From bbc6f1ba509cf9cda42ce63bbd40afe577ab028e Mon Sep 17 00:00:00 2001 From: Greg Ungerer Date: Fri, 14 Oct 2011 15:41:56 +1000 Subject: [PATCH] m68k: set register a2 to current if MMU enabled on ColdFire Virtual memory m68k systems build with register a2 dedicated to being the current proc pointer (non-MMU don't do this). Add code to the ColdFire interrupt and exception processing to set this on entry, and at context switch time. We use the same GET_CURRENT() macro that MMU enabled code uses - modifying it so that the assembler is ColdFire clean. Signed-off-by: Greg Ungerer Acked-by: Matt Waddel Acked-by: Kurt Mahan Acked-by: Geert Uytterhoeven --- arch/m68k/include/asm/entry.h | 10 +++++++++- arch/m68k/kernel/entry_no.S | 3 +++ arch/m68k/platform/coldfire/entry.S | 6 +++++- 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/m68k/include/asm/entry.h b/arch/m68k/include/asm/entry.h index c3c5a8643e15..622138dc7288 100644 --- a/arch/m68k/include/asm/entry.h +++ b/arch/m68k/include/asm/entry.h @@ -222,16 +222,24 @@ * Non-MMU systems do not reserve %a2 in this way, and this definition is * not used for them. */ +#ifdef CONFIG_MMU + #define curptr a2 #define GET_CURRENT(tmp) get_current tmp .macro get_current reg=%d0 movel %sp,\reg - andw #-THREAD_SIZE,\reg + andl #-THREAD_SIZE,\reg movel \reg,%curptr movel %curptr@,%curptr .endm +#else + +#define GET_CURRENT(tmp) + +#endif /* CONFIG_MMU */ + #else /* C source */ #define STR(X) STR1(X) diff --git a/arch/m68k/kernel/entry_no.S b/arch/m68k/kernel/entry_no.S index ac86a9ffc1d7..d80cba45589f 100644 --- a/arch/m68k/kernel/entry_no.S +++ b/arch/m68k/kernel/entry_no.S @@ -44,6 +44,7 @@ ENTRY(buserr) SAVE_ALL_INT + GET_CURRENT(%d0) movel %sp,%sp@- /* stack frame pointer argument */ jsr buserr_c addql #4,%sp @@ -51,6 +52,7 @@ ENTRY(buserr) ENTRY(trap) SAVE_ALL_INT + GET_CURRENT(%d0) movel %sp,%sp@- /* stack frame pointer argument */ jsr trap_c addql #4,%sp @@ -61,6 +63,7 @@ ENTRY(trap) .globl dbginterrupt ENTRY(dbginterrupt) SAVE_ALL_INT + GET_CURRENT(%d0) movel %sp,%sp@- /* stack frame pointer argument */ jsr dbginterrupt_c addql #4,%sp diff --git a/arch/m68k/platform/coldfire/entry.S b/arch/m68k/platform/coldfire/entry.S index f567a163bc40..863889fc31c9 100644 --- a/arch/m68k/platform/coldfire/entry.S +++ b/arch/m68k/platform/coldfire/entry.S @@ -62,6 +62,7 @@ enosys: ENTRY(system_call) SAVE_ALL_SYS move #0x2000,%sr /* enable intrs again */ + GET_CURRENT(%d2) cmpl #NR_syscalls,%d0 jcc enosys @@ -165,6 +166,7 @@ Lsignal_return: */ ENTRY(inthandler) SAVE_ALL_INT + GET_CURRENT(%d2) movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */ andl #0x03fc,%d0 /* mask out vector only */ @@ -190,7 +192,9 @@ ENTRY(resume) movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */ RDUSP /* movel %usp,%a3 */ movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */ - +#ifdef CONFIG_MMU + movel %a1,%a2 /* set new current */ +#endif movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */ WRUSP /* movel %a3,%usp */ movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */