ARM: ARMv7-M: implement read_cpuid_ext

On v7-M the extended cpuid registers are not available from CP15 but they
are memory mapped in the System Control Space.
There isn't an equivalent available for CPUID_{CACHETYPE,TCM,TLBTYPE,MPIDR}.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

arch/arm/include/asm/cputype.h

@@ -10,6 +10,22 @@
 #define CPUID_TLBTYPE	3
 #define CPUID_MPIDR	5
 
+#ifdef CONFIG_CPU_V7M
+#define CPUID_EXT_PFR0	0x40
+#define CPUID_EXT_PFR1	0x44
+#define CPUID_EXT_DFR0	0x48
+#define CPUID_EXT_AFR0	0x4c
+#define CPUID_EXT_MMFR0	0x50
+#define CPUID_EXT_MMFR1	0x54
+#define CPUID_EXT_MMFR2	0x58
+#define CPUID_EXT_MMFR3	0x5c
+#define CPUID_EXT_ISAR0	0x60
+#define CPUID_EXT_ISAR1	0x64
+#define CPUID_EXT_ISAR2	0x68
+#define CPUID_EXT_ISAR3	0x6c
+#define CPUID_EXT_ISAR4	0x70
+#define CPUID_EXT_ISAR5	0x74
+#else
 #define CPUID_EXT_PFR0	"c1, 0"
 #define CPUID_EXT_PFR1	"c1, 1"
 #define CPUID_EXT_DFR0	"c1, 2"
@@ -24,6 +40,7 @@
 #define CPUID_EXT_ISAR3	"c2, 3"
 #define CPUID_EXT_ISAR4	"c2, 4"
 #define CPUID_EXT_ISAR5	"c2, 5"
+#endif
 
 #define MPIDR_SMP_BITMASK (0x3 << 30)
 #define MPIDR_SMP_VALUE (0x2 << 30)
@@ -79,7 +96,23 @@ extern unsigned int processor_id;
 		__val;							\
 	})
 
-#else /* ifdef CONFIG_CPU_CP15 */
+#elif defined(CONFIG_CPU_V7M)
+
+#include <asm/io.h>
+#include <asm/v7m.h>
+
+#define read_cpuid(reg)							\
+	({								\
+		WARN_ON_ONCE(1);					\
+		0;							\
+	})
+
+static inline unsigned int __attribute_const__ read_cpuid_ext(unsigned offset)
+{
+	return readl(BASEADDR_V7M_SCB + offset);
+}
+
+#else /* ifdef CONFIG_CPU_CP15 / elif defined (CONFIG_CPU_V7M) */
 
 /*
  * read_cpuid and read_cpuid_ext should only ever be called on machines that
@@ -108,9 +141,6 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void)
 
 #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);

arch/arm/mm/proc-v7m.S

@@ -144,7 +144,7 @@ __v7m_proc_info:
 	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	HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT
 	.long	cpu_v7m_name
 	.long	v7m_processor_functions	@ proc_info_list.proc
 	.long	0			@ proc_info_list.tlb