/* we have the following possibilities to act on an interruption: * - handle in assembly and use shadowed registers only
* - save registers to kernel stack and handle in assembly or C */
/* * We need seven instructions after a TLB insert for it to take effect. * The PA8800/PA8900 processors are an exception and need 12 instructions. * The RFI changes both IAOQ_Back and IAOQ_Front, so it counts as one.
*/
#ifdef CONFIG_64BIT
#define NUM_PIPELINE_INSNS 12
#else
#define NUM_PIPELINE_INSNS 7
#endif
/* Insert num nops */
.macro insert_nops num
.rept \num
nop
.endr
.endm
/* Get aligned page_table_lock address for this mm from cr28/tr4 */
.macro get_ptl reg
mfctl %cr28,\reg
.endm
/* space_to_prot macro creates a prot id from a space id */
#if (SPACEID_SHIFT) == 0
.macro space_to_prot spc prot
depd,z \spc,62,31,\prot
.endm
#else
.macro space_to_prot spc prot
extrd,u \spc,(64 - (SPACEID_SHIFT)),32,\prot
.endm
#endif /* * The "get_stack" macros are responsible for determining the * kernel stack value. * * If sr7 == 0 * Already using a kernel stack, so call the * get_stack_use_r30 macro to push a pt_regs structure * on the stack, and store registers there. * else * Need to set up a kernel stack, so call the * get_stack_use_cr30 macro to set up a pointer * to the pt_regs structure contained within the * task pointer pointed to by cr30. Load the stack * pointer from the task structure. * * Note that we use shadowed registers for temps until * we can save %r26 and %r29. %r26 is used to preserve * %r8 (a shadowed register) which temporarily contained * either the fault type ("code") or the eirr. We need * to use a non-shadowed register to carry the value over * the rfir in virt_map. We use %r26 since this value winds * up being passed as the argument to either do_cpu_irq_mask * or handle_interruption. %r29 is used to hold a pointer * the register save area, and once again, it needs to * be a non-shadowed register so that it survives the rfir.
*/
/* HPMC handler */
.macro hpmc code
nop /* must be a NOP, will be patched later */
load32 PA(os_hpmc), %r3
bv,n 0(%r3)
nop
.word0/* checksum (will be patched) */
.word0/* address of handler */
.word0/* length of handler */
.endm
/* * Performance Note: Instructions will be moved up into * this part of the code later on, once we are sure * that the tlb miss handlers are close to final form.
*/
/* Register definitions for tlb miss handler macros */
va = r8 /* virtual address for which the trap occurred */
spc = r24 /* space for which the trap occurred */
/* * dirty bit trap interruption handler (parisc 2.0)
*/
.macro dbit_20 code
mfctl %isr,spc
#ifdef CONFIG_64BIT
b dbit_trap_20w
#else
b dbit_trap_20
#endif
mfctl %ior,va
.align32
.endm
/* In LP64, the space contains part of the upper 32 bits of the * fault. We have to extract this and place it in the va,
* zeroing the corresponding bits in the space register */
.macro space_adjust spc,va,tmp
#ifdef CONFIG_64BIT
extrd,u \spc,63,SPACEID_SHIFT,\tmp
depd %r0,63,SPACEID_SHIFT,\spc
depd \tmp,31,SPACEID_SHIFT,\va
#endif
.endm
.import swapper_pg_dir,code
/* Get the pgd. For faults on space zero (kernel space), this * is simply swapper_pg_dir. For user space faults, the
* pgd is stored in %cr25 */
.macro get_pgd spc,reg
ldil L%PA(swapper_pg_dir),\reg
ldo R%PA(swapper_pg_dir)(\reg),\reg
or,COND(=) %r0,\spc,%r0
mfctl %cr25,\reg
.endm
/* space_check(spc,tmp,fault)
spc - The space we saw the fault with. tmp - The place to store the current space. fault - Function to call on failure.
