arch/csky/kernel/entry.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/linkage.h>
   5 #include <abi/entry.h>
   6 #include <abi/pgtable-bits.h>
   7 #include <asm/errno.h>
   8 #include <asm/setup.h>
   9 #include <asm/unistd.h>
  10 #include <asm/asm-offsets.h>
  11 #include <linux/threads.h>
  12 #include <asm/setup.h>
  13 #include <asm/page.h>
  14 #include <asm/thread_info.h>
  15
  16 #define PTE_INDX_MSK    0xffc
  17 #define PTE_INDX_SHIFT  10
  18 #define _PGDIR_SHIFT    22
  19
  20 .macro  zero_fp
  21 #ifdef CONFIG_STACKTRACE
  22         movi    r8, 0
  23 #endif
  24 .endm
  25
  26 .macro tlbop_begin name, val0, val1, val2
  27 ENTRY(csky_\name)
  28         mtcr    a3, ss2
  29         mtcr    r6, ss3
  30         mtcr    a2, ss4
  31
  32         RD_PGDR r6
  33         RD_MEH  a3
  34 #ifdef CONFIG_CPU_HAS_TLBI
  35         tlbi.vaas a3
  36         sync.is
  37
  38         btsti   a3, 31
  39         bf      1f
  40         RD_PGDR_K r6
  41 1:
  42 #else
  43         bgeni   a2, 31
  44         WR_MCIR a2
  45         bgeni   a2, 25
  46         WR_MCIR a2
  47 #endif
  48         bclri   r6, 0
  49         lrw     a2, va_pa_offset
  50         ld.w    a2, (a2, 0)
  51         subu    r6, a2
  52         bseti   r6, 31
  53
  54         mov     a2, a3
  55         lsri    a2, _PGDIR_SHIFT
  56         lsli    a2, 2
  57         addu    r6, a2
  58         ldw     r6, (r6)
  59
  60         lrw     a2, va_pa_offset
  61         ld.w    a2, (a2, 0)
  62         subu    r6, a2
  63         bseti   r6, 31
  64
  65         lsri    a3, PTE_INDX_SHIFT
  66         lrw     a2, PTE_INDX_MSK
  67         and     a3, a2
  68         addu    r6, a3
  69         ldw     a3, (r6)
  70
  71         movi    a2, (_PAGE_PRESENT | \val0)
  72         and     a3, a2
  73         cmpne   a3, a2
  74         bt      \name
  75
  76         /* First read/write the page, just update the flags */
  77         ldw     a3, (r6)
  78         bgeni   a2, PAGE_VALID_BIT
  79         bseti   a2, PAGE_ACCESSED_BIT
  80         bseti   a2, \val1
  81         bseti   a2, \val2
  82         or      a3, a2
  83         stw     a3, (r6)
  84
  85         /* Some cpu tlb-hardrefill bypass the cache */
  86 #ifdef CONFIG_CPU_NEED_TLBSYNC
  87         movi    a2, 0x22
  88         bseti   a2, 6
  89         mtcr    r6, cr22
  90         mtcr    a2, cr17
  91         sync
  92 #endif
  93
  94         mfcr    a3, ss2
  95         mfcr    r6, ss3
  96         mfcr    a2, ss4
  97         rte
  98 \name:
  99         mfcr    a3, ss2
 100         mfcr    r6, ss3
 101         mfcr    a2, ss4
 102         SAVE_ALL 0
 103 .endm
 104 .macro tlbop_end is_write
 105         zero_fp
 106         RD_MEH  a2
 107         psrset  ee, ie
 108         mov     a0, sp
 109         movi    a1, \is_write
 110         jbsr    do_page_fault
 111         jmpi    ret_from_exception
 112 .endm
 113
 114 .text
 115
 116 tlbop_begin tlbinvalidl, _PAGE_READ, PAGE_VALID_BIT, PAGE_ACCESSED_BIT
 117 tlbop_end 0
 118
 119 tlbop_begin tlbinvalids, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BIT
 120 tlbop_end 1
 121
 122 tlbop_begin tlbmodified, _PAGE_WRITE, PAGE_DIRTY_BIT, PAGE_MODIFIED_BIT
 123 #ifndef CONFIG_CPU_HAS_LDSTEX
 124 jbsr csky_cmpxchg_fixup
 125 #endif
 126 tlbop_end 1
 127
 128 ENTRY(csky_systemcall)
 129         SAVE_ALL TRAP0_SIZE
 130         zero_fp
 131 #ifdef CONFIG_RSEQ_DEBUG
 132         mov     a0, sp
 133         jbsr    rseq_syscall
