linux/arch/tile/kernel/intvec_64.S
Chris Metcalf b8ace0833f arch/tile: fix hardwall for tilegx and generalize for idn and ipi
The hardwall drain code was not properly implemented for tilegx,
just tilepro, so you couldn't reliably restart an application that
made use of the udn.

In addition, the code was only applicable to the udn (user dynamic
network).  On tilegx there is a second user network that is available
(the "idn"), and there is support for having I/O shims deliver
user-level interrupts to applications ("ipi") which functions in a
very similar way to the inter-core permissions used for udn/idn.
So this change also generalizes the code from supporting just the udn
to supports udn/idn/ipi on tilegx.

By default we now use /dev/hardwall/{udn,idn,ipi} with separate
minor numbers for the three devices.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-05-25 12:48:27 -04:00

1298 lines
35 KiB
ArmAsm

/*
* Copyright 2011 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/unistd.h>
#include <asm/ptrace.h>
#include <asm/thread_info.h>
#include <asm/irqflags.h>
#include <asm/asm-offsets.h>
#include <asm/types.h>
#include <asm/signal.h>
#include <hv/hypervisor.h>
#include <arch/abi.h>
#include <arch/interrupts.h>
#include <arch/spr_def.h>
#ifdef CONFIG_PREEMPT
# error "No support for kernel preemption currently"
#endif
#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=-8
{
st \ptr, \reg
addli \ptr, \ptr, \delta
}
.endm
.macro pop_reg reg, ptr=sp, delta=8
{
ld \reg, \ptr
addli \ptr, \ptr, \delta
}
.endm
.macro pop_reg_zero reg, zreg, ptr=sp, delta=8
{
move \zreg, zero
ld \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, hw2_last(1b)
}
{
shl16insli r0, r0, hw1(1b)
}
{
shl16insli r0, r0, hw0(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:
/* Temporarily save a register so we have somewhere to work. */
mtspr SPR_SYSTEM_SAVE_K_1, r0
mfspr r0, SPR_EX_CONTEXT_K_1
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.
*/
beqz 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.
*/
{
bnez 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.
*
* FIXME: if we end up never using this path, perhaps we should
* prevent the hypervisor from generating downcalls in this case.
* The advantage of getting a downcall is we can panic in Linux.
*/
mfspr r0, SPR_SYSTEM_SAVE_K_2
{
bltz r0, 0f /* high bit in S_S_1_2 is for a PC to use */
move r0, sp
}
.endif
/*
* 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, zero, LOG2_THREAD_SIZE, 63
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 8 just below the r0 value this "andi" computes.
* Note that we never write to cache line 8, and we skip
* cache lines 1-3 for syscalls.
*
* cache line 8: ptregs padding (two words)
* cache line 7: sp, lr, pc, ex1, faultnum, orig_r0, flags, cmpexch
* cache line 6: r46...r53 (tp)
* cache line 5: r38...r45
* cache line 4: r30...r37
* cache line 3: r22...r29
* cache line 2: r14...r21
* cache line 1: r6...r13
* cache line 0: 2 x frame, r0..r5
*/
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,
* and needs sp set to its final location at the bottom of
* the stack frame.
