ivt.s

优龙2410linux2.6.8内核源代码

	/*
	 * There is no particular reason for this code to be here, other than that
	 * there happens to be space here that would go unused otherwise.  If this
	 * fault ever gets "unreserved", simply moved the following code to a more
	 * suitable spot...
	 *
	 * ia64_syscall_setup() is a separate subroutine so that it can
	 *	allocate stacked registers so it can safely demine any
	 *	potential NaT values from the input registers.
	 *
	 * On entry:
	 *	- executing on bank 0 or bank 1 register set (doesn't matter)
	 *	-  r1: stack pointer
	 *	-  r2: current task pointer
	 *	-  r3: preserved
	 *	- r11: original contents (saved ar.pfs to be saved)
	 *	- r12: original contents (sp to be saved)
	 *	- r13: original contents (tp to be saved)
	 *	- r15: original contents (syscall # to be saved)
	 *	- r18: saved bsp (after switching to kernel stack)
	 *	- r19: saved b6
	 *	- r20: saved r1 (gp)
	 *	- r21: saved ar.fpsr
	 *	- r22: kernel's register backing store base (krbs_base)
	 *	- r23: saved ar.bspstore
	 *	- r24: saved ar.rnat
	 *	- r25: saved ar.unat
	 *	- r26: saved ar.pfs
	 *	- r27: saved ar.rsc
	 *	- r28: saved cr.iip
	 *	- r29: saved cr.ipsr
	 *	- r31: saved pr
	 *	-  b0: original contents (to be saved)
	 * On exit:
	 *	- executing on bank 1 registers
	 *	- psr.ic enabled, interrupts restored
	 *	-  r1: kernel's gp
	 *	-  r3: preserved (same as on entry)
	 *	- r12: points to kernel stack
	 *	- r13: points to current task
	 *	- p15: TRUE if interrupts need to be re-enabled
	 *	- ar.fpsr: set to kernel settings
	 */
GLOBAL_ENTRY(ia64_syscall_setup)
#if PT(B6) != 0
# error This code assumes that b6 is the first field in pt_regs.
#endif
	st8 [r1]=r19				// save b6
	add r16=PT(CR_IPSR),r1			// initialize first base pointer
	add r17=PT(R11),r1			// initialize second base pointer
	;;
	alloc r19=ar.pfs,8,0,0,0		// ensure in0-in7 are writable
	st8 [r16]=r29,PT(CR_IFS)-PT(CR_IPSR)	// save cr.ipsr
	tnat.nz p8,p0=in0

	st8.spill [r17]=r11,PT(CR_IIP)-PT(R11)	// save r11
	tnat.nz p9,p0=in1
(pKStk)	mov r18=r0				// make sure r18 isn't NaT
	;;

	st8 [r17]=r28,PT(AR_UNAT)-PT(CR_IIP)	// save cr.iip
	mov r28=b0				// save b0 (2 cyc)
(p8)	mov in0=-1
	;;

	st8 [r16]=r0,PT(AR_PFS)-PT(CR_IFS)	// clear cr.ifs
	st8 [r17]=r25,PT(AR_RSC)-PT(AR_UNAT)	// save ar.unat
(p9)	mov in1=-1
	;;

	st8 [r16]=r26,PT(AR_RNAT)-PT(AR_PFS)	// save ar.pfs
	st8 [r17]=r27,PT(AR_BSPSTORE)-PT(AR_RSC)// save ar.rsc
	tnat.nz p10,p0=in2

(pUStk) sub r18=r18,r22				// r18=RSE.ndirty*8
	tbit.nz p15,p0=r29,IA64_PSR_I_BIT
	tnat.nz p11,p0=in3
	;;
(pKStk) adds r16=PT(PR)-PT(AR_RNAT),r16		// skip over ar_rnat field
(pKStk) adds r17=PT(B0)-PT(AR_BSPSTORE),r17	// skip over ar_bspstore field
(p10)	mov in2=-1

(p11)	mov in3=-1
	tnat.nz p12,p0=in4
	tnat.nz p13,p0=in5
	;;
(pUStk) st8 [r16]=r24,PT(PR)-PT(AR_RNAT)	// save ar.rnat
(pUStk) st8 [r17]=r23,PT(B0)-PT(AR_BSPSTORE)	// save ar.bspstore
	shl r18=r18,16				// compute ar.rsc to be used for "loadrs"
	;;
	st8 [r16]=r31,PT(LOADRS)-PT(PR)		// save predicates
	st8 [r17]=r28,PT(R1)-PT(B0)		// save b0
(p12)	mov in4=-1
	;;
	st8 [r16]=r18,PT(R12)-PT(LOADRS)	// save ar.rsc value for "loadrs"
	st8.spill [r17]=r20,PT(R13)-PT(R1)	// save original r1
(p13)	mov in5=-1
	;;

