From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luis R. Rodriguez" Subject: Re: [PATCH v5 09/14] jump_label: port __jump_table to linker tables Date: Tue, 3 Jan 2017 22:27:44 +0100 Message-ID: <20170103212744.GF13946@wotan.suse.de> References: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> <20161222023811.21246-1-mcgrof@kernel.org> <20161222023811.21246-10-mcgrof@kernel.org> <1482415702.9552.125.camel@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <1482415702.9552.125.camel@linux.intel.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Andy Shevchenko Cc: gnomes@lxorguk.ukuu.org.uk, dalias@libc.org, linux-ia64@vger.kernel.org, jkosina@suse.cz, benh@kernel.crashing.org, ming.lei@canonical.com, heiko.carstens@de.ibm.com, platform-driver-x86@vger.kernel.org, James.Bottomley@HansenPartnership.com, paul.gortmaker@windriver.com, paulus@samba.org, mpe@ellerman.id.au, hpa@zytor.com, masami.hiramatsu.pt@hitachi.com, wangnan0@huawei.com, mchehab@osg.samsung.com, linux-arch@vger.kernel.org, markus.heiser@darmarit.de, sparclinux@vger.kernel.org, xen-devel@lists.xensource.com, linux@arm.linux.org.uk, linux-sh@vger.kernel.org, will.deacon@arm.com, korea.drzix@gmail.com, x86@kernel.org, anil.s.keshavamurthy@intel.com, fontana@sharpeleven.org, mingo@redhat.com, dsahern@gmail.com, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, dvhart@infradead.org, dwmw2@infradead.org, linux@roeck-us.net, david.vrabel@citrix.com, linux-xte List-Id: linux-arch.vger.kernel.org T24gVGh1LCBEZWMgMjIsIDIwMTYgYXQgMDQ6MDg6MjJQTSArMDIwMCwgQW5keSBTaGV2Y2hlbmtv IHdyb3RlOgo+IE9uIFdlZCwgMjAxNi0xMi0yMSBhdCAxODozOCAtMDgwMCwgTHVpcyBSLiBSb2Ry aWd1ZXogd3JvdGU6Cj4gPiBNb3ZlIHRoZSBfX2p1bXBfdGFibGUgZnJvbSB0aGUgYSBjdXN0b20g c2VjdGlvbiBzb2x1dGlvbgo+ID4gdG8gYSBnZW5lcmljIHNvbHV0aW9uLCB0aGlzIGF2b2lkaW5n IGV4dHJhIHZtbGludXgubGRzLmgKPiA+IGN1c3RvbWl6YXRpb25zLgo+ID4gCj4gPiBUaGlzIGFs c28gZGVtb3MgdGhlIHVzZSBvZiB0aGUgLmRhdGEgbGlua2VyIHRhYmxlIGFuZCBvZgo+ID4gdGhl IHNoYXJlZCBhc20gY2FsbCBwdXNoX3NlY3Rpb25fdGJsKCkuCj4gPiAKPiAKPiA+IMKgewo+ID4g wqAJYXNtX3ZvbGF0aWxlX2dvdG8oIjE6XG5cdCIKPiA+IMKgCQnCoFdBU00obm9wKSAiXG5cdCIK PiA+IC0JCcKgIi5wdXNoc2VjdGlvbiBfX2p1bXBfdGFibGUswqDCoFwiYXdcIlxuXHQiCj4gPiAr CQnCoHB1c2hfc2VjdGlvbl90YmxfYW55KC5kYXRhLCBfX2p1bXBfdGFibGUsIGF3KQo+ID4gwqAJ CcKgIi53b3JkIDFiLCAlbFtsX3llc10sICVjMFxuXHQiCj4gPiDCoAkJwqAiLnBvcHNlY3Rpb25c blx0Igo+ID4gwqAJCcKgOiA6wqDCoCJpIiAoJigoY2hhciAqKWtleSlbYnJhbmNoXSkgOsKgwqA6 IGxfeWVzKTsKPiA+IEBAIC0yNiw3ICsyOCw3IEBAIHN0YXRpYyBfX2Fsd2F5c19pbmxpbmUgYm9v bAo+ID4gYXJjaF9zdGF0aWNfYnJhbmNoX2p1bXAoc3RydWN0IHN0YXRpY19rZXkgKmtleSwgYm9v bAo+ID4gwqB7Cj4gPiDCoAlhc21fdm9sYXRpbGVfZ290bygiMTpcblx0Igo+ID4gwqAJCcKgV0FT TShiKSAiICVsW2xfeWVzXVxuXHQiCj4gPiAtCQnCoCIucHVzaHNlY3Rpb24gX19qdW1wX3RhYmxl LMKgwqBcImF3XCJcblx0Igo+ID4gKwkJwqBwdXNoX3NlY3Rpb25fdGJsX2FueSguZGF0YSwgX19q dW1wX3RhYmxlLCBhdykKPiA+IMKgCQnCoCIud29yZCAxYiwgJWxbbF95ZXNdLCAlYzBcblx0Igo+ ID4gwqAJCcKgIi5wb3BzZWN0aW9uXG5cdCIKPiAKPiBEb2VzIGl0IG1ha2Ugc2Vuc2UgdG8gaW50 cm9kdWNlIHNvbWV0aGluZyBsaWtlCj4gCj4gI2RlZmluZSBwb3Bfc2VjdGlvbl90YmwgIi5wb3Bz ZWN0aW9uXG5cdCIKPiAjZGVmaW5lIHBvcF9zZWN0aW9uX3RibF9hbnkgcG9wX3NlY3Rpb25fdGJs CgpBYnNvbHV0ZWx5ICEgSG93ZXZlciB0aGlzIHdvdWxkIGJlIGFuIGV2b2x1dGlvbiwgYW5kIEkg