Only allow faults on different spaces from the currently active one if we're the kernel
*/
.macro space_check spc,tmp,fault
mfsp %sr7,\tmp /* check against %r0 which is same value as LINUX_GATEWAY_SPACE */
or,COND(<>) %r0,\spc,%r0 /* user may execute gateway page * as kernel, so defeat the space
* check if it is */
copy \spc,\tmp
or,COND(=) %r0,\tmp,%r0 /* nullify if executing as kernel */
cmpb,COND(<>),n \tmp,\spc,\fault
.endm
/* Look up a PTE in a 2-Level scheme (faulting at each * level if the entry isn't present * * NOTE: we use ldw even for LP64, since the short pointers * can address up to 1TB
*/
.macro L2_ptep pmd,pte,index,va,fault
#if CONFIG_PGTABLE_LEVELS == 3
extru_safe \va,31-ASM_PMD_SHIFT,ASM_BITS_PER_PMD,\index
#else
extru_safe \va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
#endif
dep %r0,31,PAGE_SHIFT,\pmd /* clear offset */
#if CONFIG_PGTABLE_LEVELS < 3
copy %r0,\pte
#endif
ldw,s \index(\pmd),\pmd
bb,>=,n \pmd,_PxD_PRESENT_BIT,\fault
dep %r0,31,PxD_FLAG_SHIFT,\pmd /* clear flags */
SHLREG \pmd,PxD_VALUE_SHIFT,\pmd
extru_safe \va,31-PAGE_SHIFT,ASM_BITS_PER_PTE,\index
dep %r0,31,PAGE_SHIFT,\pmd /* clear offset */
shladd \index,BITS_PER_PTE_ENTRY,\pmd,\pmd /* pmd is now pte */
.endm
/* Look up PTE in a 3-Level scheme. */
.macro L3_ptep pgd,pte,index,va,fault
#if CONFIG_PGTABLE_LEVELS == 3
copy %r0,\pte
extrd,u \va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
ldw,s \index(\pgd),\pgd
bb,>=,n \pgd,_PxD_PRESENT_BIT,\fault
shld \pgd,PxD_VALUE_SHIFT,\pgd
#endif
L2_ptep \pgd,\pte,\index,\va,\fault
.endm
/* Release page_table_lock if for user space. We use an ordered store to ensure all prior accesses are performed prior to releasing the lock. Note stw may not be executed, so we
provide one extra nop when CONFIG_TLB_PTLOCK is defined. */
.macro ptl_unlock spc,tmp,tmp2
#ifdef CONFIG_TLB_PTLOCK 98: get_ptl \tmp
ldi __ARCH_SPIN_LOCK_UNLOCKED_VAL, \tmp2
or,COND(=) %r0,\spc,%r0
stw,ma \tmp2,0(\tmp) 99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
insert_nops NUM_PIPELINE_INSNS - 4
#else
insert_nops NUM_PIPELINE_INSNS - 1
#endif
.endm
/* Set the _PAGE_ACCESSED bit of the PTE. Be clever and
* don't needlessly dirty the cache line if it was already set */
.macro update_accessed ptp,pte,tmp,tmp1
ldi _PAGE_ACCESSED,\tmp1
or \tmp1,\pte,\tmp
and,COND(<>) \tmp1,\pte,%r0
STREG \tmp,0(\ptp)
.endm
/* Set the dirty bit (and accessed bit). No need to be
* clever, this is only used from the dirty fault */
.macro update_dirty ptp,pte,tmp
ldi _PAGE_ACCESSED|_PAGE_DIRTY,\tmp
or \tmp,\pte,\pte
STREG \pte,0(\ptp)
.endm
/* We have (depending on the page size): * - 38 to 52-bit Physical Page Number * - 12 to 26-bit page offset
*/ /* bitshift difference between a PFN (based on kernel's PAGE_SIZE)
* to a CPU TLB 4k PFN (4k => 12 bits to shift) */
#define PAGE_ADD_SHIFT (PAGE_SHIFT-12)
#define PAGE_ADD_HUGE_SHIFT (REAL_HPAGE_SHIFT-12)
#define PFN_START_BIT (63-ASM_PFN_PTE_SHIFT+(63-58)-PAGE_ADD_SHIFT)
/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
.macro convert_for_tlb_insert20 pte,tmp
#ifdef CONFIG_HUGETLB_PAGE
copy \pte,\tmp
extrd,u \tmp,PFN_START_BIT,PFN_START_BIT+1,\pte
/* Convert the pte and prot to tlb insertion values. How
* this happens is quite subtle, read below */
.macro make_insert_tlb spc,pte,prot,tmp
space_to_prot \spc \prot /* create prot id from space */
#if _PAGE_SPECIAL_BIT == _PAGE_DMB_BIT /* need to drop DMB bit, as it's used as SPECIAL flag */
depi 0,_PAGE_SPECIAL_BIT,1,\pte
#endif
/* The following is the real subtlety. This is depositing * T <-> _PAGE_REFTRAP * D <-> _PAGE_DIRTY * B <-> _PAGE_DMB (memory break) * * Then incredible subtlety: The access rights are * _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE * See 3-14 of the parisc 2.0 manual * * Finally, _PAGE_READ goes in the top bit of PL1 (so we * trigger an access rights trap in user space if the user
* tries to read an unreadable page */
depd \pte,8,7,\prot
/* PAGE_USER indicates the page can be read with user privileges, * so deposit X1|11 to PL1|PL2 (remember the upper bit of PL1 * contains _PAGE_READ). While the kernel can't directly write * user pages which have _PAGE_WRITE zero, it can read pages * which have _PAGE_READ zero (PL <= PL1). Thus, the kernel * exception fault handler doesn't trigger when reading pages
* that aren't user read accessible */
extrd,u,*= \pte,_PAGE_USER_BIT+32,1,%r0
depdi 7,11,3,\prot
/* If we're a gateway page, drop PL2 back to zero for promotion * to kernel privilege (so we can execute the page as kernel).
