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Diffstat (limited to 'arch/tile/kernel/intvec_32.S')
| -rw-r--r-- | arch/tile/kernel/intvec_32.S | 1906 |
1 files changed, 0 insertions, 1906 deletions
diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S deleted file mode 100644 index 9ff75e3a318a..000000000000 --- a/arch/tile/kernel/intvec_32.S +++ /dev/null @@ -1,1906 +0,0 @@ -/* - * Copyright 2010 Tilera Corporation. All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation, version 2. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for - * more details. - * - * Linux interrupt vectors. - */ - -#include <linux/linkage.h> -#include <linux/errno.h> -#include <linux/init.h> -#include <linux/unistd.h> -#include <asm/ptrace.h> -#include <asm/thread_info.h> -#include <asm/irqflags.h> -#include <asm/atomic_32.h> -#include <asm/asm-offsets.h> -#include <hv/hypervisor.h> -#include <arch/abi.h> -#include <arch/interrupts.h> -#include <arch/spr_def.h> - -#define PTREGS_PTR(reg, ptreg) addli reg, sp, C_ABI_SAVE_AREA_SIZE + (ptreg) - -#define PTREGS_OFFSET_SYSCALL PTREGS_OFFSET_REG(TREG_SYSCALL_NR) - - .macro push_reg reg, ptr=sp, delta=-4 - { - sw \ptr, \reg - addli \ptr, \ptr, \delta - } - .endm - - .macro pop_reg reg, ptr=sp, delta=4 - { - lw \reg, \ptr - addli \ptr, \ptr, \delta - } - .endm - - .macro pop_reg_zero reg, zreg, ptr=sp, delta=4 - { - move \zreg, zero - lw \reg, \ptr - addi \ptr, \ptr, \delta - } - .endm - - .macro push_extra_callee_saves reg - PTREGS_PTR(\reg, PTREGS_OFFSET_REG(51)) - push_reg r51, \reg - push_reg r50, \reg - push_reg r49, \reg - push_reg r48, \reg - push_reg r47, \reg - push_reg r46, \reg - push_reg r45, \reg - push_reg r44, \reg - push_reg r43, \reg - push_reg r42, \reg - push_reg r41, \reg - push_reg r40, \reg - push_reg r39, \reg - push_reg r38, \reg - push_reg r37, \reg - push_reg r36, \reg - push_reg r35, \reg - push_reg r34, \reg, PTREGS_OFFSET_BASE - PTREGS_OFFSET_REG(34) - .endm - - .macro panic str - .pushsection .rodata, "a" -1: - .asciz "\str" - .popsection - { - moveli r0, lo16(1b) - } - { - auli r0, r0, ha16(1b) - jal panic - } - .endm - -#ifdef __COLLECT_LINKER_FEEDBACK__ - .pushsection .text.intvec_feedback,"ax" -intvec_feedback: - .popsection -#endif - - /* - * Default interrupt handler. - * - * vecnum is where we'll put this code. - * c_routine is the C routine we'll call. - * - * The C routine is passed two arguments: - * - A pointer to the pt_regs state. - * - The interrupt vector number. - * - * The "processing" argument specifies the code for processing - * the interrupt. Defaults to "handle_interrupt". - */ - .macro int_hand vecnum, vecname, c_routine, processing=handle_interrupt - .org (\vecnum << 8) -intvec_\vecname: - .ifc \vecnum, INT_SWINT_1 - blz TREG_SYSCALL_NR_NAME, sys_cmpxchg - .endif - - /* Temporarily save a register so we have somewhere to work. */ - - mtspr SPR_SYSTEM_SAVE_K_1, r0 - mfspr r0, SPR_EX_CONTEXT_K_1 - - /* The cmpxchg code clears sp to force us to reset it here on fault. */ - { - bz sp, 2f - andi r0, r0, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ - } - - .ifc \vecnum, INT_DOUBLE_FAULT - /* - * For double-faults from user-space, fall through to the normal - * register save and stack setup path. Otherwise, it's the - * hypervisor giving us one last chance to dump diagnostics, and we - * branch to the kernel_double_fault routine to do so. - */ - bz r0, 1f - j _kernel_double_fault -1: - .else - /* - * If we're coming from user-space, then set sp to the top of - * the kernel stack. Otherwise, assume sp is already valid. - */ - { - bnz r0, 0f - move r0, sp - } - .endif - - .ifc \c_routine, do_page_fault - /* - * The page_fault handler may be downcalled directly by the - * hypervisor even when Linux is running and has ICS set. - * - * In this case the contents of EX_CONTEXT_K_1 reflect the - * previous fault and can't be relied on to choose whether or - * not to reinitialize the stack pointer. So we add a test - * to see whether SYSTEM_SAVE_K_2 has the high bit set, - * and if so we don't reinitialize sp, since we must be coming - * from Linux. (In fact the precise case is !(val & ~1), - * but any Linux PC has to have the high bit set.) - * - * Note that the hypervisor *always* sets SYSTEM_SAVE_K_2 for - * any path that turns into a downcall to one of our TLB handlers. - */ - mfspr r0, SPR_SYSTEM_SAVE_K_2 - { - blz r0, 0f /* high bit in S_S_1_2 is for a PC to use */ - move r0, sp - } - .endif - -2: - /* - * SYSTEM_SAVE_K_0 holds the cpu number in the low bits, and - * the current stack top in the higher bits. So we recover - * our stack top by just masking off the low bits, then - * point sp at the top aligned address on the actual stack page. - */ - mfspr r0, SPR_SYSTEM_SAVE_K_0 - mm r0, r0, zero, LOG2_NR_CPU_IDS, 31 - -0: - /* - * Align the stack mod 64 so we can properly predict what - * cache lines we need to write-hint to reduce memory fetch - * latency as we enter the kernel. The layout of memory is - * as follows, with cache line 0 at the lowest VA, and cache - * line 4 just below the r0 value this "andi" computes. - * Note that we never write to cache line 4, and we skip - * cache line 1 for syscalls. - * - * cache line 4: ptregs padding (two words) - * cache line 3: r46...lr, pc, ex1, faultnum, orig_r0, flags, pad - * cache line 2: r30...r45 - * cache line 1: r14...r29 - * cache line 0: 2 x frame, r0..r13 - */ -#if STACK_TOP_DELTA != 64 -#error STACK_TOP_DELTA must be 64 for assumptions here and in task_pt_regs() -#endif - andi r0, r0, -64 - - /* - * Push the first four registers on the stack, so that we can set - * them to vector-unique values before we jump to the common code. - * - * Registers are pushed on the stack as a struct pt_regs, - * with the sp initially just above the struct, and when we're - * done, sp points to the base of the struct, minus - * C_ABI_SAVE_AREA_SIZE, so we can directly jal to C code. - * - * This routine saves just the first four registers, plus the - * stack context so we can do proper backtracing right away, - * and defers to handle_interrupt to save the rest. - * The backtracer needs pc, ex1, lr, sp, r52, and faultnum. - */ - addli r0, r0, PTREGS_OFFSET_LR - (PTREGS_SIZE + KSTK_PTREGS_GAP) - wh64 r0 /* cache line 3 */ - { - sw r0, lr - addli r0, r0, PTREGS_OFFSET_SP - PTREGS_OFFSET_LR - } - { - sw r0, sp - addli sp, r0, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_SP - } - { - sw sp, r52 - addli sp, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(52) - } - wh64 sp /* cache line 0 */ - { - sw sp, r1 - addli sp, sp, PTREGS_OFFSET_REG(2) - PTREGS_OFFSET_REG(1) - } - { - sw sp, r2 - addli sp, sp, PTREGS_OFFSET_REG(3) - PTREGS_OFFSET_REG(2) - } - { - sw sp, r3 - addli sp, sp, PTREGS_OFFSET_PC - PTREGS_OFFSET_REG(3) - } - mfspr r0, SPR_EX_CONTEXT_K_0 - .ifc \processing,handle_syscall - /* - * Bump the saved PC by one bundle so that when we return, we won't - * execute the same swint instruction again. We need to do this while - * we're in the critical section. - */ - addi r0, r0, 8 - .endif - { - sw sp, r0 - addli sp, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC - } - mfspr r0, SPR_EX_CONTEXT_K_1 - { - sw sp, r0 - addi sp, sp, PTREGS_OFFSET_FAULTNUM - PTREGS_OFFSET_EX1 - /* - * Use r0 for syscalls so it's a temporary; use r1 for interrupts - * so that it gets passed through unchanged to the handler routine. - * Note that the .if conditional confusingly spans bundles. - */ - .ifc \processing,handle_syscall - movei r0, \vecnum - } - { - sw sp, r0 - .else - movei r1, \vecnum - } - { - sw sp, r1 - .endif - addli sp, sp, PTREGS_OFFSET_REG(0) - PTREGS_OFFSET_FAULTNUM - } - mfspr r0, SPR_SYSTEM_SAVE_K_1 /* Original r0 */ - { - sw sp, r0 - addi sp, sp, -PTREGS_OFFSET_REG(0) - 4 - } - { - sw sp, zero /* write zero into "Next SP" frame pointer */ - addi sp, sp, -4 /* leave SP pointing at bottom of frame */ - } - .ifc \processing,handle_syscall - j handle_syscall - .else - /* - * Capture per-interrupt SPR context to registers. - * We overload the meaning of r3 on this path such that if its bit 31 - * is set, we have to mask all interrupts including NMIs before - * clearing the interrupt critical section bit. - * See discussion below at "finish_interrupt_save". - */ - .ifc \c_routine, do_page_fault - mfspr r2, SPR_SYSTEM_SAVE_K_3 /* address of page fault */ - mfspr r3, SPR_SYSTEM_SAVE_K_2 /* info about page fault */ - .else - .ifc \vecnum, INT_DOUBLE_FAULT - { - mfspr r2, SPR_SYSTEM_SAVE_K_2 /* double fault info from HV */ - movei r3, 0 - } - .else - .ifc \c_routine, do_trap - { - mfspr r2, GPV_REASON - movei r3, 0 - } - .else - .ifc \c_routine, handle_perf_interrupt - { - mfspr r2, PERF_COUNT_STS - movei r3, -1 /* not used, but set for consistency */ - } - .else - .ifc \c_routine, handle_perf_interrupt - { - mfspr r2, AUX_PERF_COUNT_STS - movei r3, -1 /* not used, but set for consistency */ - } - .else - movei r3, 0 - .endif - .endif - .endif - .endif - .endif - /* Put function pointer in r0 */ - moveli r0, lo16(\c_routine) - { - auli r0, r0, ha16(\c_routine) - j \processing - } - .endif - ENDPROC(intvec_\vecname) - -#ifdef __COLLECT_LINKER_FEEDBACK__ - .pushsection .text.intvec_feedback,"ax" - .org (\vecnum << 5) - FEEDBACK_ENTER_EXPLICIT(intvec_\vecname, .intrpt, 1 << 8) - jrp lr - .popsection -#endif - - .endm - - - /* - * Save the rest of the registers that we didn't save in the actual - * vector itself. We can't use r0-r10 inclusive here. - */ - .macro finish_interrupt_save, function - - /* If it's a syscall, save a proper orig_r0, otherwise just zero. */ - PTREGS_PTR(r52, PTREGS_OFFSET_ORIG_R0) - { - .ifc \function,handle_syscall - sw r52, r0 - .else - sw r52, zero - .endif - PTREGS_PTR(r52, PTREGS_OFFSET_TP) - } - - /* - * For ordinary syscalls, we save neither caller- nor callee- - * save registers, since the syscall invoker doesn't expect the - * caller-saves to be saved, and the called kernel functions will - * take care of saving the callee-saves for us. - * - * For interrupts we save just the caller-save registers. Saving - * them is required (since the "caller" can't save them). Again, - * the called kernel functions will restore the callee-save - * registers for us appropriately. - * - * On return, we normally restore nothing special for syscalls, - * and just the caller-save registers for interrupts. - * - * However, there are some important caveats to all this: - * - * - We always save a few callee-save registers to give us - * some scratchpad registers to carry across function calls. - * - * - fork/vfork/etc require us to save all the callee-save - * registers, which we do in PTREGS_SYSCALL_ALL_REGS, below. - * - * - We always save r0..r5 and r10 for syscalls, since we need - * to reload them a bit later for the actual kernel call, and - * since we might need them for -ERESTARTNOINTR, etc. - * - * - Before invoking a signal handler, we save the unsaved - * callee-save registers so they are visible to the - * signal handler or any ptracer. - * - * - If the unsaved callee-save registers are modified, we set - * a bit in pt_regs so we know to reload them from pt_regs - * and not just rely on the kernel function unwinding. - * (Done for ptrace register writes and SA_SIGINFO handler.) - */ - { - sw r52, tp - PTREGS_PTR(r52, PTREGS_OFFSET_REG(33)) - } - wh64 r52 /* cache line 2 */ - push_reg r33, r52 - push_reg r32, r52 - push_reg r31, r52 - .ifc \function,handle_syscall - push_reg r30, r52, PTREGS_OFFSET_SYSCALL - PTREGS_OFFSET_REG(30) - push_reg TREG_SYSCALL_NR_NAME, r52, \ - PTREGS_OFFSET_REG(5) - PTREGS_OFFSET_SYSCALL - .else - - push_reg r30, r52, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(30) - wh64 r52 /* cache line 1 */ - push_reg r29, r52 - push_reg r28, r52 - push_reg r27, r52 - push_reg r26, r52 - push_reg r25, r52 - push_reg r24, r52 - push_reg r23, r52 - push_reg r22, r52 - push_reg r21, r52 - push_reg r20, r52 - push_reg r19, r52 - push_reg r18, r52 - push_reg r17, r52 - push_reg r16, r52 - push_reg r15, r52 - push_reg r14, r52 - push_reg r13, r52 - push_reg r12, r52 - push_reg r11, r52 - push_reg r10, r52 - push_reg r9, r52 - push_reg r8, r52 - push_reg r7, r52 - push_reg r6, r52 - - .endif - - push_reg r5, r52 - sw r52, r4 - - /* Load tp with our per-cpu offset. */ -#ifdef CONFIG_SMP - { - mfspr r20, SPR_SYSTEM_SAVE_K_0 - moveli r21, lo16(__per_cpu_offset) - } - { - auli r21, r21, ha16(__per_cpu_offset) - mm r20, r20, zero, 0, LOG2_NR_CPU_IDS-1 - } - s2a r20, r20, r21 - lw tp, r20 -#else - move tp, zero -#endif - - /* - * If we will be returning to the kernel, we will need to - * reset the interrupt masks to the state they had before. - * Set DISABLE_IRQ in flags iff we came from PL1 with irqs disabled. - * We load flags in r32 here so we can jump to .Lrestore_regs - * directly after do_page_fault_ics() if necessary. - */ - mfspr r32, SPR_EX_CONTEXT_K_1 - { - andi r32, r32, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ - PTREGS_PTR(r21, PTREGS_OFFSET_FLAGS) - } - bzt r32, 1f /* zero if from user space */ - IRQS_DISABLED(r32) /* zero