[SPARC64]: Add initial code to twiddle %gl on trap entry/exit.

Instead of setting/clearing PSTATE_AG we have to change
the %gl register value on sun4v.

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

4 files changed, 53 insertions, 3 deletions

diff --git a/arch/sparc64/kernel/etrap.S b/arch/sparc64/kernel/etrap.S
index f2556146a735..4d644949ad49 100644
--- a/arch/sparc64/kernel/etrap.S
+++ b/arch/sparc64/kernel/etrap.S
@@ -102,7 +102,14 @@ etrap_save:	save	%g2, -STACK_BIAS, %sp
 2:              mov     %g4, %l4
                 mov     %g5, %l5
                 add     %g7, 4, %l2
-                wrpr    %g0, ETRAP_PSTATE1, %pstate
+
+                /* Go to trap time globals so we can save them.  */
+661:            wrpr    %g0, ETRAP_PSTATE1, %pstate
+                .section .gl_1insn_patch, "ax"
+                .word   661b
+                SET_GL(0)
+                .previous
+
                 stx     %g1, [%sp + PTREGS_OFF + PT_V9_G1]
                 stx     %g2, [%sp + PTREGS_OFF + PT_V9_G2]
                 sllx    %l7, 24, %l7
@@ -195,9 +202,15 @@ etraptl1:	/* Save tstate/tpc/tnpc of TL 1-->4 and the tl register itself.
                 rdpr    %tt, %g3
                 stx     %g3, [%g2 + STACK_BIAS + 0x78]
 
-                wrpr    %g1, %tl
                 stx     %g1, [%g2 + STACK_BIAS + 0x80]
 
+                wrpr    %g0, 1, %tl
+661:            nop
+                .section .gl_1insn_patch, "ax"
+                .word   661b
+                SET_GL(1)
+                .previous
+
                 rdpr    %tstate, %g1
                 sub     %g2, STACKFRAME_SZ + TRACEREG_SZ - STACK_BIAS, %g2
                 ba,pt   %xcc, 1b
diff --git a/arch/sparc64/kernel/rtrap.S b/arch/sparc64/kernel/rtrap.S
index ecfbbdc56125..e6130956307f 100644
--- a/arch/sparc64/kernel/rtrap.S
+++ b/arch/sparc64/kernel/rtrap.S
@@ -230,7 +230,14 @@ rt_continue:	ldx			[%sp + PTREGS_OFF + PT_V9_G1], %g1
 1:
                 ldx                     [%sp + PTREGS_OFF + PT_V9_G6], %g6
                 ldx                     [%sp + PTREGS_OFF + PT_V9_G7], %g7
-                wrpr                    %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate
+
+                /* Normal globals are restored, go to trap globals.  */
+661:            wrpr                    %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate
+                .section                .gl_1insn_patch, "ax"
+                .word                   661b
+                SET_GL(1)
+                .previous
+
                 ldx                     [%sp + PTREGS_OFF + PT_V9_I0], %i0
                 ldx                     [%sp + PTREGS_OFF + PT_V9_I1], %i1
 
@@ -304,6 +311,13 @@ user_rtt_fill_fixup:
                 mov     %g6, %l1
                 wrpr    %g0, 0x0, %tl
                 wrpr    %g0, RTRAP_PSTATE, %pstate
+
+661:            nop
+                .section                .gl_1insn_patch, "ax"
+                .word                   661b
+                SET_GL(0)
+                .previous
+
                 mov     %l1, %g6
                 ldx     [%g6 + TI_TASK], %g4
                 LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3)
diff --git a/arch/sparc64/kernel/setup.c b/arch/sparc64/kernel/setup.c
index 2918ed3eb1ba..aaab319ad885 100644
--- a/arch/sparc64/kernel/setup.c
+++ b/arch/sparc64/kernel/setup.c
@@ -545,6 +545,24 @@ static void __init per_cpu_patch(void)
 #endif
 }
 
+static void __init gl_patch(void)
+{
+        struct gl_1insn_patch_entry *p;
+
+        if (tlb_type != hypervisor)
+                return;
+
+        p = &__gl_1insn_patch;
+        while (p < &__gl_1insn_patch_end) {
+                unsigned long addr = p->addr;
+
+                *(unsigned int *) (addr +  0) = p->insn;
+                __asm__ __volatile__("flush     %0" : : "r" (addr +  0));
+
+                p++;
+        }
+}
+
 void __init setup_arch(char **cmdline_p)
 {
         /* Initialize PROM console and command line. */
@@ -567,6 +585,8 @@ void __init setup_arch(char **cmdline_p)
          */
         per_cpu_patch();
 
+        gl_patch();
+
         boot_flags_init(*cmdline_p);
 
         idprom_init();
diff --git a/arch/sparc64/kernel/vmlinux.lds.S b/arch/sparc64/kernel/vmlinux.lds.S
index 1639d9c935c3..482d1ed87f4d 100644
--- a/arch/sparc64/kernel/vmlinux.lds.S
+++ b/arch/sparc64/kernel/vmlinux.lds.S
@@ -77,6 +77,9 @@ SECTIONS
   __cpuid_patch = .;
   .cpuid_patch : { *(.cpuid_patch) }
   __cpuid_patch_end = .;
+  __gl_1insn_patch = .;
+  .gl_1insn_patch : { *(.gl_1insn_patch) }
+  __gl_1insn_patch_end = .;
   . = ALIGN(8192); 
   __initramfs_start = .;
   .init.ramfs : { *(.init.ramfs) }