ia64/pv_ops/xen: paravirtualize DO_SAVE_MIN for xen.
authorIsaku Yamahata <yamahata@valinux.co.jp>
Fri, 17 Oct 2008 02:18:02 +0000 (11:18 +0900)
committerTony Luck <tony.luck@intel.com>
Fri, 17 Oct 2008 17:04:13 +0000 (10:04 -0700)
paravirtualize DO_SAVE_MIN in minstate.h for xen.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
arch/ia64/include/asm/xen/inst.h
arch/ia64/include/asm/xen/minstate.h [new file with mode: 0644]

index 03895e9..1e92ed0 100644 (file)
@@ -22,6 +22,8 @@
 
 #include <asm/xen/privop.h>
 
+#define DO_SAVE_MIN                            XEN_DO_SAVE_MIN
+
 #define MOV_FROM_IFA(reg)      \
        movl reg = XSI_IFA;     \
        ;;                      \
diff --git a/arch/ia64/include/asm/xen/minstate.h b/arch/ia64/include/asm/xen/minstate.h
new file mode 100644 (file)
index 0000000..4d92d9b
--- /dev/null
@@ -0,0 +1,134 @@
+/*
+ * 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
+ * CONFIG_XEN note: p6/p7 are not 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 XEN_DO_SAVE_MIN(__COVER,SAVE_IFS,EXTRA,WORKAROUND)                                     \
+       mov r16=IA64_KR(CURRENT);       /* M */                                                 \
+       mov r27=ar.rsc;                 /* M */                                                 \
+       mov r20=r1;                     /* A */                                                 \
+       mov r25=ar.unat;                /* M */                                                 \
+       MOV_FROM_IPSR(p0,r29);          /* M */                                                 \
+       MOV_FROM_IIP(r28);              /* M */                                                 \
+       mov r21=ar.fpsr;                /* M */                                                 \
+       mov r26=ar.pfs;                 /* I */                                                 \
+       __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;*/ /* see xen special handling below */                                     \
+       cmp.eq pKStk,pUStk=r0,r17;              /* are we in kernel mode already? */            \
+       ;;                                                                                      \
+(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 */             \
+       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                                                                              \
+       ;;                                                                                      \
+       WORKAROUND;                                                                             \
+       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;                                                       \
+       movl r8=XSI_PRECOVER_IFS;                                                               \
+.mem.offset 8,0; st8.spill [r17]=r11,24;                                                       \
+        ;;                                                                                     \
+       /* xen special handling for possibly lazy cover */                                      \
+       /* SAVE_MIN case in dispatch_ia32_handler: mov r30=r0 */                                \
+       ld8 r30=[r8];                                                                           \
+(pUStk)        sub r18=r18,r22;        /* r18=RSE.ndirty*8 */                                          \
+       st8 [r16]=r28,16;       /* save cr.iip */                                               \
+       ;;                                                                                      \
+       st8 [r17]=r30,16;       /* save cr.ifs */                                               \
+       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;                                                                \
+       ACCOUNT_GET_STAMP                                                                       \
+       adds r2=IA64_PT_REGS_R16_OFFSET,r1;                                                     \
+       ;;                                                                                      \
+       EXTRA;                                                                                  \
+       movl r1=__gp;           /* establish kernel global pointer */                           \
+       ;;                                                                                      \
+       ACCOUNT_SYS_ENTER                                                                       \
+       BSW_1(r3,r14);  /* switch back to bank 1 (must be last in insn group) */                \
+       ;;