[PATCH v2 8/8] ARM: V7M: Add support for the Cortex-M7 processor

[Vladimir Murzin]

From: Jonathan Austin <jonathan.austin at arm.com>

Cortex-M7 is a new member of the V7M processor family that adds, among
other things, caches over the features available in Cortex-M4.

This patch adds support for recognising the processor at boot time, and
make use of recently introduced cache functions.

Signed-off-by: Jonathan Austin <jonathan.austin at arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
---
 arch/arm/mm/proc-v7m.S |   56 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S
index 796a983..e6786f0 100644
--- a/arch/arm/mm/proc-v7m.S
+++ b/arch/arm/mm/proc-v7m.S
@@ -74,14 +74,42 @@ ENTRY(cpu_v7m_do_resume)
 ENDPROC(cpu_v7m_do_resume)
 #endif
 
+ENTRY(cpu_cm7_dcache_clean_area)
+	dcache_line_size r2, r3
+	movw	r3, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
+	movt	r3, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
+
+1:	str	r0, [r3]		@ clean D entry
+	add	r0, r0, r2
+	subs	r1, r1, r2
+	bhi	1b
+	dsb
+	ret	lr
+ENDPROC(cpu_cm7_dcache_clean_area)
+
+ENTRY(cpu_cm7_proc_fin)
+	movw	r2, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
+	movt	r2, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
+	ldr	r0, [r2]
+	bic	r0, r0, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC)
+	str	r0, [r2]
+	ret	lr
+ENDPROC(cpu_cm7_proc_fin)
+
 	.section ".text.init", #alloc, #execinstr
 
+__v7m_cm7_setup:
+	mov	r8, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC| V7M_SCB_CCR_BP)
+	b	__v7m_setup_cont
 /*
  *	__v7m_setup
  *
  *	This should be able to cover all ARMv7-M cores.
  */
 __v7m_setup:
+	mov	r8, 0
+
+__v7m_setup_cont:
 	@ Configure the vector table base address
 	ldr	r0, =BASEADDR_V7M_SCB
 	ldr	r12, =vector_table
@@ -116,14 +144,32 @@ __v7m_setup:
 	mov	r1, #1
 	msr	control, r1		@ Thread mode has unpriviledged access
 
+	@ Configure caches (if implemented)
+	teq     r8, #0
+	stmneia	r12, {r0-r6, lr}	@ v7m_invalidate_l1 touches r0-r6
+	blne	v7m_invalidate_l1
+	teq     r8, #0			@ re-evalutae condition
+	ldmneia	r12, {r0-r6, lr}
+
 	@ Configure the System Control Register to ensure 8-byte stack alignment
 	@ Note the STKALIGN bit is either RW or RAO.
 	ldr	r0, [r0, V7M_SCB_CCR]   @ system control register
 	orr	r0, #V7M_SCB_CCR_STKALIGN
+	orr	r0, r0, r8
+
 	ret	lr
 ENDPROC(__v7m_setup)
 
+/*
+ * Cortex-M7 processor functions
+ */
+	globl_equ	cpu_cm7_proc_init,	cpu_v7m_proc_init
+	globl_equ	cpu_cm7_reset,		cpu_v7m_reset
+	globl_equ	cpu_cm7_do_idle,	cpu_v7m_do_idle
+	globl_equ	cpu_cm7_switch_mm,	cpu_v7m_switch_mm
+
 	define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
+	define_processor_functions cm7, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
 
 	.section ".rodata"
 	string cpu_arch_name, "armv7m"
@@ -147,6 +193,16 @@ ENDPROC(__v7m_setup)
 .endm
 
 	/*
+	 * Match ARM Cortex-M7 processor.
+	 */
+	.type	__v7m_cm7_proc_info, #object
+__v7m_cm7_proc_info:
+	.long	0x410fc270		/* ARM Cortex-M7 0xC27 */
+	.long	0xff0ffff0		/* Mask off revision, patch release */
+	__v7m_proc __v7m_cm7_proc_info, __v7m_cm7_setup, hwcaps = HWCAP_EDSP, cache_fns = v7m_cache_fns, proc_fns = cm7_processor_functions
+	.size	__v7m_cm7_proc_info, . - __v7m_cm7_proc_info
+
+	/*
 	 * Match ARM Cortex-M4 processor.
 	 */
 	.type	__v7m_cm4_proc_info, #object
-- 
1.7.9.5