- the motivation was to be remove blatent copy-paste due to hasty support of CONFIG_ARC_IRQ_NO_AUTOSAVE support - but with refactoring we could use LDD/STD to greatly optimize the code Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx> --- arch/arc/include/asm/entry-arcv2.h | 297 +++++++++++++++++-------------------- arch/arc/include/asm/linkage.h | 18 +++ arch/arc/kernel/asm-offsets.c | 7 + arch/arc/kernel/entry-arcv2.S | 4 +- 4 files changed, 167 insertions(+), 159 deletions(-) diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h index beaf655666cb..0733752ce7fe 100644 --- a/arch/arc/include/asm/entry-arcv2.h +++ b/arch/arc/include/asm/entry-arcv2.h @@ -46,7 +46,8 @@ */ /*------------------------------------------------------------------------*/ -.macro INTERRUPT_PROLOGUE called_from +.macro INTERRUPT_PROLOGUE + ; (A) Before jumping to Interrupt Vector, hardware micro-ops did following: ; 1. SP auto-switched to kernel mode stack ; 2. STATUS32.Z flag set if in U mode at time of interrupt (U:1,K:0) @@ -57,39 +58,87 @@ ; (B) Manually saved some regs: r12,r25,r30, sp,fp,gp, ACCL pair #ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE -.ifnc \called_from, exception - st.as r9, [sp, -10] ; save r9 in it's final stack slot - sub sp, sp, 12 ; skip JLI, LDI, EI - - PUSH lp_count - PUSHAX lp_start - PUSHAX lp_end - PUSH blink - - PUSH r11 - PUSH r10 - - sub sp, sp, 4 ; skip r9 - - PUSH r8 - PUSH r7 - PUSH r6 - PUSH r5 - PUSH r4 - PUSH r3 - PUSH r2 - PUSH r1 - PUSH r0 -.endif -#endif + ; carve pt_regs on stack (case #3), PC/STAT32 already on stack + sub sp, sp, SZ_PT_REGS - 8 -#ifdef CONFIG_ARC_HAS_ACCL_REGS - PUSH r59 - PUSH r58 + __SAVE_REGFILE_HARD +#else + ; carve pt_regs on stack (case #4), which grew partially already + sub sp, sp, PT_r0 #endif - PUSH r30 - PUSH r12 + __SAVE_REGFILE_SOFT +.endm + +/*------------------------------------------------------------------------*/ +.macro EXCEPTION_PROLOGUE + + ; (A) Before jumping to Exception Vector, hardware micro-ops did following: + ; 1. SP auto-switched to kernel mode stack + ; 2. STATUS32.Z flag set if in U mode at time of exception (U:1,K:0) + ; + ; (B) Manually save the complete reg file below + + sub sp, sp, SZ_PT_REGS ; carve pt_regs + + ; _HARD saves r10 clobbered by _SOFT as scratch hence comes first + + __SAVE_REGFILE_HARD + __SAVE_REGFILE_SOFT + + st r0, [sp] ; orig_r0 + + lr r10, [eret] + lr r11, [erstatus] + ST2 r10, r11, PT_ret + + lr r10, [ecr] + lr r11, [erbta] + ST2 r10, r11, PT_event + mov r9, r10 + + ; OUTPUT: r9 has ECR +.endm + +/*------------------------------------------------------------------------ + * This macro saves the registers manually which would normally be autosaved + * by hardware on taken interrupts. It is used by + * - exception handlers (which don't have autosave) + * - interrupt autosave disabled due to CONFIG_ARC_IRQ_NO_AUTOSAVE + */ +.macro __SAVE_REGFILE_HARD + + ST2 r0, r1, PT_r0 + ST2 r2, r3, PT_r2 + ST2 r4, r5, PT_r4 + ST2 r6, r7, PT_r6 + ST2 r8, r9, PT_r8 + ST2 r10, r11, PT_r10 + + st blink, [sp, PT_blink] + + lr r10, [lp_end] + lr r11, [lp_start] + ST2 r10, r11, PT_lpe + + st lp_count, [sp, PT_lpc] + + ; skip JLI, LDI, EI for now +.endm + +/*------------------------------------------------------------------------ + * This macros saves a bunch of other registers which can't be autosaved for + * various reasons: + * - r12: the last caller saved scratch reg since hardware saves in pairs so r0-r11 + * - r30: free reg, used by gcc as scratch + * - ACCL/ACCH pair when they exist + */ +.macro __SAVE_REGFILE_SOFT + + ST2 gp, fp, PT_r26 ; gp (r26), fp (r27) + + st