*/
addli r0, r0, PTREGS_OFFSET_LR - (PTREGS_SIZE + KSTK_PTREGS_GAP)
wh64 r0 /* cache line 7 */
{
st r0, lr
addli r0, r0, PTREGS_OFFSET_SP - PTREGS_OFFSET_LR
}
{
st r0, sp
addli sp, r0, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_SP
}
wh64 sp /* cache line 6 */
{
st sp, r52
addli sp, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(52)
}
wh64 sp /* cache line 0 */
{
st sp, r1
addli sp, sp, PTREGS_OFFSET_REG(2) - PTREGS_OFFSET_REG(1)
}
{
st sp, r2
addli sp, sp, PTREGS_OFFSET_REG(3) - PTREGS_OFFSET_REG(2)
}
{
st 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
{
st sp, r0
addli sp, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC
}
mfspr r0, SPR_EX_CONTEXT_K_1
{
st 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
}
{
st sp, r0
.else
movei r1, \vecnum
}
{
st sp, r1
.endif
addli sp, sp, PTREGS_OFFSET_REG(0) - PTREGS_OFFSET_FAULTNUM
}
mfspr r0, SPR_SYSTEM_SAVE_K_1 /* Original r0 */
{
st sp, r0
addi sp, sp, -PTREGS_OFFSET_REG(0) - 8
}
{
st sp, zero /* write zero into "Next SP" frame pointer */
addi sp, sp, -8 /* leave SP pointing at bottom of frame */
}
.ifc \processing,handle_syscall
j handle_syscall
.else
/* Capture per-interrupt SPR context to registers. */
.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_ILL_TRANS
mfspr r2, ILL_TRANS_REASON
.else
.ifc \vecnum, INT_DOUBLE_FAULT
mfspr r2, SPR_SYSTEM_SAVE_K_2 /* double fault info from HV */
.else
.ifc \c_routine, do_trap
mfspr r2, GPV_REASON
.else
.ifc \c_routine, op_handle_perf_interrupt
mfspr r2, PERF_COUNT_STS
#if CHIP_HAS_AUX_PERF_COUNTERS()
.else
.ifc \c_routine, op_handle_aux_perf_interrupt
mfspr r2, AUX_PERF_COUNT_STS
.endif
#endif
.endif
.endif
.endif
.endif
.endif
/* Put function pointer in r0 */
moveli r0, hw2_last(\c_routine)
shl16insli r0, r0, hw1(\c_routine)
{
shl16insli r0, r0, hw0(\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, .intrpt1, 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
st r52, r0
.else
st r52, zero
.endif
PTREGS_PTR(r52, PTREGS_OFFSET_TP)
}
st r52, tp
{
mfspr tp, CMPEXCH_VALUE
PTREGS_PTR(r52, PTREGS_OFFSET_CMPEXCH)
}
/*
* 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.)
*/
{
st r52, tp
PTREGS_PTR(r52, PTREGS_OFFSET_REG(33))
}
wh64 r52 /* cache line 4 */
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 3 */
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
wh64 r52 /* cache line 2 */
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
wh64 r52 /* cache line 1 */
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
st r52, r4
/*
* 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.
*/
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)
}
beqzt 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
st r21, r32
/*
* 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.
*
* It's important that no code before this point touch memory
* other than our own stack (to keep the invariant that this
* is all that gets touched under ICS), and that no code after
* this point reference any interrupt-specific SPR, in particular
* the EX_CONTEXT_K_ values.
*/
.ifc \function,handle_nmi
IRQ_DISABLE_ALL(r20)
.else
IRQ_DISABLE(r20, r21)
.endif
mtspr INTERRUPT_CRITICAL_SECTION, zero
/* Load tp with our per-cpu offset. */
#ifdef CONFIG_SMP
{
mfspr r20, SPR_SYSTEM_SAVE_K_0
moveli r21, hw2_last(__per_cpu_offset)
}
{
shl16insli r21, r21, hw1(__per_cpu_offset)
bfextu r20, r20, 0, LOG2_THREAD_SIZE-1
}
shl16insli r21, r21, hw0(__per_cpu_offset)
shl3add r20, r20, r21
ld tp, r20
#else
move tp, zero
#endif
#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
moveli r21, hw2_last(intvec_feedback)
shl16insli r21, r21, hw1(intvec_feedback)
shl16insli r21, r21, hw0(intvec_feedback)
add r20, r20, r21
jalr r20
/* And now notify the feedback routines that we are here. */
FEEDBACK_ENTER(\function)
#endif
/*
* Prepare the first 256 stack bytes to be rapidly accessible
* without having to fetch the background data.
*/
addi r52, sp, -64
{
wh64 r52
addi r52, r52, -64
}
{
wh64 r52
addi r52, r52, -64
}
{
wh64 r52
addi r52, r52, -64
}
wh64 r52
#ifdef CONFIG_TRACE_IRQFLAGS
.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
.ifnc \function,handle_syscall
{ move r0, r30; move r1, r31 }
{ move r2, r32; move r3, r33 }
.endif
.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
/* 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. */
{
bnez r30, .Lrestore_all /* NMIs don't special-case user-space */
PTREGS_PTR(r29, PTREGS_OFFSET_EX1)
}
ld r29, r29
andi r29, r29, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */
{
beqzt r29, .Lresume_userspace
PTREGS_PTR(r29, PTREGS_OFFSET_PC)
}
/* If we're resuming to _cpu_idle_nap, bump PC forward by 8. */
moveli r27, hw2_last(_cpu_idle_nap)
{
ld r28, r29
shl16insli r27, r27, hw1(_cpu_idle_nap)
}
{
shl16insli r27, r27, hw0(_cpu_idle_nap)
}
{
cmpeq r27, r27, r28
}
{
blbc r27, .Lrestore_all
addi r28, r28, 8
}
st r29, r28
j .Lrestore_all
.Lresume_userspace:
FEEDBACK_REENTER(interrupt_return)
/*
* Use r33 to hold whether we have already loaded the callee-saves
* into ptregs. We don't want to do it twice in this loop, since
* then we'd clobber whatever changes are made by ptrace, etc.
