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: 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. Paul.
