arch/parisc/kernel/real2.S

   1 /*
   2  *
   3  * This file is subject to the terms and conditions of the GNU General Public
   4  * License.  See the file "COPYING" in the main directory of this archive
   5  * for more details.
   6  *
   7  * Copyright (C) 2000 Hewlett Packard (Paul Bame bame@puffin.external.hp.com)
   8  *
   9  */
  10
  11 #include <asm/pdc.h>
  12 #include <asm/psw.h>
  13 #include <asm/assembly.h>
  14 #include <asm/asm-offsets.h>
  15
  16 #include <linux/linkage.h>
  17
  18
  19         .section        .bss
  20
  21         .export pdc_result
  22         .export pdc_result2
  23         .align 8
  24 pdc_result:
  25         .block  ASM_PDC_RESULT_SIZE
  26 pdc_result2:
  27         .block  ASM_PDC_RESULT_SIZE
  28
  29         .export real_stack
  30         .export real32_stack
  31         .export real64_stack
  32         .align  64
  33 real_stack:
  34 real32_stack:
  35 real64_stack:
  36         .block  8192
  37
  38 #ifdef CONFIG_64BIT
  39 #  define REG_SZ 8
  40 #else
  41 #  define REG_SZ 4
  42 #endif
  43
  44 #define N_SAVED_REGS 9
  45
  46 save_cr_space:
  47         .block  REG_SZ * N_SAVED_REGS
  48 save_cr_end:
  49
  50
  51 /************************ 32-bit real-mode calls ***********************/
  52 /* This can be called in both narrow and wide kernels */
  53
  54         .text
  55
  56         /* unsigned long real32_call_asm(unsigned int *sp,
  57          *              unsigned int *arg0p,
  58          *              unsigned int iodc_fn)
  59          *      sp is value of stack pointer to adopt before calling PDC (virt)
  60          *      arg0p points to where saved arg values may be found
  61          *      iodc_fn is the IODC function to call
  62          */
  63
  64 ENTRY(real32_call_asm)
  65         STREG   %rp, -RP_OFFSET(%sp)    /* save RP */
  66 #ifdef CONFIG_64BIT
  67         callee_save
  68         ldo     2*REG_SZ(%sp), %sp      /* room for a couple more saves */
  69         STREG   %r27, -1*REG_SZ(%sp)
  70         STREG   %r29, -2*REG_SZ(%sp)
  71 #endif
  72         STREG   %sp, -REG_SZ(%arg0)     /* save SP on real-mode stack */
  73         copy    %arg0, %sp              /* adopt the real-mode SP */
  74
  75         /* save iodc_fn */
  76         copy    %arg2, %r31
  77
  78         /* load up the arg registers from the saved arg area */
  79         /* 32-bit calling convention passes first 4 args in registers */
  80         ldw     0(%arg1), %arg0         /* note overwriting arg0 */
  81         ldw     -8(%arg1), %arg2
  82         ldw     -12(%arg1), %arg3
  83         ldw     -4(%arg1), %arg1        /* obviously must do this one last! */
  84
  85         tophys_r1  %sp
  86
  87         b,l     rfi_virt2real,%r2
  88         nop
  89
  90         b,l     save_control_regs,%r2           /* modifies r1, r2, r28 */
  91         nop
  92
  93 #ifdef CONFIG_64BIT
  94         rsm     PSW_SM_W, %r0           /* go narrow */
  95 #endif
  96
  97         load32  PA(ric_ret), %r2
  98         bv      0(%r31)
  99         nop
 100 ric_ret:
 101 #ifdef CONFIG_64BIT
 102         ssm     PSW_SM_W, %r0           /* go wide */
 103 #endif
 104         /* restore CRs before going virtual in case we page fault */
 105         b,l     restore_control_regs, %r2       /* modifies r1, r2, r26 */
 106         nop
 107
 108         b,l     rfi_real2virt,%r2
 109         nop
 110
 111         tovirt_r1 %sp
 112         LDREG   -REG_SZ(%sp), %sp       /* restore SP */
 113 #ifdef CONFIG_64BIT
 114         LDREG   -1*REG_SZ(%sp), %r27
 115         LDREG   -2*REG_SZ(%sp), %r29
 116         ldo     -2*REG_SZ(%sp), %sp
 117         callee_rest
 118 #endif
 119         LDREG   -RP_OFFSET(%sp), %rp    /* restore RP */
 120         bv      0(%rp)
 121         nop
 122 ENDPROC(real32_call_asm)
 123
 124
 125 #  define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
 126 #  define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r
 127
 128         .text
 129 save_control_regs:
 130         load32  PA(save_cr_space), %r28
 131         PUSH_CR(%cr24, %r28)
 132         PUSH_CR(%cr25, %r28)
 133         PUSH_CR(%cr26, %r28)
 134         PUSH_CR(%cr27, %r28)
 135         PUSH_CR(%cr28, %r28)
 136         PUSH_CR(%cr29, %r28)
 137         PUSH_CR(%cr30, %r28)
 138         PUSH_CR(%cr31, %r28)
 139         PUSH_CR(%cr15, %r28)
 140         bv 0(%r2)
 141         nop
 142
 143 restore_control_regs:
 144         load32  PA(save_cr_end), %r26
 145         POP_CR(%cr15, %r26)
 146         POP_CR(%cr31, %r26)
 147         POP_CR(%cr30, %r26)
 148         POP_CR(%cr29, %r26)
 149         POP_CR(%cr28, %r26)
 150         POP_CR(%cr27, %r26)
 151         POP_CR(%cr26, %r26)
 152         POP_CR(%cr25, %r26)
 153         POP_CR(%cr24, %r26)
 154         bv 0(%r2)
 155         nop
 156
 157 /* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