*/
{
movei r33, 0
move r32, sp
}
/* Get base of stack in r32. */
EXTRACT_THREAD_INFO(r32)
.Lretry_work_pending:
/*
* 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 */
/* Check to see if there is any work to do before returning to user. */
{
addi r29, r32, THREAD_INFO_FLAGS_OFFSET
moveli r1, hw1_last(_TIF_ALLWORK_MASK)
}
{
ld r29, r29
shl16insli r1, r1, hw0(_TIF_ALLWORK_MASK)
}
and r1, r29, r1
beqzt r1, .Lrestore_all
/*
* Make sure we have all the registers saved for signal
* handling or notify-resume. Call out to C code to figure out
* exactly what we need to do for each flag bit, then if
* necessary, reload the flags and recheck.
*/
{
PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
bnez r33, 1f
}
push_extra_callee_saves r0
movei r33, 1
1: jal do_work_pending
bnez r0, .Lretry_work_pending
/*
* 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.
*/
.Lrestore_all:
PTREGS_PTR(r0, PTREGS_OFFSET_EX1)
{
ld r0, r0
PTREGS_PTR(r32, PTREGS_OFFSET_FLAGS)
}
{
andi r0, r0, SPR_EX_CONTEXT_1_1__PL_MASK
ld r32, r32
}
bnez r0, 1f
j 2f
#if PT_FLAGS_DISABLE_IRQ != 1
# error Assuming PT_FLAGS_DISABLE_IRQ == 1 so we can use blbct below
#endif
1: blbct r32, 2f
IRQ_DISABLE(r20,r21)
TRACE_IRQS_OFF
movei r0, 1
mtspr INTERRUPT_CRITICAL_SECTION, r0
beqzt r30, .Lrestore_regs
j 3f
2: TRACE_IRQS_ON
IRQ_ENABLE_LOAD(r20, r21)
movei r0, 1
mtspr INTERRUPT_CRITICAL_SECTION, r0
IRQ_ENABLE_APPLY(r20, r21)
beqzt r30, .Lrestore_regs
3:
/*
* 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:
/*
* 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
{
rotli r20, r32, 62
PTREGS_PTR(sp, PTREGS_OFFSET_REG(0))
}
/*
* Load cache lines 0, 4, 6 and 7, 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 r0, sp, PTREGS_OFFSET_REG(30) - PTREGS_OFFSET_REG(0)
pop_reg r30, sp, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_REG(30)
pop_reg_zero r52, r3, sp, PTREGS_OFFSET_CMPEXCH - PTREGS_OFFSET_REG(52)
pop_reg_zero r21, r27, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_CMPEXCH
pop_reg_zero lr, r2, sp, PTREGS_OFFSET_PC - PTREGS_OFFSET_EX1
{
mtspr CMPEXCH_VALUE, r21
move r4, zero
}
pop_reg r21, sp, PTREGS_OFFSET_REG(31) - PTREGS_OFFSET_PC
{
mtspr SPR_EX_CONTEXT_K_1, lr
andi lr, lr, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */
}
{
mtspr SPR_EX_CONTEXT_K_0, r21
move r5, zero
}
/* Restore callee-saveds that we actually use. */
pop_reg_zero r31, r6
pop_reg_zero r32, r7
pop_reg_zero r33, r8, 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 r9, zero
blbs r20, .Lrestore_callees
}
.Lcontinue_restore_regs:
/* Check if we're returning from a syscall. */
{
move r10, zero
bltzt 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)
bnez 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, r11, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR
pop_reg_zero tp, r12, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP
{
ld sp, sp
move r13, zero
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 }
/* Set r1 to errno if we are returning an error, otherwise zero. */
{
moveli r29, 4096
sub r1, zero, r0
}
{
move r28, zero
cmpltu r29, r1, r29
}
{
mnz r1, r29, r1
move r29, zero
}
iret
/*
* Not a syscall, so restore caller-saved registers.
* First kick off loads for cache lines 1-3, which we're touching
* for the first time here.
