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>
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 05ee9ee..a5fef71 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 7652712..4eb94a3 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -106,7 +106,17 @@
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 cca9f15..65c9faf 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 b6e9f2c..6b70f1b 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 ac1dd54..f2f39bc 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 1e6cca5..3b763d6 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 @@
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 @@
{
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 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 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 3d52ee1..04c99f3 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -45,6 +45,7 @@
*/
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 @@
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 dfd386d..720ea03 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 0000000..fa88d09
--- /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