 134 #endif
 135         psrset  ee, ie
 136
 137         lrw     r11, __NR_syscalls
 138         cmphs   syscallid, r11          /* Check nr of syscall */
 139         bt      ret_from_exception
 140
 141         lrw     r13, sys_call_table
 142         ixw     r13, syscallid
 143         ldw     r11, (r13)
 144         cmpnei  r11, 0
 145         bf      ret_from_exception
 146
 147         mov     r9, sp
 148         bmaski  r10, THREAD_SHIFT
 149         andn    r9, r10
 150         ldw     r12, (r9, TINFO_FLAGS)
 151         ANDI_R3 r12, (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
 152         cmpnei  r12, 0
 153         bt      csky_syscall_trace
 154 #if defined(__CSKYABIV2__)
 155         subi    sp, 8
 156         stw     r5, (sp, 0x4)
 157         stw     r4, (sp, 0x0)
 158         jsr     r11                      /* Do system call */
 159         addi    sp, 8
 160 #else
 161         jsr     r11
 162 #endif
 163         stw     a0, (sp, LSAVE_A0)      /* Save return value */
 164         jmpi    ret_from_exception
 165
 166 csky_syscall_trace:
 167         mov     a0, sp                  /* sp = pt_regs pointer */
 168         jbsr    syscall_trace_enter
 169         /* Prepare args before do system call */
 170         ldw     a0, (sp, LSAVE_A0)
 171         ldw     a1, (sp, LSAVE_A1)
 172         ldw     a2, (sp, LSAVE_A2)
 173         ldw     a3, (sp, LSAVE_A3)
 174 #if defined(__CSKYABIV2__)
 175         subi    sp, 8
 176         stw     r5, (sp, 0x4)
 177         stw     r4, (sp, 0x0)
 178 #else
 179         ldw     r6, (sp, LSAVE_A4)
 180         ldw     r7, (sp, LSAVE_A5)
 181 #endif
 182         jsr     r11                     /* Do system call */
 183 #if defined(__CSKYABIV2__)
 184         addi    sp, 8
 185 #endif
 186         stw     a0, (sp, LSAVE_A0)      /* Save return value */
 187
 188         mov     a0, sp                  /* right now, sp --> pt_regs */
 189         jbsr    syscall_trace_exit
 190         br      ret_from_exception
 191
 192 ENTRY(ret_from_kernel_thread)
 193         jbsr    schedule_tail
 194         mov     a0, r10
 195         jsr     r9
 196         jbsr    ret_from_exception
 197
 198 ENTRY(ret_from_fork)
 199         jbsr    schedule_tail
 200         mov     r9, sp
 201         bmaski  r10, THREAD_SHIFT
 202         andn    r9, r10
 203         ldw     r12, (r9, TINFO_FLAGS)
 204         ANDI_R3 r12, (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT)
 205         cmpnei  r12, 0
 206         bf      ret_from_exception
 207         mov     a0, sp                  /* sp = pt_regs pointer */
 208         jbsr    syscall_trace_exit
 209
 210 ret_from_exception:
 211         ld      syscallid, (sp, LSAVE_PSR)
 212         btsti   syscallid, 31
 213         bt      1f
 214
 215         /*
 216          * Load address of current->thread_info, Then get address of task_struct
 217          * Get task_needreshed in task_struct
 218          */
 219         mov     r9, sp
 220         bmaski  r10, THREAD_SHIFT
 221         andn    r9, r10
 222
 223         ldw     r12, (r9, TINFO_FLAGS)
 224         andi    r12, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | _TIF_UPROBE)
 225         cmpnei  r12, 0
 226         bt      exit_work
 227 1:
 228 #ifdef CONFIG_TRACE_IRQFLAGS
 229         ld      r10, (sp, LSAVE_PSR)
 230         btsti   r10, 6
 231         bf      2f
 232         jbsr    trace_hardirqs_on
 233 2:
 234 #endif
 235         RESTORE_ALL
 236
 237 exit_work:
