From 16f9afe651e8197fb7ce6df0990d8e2ad779e1af Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 27 May 2013 21:43:41 +0530 Subject: ARC: pt_regs update #3: Remove unused gutter at start of callee_regs This is trickier than prev two: * context switching code saves kernel mode callee regs in the format of struct callee_regs thus needs adjustment. This also reduces the height of topmost kernel stack frame by 1 word. * Since kernel stack unwinder is sensitive to height of topmost kernel stack frame, that needs a word of adjustment too. ptrace needs a bit of updating since pt_regs now diverges from user_regs_struct. Signed-off-by: Vineet Gupta --- arch/arc/include/asm/entry.h | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) (limited to 'arch/arc/include/asm/entry.h') diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h index 5ff7b8dd3d5b..820202af21a5 100644 --- a/arch/arc/include/asm/entry.h +++ b/arch/arc/include/asm/entry.h @@ -124,8 +124,6 @@ st.a r25, [sp, -4] #endif - /* move up by 1 word to "create" callee_regs->"stack_place_holder" */ - sub sp, sp, 4 .endm /*-------------------------------------------------------------- @@ -148,10 +146,9 @@ st.a r23, [sp, -4] st.a r24, [sp, -4] #ifdef CONFIG_ARC_CURR_IN_REG - sub sp, sp, 8 + sub sp, sp, 4 #else st.a r25, [sp, -4] - sub sp, sp, 4 #endif .endm @@ -168,14 +165,11 @@ *-------------------------------------------------------------*/ .macro RESTORE_CALLEE_SAVED_KERNEL - #ifdef CONFIG_ARC_CURR_IN_REG - add sp, sp, 8 /* skip callee_reg gutter and user r25 placeholder */ + add sp, sp, 4 /* skip usual r25 placeholder */ #else - add sp, sp, 4 /* skip "callee_regs->stack_place_holder" */ ld.ab r25, [sp, 4] #endif - ld.ab r24, [sp, 4] ld.ab r23, [sp, 4] ld.ab r22, [sp, 4] @@ -203,8 +197,6 @@ *-------------------------------------------------------------*/ .macro RESTORE_CALLEE_SAVED_USER - add sp, sp, 4 /* skip "callee_regs->stack_place_holder" */ - #ifdef CONFIG_ARC_CURR_IN_REG ld.ab r12, [sp, 4] st r12, [r25, TASK_THREAD + THREAD_USER_R25] @@ -230,7 +222,7 @@ * Super FAST Restore callee saved regs by simply re-adjusting SP *-------------------------------------------------------------*/ .macro DISCARD_CALLEE_SAVED_USER - add sp, sp, 14 * 4 + add sp, sp, SZ_CALLEE_REGS .endm /*-------------------------------------------------------------- -- cgit v1.2.3