source: mainline/kernel/arch/ia64/src/asm.S@ 849ed54

#
# Copyright (c) 2005 Jakub Jermar
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#
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# modification, are permitted provided that the following conditions
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# - Redistributions of source code must retain the above copyright
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#include <arch/register.h>

.text

/** Copy memory from/to userspace.
 *
 * This memcpy() has been taken from the assembler output of
 * the generic _memcpy() and modified to have the failover part.
 *
 * @param in0 Destination address.
 * @param in1 Source address.
 * @param in2 Number of byte to copy.
 */
.global memcpy
.global memcpy_from_uspace
.global memcpy_to_uspace
.global memcpy_from_uspace_failover_address
.global memcpy_to_uspace_failover_address
memcpy:
memcpy_from_uspace:
memcpy_to_uspace:
        alloc loc0 = ar.pfs, 3, 1, 0, 0

        adds r14 = 7, in1
        mov r2 = ar.lc
        mov r8 = in0 ;;
        and r14 = -8, r14 ;;
        cmp.ne p6, p7 = r14, in1
(p7)    br.cond.dpnt 3f ;;
0:
        cmp.ne p6, p7 = 0, in2
(p7)    br.cond.dpnt 2f ;;
(p6)    adds r14 = -1, in2
(p6)    mov r16 = r0
(p6)    mov r17 = r0 ;;
(p6)    mov ar.lc = r14
1:
        add r14 = r16, in1 
        add r15 = r16, in0
        adds r17 = 1, r17 ;;
        ld1 r14 = [r14]
        mov r16 = r17 ;;
        st1 [r15] = r14
        br.cloop.sptk.few 1b ;;
2:
        mov ar.lc = r2
        mov ar.pfs = loc0
        br.ret.sptk.many rp
3:
        adds r14 = 7, in0 ;;
        and r14 = -8, r14 ;;
        cmp.eq p6, p7 = r14, in0
(p7)    br.cond.dptk 0b
        shr.u r18 = in2, 3 ;;
        cmp.ne p6, p7 = 0, r18
(p7)    br.cond.dpnt 5f ;;
(p6)    adds r14 = -1, r18
(p6)    mov r16 = r0
(p6)    mov r17 = r0 ;;
(p6)    mov ar.lc = r14
4:
        shladd r14 = r16, 3, r0
        adds r16 = 1, r17 ;;
        add r15 = in1, r14
        add r14 = in0, r14
        mov r17 = r16 ;;
        ld8 r15 = [r15] ;;
        st8 [r14] = r15
        br.cloop.sptk.few 4b
5:
        and r15 = 7, in2
        shladd r14 = r18, 3, r0
        mov r16 = r0
        mov r18 = r0 ;;
        cmp.eq p6, p7 = 0, r15
        add in0 = r14, in0
        adds r15 = -1, r15
        add r17 = r14, in1 
(p6)    br.cond.dpnt 2b ;;
        mov ar.lc = r15
6:
        add r14 = r16, r17
        add r15 = r16, in0
        adds r16 = 1, r18 ;;
        ld1 r14 = [r14]
        mov r18 = r16 ;;
        st1 [r15] = r14
        br.cloop.sptk.few 6b ;;
        mov ar.lc = r2
        mov ar.pfs = loc0
        br.ret.sptk.many rp
        
memcpy_from_uspace_failover_address:
memcpy_to_uspace_failover_address:
        mov r8 = r0                     /* return 0 on failure */
        mov ar.pfs = loc0
        br.ret.sptk.many rp

.global memsetb
memsetb:
        br _memsetb

.global memsetw
memsetw:
        br _memsetw

.global cpu_halt
cpu_halt:
        br cpu_halt

.global panic_printf
panic_printf:
        {
                br.call.sptk.many b0=printf
        }
        br halt

/** Switch to userspace - low level code.
 *
 * @param in0 Userspace entry point address.
 * @param in1 Userspace stack pointer address.
 * @param in2 Userspace register stack pointer address.
 * @param in3 Userspace address of thread uspace_arg_t structure.
 * @param in4 Value to be stored in IPSR.
 * @param in5 Value to be stored in RSC.
 */
.global switch_to_userspace
switch_to_userspace:
        alloc loc0 = ar.pfs, 6, 3, 0, 0
        rsm (PSR_IC_MASK | PSR_I_MASK)          /* disable interruption collection and interrupts */
        srlz.d ;;
        srlz.i ;;
        
        mov cr.ipsr = in4
        mov cr.iip = in0
        mov r12 = in1

        xor r1 = r1, r1
        
        /* r2 is defined to hold pcb_ptr - set it to 0 */
        xor r2 = r2, r2
        
        mov loc1 = cr.ifs
        movl loc2 = PFM_MASK ;;
        and loc1 = loc2, loc1 ;;
        mov cr.ifs = loc1 ;;                    /* prevent decrementing BSP by rfi */

        invala
        
        mov loc1 = ar.rsc ;;
        and loc1 = ~3, loc1 ;;                  
        mov ar.rsc = loc1 ;;                    /* put RSE into enforced lazy mode */

        flushrs ;;
        
        mov ar.bspstore = in2 ;;
        mov ar.rsc = in5 ;;
        
        mov r8 = in3
        
        rfi ;;