ARM: 8609/1: V7M: Add support for the Cortex-M7 processor

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@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Andras Szemzo <sza@esh.hu>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 56 insertions, 0 deletions

diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S
index 796a9836cfdb..e6786f007a59 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