.mem.offset 0,0; st8.spill [r16]=r12,PT(AR_FPSR)-PT(R12)	// save r12
.mem.offset 8,0; st8.spill [r17]=r13,PT(R15)-PT(R13)		// save r13
	tnat.nz p14,p0=in6
	;;
	st8 [r16]=r21,PT(R8)-PT(AR_FPSR)	// save ar.fpsr
	st8.spill [r17]=r15			// save r15
	tnat.nz p8,p0=in7
	;;
	stf8 [r16]=f1		// ensure pt_regs.r8 != 0 (see handle_syscall_error)
	adds r12=-16,r1		// switch to kernel memory stack (with 16 bytes of scratch)
(p14)	mov in6=-1

	mov r13=r2				// establish `current'
	movl r1=__gp				// establish kernel global pointer
	;;
(p8)	mov in7=-1
	tnat.nz p9,p0=r15

	cmp.eq pSys,pNonSys=r0,r0		// set pSys=1, pNonSys=0
	movl r17=FPSR_DEFAULT
	;;
	mov.m ar.fpsr=r17			// set ar.fpsr to kernel default value
(p9)	mov r15=-1
	br.ret.sptk.many b7
END(ia64_syscall_setup)

	.org ia64_ivt+0x3c00
/////////////////////////////////////////////////////////////////////////////////////////
// 0x3c00 Entry 15 (size 64 bundles) Reserved
	DBG_FAULT(15)
	FAULT(15)

	/*
	 * Squatting in this space ...
	 *
	 * This special case dispatcher for illegal operation faults allows preserved
	 * registers to be modified through a callback function (asm only) that is handed
	 * back from the fault handler in r8. Up to three arguments can be passed to the
	 * callback function by returning an aggregate with the callback as its first
	 * element, followed by the arguments.
	 */
ENTRY(dispatch_illegal_op_fault)
	SAVE_MIN_WITH_COVER
	ssm psr.ic | PSR_DEFAULT_BITS
	;;
	srlz.i		// guarantee that interruption collection is on
	;;
(p15)	ssm psr.i	// restore psr.i
	adds r3=8,r2	// set up second base pointer for SAVE_REST
	;;
	alloc r14=ar.pfs,0,0,1,0	// must be first in insn group
	mov out0=ar.ec
	;;
	SAVE_REST
	;;
	br.call.sptk.many rp=ia64_illegal_op_fault
.ret0:	;;
	alloc r14=ar.pfs,0,0,3,0	// must be first in insn group
	mov out0=r9
	mov out1=r10
	mov out2=r11
	movl r15=ia64_leave_kernel
	;;
	mov rp=r15
	mov b6=r8
	;;
	cmp.ne p6,p0=0,r8
(p6)	br.call.dpnt.many b6=b6		// call returns to ia64_leave_kernel
	br.sptk.many ia64_leave_kernel
END(dispatch_illegal_op_fault)

	.org ia64_ivt+0x4000
/////////////////////////////////////////////////////////////////////////////////////////
// 0x4000 Entry 16 (size 64 bundles) Reserved
	DBG_FAULT(16)
	FAULT(16)

	.org ia64_ivt+0x4400
/////////////////////////////////////////////////////////////////////////////////////////
// 0x4400 Entry 17 (size 64 bundles) Reserved
	DBG_FAULT(17)
	FAULT(17)

ENTRY(non_syscall)
	SAVE_MIN_WITH_COVER

	// There is no particular reason for this code to be here, other than that
	// there happens to be space here that would go unused otherwise.  If this
	// fault ever gets "unreserved", simply moved the following code to a more
	// suitable spot...

	alloc r14=ar.pfs,0,0,2,0
	mov out0=cr.iim
	add out1=16,sp
	adds r3=8,r2			// set up second base pointer for SAVE_REST

	ssm psr.ic | PSR_DEFAULT_BITS
	;;
	srlz.i				// guarantee that interruption collection is on
	;;
(p15)	ssm psr.i			// restore psr.i
	movl r15=ia64_leave_kernel
	;;
	SAVE_REST
	mov rp=r15
	;;
	br.call.sptk.many b6=ia64_bad_break	// avoid WAW on CFM and ignore return addr
END(non_syscall)

	.org ia64_ivt+0x4800
/////////////////////////////////////////////////////////////////////////////////////////
// 0x4800 Entry 18 (size 64 bundles) Reserved
	DBG_FAULT(18)
	FAULT(18)

	/*
	 * There is no particular reason for this code to be here, other than that
	 * there happens to be space here that would go unused otherwise.  If this
	 * fault ever gets "unreserved", simply moved the following code to a more
	 * suitable spot...
	 */

ENTRY(dispatch_unaligned_handler)
	SAVE_MIN_WITH_COVER
	;;
	alloc r14=ar.pfs,0,0,2,0		// now it's safe (must be first in insn group!)
	mov out0=cr.ifa
	adds out1=16,sp

	ssm psr.ic | PSR_DEFAULT_BITS
	;;
	srlz.i					// guarantee that interruption collection is on
	;;
(p15)	ssm psr.i				// restore psr.i
	adds r3=8,r2				// set up second base pointer
	;;
	SAVE_REST
	movl r14=ia64_leave_kernel
	;;
	mov rp=r14
	br.sptk.many ia64_prepare_handle_unaligned
END(dispatch_unaligned_handler)