 158  * more general-purpose use by the several places which need RFIs
 159  */
 160         .text
 161         .align 128
 162 rfi_virt2real:
 163         /* switch to real mode... */
 164         rsm             PSW_SM_I,%r0
 165         load32          PA(rfi_v2r_1), %r1
 166         nop
 167         nop
 168         nop
 169         nop
 170         nop
 171
 172         rsm             PSW_SM_Q,%r0  /* disable Q & I bits to load iia queue */
 173         mtctl           %r0, %cr17      /* Clear IIASQ tail */
 174         mtctl           %r0, %cr17      /* Clear IIASQ head */
 175         mtctl           %r1, %cr18      /* IIAOQ head */
 176         ldo             4(%r1), %r1
 177         mtctl           %r1, %cr18      /* IIAOQ tail */
 178         load32          REAL_MODE_PSW, %r1
 179         mtctl           %r1, %cr22
 180         rfi
 181
 182         nop
 183         nop
 184         nop
 185         nop
 186         nop
 187         nop
 188         nop
 189         nop
 190 rfi_v2r_1:
 191         tophys_r1 %r2
 192         bv      0(%r2)
 193         nop
 194
 195         .text
 196         .align 128
 197 rfi_real2virt:
 198         rsm             PSW_SM_I,%r0
 199         load32          (rfi_r2v_1), %r1
 200         nop
 201         nop
 202         nop
 203         nop
 204         nop
 205
 206         rsm             PSW_SM_Q,%r0    /* disable Q bit to load iia queue */
 207         mtctl           %r0, %cr17      /* Clear IIASQ tail */
 208         mtctl           %r0, %cr17      /* Clear IIASQ head */
 209         mtctl           %r1, %cr18      /* IIAOQ head */
 210         ldo             4(%r1), %r1
 211         mtctl           %r1, %cr18      /* IIAOQ tail */
 212         load32          KERNEL_PSW, %r1
 213         mtctl           %r1, %cr22
 214         rfi
 215
 216         nop
 217         nop
 218         nop
 219         nop
 220         nop
 221         nop
 222         nop
 223         nop
 224 rfi_r2v_1:
 225         tovirt_r1 %r2
 226         bv      0(%r2)
 227         nop
 228
 229 #ifdef CONFIG_64BIT
 230
 231 /************************ 64-bit real-mode calls ***********************/
 232 /* This is only usable in wide kernels right now and will probably stay so */
 233         .text
 234         /* unsigned long real64_call_asm(unsigned long *sp,
 235          *              unsigned long *arg0p,
 236          *              unsigned long fn)
 237          *      sp is value of stack pointer to adopt before calling PDC (virt)
 238          *      arg0p points to where saved arg values may be found
 239          *      iodc_fn is the IODC function to call
 240          */
 241 ENTRY(real64_call_asm)
 242         std     %rp, -0x10(%sp)         /* save RP */
 243         std     %sp, -8(%arg0)          /* save SP on real-mode stack */
 244         copy    %arg0, %sp              /* adopt the real-mode SP */
 245
 246         /* save fn */
 247         copy    %arg2, %r31
 248
 249         /* set up the new ap */
 250         ldo     64(%arg1), %r29
 251
 252         /* load up the arg registers from the saved arg area */
 253         /* 32-bit calling convention passes first 4 args in registers */
 254         ldd     0*REG_SZ(%arg1), %arg0          /* note overwriting arg0 */
 255         ldd     2*REG_SZ(%arg1), %arg2
 256         ldd     3*REG_SZ(%arg1), %arg3
 257         ldd     4*REG_SZ(%arg1), %r22
 258         ldd     5*REG_SZ(%arg1), %r21
 259         ldd     6*REG_SZ(%arg1), %r20
 260         ldd     7*REG_SZ(%arg1), %r19
 261         ldd     1*REG_SZ(%arg1), %arg1          /* do this one last! */
 262
 263         tophys_r1 %sp
 264
 265         b,l     rfi_virt2real,%r2
 266         nop
 267
 268         b,l     save_control_regs,%r2           /* modifies r1, r2, r28 */
 269         nop
 270
 271         load32  PA(r64_ret), %r2
 272         bv      0(%r31)
 273         nop
 274 r64_ret:
 275         /* restore CRs before going virtual in case we page fault */
 276         b,l     restore_control_regs, %r2       /* modifies r1, r2, r26 */
 277         nop
 278
 279         b,l     rfi_real2virt,%r2
 280         nop
 281
 282         tovirt_r1 %sp
 283         ldd     -8(%sp), %sp            /* restore SP */
 284         ldd     -0x10(%sp), %rp         /* restore RP */
 285         bv      0(%rp)
 286         nop
 287 ENDPROC(real64_call_asm)
 288
 289 #endif
 290
 291         .text
 292         /* http://lists.parisc-linux.org/hypermail/parisc-linux/10916.html
 293         **      GCC 3.3 and later has a new function in libgcc.a for
 294         **      comparing function pointers.
 295         */
 296 ENTRY(__canonicalize_funcptr_for_compare)
 297 #ifdef CONFIG_64BIT
 298         bve (%r2)
 299 #else
 300         bv %r0(%r2)
 301 #endif
 302         copy %r26,%r28
 303 ENDPROC(__canonicalize_funcptr_for_compare)
 304