* Any privilege promotion page always denys read and write */
extrd,u,*= \pte,_PAGE_GATEWAY_BIT+32,1,%r0
depd %r0,11,2,\prot /* If Gateway, Set PL2 to 0 */
/* Enforce uncacheable pages. * This should ONLY be use for MMIO on PA 2.0 machines. * Memory/DMA is cache coherent on all PA2.0 machines we support * (that means T-class is NOT supported) and the memory controllers * on most of those machines only handles cache transactions.
*/
extrd,u,*= \pte,_PAGE_NO_CACHE_BIT+32,1,%r0
depdi 1,12,1,\prot
/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
convert_for_tlb_insert20 \pte \tmp
.endm
/* Identical macro to make_insert_tlb above, except it * makes the tlb entry for the differently formatted pa11
* insertion instructions */
.macro make_insert_tlb_11 spc,pte,prot
#if _PAGE_SPECIAL_BIT == _PAGE_DMB_BIT /* need to drop DMB bit, as it's used as SPECIAL flag */
depi 0,_PAGE_SPECIAL_BIT,1,\pte
#endif
zdep \spc,30,15,\prot
dep \pte,8,7,\prot
extru,= \pte,_PAGE_NO_CACHE_BIT,1,%r0
depi 1,12,1,\prot
extru,= \pte,_PAGE_USER_BIT,1,%r0
depi 7,11,3,\prot /* Set for user space (1 rsvd for read) */
extru,= \pte,_PAGE_GATEWAY_BIT,1,%r0
depi 0,11,2,\prot /* If Gateway, Set PL2 to 0 */
/* Get rid of prot bits and convert to page addr for iitlba */
/* This is for ILP32 PA2.0 only. The TLB insertion needs * to extend into I/O space if the address is 0xfXXXXXXX * so we extend the f's into the top word of the pte in
* this case */
.macro f_extend pte,tmp
extrd,s \pte,42,4,\tmp
addi,<> 1,\tmp,%r0
extrd,s \pte,63,25,\pte
.endm
/* The alias region is comprised of a pair of 4 MB regions * aligned to 8 MB. It is used to clear/copy/flush user pages * using kernel virtual addresses congruent with the user * virtual address. * * To use the alias page, you set %r26 up with the to TLB * entry (identifying the physical page) and %r23 up with * the from tlb entry (or nothing if only a to entry---for
* clear_user_page_asm) */
.macro do_alias spc,tmp,tmp1,va,pte,prot,fault,patype
cmpib,COND(<>),n 0,\spc,\fault
ldil L%(TMPALIAS_MAP_START),\tmp
copy \va,\tmp1
depi_safe 0,31,TMPALIAS_SIZE_BITS+1,\tmp1
cmpb,COND(<>),n \tmp,\tmp1,\fault
mfctl %cr19,\tmp /* iir */ /* get the opcode (first six bits) into \tmp */
extrw,u \tmp,5,6,\tmp /* * Only setting the T bit prevents data cache movein * Setting access rights to zero prevents instruction cache movein * * Note subtlety here: _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE go * to type field and _PAGE_READ goes to top bit of PL1
*/
ldi (_PAGE_REFTRAP|_PAGE_READ|_PAGE_WRITE),\prot /* * so if the opcode is one (i.e. this is a memory management * instruction) nullify the next load so \prot is only T. * Otherwise this is a normal data operation
*/
cmpiclr,= 0x01,\tmp,%r0
ldi (_PAGE_DIRTY|_PAGE_READ|_PAGE_WRITE),\prot
.ifc \patype,20
depd,z \prot,8,7,\prot
.else
.ifc \patype,11
depw,z \prot,8,7,\prot
.else
.error "undefined PA type to do_alias"
.endif
.endif /* * OK, it is in the temp alias region, check whether "from" or "to". * Check "subtle" note in pacache.S re: r23/r26.
