_area
+ .equ nop_dma_map_area, nop_flush_icache_all
+
+ .globl nop_dma_unmap_area
+ .equ nop_dma_unmap_area, nop_flush_icache_all
+
+ __INITDATA
+
+ @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
+ define_cache_functions nop
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index d51225f90ae2..dd3a6c670f08 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -20,12 +20,19 @@
void __init arm_mm_memblock_reserve(void)
{
+#ifndef CONFIG_CPU_V7M
/*
* Register the exception vector page.
* some architectures which the DRAM is the exception vector to trap,
* alloc_page breaks with error, although it is not NULL, but "0."
*/
memblock_reserve(CONFIG_VECTORS_BASE, PAGE_SIZE);
+#else /* ifndef CONFIG_CPU_V7M */
+ /*
+ * There is no dedicated vector page on V7-M. So nothing needs to be
+ * reserved here.
+ */
+#endif
}
void __init sanity_check_meminfo(void)
diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S
new file mode 100644
index 000000000000..000499cfceb3
--- /dev/null
+++ b/arch/arm/mm/proc-v7m.S
@@ -0,0 +1,157 @@
+/*
+ * linux/arch/arm/mm/proc-v7m.S
+ *
+ * Copyright (C) 2008 ARM Ltd.
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This is the "shell" of the ARMv7-M processor support.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/v7m.h>
+#include "proc-macros.S"
+
+ENTRY(cpu_v7m_proc_init)
+ mov pc, lr
+ENDPROC(cpu_v7m_proc_init)
+
+ENTRY(cpu_v7m_proc_fin)
+ mov pc, lr
+ENDPROC(cpu_v7m_proc_fin)
+
+/*
+ * cpu_v7m_reset(loc)
+ *
+ * Perform a soft reset of the system. Put the CPU into the
+ * same state as it would be if it had been reset, and branch
+ * to what would be the reset vector.
+ *
+ * - loc - location to jump to for soft reset
+ */
+ .align 5
+ENTRY(cpu_v7m_reset)
+ mov pc, r0
+ENDPROC(cpu_v7m_reset)
+
+/*
+ * cpu_v7m_do_idle()
+ *
+ * Idle the processor (eg, wait for interrupt).
+ *
+ * IRQs are already disabled.
+ */
+ENTRY(cpu_v7m_do_idle)
+ wfi
+ mov pc, lr
+ENDPROC(cpu_v7m_do_idle)
+
+ENTRY(cpu_v7m_dcache_clean_area)
+ mov pc, lr
+ENDPROC(cpu_v7m_dcache_clean_area)
+
+/*
+ * There is no MMU, so here is nothing to do.
+ */
+ENTRY(cpu_v7m_switch_mm)
+ mov pc, lr
+ENDPROC(cpu_v7m_switch_mm)
+
+.globl cpu_v7m_suspend_size
+.equ cpu_v7m_suspend_size, 0
+
+#ifdef CONFIG_ARM_CPU_SUSPEND
+ENTRY(cpu_v7m_do_suspend)
+ mov pc, lr
+ENDPROC(cpu_v7m_do_suspend)
+
+ENTRY(cpu_v7m_do_resume)
+ mov pc, lr
+ENDPROC(cpu_v7m_do_resume)
+#endif
+
+ .section ".text.init", #alloc, #execinstr
+
+/*
+ * __v7m_setup
+ *
+ * This should be able to cover all ARMv7-M cores.
+ */
+__v7m_setup:
+ @ Configure the vector table base address
+ ldr r0, =BASEADDR_V7M_SCB
+ ldr r12, =vector_table
+ str r12, [r0, V7M_SCB_VTOR]
+
+ @ enable UsageFault, BusFault and MemManage fault.
+ ldr r5, [r0, #V7M_SCB_SHCSR]
+ orr r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
+ str r5, [r0, #V7M_SCB_SHCSR]
+
+ @ Lower the priority of the SVC and PendSV exceptions
+ mov r5, #0x80000000
+ str r5, [r0, V7M_SCB_SHPR2] @ set SVC priority
+ mov r5, #0x00800000
+ str r5, [r0, V7M_SCB_SHPR3] @ set PendSV priority
+
+ @ SVC to run the kernel in this mode
+ adr r1, BSYM(1f)
+ ldr r5, [r12, #11 * 4] @ read the SVC vector entry
+ str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
+ mov r6, lr @ save LR
+ mov r7, sp @ save SP
+ ldr sp, =__v7m_setup_stack_top
+ cpsie i
+ svc #0
+1: cpsid i
+ str r5, [r12, #11 * 4] @ restore the original SVC vector entry
+ mov lr, r6 @ restore LR
+ mov sp, r7 @ restore SP
+
+ @ Special-purpose control register
+ mov r1, #1
+ msr control, r1 @ Thread mode has unpriviledged access
+
+ @ Configure the System Control Register to ensure 8-byte stack alignment
+ @ Note the STKALIGN bit is either RW or RAO.
+ ldr r12, [r0, V7M_SCB_CCR] @ system control register
+ orr r12, #V7M_SCB_CCR_STKALIGN
+ str r12, [r0, V7M_SCB_CCR]
+ mov pc, lr
+ENDPROC(__v7m_setup)
+
+ define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
+
+ .section ".rodata"
+ string cpu_arch_name, "armv7m"
+ string cpu_elf_name "v7m"
+ string cpu_v7m_name "ARMv7-M"
+
+ .section ".proc.info.init", #alloc, #execinstr
+
+ /*
+ * Match any ARMv7-M processor core.
+ */
+ .type __v7m_proc_info, #object
+__v7m_proc_info:
+ .long 0x000f0000 @ Required ID value
+ .long 0x000f0000 @ Mask for ID
+ .long 0 @ proc_info_list.__cpu_mm_mmu_flags
+ .long 0 @ proc_info_list.__cpu_io_mmu_flags
+ b __v7m_setup @ proc_info_list.__cpu_flush
+ .long cpu_arch_name
+ .long cpu_elf_name
+ .long HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_IDIVT
+ .long cpu_v7m_name
+ .long v7m_processor_functions @ proc_info_list.proc
+ .long 0 @ proc_info_list.tlb
+ .long 0 @ proc_info_list.user
+ .long nop_cache_fns @ proc_info_list.cache
+ .size __v7m_proc_info, . - __v7m_proc_info
+
+__v7m_setup_stack:
+ .space 4 * 8 @ 8 registers
+__v7m_setup_stack_top: