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kernel-fxtec-pro1x/arch/ia64/kernel/minstate.h
David Mosberger-Tang 966dc11fcc [IA64] Fix stack placement when INIT hits in kernel mode. 
Without this patch, the stack is placed _below_ the current task
structure, which is risky at best.

Tony, I think this patch needs to go into 2.6.12, since it fixes a
real bug.  Without it, INIT may case secondary errors, which would be
most unpleasant.

Signed-off-by: David Mosberger-Tang <davidm@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-05-06 10:16:07 -07:00

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#include <linux/config.h>
#include <asm/cache.h>
#include "entry.h"
/*
* For ivt.s we want to access the stack virtually so we don't have to disable translation
* on interrupts.
*
* On entry:
* r1: pointer to current task (ar.k6)
*/
#define MINSTATE_START_SAVE_MIN_VIRT \
(pUStk) mov ar.rsc=0; /* set enforced lazy mode, pl 0, little-endian, loadrs=0 */ \
;; \
(pUStk) mov.m r24=ar.rnat; \
(pUStk) addl r22=IA64_RBS_OFFSET,r1; /* compute base of RBS */ \
(pKStk) mov r1=sp; /* get sp */ \
;; \
(pUStk) lfetch.fault.excl.nt1 [r22]; \
(pUStk) addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r1; /* compute base of memory stack */ \
(pUStk) mov r23=ar.bspstore; /* save ar.bspstore */ \
;; \
(pUStk) mov ar.bspstore=r22; /* switch to kernel RBS */ \
(pKStk) addl r1=-IA64_PT_REGS_SIZE,r1; /* if in kernel mode, use sp (r12) */ \
;; \
(pUStk) mov r18=ar.bsp; \
(pUStk) mov ar.rsc=0x3; /* set eager mode, pl 0, little-endian, loadrs=0 */
#define MINSTATE_END_SAVE_MIN_VIRT \
bsw.1; /* switch back to bank 1 (must be last in insn group) */ \
;;
/*
* For mca_asm.S we want to access the stack physically since the state is saved before we
* go virtual and don't want to destroy the iip or ipsr.
*/
#define MINSTATE_START_SAVE_MIN_PHYS \
(pKStk) mov r3=IA64_KR(PER_CPU_DATA);; \
(pKStk) addl r3=THIS_CPU(ia64_mca_data),r3;; \
(pKStk) ld8 r3 = [r3];; \
(pKStk) addl r3=IA64_MCA_CPU_INIT_STACK_OFFSET,r3;; \
(pKStk) addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r3; \
(pUStk) mov ar.rsc=0; /* set enforced lazy mode, pl 0, little-endian, loadrs=0 */ \
(pUStk) addl r22=IA64_RBS_OFFSET,r1; /* compute base of register backing store */ \
;; \
(pUStk) mov r24=ar.rnat; \
(pUStk) addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r1; /* compute base of memory stack */ \
(pUStk) mov r23=ar.bspstore; /* save ar.bspstore */ \
(pUStk) dep r22=-1,r22,61,3; /* compute kernel virtual addr of RBS */ \
;; \
(pUStk) mov ar.bspstore=r22; /* switch to kernel RBS */ \
;; \
(pUStk) mov r18=ar.bsp; \
(pUStk) mov ar.rsc=0x3; /* set eager mode, pl 0, little-endian, loadrs=0 */ \
#define MINSTATE_END_SAVE_MIN_PHYS \
dep r12=-1,r12,61,3; /* make sp a kernel virtual address */ \
;;
#ifdef MINSTATE_VIRT
# define MINSTATE_GET_CURRENT(reg) mov reg=IA64_KR(CURRENT)
# define MINSTATE_START_SAVE_MIN MINSTATE_START_SAVE_MIN_VIRT
# define MINSTATE_END_SAVE_MIN MINSTATE_END_SAVE_MIN_VIRT
#endif
#ifdef MINSTATE_PHYS
# define MINSTATE_GET_CURRENT(reg) mov reg=IA64_KR(CURRENT);; tpa reg=reg
# define MINSTATE_START_SAVE_MIN MINSTATE_START_SAVE_MIN_PHYS
# define MINSTATE_END_SAVE_MIN MINSTATE_END_SAVE_MIN_PHYS
#endif
/*
* DO_SAVE_MIN switches to the kernel stacks (if necessary) and saves
* the minimum state necessary that allows us to turn psr.ic back
* on.
*
* Assumed state upon entry:
* psr.ic: off
* r31: contains saved predicates (pr)
*
* Upon exit, the state is as follows:
* psr.ic: off
* r2 = points to &pt_regs.r16
* r8 = contents of ar.ccv
* r9 = contents of ar.csd
* r10 = contents of ar.ssd
* r11 = FPSR_DEFAULT
* r12 = kernel sp (kernel virtual address)
* r13 = points to current task_struct (kernel virtual address)
* p15 = TRUE if psr.i is set in cr.ipsr
* predicate registers (other than p2, p3, and p15), b6, r3, r14, r15:
* preserved
*
* Note that psr.ic is NOT turned on by this macro. This is so that
* we can pass interruption state as arguments to a handler.
*/
#define DO_SAVE_MIN(COVER,SAVE_IFS,EXTRA) \
MINSTATE_GET_CURRENT(r16); /* M (or M;;I) */ \
mov r27=ar.rsc; /* M */ \
mov r20=r1; /* A */ \
mov r25=ar.unat; /* M */ \
mov r29=cr.ipsr; /* M */ \
mov r26=ar.pfs; /* I */ \
mov r28=cr.iip; /* M */ \
mov r21=ar.fpsr; /* M */ \
COVER; /* B;; (or nothing) */ \
;; \
adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16; \
;; \
ld1 r17=[r16]; /* load current->thread.on_ustack flag */ \
st1 [r16]=r0; /* clear current->thread.on_ustack flag */ \
adds r1=-IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 \
/* switch from user to kernel RBS: */ \
;; \
invala; /* M */ \
SAVE_IFS; \
cmp.eq pKStk,pUStk=r0,r17; /* are we in kernel mode already? */ \
;; \
MINSTATE_START_SAVE_MIN \
adds r17=2*L1_CACHE_BYTES,r1; /* really: biggest cache-line size */ \
adds r16=PT(CR_IPSR),r1; \
;; \
lfetch.fault.excl.nt1 [r17],L1_CACHE_BYTES; \
st8 [r16]=r29; /* save cr.ipsr */ \
;; \
lfetch.fault.excl.nt1 [r17]; \
tbit.nz p15,p0=r29,IA64_PSR_I_BIT; \
mov r29=b0 \
;; \
adds r16=PT(R8),r1; /* initialize first base pointer */ \
adds r17=PT(R9),r1; /* initialize second base pointer */ \
(pKStk) mov r18=r0; /* make sure r18 isn't NaT */ \
;; \
.mem.offset 0,0; st8.spill [r16]=r8,16; \
.mem.offset 8,0; st8.spill [r17]=r9,16; \
;; \
.mem.offset 0,0; st8.spill [r16]=r10,24; \
.mem.offset 8,0; st8.spill [r17]=r11,24; \
;; \
st8 [r16]=r28,16; /* save cr.iip */ \
st8 [r17]=r30,16; /* save cr.ifs */ \
(pUStk) sub r18=r18,r22; /* r18=RSE.ndirty*8 */ \
mov r8=ar.ccv; \
mov r9=ar.csd; \
mov r10=ar.ssd; \
movl r11=FPSR_DEFAULT; /* L-unit */ \
;; \
st8 [r16]=r25,16; /* save ar.unat */ \
st8 [r17]=r26,16; /* save ar.pfs */ \
shl r18=r18,16; /* compute ar.rsc to be used for "loadrs" */ \
;; \
st8 [r16]=r27,16; /* save ar.rsc */ \
(pUStk) st8 [r17]=r24,16; /* save ar.rnat */ \
(pKStk) adds r17=16,r17; /* skip over ar_rnat field */ \
;; /* avoid RAW on r16 & r17 */ \
(pUStk) st8 [r16]=r23,16; /* save ar.bspstore */ \
st8 [r17]=r31,16; /* save predicates */ \
(pKStk) adds r16=16,r16; /* skip over ar_bspstore field */ \
;; \
st8 [r16]=r29,16; /* save b0 */ \
st8 [r17]=r18,16; /* save ar.rsc value for "loadrs" */ \
cmp.eq pNonSys,pSys=r0,r0 /* initialize pSys=0, pNonSys=1 */ \
;; \
.mem.offset 0,0; st8.spill [r16]=r20,16; /* save original r1 */ \
.mem.offset 8,0; st8.spill [r17]=r12,16; \
adds r12=-16,r1; /* switch to kernel memory stack (with 16 bytes of scratch) */ \
;; \
.mem.offset 0,0; st8.spill [r16]=r13,16; \
.mem.offset 8,0; st8.spill [r17]=r21,16; /* save ar.fpsr */ \
mov r13=IA64_KR(CURRENT); /* establish `current' */ \
;; \
.mem.offset 0,0; st8.spill [r16]=r15,16; \
.mem.offset 8,0; st8.spill [r17]=r14,16; \
;; \
.mem.offset 0,0; st8.spill [r16]=r2,16; \
.mem.offset 8,0; st8.spill [r17]=r3,16; \
adds r2=IA64_PT_REGS_R16_OFFSET,r1; \
;; \
EXTRA; \
movl r1=__gp; /* establish kernel global pointer */ \
;; \
MINSTATE_END_SAVE_MIN
/*
* SAVE_REST saves the remainder of pt_regs (with psr.ic on).
*
* Assumed state upon entry:
* psr.ic: on
* r2: points to &pt_regs.r16
* r3: points to &pt_regs.r17
* r8: contents of ar.ccv
* r9: contents of ar.csd
* r10: contents of ar.ssd
* r11: FPSR_DEFAULT
*
* Registers r14 and r15 are guaranteed not to be touched by SAVE_REST.
*/
#define SAVE_REST \
.mem.offset 0,0; st8.spill [r2]=r16,16; \
.mem.offset 8,0; st8.spill [r3]=r17,16; \
;; \
.mem.offset 0,0; st8.spill [r2]=r18,16; \
.mem.offset 8,0; st8.spill [r3]=r19,16; \
;; \
.mem.offset 0,0; st8.spill [r2]=r20,16; \
.mem.offset 8,0; st8.spill [r3]=r21,16; \
mov r18=b6; \
;; \
.mem.offset 0,0; st8.spill [r2]=r22,16; \
.mem.offset 8,0; st8.spill [r3]=r23,16; \
mov r19=b7; \
;; \
.mem.offset 0,0; st8.spill [r2]=r24,16; \
.mem.offset 8,0; st8.spill [r3]=r25,16; \
;; \
.mem.offset 0,0; st8.spill [r2]=r26,16; \
.mem.offset 8,0; st8.spill [r3]=r27,16; \
;; \
.mem.offset 0,0; st8.spill [r2]=r28,16; \
.mem.offset 8,0; st8.spill [r3]=r29,16; \
;; \
.mem.offset 0,0; st8.spill [r2]=r30,16; \
.mem.offset 8,0; st8.spill [r3]=r31,32; \
;; \
mov ar.fpsr=r11; /* M-unit */ \
st8 [r2]=r8,8; /* ar.ccv */ \
adds r24=PT(B6)-PT(F7),r3; \
;; \
stf.spill [r2]=f6,32; \
stf.spill [r3]=f7,32; \
;; \
stf.spill [r2]=f8,32; \
stf.spill [r3]=f9,32; \
;; \
stf.spill [r2]=f10; \
stf.spill [r3]=f11; \
adds r25=PT(B7)-PT(F11),r3; \
;; \
st8 [r24]=r18,16; /* b6 */ \
st8 [r25]=r19,16; /* b7 */ \
;; \
st8 [r24]=r9; /* ar.csd */ \
st8 [r25]=r10; /* ar.ssd */ \
;;
#define SAVE_MIN_WITH_COVER DO_SAVE_MIN(cover, mov r30=cr.ifs,)
#define SAVE_MIN_WITH_COVER_R19 DO_SAVE_MIN(cover, mov r30=cr.ifs, mov r15=r19)
#define SAVE_MIN DO_SAVE_MIN( , mov r30=r0, )
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