entry.s

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
 *
 * kernel entry points (interruptions, system call wrappers)
 *  Copyright (C) 1999,2000 Philipp Rumpf 
 *  Copyright (C) 1999 SuSE GmbH Nuernberg 
 *  Copyright (C) 2000 Hewlett-Packard (John Marvin)
 *  Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>
#include <asm/offset.h>

/* we have the following possibilities to act on an interruption:
 *  - handle in assembly and use shadowed registers only
 *  - save registers to kernel stack and handle in assembly or C */


#include <asm/assembly.h>	/* for LDREG/STREG defines */
#include <asm/pgtable.h>
#include <asm/psw.h>
#include <asm/signal.h>
#include <asm/unistd.h>

#ifdef __LP64__
#define FRAME_SIZE	128
#define CMPIB           cmpib,*
#define CMPB            cmpb,*

	.level 2.0w
#else
#define FRAME_SIZE	64
#define CMPIB           cmpib,
#define CMPB            cmpb,

	.level 2.0
#endif

	.import         pa_dbit_lock,data

	/* space_to_prot macro creates a prot id from a space id */

#if (SPACEID_SHIFT) == 0
	.macro  space_to_prot spc prot
	depd,z  \spc,62,31,\prot
	.endm
#else
	.macro  space_to_prot spc prot
	extrd,u \spc,(64 - (SPACEID_SHIFT)),32,\prot
	.endm
#endif

	/* Switch to virtual mapping, trashing only %r1 */
	.macro  virt_map
	rsm     PSW_SM_Q,%r0
	tovirt_r1 %r29
	mfsp	%sr7, %r1
	or,=    %r0,%r1,%r0 /* Only save sr7 in sr3 if sr7 != 0 */
	mtsp	%r1, %sr3
	mtsp	%r0, %sr4
	mtsp	%r0, %sr5
	mtsp	%r0, %sr6
	mtsp	%r0, %sr7
	ldil	L%KERNEL_PSW, %r1
	ldo	R%KERNEL_PSW(%r1), %r1
	mtctl	%r1, %cr22
	mtctl	%r0, %cr17
	mtctl	%r0, %cr17
	ldil	L%4f, %r1
	ldo	R%4f(%r1), %r1
	mtctl	%r1, %cr18
	ldo	4(%r1), %r1
	mtctl	%r1, %cr18
	rfir
	nop
4:
	.endm

	/*
	 * The "get_stack" macros are responsible for determining the
	 * kernel stack value.
	 *
	 * For Faults:
	 *      If sr7 == 0
	 *          Already using a kernel stack, so call the
	 *          get_stack_use_r30 macro to push a pt_regs structure
	 *          on the stack, and store registers there.
	 *      else
	 *          Need to set up a kernel stack, so call the
	 *          get_stack_use_cr30 macro to set up a pointer
	 *          to the pt_regs structure contained within the
	 *          task pointer pointed to by cr30. Set the stack
	 *          pointer to point to the end of the task structure.
	 *
	 * For Interrupts:
	 *      If sr7 == 0
	 *          Already using a kernel stack, check to see if r30
	 *          is already pointing to the per processor interrupt
	 *          stack. If it is, call the get_stack_use_r30 macro
	 *          to push a pt_regs structure on the stack, and store
	 *          registers there. Otherwise, call get_stack_use_cr31
	 *          to get a pointer to the base of the interrupt stack
	 *          and push a pt_regs structure on that stack.
	 *      else
	 *          Need to set up a kernel stack, so call the
	 *          get_stack_use_cr30 macro to set up a pointer
	 *          to the pt_regs structure contained within the
	 *          task pointer pointed to by cr30. Set the stack
	 *          pointer to point to the end of the task structure.
	 *          N.B: We don't use the interrupt stack for the
	 *          first interrupt from userland, because signals/
	 *          resched's are processed when returning to userland,
	 *          and we can sleep in those cases.
	 *
	 * Note that we use shadowed registers for temps until
	 * we can save %r26 and %r29. %r26 is used to preserve
	 * %r8 (a shadowed register) which temporarily contained
	 * either the fault type ("code") or the eirr. We need
	 * to use a non-shadowed register to carry the value over
	 * the rfir in virt_map. We use %r26 since this value winds
	 * up being passed as the argument to either do_cpu_irq_mask
	 * or handle_interruption. %r29 is used to hold a pointer
	 * the register save area, and once again, it needs to
	 * be a non-shadowed register so that it survives the rfir.
	 *
	 * N.B. TASK_SZ_ALGN and PT_SZ_ALGN include space for a stack frame.
	 */

