[SPARC64]: Fix some SUN4V TLB miss bugs.

Code patching did not sign extend negative branch
offsets correctly.

Kernel TLB miss path needs patching and %g4 register
preservation in order to handle SUN4V correctly.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S
index f6bb2e0..2d333ab 100644 (file)
--- a/arch/sparc64/kernel/ktlb.S
+++ b/arch/sparc64/kernel/ktlb.S
@@ -48,7 +48,7 @@ kvmap_itlb_tsb_miss:
 kvmap_itlb_vmalloc_addr:
        KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_itlb_longpath)
 
-       KTSB_LOCK_TAG(%g1, %g2, %g4)
+       KTSB_LOCK_TAG(%g1, %g2, %g7)
 
        /* Load and check PTE.  */
        ldxa            [%g5] ASI_PHYS_USE_EC, %g5
@@ -60,8 +60,29 @@ kvmap_itlb_vmalloc_addr:
        /* fallthrough to TLB load */
 
 kvmap_itlb_load:
-       stxa            %g5, [%g0] ASI_ITLB_DATA_IN     ! Reload TLB
+
+661:   stxa            %g5, [%g0] ASI_ITLB_DATA_IN
        retry
+       .section        .sun4v_2insn_patch, "ax"
+       .word           661b
+       nop
+       nop
+       .previous
+
+       /* For sun4v the ASI_ITLB_DATA_IN store and the retry
+        * instruction get nop'd out and we get here to branch
+        * to the sun4v tlb load code.  The registers are setup
+        * as follows:
+        *
+        * %g4: vaddr
+        * %g5: PTE
+        * %g6: TAG
+        *
+        * The sun4v TLB load wants the PTE in %g3 so we fix that
+        * up here.
+        */
+       ba,pt           %xcc, sun4v_itlb_load
+        mov            %g5, %g3
 
 kvmap_itlb_longpath:
 
@@ -80,7 +101,7 @@ kvmap_itlb_longpath:
 kvmap_itlb_obp:
        OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_itlb_longpath)
 
-       KTSB_LOCK_TAG(%g1, %g2, %g4)
+       KTSB_LOCK_TAG(%g1, %g2, %g7)
 
        KTSB_WRITE(%g1, %g5, %g6)
 
@@ -90,7 +111,7 @@ kvmap_itlb_obp:
 kvmap_dtlb_obp:
        OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_dtlb_longpath)
 
-       KTSB_LOCK_TAG(%g1, %g2, %g4)
+       KTSB_LOCK_TAG(%g1, %g2, %g7)
 
        KTSB_WRITE(%g1, %g5, %g6)
 
@@ -129,7 +150,7 @@ kvmap_linear_patch:
 kvmap_dtlb_vmalloc_addr:
        KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath)
 
-       KTSB_LOCK_TAG(%g1, %g2, %g4)
+       KTSB_LOCK_TAG(%g1, %g2, %g7)
 
        /* Load and check PTE.  */
        ldxa            [%g5] ASI_PHYS_USE_EC, %g5
@@ -141,8 +162,29 @@ kvmap_dtlb_vmalloc_addr:
        /* fallthrough to TLB load */
 
 kvmap_dtlb_load:
-       stxa            %g5, [%g0] ASI_DTLB_DATA_IN     ! Reload TLB
+
+661:   stxa            %g5, [%g0] ASI_DTLB_DATA_IN     ! Reload TLB
        retry
+       .section        .sun4v_2insn_patch, "ax"
+       .word           661b
+       nop
+       nop
+       .previous
+
+       /* For sun4v the ASI_DTLB_DATA_IN store and the retry
+        * instruction get nop'd out and we get here to branch
+        * to the sun4v tlb load code.  The registers are setup
+        * as follows:
+        *
+        * %g4: vaddr
+        * %g5: PTE
+        * %g6: TAG
+        *
+        * The sun4v TLB load wants the PTE in %g3 so we fix that
+        * up here.
+        */
+       ba,pt           %xcc, sun4v_dtlb_load
+        mov            %g5, %g3
 
 kvmap_dtlb_nonlinear:
        /* Catch kernel NULL pointer derefs.  */
@@ -185,10 +227,17 @@ kvmap_dtlb_longpath:
        nop
        .previous
 