*/
extrw,u,= \va,31-TMPALIAS_SIZE_BITS,1,%r0
or,COND(tr) %r23,%r0,\pte
or %r26,%r0,\pte
/* convert phys addr in \pte (from r23 or r26) to tlb insert format */
SHRREG \pte,PAGE_SHIFT+PAGE_ADD_SHIFT-5, \pte
depi_safe _PAGE_SIZE_ENCODING_DEFAULT, 31,5, \pte
.endm
/* * Fault_vectors are architecturally required to be aligned on a 2K * boundary
*/
.section .text.hot
.align2048
ENTRY(fault_vector_20) /* First vector is invalid (0) */
.ascii"cows can fly"
.byte 0
.align32
/* * Common rfi return path for interruptions, kernel execve, and * sys_rt_sigreturn (sometimes). The sys_rt_sigreturn syscall will * return via this path if the signal was received when the process * was running; if the process was blocked on a syscall then the * normal syscall_exit path is used. All syscalls for traced * proceses exit via intr_restore. * * XXX If any syscalls that change a processes space id ever exit * this way, then we will need to copy %sr3 in to PT_SR[3..7], and * adjust IASQ[0..1]. *
*/
.align PAGE_SIZE
ENTRY_CFI(syscall_exit_rfi)
mfctl %cr30,%r16 /* task_struct */
ldo TASK_REGS(%r16),%r16 /* Force iaoq to userspace, as the user has had access to our current * context via sigcontext. Also Filter the PSW for the same reason.
*/
LDREG PT_IAOQ0(%r16),%r19
depi PRIV_USER,31,2,%r19
STREG %r19,PT_IAOQ0(%r16)
LDREG PT_IAOQ1(%r16),%r19
depi PRIV_USER,31,2,%r19
STREG %r19,PT_IAOQ1(%r16)
LDREG PT_PSW(%r16),%r19
load32 USER_PSW_MASK,%r1
#ifdef CONFIG_64BIT
load32 USER_PSW_HI_MASK,%r20
depd %r20,31,32,%r1
#endif
and %r19,%r1,%r19 /* Mask out bits that user shouldn't play with */
load32 USER_PSW,%r1
or %r19,%r1,%r19 /* Make sure default USER_PSW bits are set */
STREG %r19,PT_PSW(%r16)
/* * If we aren't being traced, we never saved space registers * (we don't store them in the sigcontext), so set them * to "proper" values now (otherwise we'll wind up restoring * whatever was last stored in the task structure, which might * be inconsistent if an interrupt occurred while on the gateway * page). Note that we may be "trashing" values the user put in * them, but we don't support the user changing them.
*/
.import do_notify_resume,code
intr_check_sig: /* As above */
mfctl %cr30,%r1
LDREG TASK_TI_FLAGS(%r1),%r19
ldi (_TIF_USER_WORK_MASK & ~_TIF_NEED_RESCHED), %r20
and,COND(<>) %r19, %r20, %r0
b,n intr_restore /* skip past if we've nothing to do */
/* This check is critical to having LWS * working. The IASQ is zero on the gateway * page and we cannot deliver any signals until * we get off the gateway page. * * Only do signals if we are returning to user space
*/
LDREG PT_IASQ0(%r16), %r20
cmpib,COND(=),n LINUX_GATEWAY_SPACE, %r20, intr_restore /* forward */
LDREG PT_IASQ1(%r16), %r20
cmpib,COND(=),n LINUX_GATEWAY_SPACE, %r20, intr_restore /* forward */
copy %r0, %r25 /* long in_syscall = 0 */
#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
#endif
/* NOTE: We need to enable interrupts if we have to deliver * signals. We used to do this earlier but it caused kernel
* stack overflows. */
ssm PSW_SM_I, %r0
.import schedule,code
intr_do_resched: /* Only call schedule on return to userspace. If we're returning * to kernel space, we may schedule if CONFIG_PREEMPTION, otherwise * we jump back to intr_restore.
*/
LDREG PT_IASQ0(%r16), %r20
cmpib,COND(=) 0, %r20, intr_do_preempt
nop
LDREG PT_IASQ1(%r16), %r20
cmpib,COND(=) 0, %r20, intr_do_preempt
nop
/* NOTE: We need to enable interrupts if we schedule. We used
* to do this earlier but it caused kernel stack overflows. */
ssm PSW_SM_I, %r0
#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
#endif
/* preempt the current task on returning to kernel * mode from an interrupt, iff need_resched is set, * and preempt_count is 0. otherwise, we continue on * our merry way back to the current running task.