if irqs enabled */ -#if PT_FLAGS_DISABLE_IRQ != 1 -# error Value of IRQS_DISABLED used to set PT_FLAGS_DISABLE_IRQ; fix -#endif -1: - .ifnc \function,handle_syscall - /* Record the fact that we saved the caller-save registers above. */ - ori r32, r32, PT_FLAGS_CALLER_SAVES - .endif - sw r21, r32 - -#ifdef __COLLECT_LINKER_FEEDBACK__ - /* - * Notify the feedback routines that we were in the - * appropriate fixed interrupt vector area. Note that we - * still have ICS set at this point, so we can't invoke any - * atomic operations or we will panic. The feedback - * routines internally preserve r0..r10 and r30 up. - */ - .ifnc \function,handle_syscall - shli r20, r1, 5 - .else - moveli r20, INT_SWINT_1 << 5 - .endif - addli r20, r20, lo16(intvec_feedback) - auli r20, r20, ha16(intvec_feedback) - jalr r20 - - /* And now notify the feedback routines that we are here. */ - FEEDBACK_ENTER(\function) -#endif - - /* - * we've captured enough state to the stack (including in - * particular our EX_CONTEXT state) that we can now release - * the interrupt critical section and replace it with our - * standard "interrupts disabled" mask value. This allows - * synchronous interrupts (and profile interrupts) to punch - * through from this point onwards. - * - * If bit 31 of r3 is set during a non-NMI interrupt, we know we - * are on the path where the hypervisor has punched through our - * ICS with a page fault, so we call out to do_page_fault_ics() - * to figure out what to do with it. If the fault was in - * an atomic op, we unlock the atomic lock, adjust the - * saved register state a little, and return "zero" in r4, - * falling through into the normal page-fault interrupt code. - * If the fault was in a kernel-space atomic operation, then - * do_page_fault_ics() resolves it itself, returns "one" in r4, - * and as a result goes directly to restoring registers and iret, - * without trying to adjust the interrupt masks at all. - * The do_page_fault_ics() API involves passing and returning - * a five-word struct (in registers) to avoid writing the - * save and restore code here. - */ - .ifc \function,handle_nmi - IRQ_DISABLE_ALL(r20) - .else - .ifnc \function,handle_syscall - bgezt r3, 1f - { - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - jal do_page_fault_ics - } - FEEDBACK_REENTER(\function) - bzt r4, 1f - j .Lrestore_regs -1: - .endif - IRQ_DISABLE(r20, r21) - .endif - mtspr INTERRUPT_CRITICAL_SECTION, zero - - /* - * Prepare the first 256 stack bytes to be rapidly accessible - * without having to fetch the background data. We don't really - * know how far to write-hint, but kernel stacks generally - * aren't that big, and write-hinting here does take some time. - */ - addi r52, sp, -64 - { - wh64 r52 - addi r52, r52, -64 - } - { - wh64 r52 - addi r52, r52, -64 - } - { - wh64 r52 - addi r52, r52, -64 - } - wh64 r52 - -#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING) - .ifnc \function,handle_nmi - /* - * We finally have enough state set up to notify the irq - * tracing code that irqs were disabled on entry to the handler. - * The TRACE_IRQS_OFF call clobbers registers r0-r29. - * For syscalls, we already have the register state saved away - * on the stack, so we don't bother to do any register saves here, - * and later we pop the registers back off the kernel stack. - * For interrupt handlers, save r0-r3 in callee-saved registers. - */ - .ifnc \function,handle_syscall - { move r30, r0; move r31, r1 } - { move r32, r2; move r33, r3 } - .endif - TRACE_IRQS_OFF -#ifdef CONFIG_CONTEXT_TRACKING - jal context_tracking_user_exit -#endif - .ifnc \function,handle_syscall - { move r0, r30; move r1, r31 } - { move r2, r32; move r3, r33 } - .endif - .endif -#endif - - .endm - - .macro check_single_stepping, kind, not_single_stepping - /* - * Check for single stepping in user-level priv - * kind can be "normal", "ill", or "syscall" - * At end, if fall-thru - * r29: thread_info->step_state - * r28: &pt_regs->pc - * r27: pt_regs->pc - * r26: thread_info->step_state->buffer - */ - - /* Check for single stepping */ - GET_THREAD_INFO(r29) - { - /* Get pointer to field holding step state */ - addi r29, r29, THREAD_INFO_STEP_STATE_OFFSET - - /* Get pointer to EX1 in register state */ - PTREGS_PTR(r27, PTREGS_OFFSET_EX1) - } - { - /* Get pointer to field holding PC */ - PTREGS_PTR(r28, PTREGS_OFFSET_PC) - - /* Load the pointer to the step state */ - lw r29, r29 - } - /* Load EX1 */ - lw r27, r27 - { - /* Points to flags */ - addi r23, r29, SINGLESTEP_STATE_FLAGS_OFFSET - - /* No single stepping if there is no step state structure */ - bzt r29, \not_single_stepping - } - { - /* mask off ICS and any other high bits */ - andi r27, r27, SPR_EX_CONTEXT_1_1__PL_MASK - - /* Load pointer to single step instruction buffer */ - lw r26, r29 - } - /* Check priv state */ - bnz r27, \not_single_stepping - - /* Get flags */ - lw r22, r23 - { - /* Branch if single-step mode not enabled */ - bbnst r22, \not_single_stepping - - /* Clear enabled flag */ - andi r22, r22, ~SINGLESTEP_STATE_MASK_IS_ENABLED - } - .ifc \kind,normal - { - /* Load PC */ - lw r27, r28 - - /* Point to the entry containing the original PC */ - addi r24, r29, SINGLESTEP_STATE_ORIG_PC_OFFSET - } - { - /* Disable single stepping flag */ - sw r23, r22 - } - { - /* Get the original pc */ - lw r24, r24 - - /* See if the PC is at the start of the single step buffer */ - seq r25, r26, r27 - } - /* - * NOTE: it is really expected that the PC be in the single step buffer - * at this point - */ - bzt r25, \not_single_stepping - - /* Restore the original PC */ - sw r28, r24 - .else - .ifc \kind,syscall - { - /* Load PC */ - lw r27, r28 - - /* Point to the entry containing the next PC */ - addi r24, r29, SINGLESTEP_STATE_NEXT_PC_OFFSET - } - { - /* Increment the stopped PC by the bundle size */ - addi r26, r26, 8 - - /* Disable single stepping flag */ - sw r23, r22 - } - { - /* Get the next pc */ - lw r24, r24 - - /* - * See if the PC is one bundle past the start of the - * single step buffer - */ - seq r25, r26, r27 - } - { - /* - * NOTE: it is really expected that the PC be in the - * single step buffer at this point - */ - bzt r25, \not_single_stepping - } - /* Set to the next PC */ - sw r28, r24 - .else - { - /* Point to 3rd bundle in buffer */ - addi r25, r26, 16 - - /* Load PC */ - lw r27, r28 - } - { - /* Disable single stepping flag */ - sw r23, r22 - - /* See if the PC is in the single step buffer */ - slte_u r24, r26, r27 - } - { - slte_u r25, r27, r25 - - /* - * NOTE: it is really expected that the PC be in the - * single step buffer at this point - */ - bzt r24, \not_single_stepping - } - bzt r25, \not_single_stepping - .endif - .endif - .endm - - /* - * Redispatch a downcall. - */ - .macro dc_dispatch vecnum, vecname - .org (\vecnum << 8) -intvec_\vecname: - j _hv_downcall_dispatch - ENDPROC(intvec_\vecname) - .endm - - /* - * Common code for most interrupts. The C function we're eventually - * going to is in r0, and the faultnum is in r1; the original - * values for those registers are on the stack. - */ - .pushsection .text.handle_interrupt,"ax" -handle_interrupt: - finish_interrupt_save handle_interrupt - - /* - * Check for if we are single stepping in user level. If so, then - * we need to restore the PC. - */ - - check_single_stepping normal, .Ldispatch_interrupt -.Ldispatch_interrupt: - - /* Jump to the C routine; it should enable irqs as soon as possible. */ - { - jalr r0 - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - } - FEEDBACK_REENTER(handle_interrupt) - { - movei r30, 0 /* not an NMI */ - j interrupt_return - } - STD_ENDPROC(handle_interrupt) - -/* - * This routine takes a boolean in r30 indicating if this is an NMI. - * If so, we also expect a boolean in r31 indicating whether to - * re-enable the oprofile interrupts. - * - * Note that .Lresume_userspace is jumped to directly in several - * places, and we need to make sure r30 is set correctly in those - * callers as well. - */ -STD_ENTRY(interrupt_return) - /* If we're resuming to kernel space, don't check thread flags. */ - { - bnz r30, .Lrestore_all /* NMIs don't special-case user-space */ - PTREGS_PTR(r29, PTREGS_OFFSET_EX1) - } - lw r29, r29 - andi r29, r29, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ - bzt r29, .Lresume_userspace - -#ifdef CONFIG_PREEMPT - /* Returning to kernel space. Check if we need preemption. */ - GET_THREAD_INFO(r29) - addli r28, r29, THREAD_INFO_FLAGS_OFFSET - { - lw r28, r28 - addli r29, r29, THREAD_INFO_PREEMPT_COUNT_OFFSET - } - { - andi r28, r28, _TIF_NEED_RESCHED - lw r29, r29 - } - bzt r28, 1f - bnz r29, 1f - /* Disable interrupts explicitly for preemption. */ - IRQ_DISABLE(r20,r21) - TRACE_IRQS_OFF - jal preempt_schedule_irq - FEEDBACK_REENTER(interrupt_return) -1: -#endif - - /* If we're resuming to _cpu_idle_nap, bump PC forward by 8. */ - { - PTREGS_PTR(r29, PTREGS_OFFSET_PC) - moveli r27, lo16(_cpu_idle_nap) - } - { - lw r28, r29 - auli r27, r27, ha16(_cpu_idle_nap) - } - { - seq r27, r27, r28 - } - { - bbns r27, .Lrestore_all - addi r28, r28, 8 - } - sw r29, r28 - j .Lrestore_all - -.Lresume_userspace: - FEEDBACK_REENTER(interrupt_return) - - /* - * Disable interrupts so as to make sure we don't - * miss an interrupt that sets any of the thread flags (like - * need_resched or sigpending) between sampling and the iret. - * Routines like schedule() or do_signal() may re-enable - * interrupts before returning. - */ - IRQ_DISABLE(r20, r21) - TRACE_IRQS_OFF /* Note: clobbers registers r0-r29 */ - - /* - * See if there are any work items (including single-shot items) - * to do. If so, save the callee-save registers to pt_regs - * and then dispatch to C code. - */ - GET_THREAD_INFO(r21) - { - addi r22, r21, THREAD_INFO_FLAGS_OFFSET - moveli r20, lo16(_TIF_ALLWORK_MASK) - } - { - lw r22, r22 - auli r20, r20, ha16(_TIF_ALLWORK_MASK) - } - and r1, r22, r20 - { - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - bzt r1, .Lrestore_all - } - push_extra_callee_saves r0 - jal prepare_exit_to_usermode - - /* - * In the NMI case we - * omit the call to single_process_check_nohz, which normally checks - * to see if we should start or stop the scheduler tick, because - * we can't call arbitrary Linux code from an NMI context. - * We always call the homecache TLB deferral code to re-trigger - * the deferral mechanism. - * - * The other chunk of responsibility this code has is to reset the - * interrupt masks appropriately to reset irqs and NMIs. We have - * to call TRACE_IRQS_OFF and TRACE_IRQS_ON to support all the - * lockdep-type stuff, but we can't set ICS until afterwards, since - * ICS can only be used in very tight chunks of code to avoid - * tripping over various assertions that it is off. - * - * (There is what looks like a window of vulnerability here since - * we might take a profile interrupt between the two SPR writes - * that set the mask, but since we write the low SPR word first, - * and our interrupt entry code checks the low SPR word, any - * profile interrupt will actually disable interrupts in both SPRs - * before returning, which is OK.) - */ -.Lrestore_all: - PTREGS_PTR(r0, PTREGS_OFFSET_EX1) - { - lw r0, r0 - PTREGS_PTR(r32, PTREGS_OFFSET_FLAGS) - } - { - andi r0, r0, SPR_EX_CONTEXT_1_1__PL_MASK - lw r32, r32 - } - bnz r0, 1f - j 2f -#if PT_FLAGS_DISABLE_IRQ != 1 -# error Assuming PT_FLAGS_DISABLE_IRQ == 1 so we can use bbnst below -#endif -1: bbnst r32, 2f - IRQ_DISABLE(r20,r21) - TRACE_IRQS_OFF - movei r0, 1 - mtspr INTERRUPT_CRITICAL_SECTION, r0 - bzt r30, .Lrestore_regs - j 3f -2: TRACE_IRQS_ON - movei r0, 1 - mtspr INTERRUPT_CRITICAL_SECTION, r0 - IRQ_ENABLE(r20, r21) - bzt r30, .Lrestore_regs -3: - - /* We are relying on INT_PERF_COUNT at 33, and AUX_PERF_COUNT at 48 */ - { - moveli r0, lo16(1 << (INT_PERF_COUNT - 32)) - bz r31, .Lrestore_regs - } - auli r0, r0, ha16(1 << (INT_AUX_PERF_COUNT - 32)) - mtspr SPR_INTERRUPT_MASK_RESET_K_1, r0 - - /* - * We now commit to returning from this interrupt, since we will be - * doing things like setting EX_CONTEXT SPRs and unwinding the stack - * frame. No calls should be made to any other code after this point. - * This code should only be entered with ICS set. - * r32 must still be set to ptregs.flags. - * We launch loads to each cache line separately first, so we can - * get some parallelism out of the memory subsystem. - * We start zeroing caller-saved registers throughout, since - * that will save some cycles if this turns out to be a syscall. - */ -.Lrestore_regs: - FEEDBACK_REENTER(interrupt_return) /* called from elsewhere */ - - /* - * Rotate so we have one high bit and one low bit to test. - * - low bit says whether to restore all the callee-saved registers, - * or just r30-r33, and r52 up. - * - high bit (i.e. sign bit) says whether to restore all the - * caller-saved registers, or just r0. - */ -#if PT_FLAGS_CALLER_SAVES != 2 || PT_FLAGS_RESTORE_REGS != 4 -# error Rotate trick does not work :-) -#endif - { - rli r20, r32, 30 - PTREGS_PTR(sp, PTREGS_OFFSET_REG(0)) - } - - /* - * Load