From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-x242.google.com (mail-pa0-x242.google.com [IPv6:2607:f8b0:400e:c03::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3r4zTK5vsnzDqCm for ; Thu, 12 May 2016 13:47:33 +1000 (AEST) Received: by mail-pa0-x242.google.com with SMTP id gh9so4980409pac.0 for ; Wed, 11 May 2016 20:47:33 -0700 (PDT) Date: Thu, 12 May 2016 13:47:22 +1000 From: Balbir Singh To: Rashmica Gupta Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH V2] powerpc/tm: Clean up duplication of code Message-ID: <20160512134722.1433311d@cotter.ozlabs.ibm.com> In-Reply-To: <1463024342-16130-1-git-send-email-rashmicy@gmail.com> References: <1463024342-16130-1-git-send-email-rashmicy@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 12 May 2016 13:39:02 +1000 Rashmica Gupta wrote: > The same logic for tm_abort appears twice, so pull it out into a > function. > > Signed-off-by: Rashmica Gupta > --- > v2: Removed some #ifdefs from inside C code and changed the formatting of the > comment. > > arch/powerpc/mm/hash_utils_64.c | 56 +++++++++++++++++++---------------------- > 1 file changed, 26 insertions(+), 30 deletions(-) > > diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c > index 7635b1c6b5da..b92cca033131 100644 > --- a/arch/powerpc/mm/hash_utils_64.c > +++ b/arch/powerpc/mm/hash_utils_64.c > @@ -1318,6 +1318,30 @@ out_exit: > local_irq_restore(flags); > } > > + /* > + * Transactions are not aborted by tlbiel, only tlbie. > + * Without, syncing a page back to a block device w/ PIO could pick up > + * transactional data (bad!) so we force an abort here. Before the > + * sync the page will be made read-only, which will flush_hash_page. > + * BIG ISSUE here: if the kernel uses a page from userspace without > + * unmapping it first, it may see the speculated version. > + */ The comments are not properly aligned to the start of the first column which it should be for the function > +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM > +static inline void tlb_flush_abort_tm(int local) > +{ > + if (local && cpu_has_feature(CPU_FTR_TM) && > + current->thread.regs && > + MSR_TM_ACTIVE(current->thread.regs->msr)) { > + tm_enable(); > + tm_abort(TM_CAUSE_TLBI); > + } > +} > +#else > +static inline void tlb_flush_abort_tm(int local) > +{ > +} static inline void tlb_flish_abort_tm(int local) {} But its a personal choice Other than that Reviewed-by: Balbir Singh > +#endif > + > /* WARNING: This is called from hash_low_64.S, if you change this prototype, > * do not forget to update the assembly call site ! > */ > @@ -1343,21 +1367,7 @@ void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize, > ppc_md.hpte_invalidate(slot, vpn, psize, psize, ssize, local); > } pte_iterate_hashed_end(); > > -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM > - /* Transactions are not aborted by tlbiel, only tlbie. > - * Without, syncing a page back to a block device w/ PIO could pick up > - * transactional data (bad!) so we force an abort here. Before the > - * sync the page will be made read-only, which will flush_hash_page. > - * BIG ISSUE here: if the kernel uses a page from userspace without > - * unmapping it first, it may see the speculated version. > - */ > - if (local && cpu_has_feature(CPU_FTR_TM) && > - current->thread.regs && > - MSR_TM_ACTIVE(current->thread.regs->msr)) { > - tm_enable(); > - tm_abort(TM_CAUSE_TLBI); > - } > -#endif > + tlb_flush_abort_tm(local); > } > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > @@ -1414,21 +1424,7 @@ void flush_hash_hugepage(unsigned long vsid, unsigned long addr, > MMU_PAGE_16M, ssize, local); > } > tm_abort: > -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM > - /* Transactions are not aborted by tlbiel, only tlbie. > - * Without, syncing a page back to a block device w/ PIO could pick up > - * transactional data (bad!) so we force an abort here. Before the > - * sync the page will be made read-only, which will flush_hash_page. > - * BIG ISSUE here: if the kernel uses a page from userspace without > - * unmapping it first, it may see the speculated version. > - */ > - if (local && cpu_has_feature(CPU_FTR_TM) && > - current->thread.regs && > - MSR_TM_ACTIVE(current->thread.regs->msr)) { > - tm_enable(); > - tm_abort(TM_CAUSE_TLBI); > - } > -#endif > + tlb_flush_abort_tm(local); > return; > } > #endif /* CONFIG_TRANSPARENT_HUGEPAGE */