	.macro  get_stack_use_cr30

	/* we save the registers in the task struct */

	mfctl   %cr30, %r1
	tophys  %r1,%r9
	ldo     TASK_REGS(%r9),%r9
	STREG   %r30, PT_GR30(%r9)
	ldo	TASK_SZ_ALGN(%r1), %r30
	STREG   %r29,PT_GR29(%r9)
	STREG   %r26,PT_GR26(%r9)
	copy    %r9,%r29
	.endm

	.macro  get_stack_use_r30

	/* we put a struct pt_regs on the stack and save the registers there */

	tophys  %r30,%r9
	STREG   %r30,PT_GR30(%r9)
	ldo	PT_SZ_ALGN(%r30),%r30
	STREG   %r29,PT_GR29(%r9)
	STREG   %r26,PT_GR26(%r9)
	copy    %r9,%r29
	.endm

	.macro  rest_stack
	LDREG   PT_GR1(%r29), %r1
	LDREG   PT_GR30(%r29),%r30
	LDREG   PT_GR29(%r29),%r29
	.endm

	/* default interruption handler
	 * (calls traps.c:handle_interruption) */
	.macro	def code
	b	intr_save
	ldi     \code, %r8
	.align	32
	.endm

	/* Interrupt interruption handler
	 * (calls irq.c:do_cpu_irq_mask) */
	.macro	extint code
	b	intr_extint
	mfsp    %sr7,%r16
	.align	32
	.endm	

	.import	os_hpmc, code

	/* HPMC handler */
	.macro	hpmc code
	nop			/* must be a NOP, will be patched later */
	ldil	L%PA(os_hpmc), %r3
	ldo	R%PA(os_hpmc)(%r3), %r3
	bv,n	0(%r3)
	nop
	.word	0		/* checksum (will be patched) */
	.word	PA(os_hpmc)	/* address of handler */
	.word	0		/* length of handler */
	.endm

	/*
	 * Performance Note: Instructions will be moved up into
	 * this part of the code later on, once we are sure
	 * that the tlb miss handlers are close to final form.
	 */

	/* Register definitions for tlb miss handler macros */

	va  = r8	/* virtual address for which the trap occured */
	spc = r24	/* space for which the trap occured */

#ifndef __LP64__

	/*
	 * itlb miss interruption handler (parisc 1.1 - 32 bit)
	 */

	.macro	itlb_11 code

	mfctl	%pcsq, spc
	b	itlb_miss_11
	mfctl	%pcoq, va

	.align		32
	.endm
#endif
	
	/*
	 * itlb miss interruption handler (parisc 2.0)
	 */

	.macro	itlb_20 code
	mfctl	%pcsq, spc
#ifdef __LP64__
	b       itlb_miss_20w
#else
	b	itlb_miss_20
#endif
	mfctl	%pcoq, va

	.align		32
	.endm
	
#ifndef __LP64__
	/*
	 * naitlb miss interruption handler (parisc 1.1 - 32 bit)
	 *
	 * Note: naitlb misses will be treated
	 * as an ordinary itlb miss for now.
	 * However, note that naitlb misses
	 * have the faulting address in the
	 * IOR/ISR.
	 */

	.macro	naitlb_11 code

	mfctl	%isr,spc
	b	itlb_miss_11
	mfctl 	%ior,va
	/* FIXME: If user causes a naitlb miss, the priv level may not be in
	 * lower bits of va, where the itlb miss handler is expecting them
	 */

	.align		32
	.endm
#endif
	
	/*
	 * naitlb miss interruption handler (parisc 2.0)
	 *
	 * Note: naitlb misses will be treated
	 * as an ordinary itlb miss for now.
	 * However, note that naitlb misses
	 * have the faulting address in the
	 * IOR/ISR.
	 */

