3 files changed, 123 insertions, 23 deletions

diff --git a/arch/ia64/hp/sim/simscsi.c b/arch/ia64/hp/sim/simscsi.c
index 56405dbfd739..a18983a3c934 100644
--- a/arch/ia64/hp/sim/simscsi.c
+++ b/arch/ia64/hp/sim/simscsi.c
@@ -233,6 +233,23 @@ simscsi_readwrite10 (struct scsi_cmnd *sc, int mode)
                 simscsi_readwrite(sc, mode, offset, ((sc->cmnd[7] << 8) | sc->cmnd[8])*512);
 }
 
+static void simscsi_fillresult(struct scsi_cmnd *sc, char *buf, unsigned len)
+{
+
+        int scatterlen = sc->use_sg;
+        struct scatterlist *slp;
+
+        if (scatterlen == 0)
+                memcpy(sc->request_buffer, buf, len);
+        else for (slp = (struct scatterlist *)sc->buffer; scatterlen-- > 0 && len > 0; slp++) {
+                unsigned thislen = min(len, slp->length);
+
+                memcpy(page_address(slp->page) + slp->offset, buf, thislen);
+                slp++;
+                len -= thislen;
+        }
+}
+
 static int
 simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 {
@@ -240,6 +257,7 @@ simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
         char fname[MAX_ROOT_LEN+16];
         size_t disk_size;
         char *buf;
+        char localbuf[36];
 #if DEBUG_SIMSCSI
         register long sp asm ("sp");
 
@@ -263,7 +281,7 @@ simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
                                 /* disk doesn't exist... */
                                 break;
                         }
-                        buf = sc->request_buffer;
+                        buf = localbuf;
                         buf[0] = 0;     /* magnetic disk */
                         buf[1] = 0;     /* not a removable medium */
                         buf[2] = 2;     /* SCSI-2 compliant device */
@@ -273,6 +291,7 @@ simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
                         buf[6] = 0;     /* reserved */
                         buf[7] = 0;     /* various flags */
                         memcpy(buf + 8, "HP      SIMULATED DISK  0.00",  28);
+                        simscsi_fillresult(sc, buf, 36);
                         sc->result = GOOD;
                         break;
 
@@ -304,16 +323,13 @@ simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
                         simscsi_readwrite10(sc, SSC_WRITE);
                         break;
 
-
                       case READ_CAPACITY:
                         if (desc[target_id] < 0 || sc->request_bufflen < 8) {
                                 break;
                         }
-                        buf = sc->request_buffer;
-
+                        buf = localbuf;
                         disk_size = simscsi_get_disk_size(desc[target_id]);
 
-                        /* pretend to be a 1GB disk (partition table contains real stuff): */
                         buf[0] = (disk_size >> 24) & 0xff;
                         buf[1] = (disk_size >> 16) & 0xff;
                         buf[2] = (disk_size >>  8) & 0xff;
@@ -323,13 +339,14 @@ simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
                         buf[5] = 0;
                         buf[6] = 2;
                         buf[7] = 0;
+                        simscsi_fillresult(sc, buf, 8);
                         sc->result = GOOD;
                         break;
 
                       case MODE_SENSE:
                       case MODE_SENSE_10:
                         /* sd.c uses this to determine whether disk does write-caching. */
-                        memset(sc->request_buffer, 0, 128);
+                        simscsi_fillresult(sc, (char *)empty_zero_page, sc->request_bufflen);
                         sc->result = GOOD;
                         break;
 