 238         lrw     syscallid, ret_from_exception
 239         mov     lr, syscallid
 240
 241         btsti   r12, TIF_NEED_RESCHED
 242         bt      work_resched
 243
 244         mov     a0, sp
 245         mov     a1, r12
 246         jmpi    do_notify_resume
 247
 248 work_resched:
 249         jmpi    schedule
 250
 251 ENTRY(csky_trap)
 252         SAVE_ALL 0
 253         zero_fp
 254         psrset  ee
 255         mov     a0, sp                 /* Push Stack pointer arg */
 256         jbsr    trap_c                 /* Call C-level trap handler */
 257         jmpi    ret_from_exception
 258
 259 /*
 260  * Prototype from libc for abiv1:
 261  * register unsigned int __result asm("a0");
 262  * asm( "trap 3" :"=r"(__result)::);
 263  */
 264 ENTRY(csky_get_tls)
 265         USPTOKSP
 266
 267         /* increase epc for continue */
 268         mfcr    a0, epc
 269         addi    a0, TRAP0_SIZE
 270         mtcr    a0, epc
 271
 272         /* get current task thread_info with kernel 8K stack */
 273         bmaski  a0, THREAD_SHIFT
 274         not     a0
 275         subi    sp, 1
 276         and     a0, sp
 277         addi    sp, 1
 278
 279         /* get tls */
 280         ldw     a0, (a0, TINFO_TP_VALUE)
 281
 282         KSPTOUSP
 283         rte
 284
 285 ENTRY(csky_irq)
 286         SAVE_ALL 0
 287         zero_fp
 288         psrset  ee
 289
 290 #ifdef CONFIG_TRACE_IRQFLAGS
 291         jbsr    trace_hardirqs_off
 292 #endif
 293
 294 #ifdef CONFIG_PREEMPTION
 295         mov     r9, sp                  /* Get current stack  pointer */
 296         bmaski  r10, THREAD_SHIFT
 297         andn    r9, r10                 /* Get thread_info */
 298
 299         /*
 300          * Get task_struct->stack.preempt_count for current,
 301          * and increase 1.
 302          */
 303         ldw     r12, (r9, TINFO_PREEMPT)
 304         addi    r12, 1
 305         stw     r12, (r9, TINFO_PREEMPT)
 306 #endif
 307
 308         mov     a0, sp
 309         jbsr    csky_do_IRQ
 310
 311 #ifdef CONFIG_PREEMPTION
 312         subi    r12, 1
 313         stw     r12, (r9, TINFO_PREEMPT)
 314         cmpnei  r12, 0
 315         bt      2f
 316         ldw     r12, (r9, TINFO_FLAGS)
 317         btsti   r12, TIF_NEED_RESCHED
 318         bf      2f
 319         jbsr    preempt_schedule_irq    /* irq en/disable is done inside */
 320 #endif
 321 2:
 322         jmpi    ret_from_exception
 323
 324 /*
 325  * a0 =  prev task_struct *
 326  * a1 =  next task_struct *
 327  * a0 =  return next
 328  */
 329 ENTRY(__switch_to)
 330         lrw     a3, TASK_THREAD
 331         addu    a3, a0
 332
 333         mfcr    a2, psr                 /* Save PSR value */
 334         stw     a2, (a3, THREAD_SR)     /* Save PSR in task struct */
 335         bclri   a2, 6                   /* Disable interrupts */
 336         mtcr    a2, psr
 337
 338         SAVE_SWITCH_STACK
 339
 340         stw     sp, (a3, THREAD_KSP)
 341
 342         /* Set up next process to run */
 343         lrw     a3, TASK_THREAD
 344         addu    a3, a1
 345
 346         ldw     sp, (a3, THREAD_KSP)    /* Set next kernel sp */
 347
 348         ldw     a2, (a3, THREAD_SR)     /* Set next PSR */
 349         mtcr    a2, psr
 350
 351 #if  defined(__CSKYABIV2__)
 352         addi    r7, a1, TASK_THREAD_INFO
 353         ldw     tls, (r7, TINFO_TP_VALUE)
 354 #endif
 355
 356         RESTORE_SWITCH_STACK
 357
 358         rts
 359 ENDPROC(__switch_to)