r12, [sp, PT_sp + 4] + st r30, [sp, PT_sp + 8] ; Saving pt_regs->sp correctly requires some extra work due to the way ; Auto stack switch works @@ -100,46 +149,32 @@ ; 2. Upon entry SP is always saved (for any inspection, unwinding etc), ; but on return, restored only if U mode - lr r9, [AUX_USER_SP] ; U mode SP + lr r10, [AUX_USER_SP] ; U mode SP - mov.nz r9, sp - add.nz r9, r9, SZ_PT_REGS - PT_sp - 4 ; K mode SP + ; ISA requires ADD.nz to have same dest and src reg operands + mov.nz r10, sp + add.nz r10, r10, SZ_PT_REGS ; K mode SP - PUSH r9 ; SP (pt_regs->sp) - - PUSH fp - PUSH gp + st r10, [sp, PT_sp] ; SP (pt_regs->sp) #ifdef CONFIG_ARC_CURR_IN_REG - PUSH r25 ; user_r25 + st r25, [sp, PT_user_r25] GET_CURR_TASK_ON_CPU r25 -#else - sub sp, sp, 4 #endif -.ifnc \called_from, exception - sub sp, sp, 12 ; BTA/ECR/orig_r0 placeholder per pt_regs -.endif +#ifdef CONFIG_ARC_HAS_ACCL_REGS + ST2 r58, r59, PT_sp + 12 +#endif .endm /*------------------------------------------------------------------------*/ -.macro INTERRUPT_EPILOGUE called_from +.macro __RESTORE_REGFILE_SOFT - ; INPUT: r0 has STAT32 of calling context - ; INPUT: Z flag set if returning to K mode -.ifnc \called_from, exception - add sp, sp, 12 ; skip BTA/ECR/orig_r0 placeholderss -.endif - -#ifdef CONFIG_ARC_CURR_IN_REG - POP r25 -#else - add sp, sp, 4 -#endif + LD2 gp, fp, PT_r26 ; gp (r26), fp (r27) - POP gp - POP fp + ld r12, [sp, PT_sp + 4] + ld r30, [sp, PT_sp + 8] ; Restore SP (into AUX_USER_SP) only if returning to U mode ; - for K mode, it will be implicitly restored as stack is unwound @@ -147,129 +182,77 @@ ; but that doesn't really matter bz 1f - POPAX AUX_USER_SP + ld r10, [sp, PT_sp] ; SP (pt_regs->sp) + sr r10, [AUX_USER_SP] 1: - POP r12 - POP r30 -#ifdef CONFIG_ARC_HAS_ACCL_REGS - POP r58 - POP r59 +#ifdef CONFIG_ARC_CURR_IN_REG + ld r25, [sp, PT_user_r25] #endif -#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE -.ifnc \called_from, exception - POP r0 - POP r1 - POP r2 - POP r3 - POP r4 - POP r5 - POP r6 - POP r7 - POP r8 - POP r9 - POP r10 - POP r11 - - POP blink - POPAX lp_end - POPAX lp_start - - POP r9 - mov lp_count, r9 - - add sp, sp, 12 ; skip JLI, LDI, EI - ld.as r9, [sp, -10] ; reload r9 which got clobbered -.endif +#ifdef CONFIG_ARC_HAS_ACCL_REGS + LD2 r58, r59, PT_sp + 12 #endif - .endm /*------------------------------------------------------------------------*/ -.macro EXCEPTION_PROLOGUE +.macro __RESTORE_REGFILE_HARD - ; (A) Before jumping to Exception Vector, hardware micro-ops did following: - ; 1. SP auto-switched to kernel mode stack - ; 2. STATUS32.Z flag set if in U mode at time of exception (U:1,K:0) - ; - ; (B) Manually save the complete reg file below + ld blink, [sp, PT_blink] - PUSH r9 ; freeup a register: slot of erstatus + LD2 r10, r11, PT_lpe + sr r10, [lp_end] + sr r11, [lp_start] - PUSHAX eret - sub sp, sp, 12 ; skip JLI, LDI, EI - PUSH lp_count - PUSHAX lp_start - PUSHAX lp_end - PUSH blink + ld r10, [sp, PT_lpc] ; lp_count can't be target of LD + mov lp_count, r10 - PUSH r11 - PUSH r10 + LD2 r0, r1, PT_r0 + LD2 r2, r3, PT_r2 + LD2 r4, r5, PT_r4 + LD2 r6, r7, PT_r6 + LD2 r8, r9, PT_r8 + LD2 r10, r11, PT_r10 +.endm - ld.as r9, [sp, 10] ; load stashed r9 (status32 stack slot) - lr r10, [erstatus] - st.as r10, [sp, 10] ; save status32 at it's right stack slot - PUSH r9 - PUSH r8 - PUSH r7 - PUSH r6 - PUSH r5 - PUSH r4 - PUSH r3 - PUSH r2 - PUSH r1 - PUSH r0 +/*------------------------------------------------------------------------*/ +.macro INTERRUPT_EPILOGUE - ; -- for interrupts, regs above are auto-saved by h/w in that order -- - ; Now do what