diff --git a/arch/ia64/kernel/mca_asm.S b/arch/ia64/kernel/mca_asm.S
index 499a065f4e60..db32fc1d3935 100644
--- a/arch/ia64/kernel/mca_asm.S
+++ b/arch/ia64/kernel/mca_asm.S
@@ -489,24 +489,27 @@ ia64_state_save:
         ;;
         st8 [temp1]=r17,16      // pal_min_state
         st8 [temp2]=r6,16       // prev_IA64_KR_CURRENT
+        mov r6=IA64_KR(CURRENT_STACK)
+        ;;
+        st8 [temp1]=r6,16       // prev_IA64_KR_CURRENT_STACK
+        st8 [temp2]=r0,16       // prev_task, starts off as NULL
         mov r6=cr.ifa
         ;;
-        st8 [temp1]=r0,16       // prev_task, starts off as NULL
-        st8 [temp2]=r12,16      // cr.isr
+        st8 [temp1]=r12,16      // cr.isr
+        st8 [temp2]=r6,16       // cr.ifa
         mov r12=cr.itir
         ;;
-        st8 [temp1]=r6,16       // cr.ifa
-        st8 [temp2]=r12,16      // cr.itir
+        st8 [temp1]=r12,16      // cr.itir
+        st8 [temp2]=r11,16      // cr.iipa
         mov r12=cr.iim
         ;;
-        st8 [temp1]=r11,16      // cr.iipa
-        st8 [temp2]=r12,16      // cr.iim
-        mov r6=cr.iha
+        st8 [temp1]=r12,16      // cr.iim
 (p1)    mov r12=IA64_MCA_COLD_BOOT
 (p2)    mov r12=IA64_INIT_WARM_BOOT
+        mov r6=cr.iha
         ;;
-        st8 [temp1]=r6,16       // cr.iha
-        st8 [temp2]=r12         // os_status, default is cold boot
+        st8 [temp2]=r6,16       // cr.iha
+        st8 [temp1]=r12         // os_status, default is cold boot
         mov r6=IA64_MCA_SAME_CONTEXT
         ;;
         st8 [temp1]=r6          // context, default is same context
@@ -823,9 +826,12 @@ ia64_state_restore:
         ld8 r12=[temp1],16      // sal_ra
         ld8 r9=[temp2],16       // sal_gp
         ;;
-        ld8 r22=[temp1],24      // pal_min_state, virtual.  skip prev_task
+        ld8 r22=[temp1],16      // pal_min_state, virtual
         ld8 r21=[temp2],16      // prev_IA64_KR_CURRENT
         ;;
+        ld8 r16=[temp1],16      // prev_IA64_KR_CURRENT_STACK
+        ld8 r20=[temp2],16      // prev_task
+        ;;
         ld8 temp3=[temp1],16    // cr.isr
         ld8 temp4=[temp2],16    // cr.ifa
         ;;
@@ -846,6 +852,45 @@ ia64_state_restore:
         ld8 r8=[temp1]          // os_status
         ld8 r10=[temp2]         // context
 
+        /* Wire IA64_TR_CURRENT_STACK to the stack that we are resuming to.  To
+         * avoid any dependencies on the algorithm in ia64_switch_to(), just
+         * purge any existing CURRENT_STACK mapping and insert the new one.
+         *
+         * r16 contains prev_IA64_KR_CURRENT_STACK, r21 contains
+         * prev_IA64_KR_CURRENT, these values may have been changed by the C
+         * code.  Do not use r8, r9, r10, r22, they contain values ready for
+         * the return to SAL.
+         */
+
+        mov r15=IA64_KR(CURRENT_STACK)          // physical granule mapped by IA64_TR_CURRENT_STACK
+        ;;
+        shl r15=r15,IA64_GRANULE_SHIFT
+        ;;
+        dep r15=-1,r15,61,3                     // virtual granule
+        mov r18=IA64_GRANULE_SHIFT<<2           // for cr.itir.ps
+        ;;
+        ptr.d r15,r18
+        ;;
+        srlz.d
+
+        extr.u r19=r21,61,3                     // r21 = prev_IA64_KR_CURRENT
+        shl r20=r16,IA64_GRANULE_SHIFT          // r16 = prev_IA64_KR_CURRENT_STACK
+        movl r21=PAGE_KERNEL                    // page properties
+        ;;
+        mov IA64_KR(CURRENT_STACK)=r16
+        cmp.ne p6,p0=RGN_KERNEL,r19             // new stack is in the kernel region?
+        or r21=r20,r21                          // construct PA | page properties
+(p6)    br.spnt 1f                              // the dreaded cpu 0 idle task in region 5:(
+        ;;
+        mov cr.itir=r18
+        mov cr.ifa=r21
+        mov r20=IA64_TR_CURRENT_STACK
+        ;;
+        itr.d dtr[r20]=r21
+        ;;
+        srlz.d
+1:
+
         br.sptk b0
 
