[IA64] MCA recovery improvements

Jack Steiner uncovered some opportunities for improvement in
the MCA recovery code.

  1) Set bsp to save registers on the kernel stack.
  2) Disable interrupts while in the MCA recovery code.
  3) Change the way the user process is killed, to avoid
     a panic in schedule.

Testing shows that these changes make the recovery code much
more reliable with the 2.6.12 kernel.

Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c
index ab478172c34956f0524e7f731fe4d5a772109caf..abc0113a821df8eee06fca411866cfe4de324a6d 100644 (file)
--- a/arch/ia64/kernel/mca_drv.c
+++ b/arch/ia64/kernel/mca_drv.c
@@ -132,8 +132,7 @@ mca_handler_bh(unsigned long paddr)
        spin_unlock(&mca_bh_lock);
 
        /* This process is about to be killed itself */
-       force_sig(SIGKILL, current);
-       schedule();
+       do_exit(SIGKILL);
 }
 
 /**
@@ -439,6 +438,7 @@ recover_from_read_error(slidx_table_t *slidx, peidx_table_t *peidx, pal_bus_chec
                        psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
                        psr2->cpl = 0;
                        psr2->ri  = 0;
+                       psr2->i  = 0;
 
                        return 1;
                }

diff --git a/arch/ia64/kernel/mca_drv_asm.S b/arch/ia64/kernel/mca_drv_asm.S
index bcfa05acc561fcd84037934cbe4a860ebc832089..2d7e0217638d29866d13070f4ca4a516e450eaef 100644 (file)
--- a/arch/ia64/kernel/mca_drv_asm.S
+++ b/arch/ia64/kernel/mca_drv_asm.S
@@ -10,6 +10,7 @@
 
 #include <asm/asmmacro.h>
 #include <asm/processor.h>
+#include <asm/ptrace.h>
 
 GLOBAL_ENTRY(mca_handler_bhhook)
        invala                                          // clear RSE ?
@@ -20,12 +21,21 @@ GLOBAL_ENTRY(mca_handler_bhhook)
        ;;                                              
        alloc           r16=ar.pfs,0,2,1,0              // make a new frame
        ;;
+       mov             ar.rsc=0
+       ;;
        mov             r13=IA64_KR(CURRENT)            // current task pointer
        ;;
-       adds            r12=IA64_TASK_THREAD_KSP_OFFSET,r13
+       mov             r2=r13
+       ;;
+       addl            r22=IA64_RBS_OFFSET,r2
+       ;;
+       mov             ar.bspstore=r22
        ;;
-       ld8             r12=[r12]                       // stack pointer
+       addl            sp=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2
        ;;
+       adds            r2=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
+       ;;
+       st1             [r2]=r0                         // clear current->thread.on_ustack flag
        mov             loc0=r16
        movl            loc1=mca_handler_bh             // recovery C function
        ;;
@@ -34,7 +44,9 @@ GLOBAL_ENTRY(mca_handler_bhhook)
        ;;
        mov             loc1=rp
        ;;
-       br.call.sptk.many    rp=b6                      // not return ...
+       ssm             psr.i
+       ;;
+       br.call.sptk.many    rp=b6                      // does not return ...
        ;;
        mov             ar.pfs=loc0
        mov             rp=loc1