cache lines 0, 2, and 3 in that order, then use - * the last loaded value, which makes it likely that the other - * cache lines have also loaded, at which point we should be - * able to safely read all the remaining words on those cache - * lines without waiting for the memory subsystem. - */ - pop_reg_zero r0, r28, sp, PTREGS_OFFSET_REG(30) - PTREGS_OFFSET_REG(0) - pop_reg_zero r30, r2, sp, PTREGS_OFFSET_PC - PTREGS_OFFSET_REG(30) - pop_reg_zero r21, r3, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC - pop_reg_zero lr, r4, sp, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_EX1 - { - mtspr SPR_EX_CONTEXT_K_0, r21 - move r5, zero - } - { - mtspr SPR_EX_CONTEXT_K_1, lr - andi lr, lr, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ - } - - /* Restore callee-saveds that we actually use. */ - pop_reg_zero r52, r6, sp, PTREGS_OFFSET_REG(31) - PTREGS_OFFSET_REG(52) - pop_reg_zero r31, r7 - pop_reg_zero r32, r8 - pop_reg_zero r33, r9, sp, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(33) - - /* - * If we modified other callee-saveds, restore them now. - * This is rare, but could be via ptrace or signal handler. - */ - { - move r10, zero - bbs r20, .Lrestore_callees - } -.Lcontinue_restore_regs: - - /* Check if we're returning from a syscall. */ - { - move r11, zero - blzt r20, 1f /* no, so go restore callee-save registers */ - } - - /* - * Check if we're returning to userspace. - * Note that if we're not, we don't worry about zeroing everything. - */ - { - addli sp, sp, PTREGS_OFFSET_LR - PTREGS_OFFSET_REG(29) - bnz lr, .Lkernel_return - } - - /* - * On return from syscall, we've restored r0 from pt_regs, but we - * clear the remainder of the caller-saved registers. We could - * restore the syscall arguments, but there's not much point, - * and it ensures user programs aren't trying to use the - * caller-saves if we clear them, as well as avoiding leaking - * kernel pointers into userspace. - */ - pop_reg_zero lr, r12, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR - pop_reg_zero tp, r13, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP - { - lw sp, sp - move r14, zero - move r15, zero - } - { move r16, zero; move r17, zero } - { move r18, zero; move r19, zero } - { move r20, zero; move r21, zero } - { move r22, zero; move r23, zero } - { move r24, zero; move r25, zero } - { move r26, zero; move r27, zero } - - /* Set r1 to errno if we are returning an error, otherwise zero. */ - { - moveli r29, 4096 - sub r1, zero, r0 - } - slt_u r29, r1, r29 - { - mnz r1, r29, r1 - move r29, zero - } - iret - - /* - * Not a syscall, so restore caller-saved registers. - * First kick off a load for cache line 1, which we're touching - * for the first time here. - */ - .align 64 -1: pop_reg r29, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(29) - pop_reg r1 - pop_reg r2 - pop_reg r3 - pop_reg r4 - pop_reg r5 - pop_reg r6 - pop_reg r7 - pop_reg r8 - pop_reg r9 - pop_reg r10 - pop_reg r11 - pop_reg r12 - pop_reg r13 - pop_reg r14 - pop_reg r15 - pop_reg r16 - pop_reg r17 - pop_reg r18 - pop_reg r19 - pop_reg r20 - pop_reg r21 - pop_reg r22 - pop_reg r23 - pop_reg r24 - pop_reg r25 - pop_reg r26 - pop_reg r27 - pop_reg r28, sp, PTREGS_OFFSET_LR - PTREGS_OFFSET_REG(28) - /* r29 already restored above */ - bnz lr, .Lkernel_return - pop_reg lr, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR - pop_reg tp, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP - lw sp, sp - iret - - /* - * We can't restore tp when in kernel mode, since a thread might - * have migrated from another cpu and brought a stale tp value. - */ -.Lkernel_return: - pop_reg lr, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_LR - lw sp, sp - iret - - /* Restore callee-saved registers from r34 to r51. */ -.Lrestore_callees: - addli sp, sp, PTREGS_OFFSET_REG(34) - PTREGS_OFFSET_REG(29) - pop_reg r34 - pop_reg r35 - pop_reg r36 - pop_reg r37 - pop_reg r38 - pop_reg r39 - pop_reg r40 - pop_reg r41 - pop_reg r42 - pop_reg r43 - pop_reg r44 - pop_reg r45 - pop_reg r46 - pop_reg r47 - pop_reg r48 - pop_reg r49 - pop_reg r50 - pop_reg r51, sp, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(51) - j .Lcontinue_restore_regs - STD_ENDPROC(interrupt_return) - - /* - * Some interrupts don't check for single stepping - */ - .pushsection .text.handle_interrupt_no_single_step,"ax" -handle_interrupt_no_single_step: - finish_interrupt_save handle_interrupt_no_single_step - { - jalr r0 - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - } - FEEDBACK_REENTER(handle_interrupt_no_single_step) - { - movei r30, 0 /* not an NMI */ - j interrupt_return - } - STD_ENDPROC(handle_interrupt_no_single_step) - - /* - * "NMI" interrupts mask ALL interrupts before calling the - * handler, and don't check thread flags, etc., on the way - * back out. In general, the only things we do here for NMIs - * are the register save/restore, fixing the PC if we were - * doing single step, and the dataplane kernel-TLB management. - * We don't (for example) deal with start/stop of the sched tick. - */ - .pushsection .text.handle_nmi,"ax" -handle_nmi: - finish_interrupt_save handle_nmi - check_single_stepping normal, .Ldispatch_nmi -.Ldispatch_nmi: - { - jalr r0 - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - } - FEEDBACK_REENTER(handle_nmi) - { - movei r30, 1 - seq r31, r0, zero - } - j interrupt_return - STD_ENDPROC(handle_nmi) - - /* - * Parallel code for syscalls to handle_interrupt. - */ - .pushsection .text.handle_syscall,"ax" -handle_syscall: - finish_interrupt_save handle_syscall - - /* - * Check for if we are single stepping in user level. If so, then - * we need to restore the PC. - */ - check_single_stepping syscall, .Ldispatch_syscall -.Ldispatch_syscall: - - /* Enable irqs. */ - TRACE_IRQS_ON - IRQ_ENABLE(r20, r21) - - /* Bump the counter for syscalls made on this tile. */ - moveli r20, lo16(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET) - auli r20, r20, ha16(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET) - add r20, r20, tp - lw r21, r20 - addi r21, r21, 1 - { - sw r20, r21 - GET_THREAD_INFO(r31) - } - - /* Trace syscalls, if requested. */ - addi r31, r31, THREAD_INFO_FLAGS_OFFSET - lw r30, r31 - andi r30, r30, _TIF_SYSCALL_TRACE - bzt r30, .Lrestore_syscall_regs - { - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - jal do_syscall_trace_enter - } - FEEDBACK_REENTER(handle_syscall) - blz r0, .Lsyscall_sigreturn_skip - - /* - * We always reload our registers from the stack at this - * point. They might be