From: Nicholas Piggin npiggin@gmail.com
commit 49c1d07fd04f54eb588c4a1dfcedc8d22c5ffd50 upstream.
Starting with ISA v3.1, LPCR[AIL] no longer controls the interrupt mode for HV=1 interrupts. Instead, a new LPCR[HAIL] bit is defined which behaves like AIL=3 for HV interrupts when set.
Set HAIL on bare metal to give us mmu-on interrupts and improve performance.
This also fixes an scv bug: we don't implement scv real mode (AIL=0) vectors because they are at an inconvenient location, so we just disable scv support when AIL can not be set. However powernv assumes that LPCR[AIL] will enable AIL mode so it enables scv support despite HV interrupts being AIL=0, which causes scv interrupts to go off into the weeds.
Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Cc: stable@vger.kernel.org # v5.9+ Signed-off-by: Nicholas Piggin npiggin@gmail.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20210402024124.545826-1-npiggin@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/include/asm/reg.h | 1 + arch/powerpc/kernel/setup_64.c | 19 ++++++++++++++++--- 2 files changed, 17 insertions(+), 3 deletions(-)
--- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -441,6 +441,7 @@ #define LPCR_VRMA_LP1 ASM_CONST(0x0000800000000000) #define LPCR_RMLS 0x1C000000 /* Implementation dependent RMO limit sel */ #define LPCR_RMLS_SH 26 +#define LPCR_HAIL ASM_CONST(0x0000000004000000) /* HV AIL (ISAv3.1) */ #define LPCR_ILE ASM_CONST(0x0000000002000000) /* !HV irqs set MSR:LE */ #define LPCR_AIL ASM_CONST(0x0000000001800000) /* Alternate interrupt location */ #define LPCR_AIL_0 ASM_CONST(0x0000000000000000) /* MMU off exception offset 0x0 */ --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -231,10 +231,23 @@ static void cpu_ready_for_interrupts(voi * If we are not in hypervisor mode the job is done once for * the whole partition in configure_exceptions(). */ - if (cpu_has_feature(CPU_FTR_HVMODE) && - cpu_has_feature(CPU_FTR_ARCH_207S)) { + if (cpu_has_feature(CPU_FTR_HVMODE)) { unsigned long lpcr = mfspr(SPRN_LPCR); - mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3); + unsigned long new_lpcr = lpcr; + + if (cpu_has_feature(CPU_FTR_ARCH_31)) { + /* P10 DD1 does not have HAIL */ + if (pvr_version_is(PVR_POWER10) && + (mfspr(SPRN_PVR) & 0xf00) == 0x100) + new_lpcr |= LPCR_AIL_3; + else + new_lpcr |= LPCR_HAIL; + } else if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + new_lpcr |= LPCR_AIL_3; + } + + if (new_lpcr != lpcr) + mtspr(SPRN_LPCR, new_lpcr); }
/*