*/
#ifdef CONFIG_PREEMPTION
.import preempt_schedule_irq,code
intr_do_preempt:
rsm PSW_SM_I, %r0 /* disable interrupts */
ENTRY_CFI(intr_save) /* for os_hpmc */
mfsp %sr7,%r16
cmpib,COND(=),n 0,%r16,1f
get_stack_use_cr30
b 2f
copy %r8,%r26
1:
get_stack_use_r30
copy %r8,%r26
2:
save_specials %r29
/* If this trap is a itlb miss, skip saving/adjusting isr/ior */
cmpib,COND(=),n PARISC_ITLB_TRAP,%r26,skip_save_ior
mfctl %isr, %r16
nop /* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
mfctl %ior, %r17
#ifdef CONFIG_64BIT /* * If the interrupted code was running with W bit off (32 bit), * clear the b bits (bits 0 & 1) in the ior. * save_specials left ipsw value in r8 for us to test.
*/
extrd,u,*<> %r8,PSW_W_BIT,1,%r0
depdi 0,1,2,%r17
/* adjust isr/ior: get high bits from isr and deposit in ior */
space_adjust %r16,%r17,%r1
#endif
STREG %r16, PT_ISR(%r29)
STREG %r17, PT_IOR(%r29)
#if defined(CONFIG_64BIT)
b,n intr_save2
skip_save_ior: /* We have a itlb miss, and when executing code above 4 Gb on ILP64, we * need to adjust iasq/iaoq here in the same way we adjusted isr/ior * above.
*/
bb,COND(>=),n %r8,PSW_W_BIT,intr_save2
LDREG PT_IASQ0(%r29), %r16
LDREG PT_IAOQ0(%r29), %r17 /* adjust iasq/iaoq */
space_adjust %r16,%r17,%r1
STREG %r16, PT_IASQ0(%r29)
STREG %r17, PT_IAOQ0(%r29)
#else
skip_save_ior:
#endif
intr_save2:
virt_map
save_general %r29
ldo PT_FR0(%r29), %r25
save_fp %r25
loadgp
copy %r29, %r25 /* arg1 is pt_regs */
#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
#endif
ldil L%intr_check_sig, %r2
copy %r25, %r16 /* save pt_regs */
b handle_interruption
ldo R%intr_check_sig(%r2), %r2
ENDPROC_CFI(intr_save)
/* * Note for all tlb miss handlers: * * cr24 contains a pointer to the kernel address space * page directory. * * cr25 contains a pointer to the current user address * space page directory. * * sr3 will contain the space id of the user address space * of the current running thread while that thread is * running in the kernel.
*/
/* * register number allocations. Note that these are all * in the shadowed registers
*/
t0 = r1 /* temporary register 0 */
va = r8 /* virtual address for which the trap occurred */
t1 = r9 /* temporary register 1 */
pte = r16 /* pte/phys page # */
prot = r17 /* prot bits */
spc = r24 /* space for which the trap occurred */
ptp = r25 /* page directory/page table pointer */
/* * Non-access misses can be caused by fdc,fic,pdc,lpa,probe and * probei instructions. The kernel no longer faults doing flushes. * Use of lpa and probe instructions is rare. Given the issue * with shadow registers, we defer everything to the "slow" path.
*/
b,n nadtlb_fault
#ifdef CONFIG_64BIT
itlb_miss_20w:
/* * I miss is a little different, since we allow users to fault * on the gateway page which is in the kernel address space.
*/
kernel_bad_space:
b intr_save
ldi 31,%r8 /* Use an unused code */
dbit_fault:
b intr_save
ldi 20,%r8
itlb_fault:
b intr_save
ldi PARISC_ITLB_TRAP,%r8
nadtlb_fault:
b intr_save
ldi 17,%r8
naitlb_fault:
b intr_save
ldi 16,%r8
dtlb_fault:
b intr_save
ldi 15,%r8
/* Register saving semantics for system calls:
%r1 clobbered by system call macro in userspace %r2 saved in PT_REGS by gateway page %r3 - %r18 preserved by C code (saved by signal code) %r19 - %r20 saved in PT_REGS by gateway page %r21 - %r22 non-standard syscall args stored in kernel stack by gateway page %r23 - %r26 arg3-arg0, saved in PT_REGS by gateway page %r27 - %r30 saved in PT_REGS by gateway page %r31 syscall return pointer
*/
/* Floating point registers (FIXME: what do we do with these?)