	.org ia64_ivt+0x4c00
/////////////////////////////////////////////////////////////////////////////////////////
// 0x4c00 Entry 19 (size 64 bundles) Reserved
	DBG_FAULT(19)
	FAULT(19)

	/*
	 * There is no particular reason for this code to be here, other than that
	 * there happens to be space here that would go unused otherwise.  If this
	 * fault ever gets "unreserved", simply moved the following code to a more
	 * suitable spot...
	 */

ENTRY(dispatch_to_fault_handler)
	/*
	 * Input:
	 *	psr.ic:	off
	 *	r19:	fault vector number (e.g., 24 for General Exception)
	 *	r31:	contains saved predicates (pr)
	 */
	SAVE_MIN_WITH_COVER_R19
	alloc r14=ar.pfs,0,0,5,0
	mov out0=r15
	mov out1=cr.isr
	mov out2=cr.ifa
	mov out3=cr.iim
	mov out4=cr.itir
	;;
	ssm psr.ic | PSR_DEFAULT_BITS
	;;
	srlz.i					// guarantee that interruption collection is on
	;;
(p15)	ssm psr.i				// restore psr.i
	adds r3=8,r2				// set up second base pointer for SAVE_REST
	;;
	SAVE_REST
	movl r14=ia64_leave_kernel
	;;
	mov rp=r14
	br.call.sptk.many b6=ia64_fault
END(dispatch_to_fault_handler)

//
// --- End of long entries, Beginning of short entries
//

	.org ia64_ivt+0x5000
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5000 Entry 20 (size 16 bundles) Page Not Present (10,22,49)
ENTRY(page_not_present)
	DBG_FAULT(20)
	mov r16=cr.ifa
	rsm psr.dt
	/*
	 * The Linux page fault handler doesn't expect non-present pages to be in
	 * the TLB.  Flush the existing entry now, so we meet that expectation.
	 */
	mov r17=PAGE_SHIFT<<2
	;;
	ptc.l r16,r17
	;;
	mov r31=pr
	srlz.d
	br.sptk.many page_fault
END(page_not_present)

	.org ia64_ivt+0x5100
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5100 Entry 21 (size 16 bundles) Key Permission (13,25,52)
ENTRY(key_permission)
	DBG_FAULT(21)
	mov r16=cr.ifa
	rsm psr.dt
	mov r31=pr
	;;
	srlz.d
	br.sptk.many page_fault
END(key_permission)

	.org ia64_ivt+0x5200
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5200 Entry 22 (size 16 bundles) Instruction Access Rights (26)
ENTRY(iaccess_rights)
	DBG_FAULT(22)
	mov r16=cr.ifa
	rsm psr.dt
	mov r31=pr
	;;
	srlz.d
	br.sptk.many page_fault
END(iaccess_rights)

	.org ia64_ivt+0x5300
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5300 Entry 23 (size 16 bundles) Data Access Rights (14,53)
ENTRY(daccess_rights)
	DBG_FAULT(23)
	mov r16=cr.ifa
	rsm psr.dt
	mov r31=pr
	;;
	srlz.d
	br.sptk.many page_fault
END(daccess_rights)

	.org ia64_ivt+0x5400
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5400 Entry 24 (size 16 bundles) General Exception (5,32,34,36,38,39)
ENTRY(general_exception)
	DBG_FAULT(24)
	mov r16=cr.isr
	mov r31=pr
	;;
	cmp4.eq p6,p0=0,r16
(p6)	br.sptk.many dispatch_illegal_op_fault
	;;
	mov r19=24		// fault number
	br.sptk.many dispatch_to_fault_handler
END(general_exception)

	.org ia64_ivt+0x5500
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5500 Entry 25 (size 16 bundles) Disabled FP-Register (35)
ENTRY(disabled_fp_reg)
	DBG_FAULT(25)
	rsm psr.dfh		// ensure we can access fph
	;;
	srlz.d
	mov r31=pr
	mov r19=25
	br.sptk.many dispatch_to_fault_handler
END(disabled_fp_reg)

	.org ia64_ivt+0x5600
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5600 Entry 26 (size 16 bundles) Nat Consumption (11,23,37,50)
ENTRY(nat_consumption)
	DBG_FAULT(26)
	FAULT(26)
END(nat_consumption)

	.org ia64_ivt+0x5700
/////////////////////////////////////////////////////////////////////////////////////////
// 0x5700 Entry 27 (size 16 bundles) Speculation (40)
ENTRY(speculation_vector)
	DBG_FAULT(27)
	/*
	 * A [f]chk.[as] instruction needs to take the branch to the recovery code but
	 * this part of the architecture is not implemented in hardware on some CPUs, such
	 * as Itanium.  Thus, in general we need to emulate the behavior.  IIM contains
	 * the relative target (not yet sign extended).  So after sign extending it we
	 * simply add it to IIP.  We also need to reset the EI field of the IPSR to zero,
	 * i.e., the slot to restart into.
	 *
	 * cr.imm contains zero_ext(imm21)
	 */
	mov r18=cr.iim
	;;
	mov r17=cr.iip