ISR prologue does (manually save r12, sp, fp, gp, r25) + ; INPUT: r0 has STAT32 of calling context + ; INPUT: Z flag set if returning to K mode - INTERRUPT_PROLOGUE exception + ; _SOFT clobbers r10 restored by _HARD hence the order - PUSHAX erbta - PUSHAX ecr ; r9 contains ECR, expected by EV_Trap + __RESTORE_REGFILE_SOFT + +#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE + __RESTORE_REGFILE_HARD + add sp, sp, SZ_PT_REGS - 8 +#else + add sp, sp, PT_r0 +#endif - PUSH r0 ; orig_r0 - ; OUTPUT: r9 has ECR .endm /*------------------------------------------------------------------------*/ .macro EXCEPTION_EPILOGUE ; INPUT: r0 has STAT32 of calling context - btst r0, STATUS_U_BIT ; Z flag set if K, used in INTERRUPT_EPILOGUE - - add sp, sp, 8 ; orig_r0/ECR don't need restoring - POPAX erbta - - INTERRUPT_EPILOGUE exception - - POP r0 - POP r1 - POP r2 - POP r3 - POP r4 - POP r5 - POP r6 - POP r7 - POP r8 - POP r9 - POP r10 - POP r11 - - POP blink - POPAX lp_end - POPAX lp_start - - POP r9 - mov lp_count, r9 - - add sp, sp, 12 ; skip JLI, LDI, EI - POPAX eret - POPAX erstatus - - ld.as r9, [sp, -12] ; reload r9 which got clobbered + + btst r0, STATUS_U_BIT ; Z flag set if K, used in restoring SP + + ld r10, [sp, PT_event + 4] + sr r10, [erbta] + + LD2 r10, r11, PT_ret + sr r10, [eret] + sr r11, [erstatus] + + __RESTORE_REGFILE_SOFT + __RESTORE_REGFILE_HARD + + add sp, sp, SZ_PT_REGS .endm .macro FAKE_RET_FROM_EXCPN diff --git a/arch/arc/include/asm/linkage.h b/arch/arc/include/asm/linkage.h index b29f1a9fd6f7..7d90163f716f 100644 --- a/arch/arc/include/asm/linkage.h +++ b/arch/arc/include/asm/linkage.h @@ -13,6 +13,24 @@ #ifdef __ASSEMBLY__ +.macro ST2 e, o, off +#ifdef CONFIG_ARC_HAS_LL64 + std \e, [sp, \off] +#else + st \e, [sp, \off] + st \o, [sp, \off+4] +#endif +.endm + +.macro LD2 e, o, off +#ifdef CONFIG_ARC_HAS_LL64 + ldd \e, [sp, \off] +#else + ld \e, [sp, \off] + ld \o, [sp, \off+4] +#endif +.endm + #define ASM_NL ` /* use '`' to mark new line in macro */ /* annotation for data we want in DCCM - if enabled in .config */ diff --git a/arch/arc/kernel/asm-offsets.c b/arch/arc/kernel/asm-offsets.c index ecaf34e9235c..e90dccecfd83 100644 --- a/arch/arc/kernel/asm-offsets.c +++ b/arch/arc/kernel/asm-offsets.c @@ -58,7 +58,14 @@ int main(void) DEFINE(PT_r5, offsetof(struct pt_regs, r5)); DEFINE(PT_r6, offsetof(struct pt_regs, r6)); DEFINE(PT_r7, offsetof(struct pt_regs, r7)); + DEFINE(PT_r8, offsetof(struct pt_regs, r8)); + DEFINE(PT_r10, offsetof(struct pt_regs, r10)); + DEFINE(PT_r26, offsetof(struct pt_regs, r26)); DEFINE(PT_ret, offsetof(struct pt_regs, ret)); + DEFINE(PT_blink, offsetof(struct pt_regs, blink)); + DEFINE(PT_lpe, offsetof(struct pt_regs, lp_end)); + DEFINE(PT_lpc, offsetof(struct pt_regs, lp_count)); + DEFINE(PT_user_r25, offsetof(struct pt_regs, user_r25)); DEFINE(SZ_CALLEE_REGS, sizeof(struct callee_regs)); DEFINE(SZ_PT_REGS, sizeof(struct pt_regs)); diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S index 562089d62d9d..6cbf0ee8a20a 100644 --- a/arch/arc/kernel/entry-arcv2.S +++ b/arch/arc/kernel/entry-arcv2.S @@ -70,7 +70,7 @@ reserved: ENTRY(handle_interrupt) - INTERRUPT_PROLOGUE irq + INTERRUPT_PROLOGUE # irq control APIs local_irq_save/restore/disable/enable fiddle with # global interrupt enable bits in STATUS32 (.IE for 1 prio, .E[] for 2 prio) @@ -226,7 +226,7 @@ debug_marker_l1: bset.nz r11, r11, AUX_IRQ_ACT_BIT_U ; NZ means U sr r11, [AUX_IRQ_ACT] - INTERRUPT_EPILOGUE irq + INTERRUPT_EPILOGUE rtie ;####### Return from Exception / pure kernel mode ####### -- 2.7.4 _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