*/
.align 64
1: pop_reg r29, sp, PTREGS_OFFSET_REG(21) - PTREGS_OFFSET_REG(29)
pop_reg r21, sp, PTREGS_OFFSET_REG(13) - PTREGS_OFFSET_REG(21)
pop_reg r13, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(13)
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, sp, 16
/* r13 already restored above */
pop_reg r14
pop_reg r15
pop_reg r16
pop_reg r17
pop_reg r18
pop_reg r19
pop_reg r20, sp, 16
/* r21 already restored above */
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 */
bnez lr, .Lkernel_return
pop_reg lr, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR
pop_reg tp, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP
ld 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
ld 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)
/*
* "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 register save/restore and 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
{
jalr r0
PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
}
FEEDBACK_REENTER(handle_nmi)
{
movei r30, 1
move r31, r0
}
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
/* Enable irqs. */
TRACE_IRQS_ON
IRQ_ENABLE(r20, r21)
/* Bump the counter for syscalls made on this tile. */
moveli r20, hw2_last(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET)
shl16insli r20, r20, hw1(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET)
shl16insli r20, r20, hw0(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET)
add r20, r20, tp
ld4s r21, r20
{
addi r21, r21, 1
move r31, sp
}
{
st4 r20, r21
EXTRACT_THREAD_INFO(r31)
}
/* Trace syscalls, if requested. */
addi r31, r31, THREAD_INFO_FLAGS_OFFSET
ld r30, r31
andi r30, r30, _TIF_SYSCALL_TRACE
{
addi r30, r31, THREAD_INFO_STATUS_OFFSET - THREAD_INFO_FLAGS_OFFSET
beqzt r30, .Lrestore_syscall_regs
}
jal do_syscall_trace
FEEDBACK_REENTER(handle_syscall)
/*
* 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:
{
ld r30, r30
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)
{
ld TREG_SYSCALL_NR_NAME, r11
moveli r21, __NR_syscalls
}
/* Ensure that the syscall number is within the legal range. */
{
moveli r20, hw2(sys_call_table)
blbs r30, .Lcompat_syscall
}
{
cmpltu r21, TREG_SYSCALL_NR_NAME, r21
shl16insli r20, r20, hw1(sys_call_table)
}
{
blbc r21, .Linvalid_syscall
shl16insli r20, r20, hw0(sys_call_table)
}
.Lload_syscall_pointer:
shl3add r20, TREG_SYSCALL_NR_NAME, r20
ld 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.
* In compat mode, sign-extend r0 before storing it.
*/
{
PTREGS_PTR(r29, PTREGS_OFFSET_REG(0))
blbct r30, 1f
}
addxi r0, r0, 0
1: st r29, r0
.Lsyscall_sigreturn_skip:
FEEDBACK_REENTER(handle_syscall)
/* Do syscall trace again, if requested. */
ld r30, r31
andi r0, r30, _TIF_SYSCALL_TRACE
{
andi r0, r30, _TIF_SINGLESTEP
beqzt r0, 1f
}
jal do_syscall_trace
FEEDBACK_REENTER(handle_syscall)
andi r0, r30, _TIF_SINGLESTEP
1: beqzt r0, 2f
/* Single stepping -- notify ptrace. */
{
movei r0, SIGTRAP
jal ptrace_notify
}
FEEDBACK_REENTER(handle_syscall)
2: {
movei r30, 0 /* not an NMI */
j .Lresume_userspace /* jump into middle of interrupt_return */
}
.Lcompat_syscall:
/*
* Load the base of the compat syscall table in r20, and
* range-check the syscall number (duplicated from 64-bit path).
* Sign-extend all the user's passed arguments to make them consistent.
* Also save the original "r(n)" values away in "r(11+n)" in
* case the syscall table entry wants to validate them.
