sh: SMP support for SH2 entry.S
The SH2 version of entry.S uses global variables, which need to be
cpu-local in order to work with SMP. For ease of access from asm,
simply use arrays indexed by cpu number, and require the availability
of an address (mmio register or properly setup per-cpu memory) from
which the current cpu's index can be read.
Signed-off-by: Rich Felker <dalias@libc.org>
diff --git a/arch/sh/kernel/cpu/sh2/entry.S b/arch/sh/kernel/cpu/sh2/entry.S
index 16bde0e..1ee0a6e 100644
--- a/arch/sh/kernel/cpu/sh2/entry.S
+++ b/arch/sh/kernel/cpu/sh2/entry.S
@@ -47,6 +47,13 @@
mov.l r3,@-sp
cli
mov.l $cpu_mode,r2
+#ifdef CONFIG_SMP
+ mov.l $cpuid,r3
+ mov.l @r3,r3
+ mov.l @r3,r3
+ shll2 r3
+ add r3,r2
+#endif
mov.l @r2,r0
mov.l @(5*4,r15),r3 ! previous SR
or r0,r3 ! set MD
@@ -57,6 +64,13 @@
mov.l __md_bit,r0
mov.l r0,@r2 ! enter kernel mode
mov.l $current_thread_info,r2
+#ifdef CONFIG_SMP
+ mov.l $cpuid,r0
+ mov.l @r0,r0
+ mov.l @r0,r0
+ shll2 r0
+ add r0,r2
+#endif
mov.l @r2,r2
mov #(THREAD_SIZE >> 8),r0
shll8 r0
@@ -265,6 +279,13 @@
lds.l @r0+,macl
mov r15,r0
mov.l $cpu_mode,r2
+#ifdef CONFIG_SMP
+ mov.l $cpuid,r3
+ mov.l @r3,r3
+ mov.l @r3,r3
+ shll2 r3
+ add r3,r2
+#endif
mov #OFF_SR,r3
mov.l @(r0,r3),r1
mov.l __md_bit,r3
@@ -281,6 +302,13 @@
mov.l r1,@r2 ! set pc
get_current_thread_info r0, r1
mov.l $current_thread_info,r1
+#ifdef CONFIG_SMP
+ mov.l $cpuid,r3
+ mov.l @r3,r3
+ mov.l @r3,r3
+ shll2 r3
+ add r3,r1
+#endif
mov.l r0,@r1
mov.l @r15+,r0
mov.l @r15+,r1
@@ -308,19 +336,41 @@
.long __current_thread_info
$cpu_mode:
.long __cpu_mode
+#ifdef CONFIG_SMP
+$cpuid:
+ .long sh2_cpuid_addr
+#endif
! common exception handler
#include "../../entry-common.S"
+
+#ifdef CONFIG_NR_CPUS
+#define NR_CPUS CONFIG_NR_CPUS
+#else
+#define NR_CPUS 1
+#endif
.data
! cpu operation mode
! bit30 = MD (compatible SH3/4)
__cpu_mode:
+ .rept NR_CPUS
.long 0x40000000
+ .endr
+
+#ifdef CONFIG_SMP
+.global sh2_cpuid_addr
+sh2_cpuid_addr:
+ .long dummy_cpuid
+dummy_cpuid:
+ .long 0
+#endif
.section .bss
__current_thread_info:
+ .rept NR_CPUS
.long 0
+ .endr
ENTRY(exception_handling_table)
.space 4*32