diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-06-18 01:51:08 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-25 00:06:56 +1000 |
| commit | f23699c93becd746295aaa506537882a46a62219 (patch) | |
| tree | ea44289996524915c83e6876b39babbe6a640ff8 /arch/powerpc/kernel/exceptions-64s.S | |
| parent | 63e40806eea984f770c992120bbfd71b589ea580 (diff) | |
powerpc/64: allow alternate return locations for soft-masked interrupts
The exception table fixup adjusts a failed page fault's interrupt return
location if it was taken at an address specified in the exception table,
to a corresponding fixup handler address.
Introduce a variation of that idea which adds a fixup table for NMIs and
soft-masked asynchronous interrupts. This will be used to protect
certain critical sections that are sensitive to being clobbered by
interrupts coming in (due to using the same SPRs and/or irq soft-mask
state).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-10-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index ee4283d014a4..b8ed1ce8c347 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -591,6 +591,36 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR) __GEN_COMMON_BODY \name .endm +.macro SEARCH_RESTART_TABLE +#ifdef CONFIG_RELOCATABLE + mr r12,r2 + ld r2,PACATOC(r13) + LOAD_REG_ADDR(r9, __start___restart_table) + LOAD_REG_ADDR(r10, __stop___restart_table) + mr r2,r12 +#else + LOAD_REG_IMMEDIATE_SYM(r9, r12, __start___restart_table) + LOAD_REG_IMMEDIATE_SYM(r10, r12, __stop___restart_table) +#endif +300: + cmpd r9,r10 + beq 302f + ld r12,0(r9) + cmpld r11,r12 + blt 301f + ld r12,8(r9) + cmpld r11,r12 + bge 301f + ld r12,16(r9) + b 303f +301: + addi r9,r9,24 + b 300b +302: + li r12,0 +303: +.endm + /* * Restore all registers including H/SRR0/1 saved in a stack frame of a * standard exception. @@ -2646,6 +2676,7 @@ EXC_COMMON_BEGIN(soft_nmi_common) mtmsrd r9,1 kuap_kernel_restore r9, r10 + EXCEPTION_RESTORE_REGS hsrr=0 RFI_TO_KERNEL @@ -2703,6 +2734,16 @@ masked_interrupt: stb r9,PACASRR_VALID(r13) .endif + SEARCH_RESTART_TABLE + cmpdi r12,0 + beq 3f + .if \hsrr + mtspr SPRN_HSRR0,r12 + .else + mtspr SPRN_SRR0,r12 + .endif +3: + ld r9,PACA_EXGEN+EX_CTR(r13) mtctr r9 lwz r9,PACA_EXGEN+EX_CCR(r13) |