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| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2019-12-21 08:32:27 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2020-01-26 22:15:09 +1100 |
| commit | 028474876f472c3b6eee633aed528a1206609657 (patch) | |
| tree | ddf5742f1232e48a0665eb5b0a157caa28567a17 /arch/powerpc/kernel/entry_32.S | |
| parent | powerpc/32: add a macro to get and/or save DAR and DSISR on stack. (diff) | |
| download | linux-dev-028474876f472c3b6eee633aed528a1206609657.tar.xz linux-dev-028474876f472c3b6eee633aed528a1206609657.zip | |
powerpc/32: prepare for CONFIG_VMAP_STACK
To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU
Translation for accessing the stack. Before doing that it must save
SRR0, SRR1 and also DAR and DSISR when relevant, in order to not
loose them in case there is a Data TLB Miss once the translation is
reactivated.
This patch adds fields in thread struct for saving those registers.
It prepares entry_32.S to handle exception entry with
Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to
save SRR0, SRR1, DAR and DSISR then reenables Data MMU.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 317ad9df8ba8..8f6617cf2689 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -140,6 +140,7 @@ transfer_to_handler: stw r12,_CTR(r11) stw r2,_XER(r11) mfspr r12,SPRN_SPRG_THREAD + tovirt_vmstack r12, r12 beq 2f /* if from user, fix up THREAD.regs */ addi r2, r12, -THREAD addi r11,r1,STACK_FRAME_OVERHEAD @@ -195,7 +196,8 @@ transfer_to_handler: transfer_to_handler_cont: 3: mflr r9 - tovirt(r2, r2) /* set r2 to current */ + tovirt_novmstack r2, r2 /* set r2 to current */ + tovirt_vmstack r9, r9 lwz r11,0(r9) /* virtual address of handler */ lwz r9,4(r9) /* where to go when done */ #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS) |