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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm/mm/proc-v7m.S
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mm/proc-v7m.S')
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/mm/proc-v7m.S
+ *
+ * Copyright (C) 2008 ARM Ltd.
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ *
+ * This is the "shell" of the ARMv7-M processor support.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/memory.h>
+#include <asm/v7m.h>
+#include "proc-macros.S"
+
+ENTRY(cpu_v7m_proc_init)
+ ret lr
+ENDPROC(cpu_v7m_proc_init)
+
+ENTRY(cpu_v7m_proc_fin)
+ ret 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)
+ ret 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
+ ret lr
+ENDPROC(cpu_v7m_do_idle)
+
+ENTRY(cpu_v7m_dcache_clean_area)
+ ret lr
+ENDPROC(cpu_v7m_dcache_clean_area)
+
+/*
+ * There is no MMU, so here is nothing to do.
+ */
+ENTRY(cpu_v7m_switch_mm)
+ ret 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)
+ ret lr
+ENDPROC(cpu_v7m_do_suspend)
+
+ENTRY(cpu_v7m_do_resume)
+ ret lr
+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 ".init.text", "ax"
+
+__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
+ 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 switch to handler mode. Notice that this requires sp to
+ @ point to writeable memory because the processor saves
+ @ some registers to the stack.
+ badr r1, 1f
+ ldr r5, [r12, #11 * 4] @ read the SVC vector entry
+ str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
+ dsb
+ mov r6, lr @ save LR
+ ldr sp, =init_thread_union + THREAD_START_SP
+ cpsie i
+ svc #0
+1: cpsid i
+ /* Calculate exc_ret */
+ orr r10, lr, #EXC_RET_THREADMODE_PROCESSSTACK
+ ldmia sp, {r0-r3, r12}
+ str r5, [r12, #11 * 4] @ restore the original SVC vector entry
+ mov lr, r6 @ restore LR
+
+ @ Special-purpose control register
+ mov r1, #1
+ msr control, r1 @ Thread mode has unpriviledged access
+
+ @ Configure caches (if implemented)
+ teq r8, #0
+ stmiane sp, {r0-r6, lr} @ v7m_invalidate_l1 touches r0-r6
+ blne v7m_invalidate_l1
+ teq r8, #0 @ re-evalutae condition
+ ldmiane sp, {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"
+ string cpu_elf_name "v7m"
+ string cpu_v7m_name "ARMv7-M"
+
+ .section ".proc.info.init", "a"
+
+.macro __v7m_proc name, initfunc, cache_fns = nop_cache_fns, hwcaps = 0, proc_fns = v7m_processor_functions
+ .long 0 /* proc_info_list.__cpu_mm_mmu_flags */
+ .long 0 /* proc_info_list.__cpu_io_mmu_flags */
+ initfn \initfunc, \name
+ .long cpu_arch_name
+ .long cpu_elf_name
+ .long HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \hwcaps
+ .long cpu_v7m_name
+ .long \proc_fns
+ .long 0 /* proc_info_list.tlb */
+ .long 0 /* proc_info_list.user */
+ .long \cache_fns
+.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
+__v7m_cm4_proc_info:
+ .long 0x410fc240 /* ARM Cortex-M4 0xC24 */
+ .long 0xff0ffff0 /* Mask off revision, patch release */
+ __v7m_proc __v7m_cm4_proc_info, __v7m_setup, hwcaps = HWCAP_EDSP
+ .size __v7m_cm4_proc_info, . - __v7m_cm4_proc_info
+
+ /*
+ * Match ARM Cortex-M3 processor.
+ */
+ .type __v7m_cm3_proc_info, #object
+__v7m_cm3_proc_info:
+ .long 0x410fc230 /* ARM Cortex-M3 0xC23 */
+ .long 0xff0ffff0 /* Mask off revision, patch release */
+ __v7m_proc __v7m_cm3_proc_info, __v7m_setup
+ .size __v7m_cm3_proc_info, . - __v7m_cm3_proc_info
+
+ /*
+ * Match any ARMv7-M processor core.
+ */
+ .type __v7m_proc_info, #object
+__v7m_proc_info:
+ .long 0x000f0000 @ Required ID value
+ .long 0x000f0000 @ Mask for ID
+ __v7m_proc __v7m_proc_info, __v7m_setup
+ .size __v7m_proc_info, . - __v7m_proc_info
+