valid, if we didn't build with - * TRACE_IRQFLAGS, and this isn't a dataplane tile, and we're not - * doing syscall tracing, but there are enough cases now that it - * seems simplest just to do the reload unconditionally. - */ -.Lrestore_syscall_regs: - PTREGS_PTR(r11, PTREGS_OFFSET_REG(0)) - pop_reg r0, r11 - pop_reg r1, r11 - pop_reg r2, r11 - pop_reg r3, r11 - pop_reg r4, r11 - pop_reg r5, r11, PTREGS_OFFSET_SYSCALL - PTREGS_OFFSET_REG(5) - pop_reg TREG_SYSCALL_NR_NAME, r11 - - /* Ensure that the syscall number is within the legal range. */ - moveli r21, __NR_syscalls - { - slt_u r21, TREG_SYSCALL_NR_NAME, r21 - moveli r20, lo16(sys_call_table) - } - { - bbns r21, .Linvalid_syscall - auli r20, r20, ha16(sys_call_table) - } - s2a r20, TREG_SYSCALL_NR_NAME, r20 - lw r20, r20 - - /* Jump to syscall handler. */ - jalr r20 -.Lhandle_syscall_link: /* value of "lr" after "jalr r20" above */ - - /* - * Write our r0 onto the stack so it gets restored instead - * of whatever the user had there before. - */ - PTREGS_PTR(r29, PTREGS_OFFSET_REG(0)) - sw r29, r0 - -.Lsyscall_sigreturn_skip: - FEEDBACK_REENTER(handle_syscall) - - /* Do syscall trace again, if requested. */ - lw r30, r31 - andi r30, r30, _TIF_SYSCALL_TRACE - bzt r30, 1f - { - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - jal do_syscall_trace_exit - } - FEEDBACK_REENTER(handle_syscall) -1: { - movei r30, 0 /* not an NMI */ - j .Lresume_userspace /* jump into middle of interrupt_return */ - } - -.Linvalid_syscall: - /* Report an invalid syscall back to the user program */ - { - PTREGS_PTR(r29, PTREGS_OFFSET_REG(0)) - movei r28, -ENOSYS - } - sw r29, r28 - { - movei r30, 0 /* not an NMI */ - j .Lresume_userspace /* jump into middle of interrupt_return */ - } - STD_ENDPROC(handle_syscall) - - /* Return the address for oprofile to suppress in backtraces. */ -STD_ENTRY_SECTION(handle_syscall_link_address, .text.handle_syscall) - lnk r0 - { - addli r0, r0, .Lhandle_syscall_link - . - jrp lr - } - STD_ENDPROC(handle_syscall_link_address) - -STD_ENTRY(ret_from_fork) - jal sim_notify_fork - jal schedule_tail - FEEDBACK_REENTER(ret_from_fork) - { - movei r30, 0 /* not an NMI */ - j .Lresume_userspace /* jump into middle of interrupt_return */ - } - STD_ENDPROC(ret_from_fork) - -STD_ENTRY(ret_from_kernel_thread) - jal sim_notify_fork - jal schedule_tail - FEEDBACK_REENTER(ret_from_fork) - { - move r0, r31 - jalr r30 - } - FEEDBACK_REENTER(ret_from_kernel_thread) - { - movei r30, 0 /* not an NMI */ - j interrupt_return - } - STD_ENDPROC(ret_from_kernel_thread) - - /* - * Code for ill interrupt. - */ - .pushsection .text.handle_ill,"ax" -handle_ill: - finish_interrupt_save handle_ill - - /* - * Check for if we are single stepping in user level. If so, then - * we need to restore the PC. - */ - check_single_stepping ill, .Ldispatch_normal_ill - - { - /* See if the PC is the 1st bundle in the buffer */ - seq r25, r27, r26 - - /* Point to the 2nd bundle in the buffer */ - addi r26, r26, 8 - } - { - /* Point to the original pc */ - addi r24, r29, SINGLESTEP_STATE_ORIG_PC_OFFSET - - /* Branch if the PC is the 1st bundle in the buffer */ - bnz r25, 3f - } - { - /* See if the PC is the 2nd bundle of the buffer */ - seq r25, r27, r26 - - /* Set PC to next instruction */ - addi r24, r29, SINGLESTEP_STATE_NEXT_PC_OFFSET - } - { - /* Point to flags */ - addi r25, r29, SINGLESTEP_STATE_FLAGS_OFFSET - - /* Branch if PC is in the second bundle */ - bz r25, 2f - } - /* Load flags */ - lw r25, r25 - { - /* - * Get the offset for the register to restore - * Note: the lower bound is 2, so we have implicit scaling by 4. - * No multiplication of the register number by the size of a register - * is needed. - */ - mm r27, r25, zero, SINGLESTEP_STATE_TARGET_LB, \ - SINGLESTEP_STATE_TARGET_UB - - /* Mask Rewrite_LR */ - andi r25, r25, SINGLESTEP_STATE_MASK_UPDATE - } - { - addi r29, r29, SINGLESTEP_STATE_UPDATE_VALUE_OFFSET - - /* Don't rewrite temp register */ - bz r25, 3f - } - { - /* Get the temp value */ - lw r29, r29 - - /* Point to where the register is stored */ - add r27, r27, sp - } - - /* Add in the C ABI save area size to the register offset */ - addi r27, r27, C_ABI_SAVE_AREA_SIZE - - /* Restore the user's register with the temp value */ - sw r27, r29 - j 3f - -2: - /* Must be in the third bundle */ - addi r24, r29, SINGLESTEP_STATE_BRANCH_NEXT_PC_OFFSET - -3: - /* set PC and continue */ - lw r26, r24 - { - sw r28, r26 - GET_THREAD_INFO(r0) - } - - /* - * Clear TIF_SINGLESTEP to prevent recursion if we execute an ill. - * The normal non-arch flow redundantly clears TIF_SINGLESTEP, but we - * need to clear it here and can't really impose on all other arches. - * So what's another write between friends? - */ - - addi r1, r0, THREAD_INFO_FLAGS_OFFSET - { - lw r2, r1 - addi r0, r0, THREAD_INFO_TASK_OFFSET /* currently a no-op */ - } - andi r2, r2, ~_TIF_SINGLESTEP - sw r1, r2 - - /* Issue a sigtrap */ - { - lw r0, r0 /* indirect thru thread_info to get task_info*/ - addi r1, sp, C_ABI_SAVE_AREA_SIZE /* put ptregs pointer into r1 */ - } - - jal send_sigtrap /* issue a SIGTRAP */ - FEEDBACK_REENTER(handle_ill) - { - movei r30, 0 /* not an NMI */ - j .Lresume_userspace /* jump into middle of interrupt_return */ - } - -.Ldispatch_normal_ill: - { - jalr r0 - PTREGS_PTR(r0, PTREGS_OFFSET_BASE) - } - FEEDBACK_REENTER(handle_ill) - { - movei r30, 0 /* not an NMI */ - j interrupt_return - } - STD_ENDPROC(handle_ill) - -/* Various stub interrupt handlers and syscall handlers */ - -STD_ENTRY_LOCAL(_kernel_double_fault) - mfspr r1, SPR_EX_CONTEXT_K_0 - move r2, lr - move r3, sp - move r4, r52 - addi sp, sp, -C_ABI_SAVE_AREA_SIZE - j kernel_double_fault - STD_ENDPROC(_kernel_double_fault) - -STD_ENTRY_LOCAL(bad_intr) - mfspr r2, SPR_EX_CONTEXT_K_0 - panic "Unhandled interrupt %#x: PC %#lx" - STD_ENDPROC(bad_intr) - -/* - * Special-case sigreturn to not write r0 to the stack on return. - * This is technically more efficient, but it also avoids difficulties - * in the 64-bit OS when handling 32-bit compat code, since we must not - * sign-extend r0 for the sigreturn return-value case. - */ -#define PTREGS_SYSCALL_SIGRETURN(x, reg) \ - STD_ENTRY(_##x); \ - addli lr, lr, .Lsyscall_sigreturn_skip - .Lhandle_syscall_link; \ - { \ - PTREGS_PTR(reg, PTREGS_OFFSET_BASE); \ - j x \ - }; \ - STD_ENDPROC(_##x) - -PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0) - -/* Save additional callee-saves to pt_regs and jump to standard function. */ -STD_ENTRY(_sys_clone) - push_extra_callee_saves r4 - j