-       rdpr    %tl, %g4
-       cmp     %g4, 1
-       mov     TLB_TAG_ACCESS, %g4
+       rdpr    %tl, %g3
+       cmp     %g3, 1
+
+661:   mov     TLB_TAG_ACCESS, %g4
        ldxa    [%g4] ASI_DMMU, %g5
+       .section .sun4v_2insn_patch, "ax"
+       .word   661b
+       mov     %g4, %g5
+       nop
+       .previous
+
        be,pt   %xcc, sparc64_realfault_common
         mov    FAULT_CODE_DTLB, %g4
        ba,pt   %xcc, winfix_trampoline

diff --git a/arch/sparc64/kernel/sun4v_tlb_miss.S b/arch/sparc64/kernel/sun4v_tlb_miss.S
index f712913..597359c 100644 (file)
--- a/arch/sparc64/kernel/sun4v_tlb_miss.S
+++ b/arch/sparc64/kernel/sun4v_tlb_miss.S
@@ -96,7 +96,7 @@ sun4v_dtlb_miss:
        
        /* Load UTSB reg into %g1.  */
        mov     SCRATCHPAD_UTSBREG1, %g1
-       ldxa    [%g1 + %g1] ASI_SCRATCHPAD, %g1
+       ldxa    [%g1] ASI_SCRATCHPAD, %g1
 
        LOAD_DTLB_INFO(%g2, %g4, %g5)
        COMPUTE_TAG_TARGET(%g6, %g4, %g5, %g3, kvmap_dtlb_4v)
@@ -149,14 +149,19 @@ sun4v_dtlb_prot:
         * SCRATCHPAD_MMU_MISS contents in %g2.
         */
 sun4v_itsb_miss:
-       ba,pt   %xcc, sun4v_tsb_miss_common
+       mov     SCRATCHPAD_UTSBREG1, %g1
+       ldxa    [%g1] ASI_SCRATCHPAD, %g1
+       brz,pn  %g5, kvmap_itlb_4v
         mov    FAULT_CODE_ITLB, %g3
 
        /* Called from trap table with TAG TARGET placed into
         * %g6 and SCRATCHPAD_UTSBREG1 contents in %g1.
         */
 sun4v_dtsb_miss:
-       mov     FAULT_CODE_DTLB, %g3
+       mov     SCRATCHPAD_UTSBREG1, %g1
+       ldxa    [%g1] ASI_SCRATCHPAD, %g1
+       brz,pn  %g5, kvmap_dtlb_4v
+        mov    FAULT_CODE_DTLB, %g3
 
        /* Create TSB pointer into %g1.  This is something like:
         *
@@ -312,7 +317,8 @@ sun4v_stdfmna:
        or      %g2, %lo(OLD), %g2; \
        sub     %g1, %g2, %g1; \
        sethi   %hi(BRANCH_ALWAYS), %g3; \
-       srl     %g1, 2, %g1; \
+       sll     %g1, 11, %g1; \
+       srl     %g1, 11 + 2, %g1; \
        or      %g3, %lo(BRANCH_ALWAYS), %g3; \
        or      %g3, %g1, %g3; \
        stw     %g3, [%g2]; \

diff --git a/include/asm-sparc64/ttable.h b/include/asm-sparc64/ttable.h
index 6bb86a7..9e28b24 100644 (file)
--- a/include/asm-sparc64/ttable.h
+++ b/include/asm-sparc64/ttable.h
@@ -186,19 +186,19 @@
        ldx     [%g2 + HV_FAULT_I_CTX_OFFSET], %g5;     \
        srlx    %g4, 22, %g7;                           \
        sllx    %g5, 48, %g6;                           \
-       brz,pn  %g5, kvmap_itlb_4v;                     \
+       ba,pt   %xcc, sun4v_itsb_miss;                  \
         or     %g6, %g7, %g6;                          \
-       ba,a,pt %xcc, sun4v_itsb_miss;
+       nop;
 
-#define SUN4V_DTSB_MISS                                \
+#define SUN4V_DTSB_MISS                                        \
        ldxa    [%g0] ASI_SCRATCHPAD, %g2;              \
        ldx     [%g2 + HV_FAULT_D_ADDR_OFFSET], %g4;    \
        ldx     [%g2 + HV_FAULT_D_CTX_OFFSET], %g5;     \
        srlx    %g4, 22, %g7;                           \
        sllx    %g5, 48, %g6;                           \
-       brz,pn  %g5, kvmap_dtlb_4v;                     \
+       ba,pt   %xcc, sun4v_dtsb_miss;                  \
         or     %g6, %g7, %g6;                          \
-       ba,a,pt %xcc, sun4v_dtsb_miss;
+       nop;
 
 /* Before touching these macros, you owe it to yourself to go and
  * see how arch/sparc64/kernel/winfixup.S works... -DaveM