	.macro	naitlb_20 code

	mfctl	%isr,spc
#ifdef __LP64__
	b       itlb_miss_20w
#else
	b	itlb_miss_20
#endif
	mfctl 	%ior,va
	/* FIXME: If user causes a naitlb miss, the priv level may not be in
	 * lower bits of va, where the itlb miss handler is expecting them
	 */

	.align		32
	.endm
	
#ifndef __LP64__
	/*
	 * dtlb miss interruption handler (parisc 1.1 - 32 bit)
	 */

	.macro	dtlb_11 code

	mfctl	%isr, spc
	b	dtlb_miss_11
	mfctl	%ior, va

	.align		32
	.endm
#endif

	/*
	 * dtlb miss interruption handler (parisc 2.0)
	 */

	.macro	dtlb_20 code

	mfctl	%isr, spc
#ifdef __LP64__
	b       dtlb_miss_20w
#else
	b	dtlb_miss_20
#endif
	mfctl	%ior, va

	.align		32
	.endm
	
#ifndef __LP64__
	/* nadtlb miss interruption handler (parisc 1.1 - 32 bit) */

	.macro	nadtlb_11 code

	mfctl	%isr,spc
	b       nadtlb_miss_11
	mfctl	%ior,va

	.align		32
	.endm
#endif
	
	/* nadtlb miss interruption handler (parisc 2.0) */

	.macro	nadtlb_20 code

	mfctl	%isr,spc
#ifdef __LP64__
	b       nadtlb_miss_20w
#else
	b       nadtlb_miss_20
#endif
	mfctl	%ior,va

	.align		32
	.endm
	
#ifndef __LP64__
	/*
	 * dirty bit trap interruption handler (parisc 1.1 - 32 bit)
	 */

	.macro	dbit_11 code

	mfctl	%isr,spc
	b	dbit_trap_11
	mfctl	%ior,va

	.align		32
	.endm
#endif

	/*
	 * dirty bit trap interruption handler (parisc 2.0)
	 */

	.macro	dbit_20 code

	mfctl	%isr,spc
#ifdef __LP64__
	b       dbit_trap_20w
#else
	b	dbit_trap_20
#endif
	mfctl	%ior,va

	.align		32
	.endm

	/*
	 * Align fault_vector_20 on 4K boundary so that both
	 * fault_vector_11 and fault_vector_20 are on the
	 * same page. This is only necessary as long as we
	 * write protect the kernel text, which we may stop
	 * doing once we use large page translations to cover
	 * the static part of the kernel address space.
	 */

	.export fault_vector_20

	.text

	.align 4096

fault_vector_20:
	/* First vector is invalid (0) */
	.ascii	"cows can fly"
	.byte 0
	.align 32

	hpmc		 1
	def		 2
	def		 3
	extint		 4
	def		 5
	itlb_20		 6
	def		 7
	def		 8
	def              9
	def		10
	def		11
	def		12
	def		13
	def		14
	dtlb_20		15
#if 0
	naitlb_20	16
#else
	def             16
#endif
	nadtlb_20	17
	def		18
	def		19
	dbit_20		20
	def		21
	def		22
	def		23
	def		24
	def		25
	def		26
	def		27
	def		28
	def		29
	def		30
	def		31

#ifndef __LP64__

	.export fault_vector_11
	
	.align 2048

fault_vector_11:
	/* First vector is invalid (0) */
	.ascii	"cows can fly"
	.byte 0
	.align 32

	hpmc		 1
	def		 2
	def		 3
	extint		 4
	def		 5
	itlb_11		 6
	def		 7
	def		 8
	def              9
	def		10
	def		11
	def		12
	def		13
	def		14
	dtlb_11		15
#if 0
	naitlb_11	16
#else
	def             16
#endif
	nadtlb_11	17
	def		18
	def		19
	dbit_11		20
	def		21
	def		22
	def		23
	def		24
	def		25
	def		26
	def		27
	def		28
	def		29
	def		30
	def		31

#endif

	.import		handle_interruption,code
	.import		handle_real_interruption,code
	.import		do_cpu_irq_mask,code
	.import		parisc_stopkernel,code

	/*
	 * r26 = function to be called
	 * r25 = argument to pass in
	 * r24 = flags for do_fork()
	 *
	 * Kernel threads don't ever return, so they don't need
	 * a true register context. We just save away the arguments
	 * for copy_thread/ret_ to properly set up the child.
	 */