sys_clone - STD_ENDPROC(_sys_clone) - -/* - * This entrypoint is taken for the cmpxchg and atomic_update fast - * swints. We may wish to generalize it to other fast swints at some - * point, but for now there are just two very similar ones, which - * makes it faster. - * - * The fast swint code is designed to have a small footprint. It does - * not save or restore any GPRs, counting on the caller-save registers - * to be available to it on entry. It does not modify any callee-save - * registers (including "lr"). It does not check what PL it is being - * called at, so you'd better not call it other than at PL0. - * The <atomic.h> wrapper assumes it only clobbers r20-r29, so if - * it ever is necessary to use more registers, be aware. - * - * It does not use the stack, but since it might be re-interrupted by - * a page fault which would assume the stack was valid, it does - * save/restore the stack pointer and zero it out to make sure it gets reset. - * Since we always keep interrupts disabled, the hypervisor won't - * clobber our EX_CONTEXT_K_x registers, so we don't save/restore them - * (other than to advance the PC on return). - * - * We have to manually validate the user vs kernel address range - * (since at PL1 we can read/write both), and for performance reasons - * we don't allow cmpxchg on the fc000000 memory region, since we only - * validate that the user address is below PAGE_OFFSET. - * - * We place it in the __HEAD section to ensure it is relatively - * near to the intvec_SWINT_1 code (reachable by a conditional branch). - * - * Our use of ATOMIC_LOCK_REG here must match do_page_fault_ics(). - * - * As we do in lib/atomic_asm_32.S, we bypass a store if the value we - * would store is the same as the value we just loaded. - */ - __HEAD - .align 64 - /* Align much later jump on the start of a cache line. */ - nop -#if PAGE_SIZE >= 0x10000 - nop -#endif -ENTRY(sys_cmpxchg) - - /* - * Save "sp" and set it zero for any possible page fault. - * - * HACK: We want to both zero sp and check r0's alignment, - * so we do both at once. If "sp" becomes nonzero we - * know r0 is unaligned and branch to the error handler that - * restores sp, so this is OK. - * - * ICS is disabled right now so having a garbage but nonzero - * sp is OK, since we won't execute any faulting instructions - * when it is nonzero. - */ - { - move r27, sp - andi sp, r0, 3 - } - - /* - * Get the lock address in ATOMIC_LOCK_REG, and also validate that the - * address is less than PAGE_OFFSET, since that won't trap at PL1. - * We only use bits less than PAGE_SHIFT to avoid having to worry - * about aliasing among multiple mappings of the same physical page, - * and we ignore the low 3 bits so we have one lock that covers - * both a cmpxchg64() and a cmpxchg() on either its low or high word. - * NOTE: this must match __atomic_hashed_lock() in lib/atomic_32.c. - */ - -#if (PAGE_OFFSET & 0xffff) != 0 -# error Code here assumes PAGE_OFFSET can be loaded with just hi16() -#endif - - { - /* Check for unaligned input. */ - bnz sp, .Lcmpxchg_badaddr - auli r23, zero, hi16(PAGE_OFFSET) /* hugepage-aligned */ - } - { - /* - * Slide bits into position for 'mm'. We want to ignore - * the low 3 bits of r0, and consider only the next - * ATOMIC_HASH_SHIFT bits. - * Because of C pointer arithmetic, we want to compute this: - * - * ((char*)atomic_locks + - * (((r0 >> 3) & ((1 << ATOMIC_HASH_SHIFT) - 1)) << 2)) - * - * Instead of two shifts we just ">> 1", and use 'mm' - * to ignore the low and high bits we don't want. - */ - shri r25, r0, 1 - - slt_u r23, r0, r23 - - /* - * Ensure that the TLB is loaded before we take out the lock. - * This will start fetching the value all the way into our L1 - * as well (and if it gets modified before we grab the lock, - * it will be invalidated from our cache before we reload it). - */ - lw r26, r0 - } - { - auli r21, zero, ha16(atomic_locks) - - bbns r23, .Lcmpxchg_badaddr - } -#if PAGE_SIZE < 0x10000 - /* atomic_locks is page-aligned so for big pages we don't need this. */ - addli r21, r21, lo16(atomic_locks) -#endif - { - /* - * Insert the hash bits into the page-aligned pointer. - * ATOMIC_HASH_SHIFT is so big that we don't actually hash - * the unmasked address bits, as that may cause unnecessary - * collisions. - */ - mm ATOMIC_LOCK_REG_NAME, r25, r21, 2, (ATOMIC_HASH_SHIFT + 2) - 1 - - seqi r23, TREG_SYSCALL_NR_NAME, __NR_FAST_cmpxchg64 - } - { - /* Branch away at this point if we're doing a 64-bit cmpxchg. */ - bbs r23, .Lcmpxchg64 - andi r23, r0, 7 /* Precompute alignment for cmpxchg64. */ - } - { - /* - * We very carefully align the code that actually runs with - * the lock held (twelve bundles) so that we know it is all in - * the icache when we start. This instruction (the jump) is - * at the start of the first cache line, address zero mod 64; - * we jump to the very end of the second cache line to get that - * line loaded in the icache, then fall through to issue the tns - * in the third cache line, at which point it's all cached. - * Note that is for performance, not correctness. - */ - j .Lcmpxchg32_tns - } - -/* Symbol for do_page_fault_ics() to use to compare against the PC. */ -.global __sys_cmpxchg_grab_lock -__sys_cmpxchg_grab_lock: - - /* - * Perform the actual cmpxchg or atomic_update. - */ -.Ldo_cmpxchg32: - { - lw r21, r0 - seqi r23, TREG_SYSCALL_NR_NAME, __NR_FAST_atomic_update - move r24, r2 - } - { - seq r22, r21, r1 /* See if cmpxchg matches. */ - and r25, r21, r1 /* If atomic_update, compute (*mem & mask) */ - } - { - or r22, r22, r23 /* Skip compare branch for atomic_update. */ - add r25, r25, r2 /* Compute (*mem & mask) + addend. */ - } - { - mvnz r24, r23, r25 /* Use atomic_update value if appropriate. */ - bbns r22, .Lcmpxchg32_nostore - } - seq r22, r24, r21 /* Are we storing the value we loaded? */ - bbs r22, .Lcmpxchg32_nostore - sw r0, r24 - - /* The following instruction is the start of the second cache line. */ - /* Do slow mtspr here so the following "mf" waits less. */ - { - move sp, r27 - mtspr SPR_EX_CONTEXT_K_0, r28 - } - mf - - { - move r0, r21 - sw ATOMIC_LOCK_REG_NAME, zero - } - iret - - /* Duplicated code here in the case where we don't overlap "mf" */ -.Lcmpxchg32_nostore: - { - move r0, r21 - sw ATOMIC_LOCK_REG_NAME, zero - } - { - move sp, r27 - mtspr SPR_EX_CONTEXT_K_0, r28 - } - iret - - /* - * The locking code is the same for 32-bit cmpxchg/atomic_update, - * and for 64-bit cmpxchg. We provide it as a macro and put - * it into both versions. We can't share the code