powerpc/32: enter syscall with MSR_EE inconditionaly set

syscalls are expected to be entered with MSR_EE set. Lets
make it inconditional by forcing MSR_EE on syscalls.

This patch adds EXC_XFER_SYS for that.

Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[splited out from benh RFC patch]

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

7 files changed, 13 insertions, 5 deletions

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index f98e6b461238..c5fd76d0caf6 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -375,7 +375,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
         DO_KVM  0xc00
 SystemCall:
         EXCEPTION_PROLOG
-        EXC_XFER_EE_LITE(0xc00, DoSyscall)
+        EXC_XFER_SYS(0xc00, DoSyscall)
 
 /* Single step - not used on 601 */
         EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index aa0131bb09b5..7221418a883f 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -123,6 +123,10 @@ label:
         EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
                           ret_from_except)
 
+#define EXC_XFER_SYS(n, hdlr)           \
+        EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL | MSR_EE, NOCOPY, transfer_to_handler, \
+                          ret_from_except)
+
 #define EXC_XFER_EE(n, hdlr)            \
         EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
                           ret_from_except_full)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index b3a2e55e1c15..3e1b8a85cc0d 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -350,7 +350,7 @@ _ENTRY(saved_ksp_limit)
 /* 0x0C00 - System Call Exception */
         START_EXCEPTION(0x0C00, SystemCall)
         EXCEPTION_PROLOG
-        EXC_XFER_EE_LITE(0xc00, DoSyscall)
+        EXC_XFER_SYS(0xc00, DoSyscall)
 
         EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_EE)
         EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_EE)
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 34a5df827b38..19268713b692 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -286,7 +286,7 @@ interrupt_base:
         /* System Call Interrupt */
         START_EXCEPTION(SystemCall)
         NORMAL_EXCEPTION_PROLOG(BOOKE_INTERRUPT_SYSCALL)
-        EXC_XFER_EE_LITE(0x0c00, DoSyscall)
+        EXC_XFER_SYS(0x0c00, DoSyscall)
 
         /* Auxiliary Processor Unavailable Interrupt */
         EXCEPTION(0x2020, BOOKE_INTERRUPT_AP_UNAVAIL, \
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 14c3eb3267b8..aa8e629f7725 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -186,7 +186,7 @@ Alignment:
         . = 0xc00
 SystemCall:
         EXCEPTION_PROLOG
-        EXC_XFER_EE_LITE(0xc00, DoSyscall)
+        EXC_XFER_SYS(0xc00, DoSyscall)
 
 /* Single step - not used on 601 */
         EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 1b22a8dea399..612f54ba1125 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -251,6 +251,10 @@ label:
         EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
                           ret_from_except)
 
+#define EXC_XFER_SYS(n, hdlr)                                           \
+        EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL | MSR_EE, NOCOPY, transfer_to_handler, \
+                          ret_from_except)
+
 #define EXC_XFER_EE(n, hdlr)            \
         EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
                           ret_from_except_full)
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 567e0ed45ca8..a7bebb996393 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -414,7 +414,7 @@ interrupt_base:
         /* System Call Interrupt */
         START_EXCEPTION(SystemCall)
         NORMAL_EXCEPTION_PROLOG(SYSCALL)
-        EXC_XFER_EE_LITE(0x0c00, DoSyscall)
+        EXC_XFER_SYS(0x0c00, DoSyscall)
 
         /* Auxiliary Processor Unavailable Interrupt */
         EXCEPTION(0x2900, AP_UNAVAIL, AuxillaryProcessorUnavailable, \