diff options
| author |   Nicholas Piggin <npiggin@gmail.com> | 2018-09-15 01:30:51 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2018-10-14 18:04:09 +1100 |
| commit | 48e7b76957457f9a6f086ca2bbe49ec1ffd75f84 (patch) | |
| tree | db169b7d3654d9371cca93c9d4ed166836952583 /arch/powerpc/include/asm | |
| parent | powerpc/64: Interrupts save PPR on stack rather than thread_struct (diff) | |
| download | linux-dev-48e7b76957457f9a6f086ca2bbe49ec1ffd75f84.tar.xz linux-dev-48e7b76957457f9a6f086ca2bbe49ec1ffd75f84.zip | |
powerpc/64s/hash: Convert SLB miss handlers to C
This patch moves SLB miss handlers completely to C, using the standard
exception handler macros to set up the stack and branch to C.
This can be done because the segment containing the kernel stack is
always bolted, so accessing it with relocation on will not cause an
SLB exception.
Arbitrary kernel memory must not be accessed when handling kernel
space SLB misses, so care should be taken there. However user SLB
misses can access any kernel memory, which can be used to move some
fields out of the paca (in later patches).
User SLB misses could quite easily reconcile IRQs and set up a first
class kernel environment and exit via ret_from_except, however that
doesn't seem to be necessary at the moment, so we only do that if a
bad fault is encountered.
[ Credit to Aneesh for bug fixes, error checks, and improvements to
bad address handling, etc ]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Disallow tracing for all of slb.c for now.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm')
| -rw-r--r-- | arch/powerpc/include/asm/asm-prototypes.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/exception-64s.h | 8 |
2 files changed, 2 insertions, 8 deletions
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h index 9bc98c239305..2741831482f4 100644 --- a/arch/powerpc/include/asm/asm-prototypes.h +++ b/arch/powerpc/include/asm/asm-prototypes.h @@ -77,6 +77,8 @@ void kernel_bad_stack(struct pt_regs *regs); void system_reset_exception(struct pt_regs *regs); void machine_check_exception(struct pt_regs *regs); void emulation_assist_interrupt(struct pt_regs *regs); +long do_slb_fault(struct pt_regs *regs, unsigned long ea); +void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err); /* signals, syscalls and interrupts */ long sys_swapcontext(struct ucontext __user *old_ctx, diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 403d73898a9a..3b4767ed3ec5 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -61,14 +61,6 @@ #define MAX_MCE_DEPTH 4 /* - * EX_LR is only used in EXSLB and where it does not overlap with EX_DAR - * EX_CCR similarly with DSISR, but being 4 byte registers there is a hole - * in the save area so it's not necessary to overlap them. Could be used - * for future savings though if another 4 byte register was to be saved. - */ -#define EX_LR EX_DAR - -/* * EX_R3 is only used by the bad_stack handler. bad_stack reloads and * saves DAR from SPRN_DAR, and EX_DAR is not used. So EX_R3 can overlap * with EX_DAR. |