%fr0 - %fr3 status/exception, not preserved %fr4 - %fr7 arguments %fr8 - %fr11 not preserved by C code %fr12 - %fr21 preserved by C code %fr22 - %fr31 not preserved by C code
*/
/* Set the return value for the child */
ENTRY(child_return)
BL schedule_tail, %r2
nop
finish_child_return:
mfctl %cr30,%r1
ldo TASK_REGS(%r1),%r1 /* get pt regs */
/* FIXME: I think we need to restore a few more things here. */
mfctl %cr30,%r1
ldo TASK_REGS(%r1),%r1 /* get pt regs */
reg_restore %r1
/* If the signal was received while the process was blocked on a * syscall, then r2 will take us to syscall_exit; otherwise r2 will * take us to syscall_exit_rfi and on to intr_return.
*/
bv %r0(%r2)
LDREG PT_GR28(%r1),%r28 /* reload original r28 for syscall_exit */
ENDPROC_CFI(sys_rt_sigreturn_wrapper)
ENTRY(syscall_exit) /* NOTE: Not all syscalls exit this way. rt_sigreturn will exit * via syscall_exit_rfi if the signal was received while the process * was running.
*/
/* save return value now */
mfctl %cr30, %r1
STREG %r28,TASK_PT_GR28(%r1)
/* Seems to me that dp could be wrong here, if the syscall involved * calling a module, and nothing got round to restoring dp on return.
*/
loadgp
syscall_check_resched:
/* check for reschedule */
mfctl %cr30,%r19
LDREG TASK_TI_FLAGS(%r19),%r19 /* long */
bb,<,n %r19, 31-TIF_NEED_RESCHED, syscall_do_resched /* forward */
.import do_signal,code
syscall_check_sig:
mfctl %cr30,%r19
LDREG TASK_TI_FLAGS(%r19),%r19
ldi (_TIF_USER_WORK_MASK & ~_TIF_NEED_RESCHED), %r26
and,COND(<>) %r19, %r26, %r0
b,n syscall_restore /* skip past if we've nothing to do */
syscall_do_signal: /* Save callee-save registers (for sigcontext). * FIXME: After this point the process structure should be * consistent with all the relevant state of the process * before the syscall. We need to verify this.
*/
mfctl %cr30,%r1
ldo TASK_REGS(%r1), %r26 /* struct pt_regs *regs */
reg_save %r26
#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
#endif
LDREG TASK_PT_SAR(%r1),%r19 /* restore SAR */
mtsar %r19
LDREG TASK_PT_GR2(%r1),%r2 /* restore user rp */
LDREG TASK_PT_GR19(%r1),%r19
LDREG TASK_PT_GR20(%r1),%r20
LDREG TASK_PT_GR21(%r1),%r21
LDREG TASK_PT_GR22(%r1),%r22
LDREG TASK_PT_GR23(%r1),%r23
LDREG TASK_PT_GR24(%r1),%r24
LDREG TASK_PT_GR25(%r1),%r25
LDREG TASK_PT_GR26(%r1),%r26
LDREG TASK_PT_GR27(%r1),%r27 /* restore user dp */
LDREG TASK_PT_GR28(%r1),%r28 /* syscall return value */
LDREG TASK_PT_GR29(%r1),%r29
LDREG TASK_PT_GR31(%r1),%r31 /* restore syscall rp */
/* NOTE: We use rsm/ssm pair to make this operation atomic */
LDREG TASK_PT_GR30(%r1),%r1 /* Get user sp */
rsm PSW_SM_I, %r0
copy %r1,%r30 /* Restore user sp */
mfsp %sr3,%r1 /* Get user space id */
mtsp %r1,%sr7 /* Restore sr7 */
ssm PSW_SM_I, %r0
/* Set sr2 to zero for userspace syscalls to work. */
mtsp %r0,%sr2
mtsp %r1,%sr4 /* Restore sr4 */
mtsp %r1,%sr5 /* Restore sr5 */
mtsp %r1,%sr6 /* Restore sr6 */
depi PRIV_USER,31,2,%r31 /* ensure return to user mode. */
#ifdef CONFIG_64BIT /* decide whether to reset the wide mode bit * * For a syscall, the W bit is stored in the lowest bit
* of sp. Extract it and reset W if it is zero */
extrd,u,*<> %r30,63,1,%r1
rsm PSW_SM_W, %r0 /* now reset the lowest bit of sp if it was set */
xor %r30,%r1,%r30
#endif
be,n 0(%sr3,%r31) /* return to user space */
/* We have to return via an RFI, so that PSW T and R bits can be set * appropriately. * This sets up pt_regs so we can return via intr_restore, which is not * the most efficient way of doing things, but it works.
