111 lines
2.2 KiB
ArmAsm
111 lines
2.2 KiB
ArmAsm
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/* bitops.S: Low level assembler bit operations.
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*
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* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
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*/
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#include <linux/config.h>
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#include <asm/ptrace.h>
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#include <asm/psr.h>
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.text
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.align 4
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.globl __bitops_begin
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__bitops_begin:
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/* Take bits in %g2 and set them in word at %g1,
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* return whether bits were set in original value
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* in %g2. %g4 holds value to restore into %o7
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* in delay slot of jmpl return, %g3 + %g5 + %g7 can be
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* used as temporaries and thus is considered clobbered
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* by all callers.
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*/
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.globl ___set_bit
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___set_bit:
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rd %psr, %g3
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nop; nop; nop;
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or %g3, PSR_PIL, %g5
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wr %g5, 0x0, %psr
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nop; nop; nop
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#ifdef CONFIG_SMP
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set bitops_spinlock, %g5
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2: ldstub [%g5], %g7 ! Spin on the byte lock for SMP.
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orcc %g7, 0x0, %g0 ! Did we get it?
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bne 2b ! Nope...
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#endif
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ld [%g1], %g7
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or %g7, %g2, %g5
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and %g7, %g2, %g2
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#ifdef CONFIG_SMP
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st %g5, [%g1]
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set bitops_spinlock, %g5
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stb %g0, [%g5]
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#else
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st %g5, [%g1]
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#endif
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wr %g3, 0x0, %psr
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nop; nop; nop
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jmpl %o7, %g0
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mov %g4, %o7
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/* Same as above, but clears the bits from %g2 instead. */
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.globl ___clear_bit
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___clear_bit:
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rd %psr, %g3
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nop; nop; nop
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or %g3, PSR_PIL, %g5
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wr %g5, 0x0, %psr
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nop; nop; nop
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#ifdef CONFIG_SMP
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set bitops_spinlock, %g5
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2: ldstub [%g5], %g7 ! Spin on the byte lock for SMP.
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orcc %g7, 0x0, %g0 ! Did we get it?
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bne 2b ! Nope...
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#endif
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ld [%g1], %g7
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andn %g7, %g2, %g5
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and %g7, %g2, %g2
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#ifdef CONFIG_SMP
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st %g5, [%g1]
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set bitops_spinlock, %g5
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stb %g0, [%g5]
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#else
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st %g5, [%g1]
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#endif
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wr %g3, 0x0, %psr
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nop; nop; nop
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jmpl %o7, %g0
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mov %g4, %o7
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/* Same thing again, but this time toggles the bits from %g2. */
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.globl ___change_bit
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___change_bit:
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rd %psr, %g3
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nop; nop; nop
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or %g3, PSR_PIL, %g5
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wr %g5, 0x0, %psr
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nop; nop; nop
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#ifdef CONFIG_SMP
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set bitops_spinlock, %g5
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2: ldstub [%g5], %g7 ! Spin on the byte lock for SMP.
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orcc %g7, 0x0, %g0 ! Did we get it?
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bne 2b ! Nope...
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#endif
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ld [%g1], %g7
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xor %g7, %g2, %g5
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and %g7, %g2, %g2
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#ifdef CONFIG_SMP
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st %g5, [%g1]
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set bitops_spinlock, %g5
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stb %g0, [%g5]
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#else
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st %g5, [%g1]
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#endif
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wr %g3, 0x0, %psr
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nop; nop; nop
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jmpl %o7, %g0
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mov %g4, %o7
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.globl __bitops_end
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__bitops_end:
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