* Martin Schwidefsky <[email protected]> wrote:
> diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
> index 3238893..84062e7 100644
> --- a/arch/s390/kernel/entry.S
> +++ b/arch/s390/kernel/entry.S
> @@ -178,17 +178,21 @@ _PIF_WORK = (_PIF_PER_TRAP)
> */
> ENTRY(__switch_to)
> stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
> - stg %r15,__THREAD_ksp(%r2) # store kernel stack of prev
> - lg %r4,__THREAD_info(%r2) # get thread_info of prev
> - lg %r5,__THREAD_info(%r3) # get thread_info of next
> + lgr %r1,%r2
> + aghi %r1,__TASK_thread # thread_struct of prev task
> + lg %r4,__TASK_thread_info(%r2) # get thread_info of prev
> + lg %r5,__TASK_thread_info(%r3) # get thread_info of next
> + stg %r15,__THREAD_ksp(%r1) # store kernel stack of prev
> + lgr %r1,%r3
> + aghi %r1,__TASK_thread # thread_struct of next task
> lgr %r15,%r5
> aghi %r15,STACK_INIT # end of kernel stack of next
> stg %r3,__LC_CURRENT # store task struct of next
> stg %r5,__LC_THREAD_INFO # store thread info of next
> stg %r15,__LC_KERNEL_STACK # store end of kernel stack
> + lg %r15,__THREAD_ksp(%r1) # load kernel stack of next
> lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
> mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next
> - lg %r15,__THREAD_ksp(%r3) # load kernel stack of next
> lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
> br %r14
Btw., I think we'd be slightly better off with the variant I sent: that way the
offset arithmetics are done in C code and are ready in the relevant registers
by
the time they are used in __switch_to().
>
> @@ -417,6 +421,7 @@ ENTRY(pgm_check_handler)
> LAST_BREAK %r14
> lg %r15,__LC_KERNEL_STACK
> lg %r14,__TI_task(%r12)
> + aghi %r14,__TASK_thread # pointer to thread_struct
> lghi %r13,__LC_PGM_TDB
> tm __LC_PGM_ILC+2,0x02 # check for transaction abort
> jz 2f
Don't we also need the chunk I have:
@@ -448,6 +449,7 @@ ENTRY(pgm_check_handler)
nill %r10,0x007f
sll %r10,2
je .Lsysc_return
+ ahi %r14,-__TASK_thread_struct # r14 now points to 'current'
lgf %r1,0(%r10,%r1) # load address of handler routine
lgr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # branch to interrupt-handler
Because the 'basr' line relies on 'r14' having task_struct, I think?
But I don't really know what I'm talking about here ...
Thanks,
Ingo
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