*/
moveli r20, hw2(compat_sys_call_table)
{
cmpltu r21, TREG_SYSCALL_NR_NAME, r21
shl16insli r20, r20, hw1(compat_sys_call_table)
}
{
blbc r21, .Linvalid_syscall
shl16insli r20, r20, hw0(compat_sys_call_table)
}
{ move r11, r0; addxi r0, r0, 0 }
{ move r12, r1; addxi r1, r1, 0 }
{ move r13, r2; addxi r2, r2, 0 }
{ move r14, r3; addxi r3, r3, 0 }
{ move r15, r4; addxi r4, r4, 0 }
{ move r16, r5; addxi r5, r5, 0 }
j .Lload_syscall_pointer
.Linvalid_syscall:
/* Report an invalid syscall back to the user program */
{
PTREGS_PTR(r29, PTREGS_OFFSET_REG(0))
movei r28, -ENOSYS
}
st 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)
/* 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)
/* Put address of pt_regs in reg and jump. */
#define PTREGS_SYSCALL(x, reg) \
STD_ENTRY(_##x); \
{ \
PTREGS_PTR(reg, PTREGS_OFFSET_BASE); \
j x \
}; \
STD_ENDPROC(_##x)
/*
* 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(sys_execve, r3)
PTREGS_SYSCALL(sys_sigaltstack, r2)
PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0)
#ifdef CONFIG_COMPAT
PTREGS_SYSCALL(compat_sys_execve, r3)
PTREGS_SYSCALL(compat_sys_sigaltstack, r2)
PTREGS_SYSCALL_SIGRETURN(compat_sys_rt_sigreturn, r0)
#endif
/* Save additional callee-saves to pt_regs, put address in r4 and jump. */
STD_ENTRY(_sys_clone)
push_extra_callee_saves r4
j sys_clone
STD_ENDPROC(_sys_clone)
/* The single-step support may need to read all the registers. */
int_unalign:
push_extra_callee_saves r0
j do_trap
/* Fill the return address stack with nonzero entries. */
STD_ENTRY(fill_ra_stack)
{
move r0, lr
jal 1f
}
1: jal 2f
2: jal 3f
3: jal 4f
4: jrp r0
STD_ENDPROC(fill_ra_stack)
/* Include .intrpt1 array of interrupt vectors */
.section ".intrpt1", "ax"
#define op_handle_perf_interrupt bad_intr
#define op_handle_aux_perf_interrupt bad_intr
#ifndef CONFIG_HARDWALL
#define do_hardwall_trap bad_intr
#endif
int_hand INT_MEM_ERROR, MEM_ERROR, do_trap
int_hand INT_SINGLE_STEP_3, SINGLE_STEP_3, bad_intr
#if CONFIG_KERNEL_PL == 2
int_hand INT_SINGLE_STEP_2, SINGLE_STEP_2, gx_singlestep_handle
int_hand INT_SINGLE_STEP_1, SINGLE_STEP_1, bad_intr
#else
int_hand INT_SINGLE_STEP_2, SINGLE_STEP_2, bad_intr
int_hand INT_SINGLE_STEP_1, SINGLE_STEP_1, gx_singlestep_handle
#endif
int_hand INT_SINGLE_STEP_0, SINGLE_STEP_0, bad_intr
int_hand INT_IDN_COMPLETE, IDN_COMPLETE, bad_intr
int_hand INT_UDN_COMPLETE, UDN_COMPLETE, bad_intr
int_hand INT_ITLB_MISS, ITLB_MISS, do_page_fault
int_hand INT_ILL, ILL, do_trap
int_hand INT_GPV, GPV, do_trap
int_hand INT_IDN_ACCESS, IDN_ACCESS, do_trap
int_hand INT_UDN_ACCESS, UDN_ACCESS, do_trap
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_ILL_TRANS, ILL_TRANS, 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_IDN_FIREWALL, IDN_FIREWALL, do_hardwall_trap
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_IDN_AVAIL, IDN_AVAIL, bad_intr
int_hand INT_UDN_AVAIL, UDN_AVAIL, bad_intr
int_hand INT_IPI_3, IPI_3, bad_intr
#if CONFIG_KERNEL_PL == 2
int_hand INT_IPI_2, IPI_2, tile_dev_intr
int_hand INT_IPI_1, IPI_1, bad_intr
#else
int_hand INT_IPI_2, IPI_2, bad_intr
int_hand INT_IPI_1, IPI_1, tile_dev_intr
#endif
int_hand INT_IPI_0, IPI_0, bad_intr
int_hand INT_PERF_COUNT, PERF_COUNT, \
op_handle_perf_interrupt, handle_nmi
int_hand INT_AUX_PERF_COUNT, AUX_PERF_COUNT, \
op_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, bad_intr
int_hand INT_I_ASID, I_ASID, bad_intr
int_hand INT_D_ASID, D_ASID, bad_intr
int_hand INT_DOUBLE_FAULT, DOUBLE_FAULT, do_trap
/* Synthetic interrupt delivered only by the simulator */
int_hand INT_BREAKPOINT, BREAKPOINT, do_breakpoint