proc-v7m.S 6.7 KB

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  1. /* SPDX-License-Identifier: GPL-2.0-only */
  2. /*
  3. * linux/arch/arm/mm/proc-v7m.S
  4. *
  5. * Copyright (C) 2008 ARM Ltd.
  6. * Copyright (C) 2001 Deep Blue Solutions Ltd.
  7. *
  8. * This is the "shell" of the ARMv7-M processor support.
  9. */
  10. #include <linux/linkage.h>
  11. #include <asm/assembler.h>
  12. #include <asm/memory.h>
  13. #include <asm/v7m.h>
  14. #include "proc-macros.S"
  15. ENTRY(cpu_v7m_proc_init)
  16. ret lr
  17. ENDPROC(cpu_v7m_proc_init)
  18. ENTRY(cpu_v7m_proc_fin)
  19. ret lr
  20. ENDPROC(cpu_v7m_proc_fin)
  21. /*
  22. * cpu_v7m_reset(loc)
  23. *
  24. * Perform a soft reset of the system. Put the CPU into the
  25. * same state as it would be if it had been reset, and branch
  26. * to what would be the reset vector.
  27. *
  28. * - loc - location to jump to for soft reset
  29. */
  30. .align 5
  31. ENTRY(cpu_v7m_reset)
  32. ret r0
  33. ENDPROC(cpu_v7m_reset)
  34. /*
  35. * cpu_v7m_do_idle()
  36. *
  37. * Idle the processor (eg, wait for interrupt).
  38. *
  39. * IRQs are already disabled.
  40. */
  41. ENTRY(cpu_v7m_do_idle)
  42. wfi
  43. ret lr
  44. ENDPROC(cpu_v7m_do_idle)
  45. ENTRY(cpu_v7m_dcache_clean_area)
  46. ret lr
  47. ENDPROC(cpu_v7m_dcache_clean_area)
  48. /*
  49. * There is no MMU, so here is nothing to do.
  50. */
  51. ENTRY(cpu_v7m_switch_mm)
  52. ret lr
  53. ENDPROC(cpu_v7m_switch_mm)
  54. .globl cpu_v7m_suspend_size
  55. .equ cpu_v7m_suspend_size, 0
  56. #ifdef CONFIG_ARM_CPU_SUSPEND
  57. ENTRY(cpu_v7m_do_suspend)
  58. ret lr
  59. ENDPROC(cpu_v7m_do_suspend)
  60. ENTRY(cpu_v7m_do_resume)
  61. ret lr
  62. ENDPROC(cpu_v7m_do_resume)
  63. #endif
  64. ENTRY(cpu_cm7_dcache_clean_area)
  65. dcache_line_size r2, r3
  66. movw r3, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
  67. movt r3, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
  68. 1: str r0, [r3] @ clean D entry
  69. add r0, r0, r2
  70. subs r1, r1, r2
  71. bhi 1b
  72. dsb
  73. ret lr
  74. ENDPROC(cpu_cm7_dcache_clean_area)
  75. ENTRY(cpu_cm7_proc_fin)
  76. movw r2, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
  77. movt r2, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
  78. ldr r0, [r2]
  79. bic r0, r0, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC)
  80. str r0, [r2]
  81. ret lr
  82. ENDPROC(cpu_cm7_proc_fin)
  83. .section ".init.text", "ax"
  84. __v7m_cm7_setup:
  85. mov r8, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC| V7M_SCB_CCR_BP)
  86. b __v7m_setup_cont
  87. /*
  88. * __v7m_setup
  89. *
  90. * This should be able to cover all ARMv7-M cores.
  91. */
  92. __v7m_setup:
  93. mov r8, 0
  94. __v7m_setup_cont:
  95. @ Configure the vector table base address
  96. ldr r0, =BASEADDR_V7M_SCB
  97. ldr r12, =vector_table
  98. str r12, [r0, V7M_SCB_VTOR]
  99. @ enable UsageFault, BusFault and MemManage fault.
  100. ldr r5, [r0, #V7M_SCB_SHCSR]
  101. orr r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
  102. str r5, [r0, #V7M_SCB_SHCSR]
  103. @ Lower the priority of the SVC and PendSV exceptions
  104. mov r5, #0x80000000
  105. str r5, [r0, V7M_SCB_SHPR2] @ set SVC priority
  106. mov r5, #0x00800000
  107. str r5, [r0, V7M_SCB_SHPR3] @ set PendSV priority
  108. @ SVC to switch to handler mode. Notice that this requires sp to
  109. @ point to writeable memory because the processor saves
  110. @ some registers to the stack.
  111. badr r1, 1f
  112. ldr r5, [r12, #11 * 4] @ read the SVC vector entry
  113. str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
  114. dsb
  115. mov r6, lr @ save LR
  116. ldr sp, =init_thread_union + THREAD_START_SP
  117. cpsie i
  118. svc #0
  119. 1: cpsid i
  120. /* Calculate exc_ret */
  121. orr r10, lr, #EXC_RET_THREADMODE_PROCESSSTACK
  122. ldmia sp, {r0-r3, r12}
  123. str r5, [r12, #11 * 4] @ restore the original SVC vector entry
  124. mov lr, r6 @ restore LR
  125. @ Special-purpose control register
  126. mov r1, #1
  127. msr control, r1 @ Thread mode has unpriviledged access
  128. @ Configure caches (if implemented)
  129. teq r8, #0
  130. stmiane sp, {r0-r6, lr} @ v7m_invalidate_l1 touches r0-r6
  131. blne v7m_invalidate_l1
  132. teq r8, #0 @ re-evalutae condition
  133. ldmiane sp, {r0-r6, lr}
  134. @ Configure the System Control Register to ensure 8-byte stack alignment
  135. @ Note the STKALIGN bit is either RW or RAO.