 //EndStub//////////////////////////////////////////////////////////////////////
@@ -982,6 +1027,7 @@ ia64_set_kernel_registers:
         add temp4=temp4, temp1  // &struct ia64_sal_os_state.os_gp
         add r12=temp1, temp3    // kernel stack pointer on MCA/INIT stack
         add r13=temp1, r3       // set current to start of MCA/INIT stack
+        add r20=temp1, r3       // physical start of MCA/INIT stack
         ;;
         ld8 r1=[temp4]          // OS GP from SAL OS state
         ;;
@@ -991,7 +1037,35 @@ ia64_set_kernel_registers:
         ;;
         mov IA64_KR(CURRENT)=r13
 
-        // FIXME: do I need to wire IA64_KR_CURRENT_STACK and IA64_TR_CURRENT_STACK?
+        /* Wire IA64_TR_CURRENT_STACK to the MCA/INIT handler stack.  To avoid
+         * any dependencies on the algorithm in ia64_switch_to(), just purge
+         * any existing CURRENT_STACK mapping and insert the new one.
+         */
+
+        mov r16=IA64_KR(CURRENT_STACK)          // physical granule mapped by IA64_TR_CURRENT_STACK
+        ;;
+        shl r16=r16,IA64_GRANULE_SHIFT
+        ;;
+        dep r16=-1,r16,61,3                     // virtual granule
+        mov r18=IA64_GRANULE_SHIFT<<2           // for cr.itir.ps
+        ;;
+        ptr.d r16,r18
+        ;;
+        srlz.d
+
+        shr.u r16=r20,IA64_GRANULE_SHIFT        // r20 = physical start of MCA/INIT stack
+        movl r21=PAGE_KERNEL                    // page properties
+        ;;
+        mov IA64_KR(CURRENT_STACK)=r16
+        or r21=r20,r21                          // construct PA | page properties
+        ;;
+        mov cr.itir=r18
+        mov cr.ifa=r13
+        mov r20=IA64_TR_CURRENT_STACK
+        ;;
+        itr.d dtr[r20]=r21
+        ;;
+        srlz.d
 
         br.sptk b0
 
diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c
index 80f83d6cdbfc..f081c60ab206 100644
--- a/arch/ia64/kernel/mca_drv.c
+++ b/arch/ia64/kernel/mca_drv.c
@@ -56,8 +56,9 @@ static struct page *page_isolate[MAX_PAGE_ISOLATE];
 static int num_page_isolate = 0;
 
 typedef enum {
-        ISOLATE_NG = 0,
-        ISOLATE_OK = 1
+        ISOLATE_NG,
+        ISOLATE_OK,
+        ISOLATE_NONE
 } isolate_status_t;
 
 /*
@@ -74,7 +75,7 @@ static struct {
  * @paddr:      poisoned memory location
  *
  * Return value:
- *      ISOLATE_OK / ISOLATE_NG
+ *      one of isolate_status_t, ISOLATE_OK/NG/NONE.
  */
 
 static isolate_status_t
@@ -85,7 +86,10 @@ mca_page_isolate(unsigned long paddr)
 
         /* whether physical address is valid or not */
         if (!ia64_phys_addr_valid(paddr))
-                return ISOLATE_NG;
+                return ISOLATE_NONE;
+
+        if (!pfn_valid(paddr))
+                return ISOLATE_NONE;
 
         /* convert physical address to physical page number */
         p = pfn_to_page(paddr>>PAGE_SHIFT);
@@ -122,10 +126,15 @@ mca_handler_bh(unsigned long paddr)
                 current->pid, current->comm);
 
         spin_lock(&mca_bh_lock);
-        if (mca_page_isolate(paddr) == ISOLATE_OK) {
+        switch (mca_page_isolate(paddr)) {
+        case ISOLATE_OK:
                 printk(KERN_DEBUG "Page isolation: ( %lx ) success.\n", paddr);
-        } else {
+                break;
+        case ISOLATE_NG:
                 printk(KERN_DEBUG "Page isolation: ( %lx ) failure.\n", paddr);
+                break;
+        default:
+                break;
         }
         spin_unlock(&mca_bh_lock);