xnu-792.25.20.tar.gz

[apple/xnu.git] / osfmk / ppc / Emulate.s

diff --git a/osfmk/ppc/Emulate.s b/osfmk/ppc/Emulate.s
index d391f0211f8a566fda3e212a857e250a5cba7464..7a4ef3ab9c875e8a868a980ef6152fb1b75fd68d 100644 (file)
--- a/osfmk/ppc/Emulate.s
+++ b/osfmk/ppc/Emulate.s
@@ -29,10 +29,10 @@
 
 */
 
-#include <cpus.h>
 #include <ppc/asm.h>
 #include <ppc/proc_reg.h>
 #include <ppc/exception.h>
+#include <ppc/cpu_capabilities.h>
 #include <mach/machine/vm_param.h>
 #include <assym.s>
 
@@ -218,9 +218,11 @@ LEXT(AlignAssist)
                        b               EXT(AlignAssist64)                              ; Jump to the 64-bit code...
                        
 aan64:         lwz             r20,savedsisr(r13)                              ; Get the DSISR
+                       li              r0,0                                                    ; Assume we emulate
                        mfsprg  r31,0                                                   ; Get the per_proc
                        mtcrf   0x10,r20                                                ; Put instruction ID in CR for later
                        lwz             r21,spcFlags(r31)                               ; Grab the special flags
+                       stw             r0,savemisc3(r13)                               ; Assume that we emulate ok
                        mtcrf   0x08,r20                                                ; Put instruction ID in CR for later
                        rlwinm. r0,r21,0,runningVMbit,runningVMbit      ; Are we running a VM?
                        mtcrf   0x04,r20                                                ; Put instruction ID in CR for later
@@ -332,15 +334,11 @@ aaComExGo:        b               EXT(EmulExit)                                   ; We are done, no tracing on...
 ;
 ;                      This is not a floating point operation
 ;
-;                      The emulation routines for these are positioned every 64 bytes (16 instructions)
-;                      in a 1024-byte aligned table.  It is indexed by taking the low order 4 bits of
+;                      The table of these emulation routines is indexed by taking the low order 4 bits of
 ;                      the instruction code in the DSISR and subtracting 7.  If this comes up negative,
 ;                      the instruction is not to be emulated.  Then we add bit 0 of the code * 4.  This
 ;                      gives us a fairly compact and almost unique index.  Both lwm and stmw map to 0 so
-;                      that one needs to be further reduced, and we end up with holes at index 6, 8, and 10.
-;                      
-;                      If the emulation routine takes more than 16 instructions, it must branch elsewhere
-;                      to finish up.
+;                      that one needs to be further reduced, and we end up with holes at a few indexes.
 ;
 
                        .align  5
@@ -361,9 +359,7 @@ aaNotFloat:
 
 ;
 ;                      This is the table of non-floating point emulation routines.
-;                      It is indexed by low 4 bits of DSISR op type - 7 + bit 0 of
-;                      op type * 4
-;
+;                      It is indexed by the code immediately above.
                
                        .align  5                                                       
 
@@ -955,9 +951,17 @@ aaSthbrx:
 
                        .align  5
 
-aaDcbz:
-                       rlwinm  r23,r23,0,0,26                                  ; Round back to a 32-byte boundary
-                       
+aaDcbz:                        
+            lwz     r0,savesrr0+4(r13)              ; get instruction address
+            li         r4,_COMM_PAGE_BASE_ADDRESS
+                       rlwinm  r23,r23,0,0,26                                  ; Round EA back to a 32-byte boundary
+            sub     r4,r0,r4                        ; compute instruction offset from base of commpage
+            cmplwi  r4,_COMM_PAGE_AREA_USED         ; did fault occur in commpage?
+            bge+    aaDcbz1                         ; skip if not in commpage
+            lwz                r4,savecr(r13)                  ; if we take a dcbz in the commpage...
+            rlwinm     r4,r4,0,0,27                    ; ...clear users cr7 as a flag for commpage code
+            stw                r4,savecr(r13)
+aaDcbz1:
                        crset   cr0_eq                                                  ; Set this to see if we failed
                        li              r0,0                                                    ; Clear this out
                        mtmsr   r22                                                             ; Flip DR, RI, and maybe PR on
@@ -994,6 +998,8 @@ aaDcbzXit:  mr              r4,r0                                                   ; Save the DAR if we failed the access
 ;
 
 aaPassAlong:
+                       li              r0,1                                                    ; Indicate that we failed to emulate
+                       stw             r0,savemisc3(r13)                               ; Assume that we emulate ok
                        b               EXT(EmulExit)