Messages in this thread | | | Subject | Re: [PATCH v3 14/16] powerpc/32: implement fast entry for syscalls on BOOKE | From | Christophe Leroy <> | Date | Thu, 23 May 2019 09:00:48 +0200 |
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Le 23/05/2019 à 08:14, Paul Mackerras a écrit : > On Tue, Apr 30, 2019 at 12:39:03PM +0000, Christophe Leroy wrote: >> This patch implements a fast entry for syscalls. >> >> Syscalls don't have to preserve non volatile registers except LR. >> >> This patch then implement a fast entry for syscalls, where >> volatile registers get clobbered. >> >> As this entry is dedicated to syscall it always sets MSR_EE >> and warns in case MSR_EE was previously off >> >> It also assumes that the call is always from user, system calls are >> unexpected from kernel. > > This is now upstream as commit 1a4b739bbb4f. On the e500mc test > config that I use, I'm getting this build failure:
Is that a standard defconfig ? If not, can you provide your .config ?
> > arch/powerpc/kernel/head_fsl_booke.o: In function `SystemCall': > arch/powerpc/kernel/head_fsl_booke.S:416: undefined reference to `kvmppc_handler_BOOKE_INTERRUPT_SYSCALL_SPRN_SRR1' > Makefile:1052: recipe for target 'vmlinux' failed > >> +.macro SYSCALL_ENTRY trapno intno >> + mfspr r10, SPRN_SPRG_THREAD >> +#ifdef CONFIG_KVM_BOOKE_HV >> +BEGIN_FTR_SECTION >> + mtspr SPRN_SPRG_WSCRATCH0, r10 >> + stw r11, THREAD_NORMSAVE(0)(r10) >> + stw r13, THREAD_NORMSAVE(2)(r10) >> + mfcr r13 /* save CR in r13 for now */ >> + mfspr r11, SPRN_SRR1 >> + mtocrf 0x80, r11 /* check MSR[GS] without clobbering reg */ >> + bf 3, 1975f >> + b kvmppc_handler_BOOKE_INTERRUPT_\intno\()_SPRN_SRR1 > > It seems to me that the "_SPRN_SRR1" on the end of this line > isn't meant to be there... However, it still fails to link with that > removed.
This SYSCALL_ENTRY macro is a slimmed version of NORMAL_EXCEPTION_PROLOG()
In NORMAL_EXCEPTION_PROLOG(), we have: DO_KVM BOOKE_INTERRUPT_##intno SPRN_SRR1;
The _SPRN_SRR1 comes from there
Then in /arch/powerpc/include/asm/kvm_booke_hv_asm.h:
.macro DO_KVM intno srr1 #ifdef CONFIG_KVM_BOOKE_HV BEGIN_FTR_SECTION mtocrf 0x80, r11 /* check MSR[GS] without clobbering reg */ bf 3, 1975f b kvmppc_handler_\intno\()_\srr1 1975: END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV) #endif .endm
Christophe
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