*/
syscall_restore_rfi:
ldo -1(%r0),%r2 /* Set recovery cntr to -1 */
mtctl %r2,%cr0 /* for immediate trap */
LDREG TASK_PT_PSW(%r1),%r2 /* Get old PSW */
ldi 0x0b,%r20 /* Create new PSW */
depi -1,13,1,%r20 /* C, Q, D, and I bits */
/* The values of SINGLESTEP_BIT and BLOCKSTEP_BIT are * set in thread_info.h and converted to PA bitmap
* numbers in asm-offsets.c */
/* if ((%r19.SINGLESTEP_BIT)) { %r20.27=1} */
extru,= %r19,TIF_SINGLESTEP_PA_BIT,1,%r0
depi -1,27,1,%r20 /* R bit */
/* if ((%r19.BLOCKSTEP_BIT)) { %r20.7=1} */
extru,= %r19,TIF_BLOCKSTEP_PA_BIT,1,%r0
depi -1,7,1,%r20 /* T bit */
STREG %r20,TASK_PT_PSW(%r1)
/* Always store space registers, since sr3 can be changed (e.g. fork) */
/* XXX W bit??? */ /* Now if old D bit is clear, it means we didn't save all registers * on syscall entry, so do that now. This only happens on TRACEME * calls, or if someone attached to us while we were on a syscall. * We could make this more efficient by not saving r3-r18, but * then we wouldn't be able to use the common intr_restore path. * It is only for traced processes anyway, so performance is not * an issue.
*/
bb,< %r2,30,pt_regs_ok /* Branch if D set */
ldo TASK_REGS(%r1),%r25
reg_save %r25 /* Save r3 to r18 */
/* Save the current sr */
mfsp %sr0,%r2
STREG %r2,TASK_PT_SR0(%r1)
/* Save the scratch sr */
mfsp %sr1,%r2
STREG %r2,TASK_PT_SR1(%r1)
/* sr2 should be set to zero for userspace syscalls */
STREG %r0,TASK_PT_SR2(%r1)
LDREG TASK_PT_GR31(%r1),%r2
depi PRIV_USER,31,2,%r2 /* ensure return to user mode. */
STREG %r2,TASK_PT_IAOQ0(%r1)
ldo 4(%r2),%r2
STREG %r2,TASK_PT_IAOQ1(%r1)
b intr_restore
copy %r25,%r16
pt_regs_ok:
LDREG TASK_PT_IAOQ0(%r1),%r2
depi PRIV_USER,31,2,%r2 /* ensure return to user mode. */
STREG %r2,TASK_PT_IAOQ0(%r1)
LDREG TASK_PT_IAOQ1(%r1),%r2
depi PRIV_USER,31,2,%r2
STREG %r2,TASK_PT_IAOQ1(%r1)
b intr_restore
copy %r25,%r16
syscall_do_resched:
load32 syscall_check_resched,%r2 /* if resched, we start over again */
load32 schedule,%r19
bv %r0(%r19) /* jumps to schedule() */
#ifdef CONFIG_64BIT
ldo -16(%r30),%r29 /* Reference param save area */
#else
nop
#endif
END(syscall_exit)
#ifdef CONFIG_FUNCTION_TRACER
.import ftrace_function_trampoline,code
.align L1_CACHE_BYTES
ENTRY_CFI(mcount, caller)
_mcount:
.export _mcount,data /* * The 64bit mcount() function pointer needs 4 dwords, of which the * first two are free. We optimize it here and put 2 instructions for * calling mcount(), and 2 instructions for ftrace_stub(). That way we * have all on one L1 cacheline.
