Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753892Ab3DWAoy (ORCPT ); Mon, 22 Apr 2013 20:44:54 -0400 Received: from gate.crashing.org ([63.228.1.57]:39173 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753346Ab3DWAox (ORCPT ); Mon, 22 Apr 2013 20:44:53 -0400 Message-ID: <1366677702.2886.9.camel@pasglop> Subject: Re: [PATCH] powerpc: Add HWCAP2 aux entry From: Benjamin Herrenschmidt To: Michael Neuling Cc: akpm@linux-foundation.org, vda.linux@googlemail.com, Nishanth Aravamudan , Steve Munroe , linux-kernel@vger.kernel.org, paulus@samba.org, viro@zeniv.linux.org.uk, Ryan Arnold , linuxppc-dev@lists.ozlabs.org Date: Tue, 23 Apr 2013 10:41:42 +1000 In-Reply-To: <32253.1366256478@ale.ozlabs.ibm.com> References: <20130402212204.GA30438@linux.vnet.ibm.com> <20130405070559.GE5082@concordia> <27144.1366001074@ale.ozlabs.ibm.com> <31546.1366255991@ale.ozlabs.ibm.com> <32253.1366256478@ale.ozlabs.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.2-0ubuntu0.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4988 Lines: 130 On Thu, 2013-04-18 at 13:41 +1000, Michael Neuling wrote: > akpm, > > If you're happy with this, is it something you can take in your tree? Andrew ? Or give me an ack ? :-) I'm happy to carry this, we need that rather urgently and we have the glibc folks on board. Cheers, Ben. > Mikey > > Michael Neuling wrote: > > We are currently out of free bits in AT_HWCAP. With POWER8, we have > > several hardware features that we need to advertise. > > > > Tested on POWER and x86. > > > > Signed-off-by: Michael Neuling > > Signed-off-by: Nishanth Aravamudan > > --- > > > > > Wouldn't it be safer to not emit AT_HWCAP2 unless it is defined by the arch? > > > > > > That way the change would only impact powerpc. > > > > Should be addressed with this version. > > > > Mikey > > > > diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h > > index fb3245e..ccadad6 100644 > > --- a/arch/powerpc/include/asm/cputable.h > > +++ b/arch/powerpc/include/asm/cputable.h > > @@ -52,6 +52,7 @@ struct cpu_spec { > > char *cpu_name; > > unsigned long cpu_features; /* Kernel features */ > > unsigned int cpu_user_features; /* Userland features */ > > + unsigned int cpu_user_features2; /* Userland features v2 */ > > unsigned int mmu_features; /* MMU features */ > > > > /* cache line sizes */ > > diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h > > index ac9790f..cc0655a 100644 > > --- a/arch/powerpc/include/asm/elf.h > > +++ b/arch/powerpc/include/asm/elf.h > > @@ -61,6 +61,7 @@ typedef elf_vrregset_t elf_fpxregset_t; > > instruction set this cpu supports. This could be done in userspace, > > but it's not easy, and we've already done it here. */ > > # define ELF_HWCAP (cur_cpu_spec->cpu_user_features) > > +# define ELF_HWCAP2 (cur_cpu_spec->cpu_user_features2) > > > > /* This yields a string that ld.so will use to load implementation > > specific libraries for optimization. This is more specific in > > diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c > > index 3939829..1f8b5d5 100644 > > --- a/fs/binfmt_elf.c > > +++ b/fs/binfmt_elf.c > > @@ -240,6 +240,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, > > NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid)); > > NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); > > NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); > > +#ifdef ELF_HWCAP2 > > + NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); > > +#endif > > NEW_AUX_ENT(AT_EXECFN, bprm->exec); > > if (k_platform) { > > NEW_AUX_ENT(AT_PLATFORM, > > diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c > > index 9c13e02..bf2381d 100644 > > --- a/fs/binfmt_elf_fdpic.c > > +++ b/fs/binfmt_elf_fdpic.c > > @@ -483,7 +483,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, > > size_t platform_len = 0, len; > > char *k_platform, *k_base_platform; > > char __user *u_platform, *u_base_platform, *p; > > - long hwcap; > > int loop; > > int nr; /* reset for each csp adjustment */ > > > > @@ -502,8 +501,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, > > return -EFAULT; > > #endif > > > > - hwcap = ELF_HWCAP; > > - > > /* > > * If this architecture has a platform capability string, copy it > > * to userspace. In some cases (Sparc), this info is impossible > > @@ -617,7 +614,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, > > > > nr = 0; > > csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); > > - NEW_AUX_ENT(AT_HWCAP, hwcap); > > + NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); > > +#ifdef ELF_HWCAP2 > > + NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); > > +#endif > > NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); > > NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); > > NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); > > diff --git a/include/uapi/linux/auxvec.h b/include/uapi/linux/auxvec.h > > index 61594d5..835c065 100644 > > --- a/include/uapi/linux/auxvec.h > > +++ b/include/uapi/linux/auxvec.h > > @@ -28,6 +28,7 @@ > > #define AT_BASE_PLATFORM 24 /* string identifying real platform, may > > * differ from AT_PLATFORM. */ > > #define AT_RANDOM 25 /* address of 16 random bytes */ > > +#define AT_HWCAP2 26 /* extension of AT_HWCAP */ > > > > #define AT_EXECFN 31 /* filename of program */ > > > > _______________________________________________ > > Linuxppc-dev mailing list > > Linuxppc-dev@lists.ozlabs.org > > https://lists.ozlabs.org/listinfo/linuxppc-dev > > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/