  136. ldr r0, [r0, V7M_SCB_CCR] @ system control register
  137. orr r0, #V7M_SCB_CCR_STKALIGN
  138. orr r0, r0, r8
  139. ret lr
  140. ENDPROC(__v7m_setup)
  141. /*
  142. * Cortex-M7 processor functions
  143. */
  144. globl_equ cpu_cm7_proc_init, cpu_v7m_proc_init
  145. globl_equ cpu_cm7_reset, cpu_v7m_reset
  146. globl_equ cpu_cm7_do_idle, cpu_v7m_do_idle
  147. globl_equ cpu_cm7_switch_mm, cpu_v7m_switch_mm
  148. define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
  149. define_processor_functions cm7, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
  150. .section ".rodata"
  151. string cpu_arch_name, "armv7m"
  152. string cpu_elf_name "v7m"
  153. string cpu_v7m_name "ARMv7-M"
  154. .section ".proc.info.init", "a"
  155. .macro __v7m_proc name, initfunc, cache_fns = nop_cache_fns, hwcaps = 0, proc_fns = v7m_processor_functions
  156. .long 0 /* proc_info_list.__cpu_mm_mmu_flags */
  157. .long 0 /* proc_info_list.__cpu_io_mmu_flags */
  158. initfn \initfunc, \name
  159. .long cpu_arch_name
  160. .long cpu_elf_name
  161. .long HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \hwcaps
  162. .long cpu_v7m_name
  163. .long \proc_fns
  164. .long 0 /* proc_info_list.tlb */
  165. .long 0 /* proc_info_list.user */
  166. .long \cache_fns
  167. .endm
  168. /*
  169. * Match ARM Cortex-M55 processor.
  170. */
  171. .type __v7m_cm55_proc_info, #object
  172. __v7m_cm55_proc_info:
  173. .long 0x410fd220 /* ARM Cortex-M55 0xD22 */
  174. .long 0xff0ffff0 /* Mask off revision, patch release */
  175. __v7m_proc __v7m_cm55_proc_info, __v7m_cm7_setup, hwcaps = HWCAP_EDSP, cache_fns = v7m_cache_fns, proc_fns = cm7_processor_functions
  176. .size __v7m_cm55_proc_info, . - __v7m_cm55_proc_info
  177. /*
  178. * Match ARM Cortex-M33 processor.
  179. */
  180. .type __v7m_cm33_proc_info, #object
  181. __v7m_cm33_proc_info:
  182. .long 0x410fd210 /* ARM Cortex-M33 0xD21 */
  183. .long 0xff0ffff0 /* Mask off revision, patch release */
  184. __v7m_proc __v7m_cm33_proc_info, __v7m_setup, hwcaps = HWCAP_EDSP
  185. .size __v7m_cm33_proc_info, . - __v7m_cm33_proc_info
  186. /*
  187. * Match ARM Cortex-M7 processor.
  188. */
  189. .type __v7m_cm7_proc_info, #object
  190. __v7m_cm7_proc_info:
  191. .long 0x410fc270 /* ARM Cortex-M7 0xC27 */
  192. .long 0xff0ffff0 /* Mask off revision, patch release */
  193. __v7m_proc __v7m_cm7_proc_info, __v7m_cm7_setup, hwcaps = HWCAP_EDSP, cache_fns = v7m_cache_fns, proc_fns = cm7_processor_functions
  194. .size __v7m_cm7_proc_info, . - __v7m_cm7_proc_info
  195. /*
  196. * Match ARM Cortex-M4 processor.
  197. */
  198. .type __v7m_cm4_proc_info, #object
  199. __v7m_cm4_proc_info:
  200. .long 0x410fc240 /* ARM Cortex-M4 0xC24 */
  201. .long 0xff0ffff0 /* Mask off revision, patch release */
  202. __v7m_proc __v7m_cm4_proc_info, __v7m_setup, hwcaps = HWCAP_EDSP
  203. .size __v7m_cm4_proc_info, . - __v7m_cm4_proc_info
  204. /*
  205. * Match ARM Cortex-M3 processor.
  206. */
  207. .type __v7m_cm3_proc_info, #object
  208. __v7m_cm3_proc_info:
  209. .long 0x410fc230 /* ARM Cortex-M3 0xC23 */
  210. .long 0xff0ffff0 /* Mask off revision, patch release */
  211. __v7m_proc __v7m_cm3_proc_info, __v7m_setup
  212. .size __v7m_cm3_proc_info, . - __v7m_cm3_proc_info
  213. /*
  214. * Match any ARMv7-M processor core.
  215. */
  216. .type __v7m_proc_info, #object
  217. __v7m_proc_info:
  218. .long 0x000f0000 @ Required ID value
  219. .long 0x000f0000 @ Mask for ID
  220. __v7m_proc __v7m_proc_info, __v7m_setup
  221. .size __v7m_proc_info, . - __v7m_proc_info