*/
ldi 0, %arg3
b ftrace_function_trampoline
copy %r3, %arg2 /* caller original %sp */
ftrace_stub:
.globl ftrace_stub
.type ftrace_stub, @function
#ifdef CONFIG_64BIT
bve (%rp)
#else
bv %r0(%rp)
#endif
nop
#ifdef CONFIG_64BIT
.dword mcount
.dword 0/* code in head.S puts value of global gp here */
#endif
ENDPROC_CFI(mcount)
ldo -PT_SZ_ALGN(%sp), %sp
LDREGM -FTRACE_FRAME_SIZE(%sp), %r1 /* Adjust return point to jump back to beginning of traced function */
ldo -4(%r1), %r1
bv,n (%r1)
/* restore original return values */
LDREG 8(%r3),%ret0
LDREG 16(%r3),%ret1
/* return from function */
#ifdef CONFIG_64BIT
bve (%rp)
#else
bv %r0(%rp)
#endif
LDREGM -FRAME_SIZE(%sp),%r3
ENDPROC_CFI(return_to_handler)
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_IRQSTACKS /* void call_on_stack(unsigned long param1, void *func,
unsigned long new_stack) */
ENTRY_CFI(call_on_stack, FRAME=2*FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP)
ENTRY(_call_on_stack)
copy %sp, %r1
/* Regarding the HPPA calling conventions for function pointers, we assume the PIC register is not changed across call. For CONFIG_64BIT, the argument pointer is left to point at the
argument region allocated for the call to call_on_stack. */
/* Switch to new stack. We allocate two frames. */
ldo 2*FRAME_SIZE(%arg2), %sp
# ifdef CONFIG_64BIT /* Save previous stack pointer and return pointer in frame marker */
STREG %rp, -FRAME_SIZE-RP_OFFSET(%sp) /* Calls always use function descriptor */
LDREG 16(%arg1), %arg1
bve,l (%arg1), %rp
STREG %r1, -FRAME_SIZE-REG_SZ(%sp)
LDREG -FRAME_SIZE-RP_OFFSET(%sp), %rp
bve (%rp)
LDREG -FRAME_SIZE-REG_SZ(%sp), %sp
# else /* Save previous stack pointer and return pointer in frame marker */
STREG %r1, -FRAME_SIZE-REG_SZ(%sp)
STREG %rp, -FRAME_SIZE-RP_OFFSET(%sp) /* Calls use function descriptor if PLABEL bit is set */
bb,>=,n %arg1, 30, 1f
depwi 0,31,2, %arg1
LDREG 0(%arg1), %arg1 1:
be,l 0(%sr4,%arg1), %sr0, %r31
copy %r31, %rp
LDREG -FRAME_SIZE-RP_OFFSET(%sp), %rp
bv (%rp)
LDREG -FRAME_SIZE-REG_SZ(%sp), %sp
# endif /* CONFIG_64BIT */
ENDPROC_CFI(call_on_stack)
#endif /* CONFIG_IRQSTACKS */
ENTRY_CFI(get_register) /* * get_register is used by the non access tlb miss handlers to * copy the value of the general register specified in r8 into * r1. This routine can't be used for shadowed registers, since * the rfir will restore the original value. So, for the shadowed * registers we put a -1 into r1 to indicate that the register * should not be used (the register being copied could also have * a -1 in it, but that is OK, it just means that we will have * to use the slow path instead).
*/
blr %r8,%r0
nop
bv %r0(%r25) /* r0 */
copy %r0,%r1
bv %r0(%r25) /* r1 - shadowed */
ldi -1,%r1
bv %r0(%r25) /* r2 */
copy %r2,%r1
bv %r0(%r25) /* r3 */
copy %r3,%r1
bv %r0(%r25) /* r4 */
copy %r4,%r1
bv %r0(%r25) /* r5 */
copy %r5,%r1
bv %r0(%r25) /* r6 */
copy %r6,%r1
bv %r0(%r25) /* r7 */
copy %r7,%r1
bv %r0(%r25) /* r8 - shadowed */
ldi -1,%r1
bv %r0(%r25) /* r9 - shadowed */
ldi -1,%r1
bv %r0(%r25) /* r10 */
copy %r10,%r1
bv %r0(%r25) /* r11 */
copy %r11,%r1
bv %r0(%r25) /* r12 */
copy %r12,%r1
bv %r0(%r25) /* r13 */
copy %r13,%r1
bv %r0(%r25) /* r14 */
copy %r14,%r1
bv %r0(%r25) /* r15 */
copy %r15,%r1
bv %r0(%r25) /* r16 - shadowed */
ldi -1,%r1
bv %r0(%r25) /* r17 - shadowed */
ldi -1,%r1
bv %r0(%r25) /* r18 */
copy %r18,%r1
bv %r0(%r25) /* r19 */
copy %r19,%r1
bv %r0(%r25) /* r20 */
copy %r20,%r1
bv %r0(%r25) /* r21 */
copy %r21,%r1
bv %r0(%r25) /* r22 */
copy %r22,%r1
bv %r0(%r25) /* r23 */
copy %r23,%r1
bv %r0(%r25) /* r24 - shadowed */
ldi -1,%r1
bv %r0(%r25) /* r25 - shadowed */
ldi -1,%r1
bv %r0(%r25) /* r26 */
copy %r26,%r1
bv %r0(%r25) /* r27 */
copy %r27,%r1
bv %r0(%r25) /* r28 */
copy %r28,%r1
bv %r0(%r25) /* r29 */
copy %r29,%r1
bv %r0(%r25) /* r30 */
copy %r30,%r1
bv %r0(%r25) /* r31 */
copy %r31,%r1
ENDPROC_CFI(get_register)
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