[Xen-ia64-devel] [patch 08/15] ia64: kexec: Add identity mapping of EFI memory to alt_dtlb_miss

[Simon Horman <horms@xxxxxxxxxxxx>]

Cc: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
Cc: Tristan Gingold <tgingold@xxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxx>
Cc: Aron Griffis <aron@xxxxxx>
Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>

--- 
Tue, 04 Dec 2007 22:19:26 +0900
* Remove duplicate comment

Thu, 06 Dec 2007 16:09:14 +0900
* rr index should be bitshifted 61 bits to the left

Thu, 24 Jan 2008 16:02:33 +0900
* Check rr7 not rr6, as the rr changes don't really take
  full affect until rr7 is switched - and checking on rr6 doesn't work
  in alt_dtlb_miss

Index: xen-unstable.hg/xen/arch/ia64/xen/ivt.S
===================================================================
--- xen-unstable.hg.orig/xen/arch/ia64/xen/ivt.S        2008-02-05 
16:18:54.000000000 +0900
+++ xen-unstable.hg/xen/arch/ia64/xen/ivt.S     2008-02-05 16:18:54.000000000 
+0900
@@ -207,17 +207,37 @@ late_alt_dtlb_miss:
 (p8)   br.cond.sptk frametable_miss ;;
 #endif
        // If it is not a Xen address, handle it via page_fault.
+       //    !( ((r22 == 0x18 || r22 == 0x1c) && rr7 == XEN_EFI_RID) ||
+       //       r22 == 0x1e )
+       // Note that rr7 == XEN_EFI_RID implies rr6 == XEN_EFI_RID
        extr.u r22=r16,59,5
        ;;
        dep r20=0,r20,IA64_ITIR_KEY,IA64_ITIR_KEY_LEN   // clear the key
-       cmp.ne p8,p0=0x1e,r22
-(p8)   br.cond.sptk page_fault
+       movl r23=7 << 61
        ;;
+       mov r23=rr[r23]
+       ;;
+       mov r25=XEN_EFI_RID
+       cmp.eq p8,p0=0x18,r22           // 0xc...
+       ;;
+       cmp.eq.or p8,p0=0x1c,r22        // 0xe...
+       ;;
+       cmp.eq.and p8,p0=r25,r23        // rr7 == XEN_EFI_RID
+       ;;
+       cmp.eq.or p8,p0=0x1e,r22        // 0xf...
+(p8)   br.cond.spnt alt_dtlb_miss_identity_map
+       br.cond.spnt page_fault
+       ;;
+alt_dtlb_miss_identity_map:
        dep r21=-1,r21,IA64_PSR_ED_BIT,1
        or r19=r19,r17          // insert PTE control bits into r19
        mov cr.itir=r20         // set itir with cleared key
        ;;
-       dep r19=r18,r19,4,1     // set bit 4 (uncached) if access to UC area
+       cmp.ne p8,p0=r0,r18             // Xen UC bit set
+       ;;
+       cmp.eq.or p8,p0=0x18,r22        // Region 6 is UC for EFI
+       ;;
+(p8)   dep r19=-1,r19,4,1      // set bit 4 (uncached) if access to UC area
 (p6)   mov cr.ipsr=r21
        ;;
 (p7)   itc.d r19               // insert the TLB entry

-- 

-- 
Horms


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