literally - * since it depends on having the right branch-back address. - */ - .macro cmpxchg_lock, bitwidth - - /* Lock; if we succeed, jump back up to the read-modify-write. */ -#ifdef CONFIG_SMP - tns r21, ATOMIC_LOCK_REG_NAME -#else - /* - * Non-SMP preserves all the lock infrastructure, to keep the - * code simpler for the interesting (SMP) case. However, we do - * one small optimization here and in atomic_asm.S, which is - * to fake out acquiring the actual lock in the atomic_lock table. - */ - movei r21, 0 -#endif - - /* Issue the slow SPR here while the tns result is in flight. */ - mfspr r28, SPR_EX_CONTEXT_K_0 - - { - addi r28, r28, 8 /* return to the instruction after the swint1 */ - bzt r21, .Ldo_cmpxchg\bitwidth - } - /* - * The preceding instruction is the last thing that must be - * hot in the icache before we do the "tns" above. - */ - -#ifdef CONFIG_SMP - /* - * We failed to acquire the tns lock on our first try. Now use - * bounded exponential backoff to retry, like __atomic_spinlock(). - */ - { - moveli r23, 2048 /* maximum backoff time in cycles */ - moveli r25, 32 /* starting backoff time in cycles */ - } -1: mfspr r26, CYCLE_LOW /* get start point for this backoff */ -2: mfspr r22, CYCLE_LOW /* test to see if we've backed off enough */ - sub r22, r22, r26 - slt r22, r22, r25 - bbst r22, 2b - { - shli r25, r25, 1 /* double the backoff; retry the tns */ - tns r21, ATOMIC_LOCK_REG_NAME - } - slt r26, r23, r25 /* is the proposed backoff too big? */ - { - mvnz r25, r26, r23 - bzt r21, .Ldo_cmpxchg\bitwidth - } - j 1b -#endif /* CONFIG_SMP */ - .endm - -.Lcmpxchg32_tns: - /* - * This is the last instruction on the second cache line. - * The nop here loads the second line, then we fall through - * to the tns to load the third line before we take the lock. - */ - nop - cmpxchg_lock 32 - - /* - * This code is invoked from sys_cmpxchg after most of the - * preconditions have been checked. We still need to check - * that r0 is 8-byte aligned, since if it's not we won't - * actually be atomic. However, ATOMIC_LOCK_REG has the atomic - * lock pointer and r27/r28 have the saved SP/PC. - * r23 is holding "r0 & 7" so we can test for alignment. - * The compare value is in r2/r3; the new value is in r4/r5. - * On return, we must put the old value in r0/r1. - */ - .align 64 -.Lcmpxchg64: - { - bzt r23, .Lcmpxchg64_tns - } - j .Lcmpxchg_badaddr - -.Ldo_cmpxchg64: - { - lw r21, r0 - addi r25, r0, 4 - } - { - lw r1, r25 - } - seq r26, r21, r2 - { - bz r26, .Lcmpxchg64_mismatch - seq r26, r1, r3 - } - { - bz r26, .Lcmpxchg64_mismatch - } - sw r0, r4 - sw r25, r5 - - /* - * The 32-bit path provides optimized "match" and "mismatch" - * iret paths, but we don't have enough bundles in this cache line - * to do that, so we just make even the "mismatch" path do an "mf". - */ -.Lcmpxchg64_mismatch: - { - move sp, r27 - mtspr SPR_EX_CONTEXT_K_0, r28 - } - mf - { - move r0, r21 - sw ATOMIC_LOCK_REG_NAME, zero - } - iret - -.Lcmpxchg64_tns: - cmpxchg_lock 64 - - - /* - * Reset sp and revector to sys_cmpxchg_badaddr(), which will - * just raise the appropriate signal and exit. Doing it this - * way means we don't have to duplicate the code in intvec.S's - * int_hand macro that locates the top of the stack. - */ -.Lcmpxchg_badaddr: - { - moveli TREG_SYSCALL_NR_NAME, __NR_cmpxchg_badaddr - move sp, r27 - } - j intvec_SWINT_1 - ENDPROC(sys_cmpxchg) - ENTRY(__sys_cmpxchg_end) - - -/* The single-step support may need to read all the registers. */ -int_unalign: - push_extra_callee_saves r0 - j do_trap - -/* Include .intrpt array of interrupt vectors */ - .section ".intrpt", "ax" - -#ifndef CONFIG_USE_PMC -#define handle_perf_interrupt bad_intr -#endif - -#ifndef CONFIG_HARDWALL -#define do_hardwall_trap bad_intr -#endif - - int_hand INT_ITLB_MISS, ITLB_MISS, \ - do_page_fault, handle_interrupt_no_single_step - int_hand INT_MEM_ERROR, MEM_ERROR, bad_intr - int_hand INT_ILL, ILL, do_trap, handle_ill - int_hand INT_GPV, GPV, do_trap - int_hand INT_SN_ACCESS, SN_ACCESS, do_trap - int_hand INT_IDN_ACCESS, IDN_ACCESS, do_trap - int_hand INT_UDN_ACCESS, UDN_ACCESS, do_trap - int_hand INT_IDN_REFILL, IDN_REFILL, bad_intr - int_hand INT_UDN_REFILL, UDN_REFILL, bad_intr - int_hand INT_IDN_COMPLETE, IDN_COMPLETE, bad_intr - int_hand INT_UDN_COMPLETE, UDN_COMPLETE, bad_intr - int_hand INT_SWINT_3, SWINT_3, do_trap - int_hand INT_SWINT_2, SWINT_2, do_trap - int_hand INT_SWINT_1, SWINT_1, SYSCALL, handle_syscall - int_hand INT_SWINT_0, SWINT_0, do_trap - int_hand INT_UNALIGN_DATA, UNALIGN_DATA, int_unalign - int_hand INT_DTLB_MISS, DTLB_MISS, do_page_fault - int_hand INT_DTLB_ACCESS, DTLB_ACCESS, do_page_fault - int_hand INT_DMATLB_MISS, DMATLB_MISS, do_page_fault - int_hand INT_DMATLB_ACCESS, DMATLB_ACCESS, do_page_fault - int_hand INT_SNITLB_MISS, SNITLB_MISS, do_page_fault - int_hand INT_SN_NOTIFY, SN_NOTIFY, bad_intr - int_hand INT_SN_FIREWALL, SN_FIREWALL, do_hardwall_trap - int_hand INT_IDN_FIREWALL, IDN_FIREWALL, bad_intr - int_hand INT_UDN_FIREWALL, UDN_FIREWALL, do_hardwall_trap - int_hand INT_TILE_TIMER, TILE_TIMER, do_timer_interrupt - int_hand INT_IDN_TIMER, IDN_TIMER, bad_intr - int_hand INT_UDN_TIMER, UDN_TIMER, bad_intr - int_hand INT_DMA_NOTIFY, DMA_NOTIFY, bad_intr - int_hand INT_IDN_CA, IDN_CA, bad_intr - int_hand INT_UDN_CA, UDN_CA, bad_intr - int_hand INT_IDN_AVAIL, IDN_AVAIL, bad_intr - int_hand INT_UDN_AVAIL, UDN_AVAIL, bad_intr - int_hand INT_PERF_COUNT, PERF_COUNT, \ - handle_perf_interrupt, handle_nmi - int_hand INT_INTCTRL_3, INTCTRL_3, bad_intr -#if CONFIG_KERNEL_PL == 2 - dc_dispatch INT_INTCTRL_2, INTCTRL_2 - int_hand INT_INTCTRL_1, INTCTRL_1, bad_intr -#else - int_hand INT_INTCTRL_2, INTCTRL_2, bad_intr - dc_dispatch INT_INTCTRL_1, INTCTRL_1 -#endif - int_hand INT_INTCTRL_0, INTCTRL_0, bad_intr - int_hand INT_MESSAGE_RCV_DWNCL, MESSAGE_RCV_DWNCL, \ - hv_message_intr - int_hand INT_DEV_INTR_DWNCL, DEV_INTR_DWNCL, \ - tile_dev_intr - int_hand INT_I_ASID, I_ASID, bad_intr - int_hand INT_D_ASID, D_ASID, bad_intr - int_hand INT_DMATLB_MISS_DWNCL, DMATLB_MISS_DWNCL, \ - do_page_fault - int_hand INT_SNITLB_MISS_DWNCL, SNITLB_MISS_DWNCL, \ - do_page_fault - int_hand INT_DMATLB_ACCESS_DWNCL, DMATLB_ACCESS_DWNCL, \ - do_page_fault - int_hand INT_SN_CPL, SN_CPL, bad_intr - int_hand INT_DOUBLE_FAULT, DOUBLE_FAULT, do_trap - int_hand INT_AUX_PERF_COUNT, AUX_PERF_COUNT, \ - handle_perf_interrupt, handle_nmi - - /* Synthetic interrupt delivered only by the simulator */ - int_hand INT_BREAKPOINT, BREAKPOINT, do_breakpoint |