d291bGQgbXVjaApwcmVmZXIgdG8gYWRkIHRoaXMgbGF0ZXIgYXMgYW4gYXRvbWljIHN0ZXAgbGF0 ZXIgdG8gZW5hYmxlIG90aGVyCnVzZXJzIHRvIGFsc28gYmUgdXNpbmcgdGhpcyBzaGFyZWQgbWFj cm8uIEkgZGlkIG5vdCBoYXZlIGFuIGltbWVkaWF0ZQpuZWVkIGZvciBhIHBvcF9zZWN0aW9uX3Ri bCgpIG1hY3JvIGFzIGl0cyBub3Qgc2VjdGlvbiBzcGVjaWZpYy4KCiAgTHVpcwoKX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVsIG1haWxpbmcg bGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5vcmcveGVuLWRl dmVsCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:57560 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761524AbdACWD6 (ORCPT ); Tue, 3 Jan 2017 17:03:58 -0500 Date: Tue, 3 Jan 2017 22:27:44 +0100 From: "Luis R. Rodriguez" Subject: Re: [PATCH v5 09/14] jump_label: port __jump_table to linker tables Message-ID: <20170103212744.GF13946@wotan.suse.de> References: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> <20161222023811.21246-1-mcgrof@kernel.org> <20161222023811.21246-10-mcgrof@kernel.org> <1482415702.9552.125.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1482415702.9552.125.camel@linux.intel.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andy Shevchenko Cc: "Luis R. Rodriguez" , hpa@zytor.com, acme@redhat.com, tglx@linutronix.de, mingo@redhat.com, jpoimboe@redhat.com, bp@alien8.de, npiggin@gmail.com, mhiramat@kernel.org, masami.hiramatsu.pt@hitachi.com, jbaron@akamai.com, heiko.carstens@de.ibm.com, ananth@linux.vnet.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, realmz6@gmail.com, dalias@libc.org, linux@arm.linux.org.uk, x86@kernel.org, luto@amacapital.net, keescook@chromium.org, linux@roeck-us.net, torvalds@linux-foundation.org, gregkh@linuxfoundation.org, rusty@rustcorp.com.au, gnomes@lxorguk.ukuu.org.uk, alan@linux.intel.com, dwmw2@infradead.org, arnd@arndb.de, ming.lei@canonical.com, linux-arch@vger.kernel.org, benh@kernel.crashing.org, pebolle@tiscali.nl, fontana@sharpeleven.org, david.vrabel@citrix.com, konrad.wilk@oracle.com, mcb30@ipxe.org, jgross@suse.com, andrew.cooper3@citrix.com, paul.gortmaker@windriver.com, xen-devel@lists.xensource.com, ak@linux.intel.com, pali.rohar@gmail.com, dvhart@infradead.org, platform-driver-x86@vger.kernel.org, mmarek@suse.com, linux@rasmusvillemoes.dk, jkosina@suse.cz, korea.drzix@gmail.com, linux-kbuild@vger.kernel.org, tony.luck@intel.com, akpm@linux-foundation.org, linux-ia64@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, rostedt@goodmis.org, jani.nikula@intel.com, mchehab@osg.samsung.com, markus.heiser@darmarit.de, jolsa@kernel.org, msalter@redhat.com, chris@zankel.net, jcmvbkbc@gmail.com, linux-xtensa@linux-xtensa.org, adrian.hunter@intel.com, dsahern@gmail.com, namhyung@kernel.org, wangnan0@huawei.com, dmitry.torokhov@gmail.com, joro@8bytes.org, paulus@samba.org, mpe@ellerman.id.au, James.Bottomley@HansenPartnership.com Message-ID: <20170103212744.e3gN6UoX1juV2utjPN1UBHaMNGSjLmLUszK-UGUAbeE@z> On Thu, Dec 22, 2016 at 04:08:22PM +0200, Andy Shevchenko wrote: > On Wed, 2016-12-21 at 18:38 -0800, Luis R. Rodriguez wrote: > > Move the __jump_table from the a custom section solution > > to a generic solution, this avoiding extra vmlinux.lds.h > > customizations. > > > > This also demos the use of the .data linker table and of > > the shared asm call push_section_tbl(). > > > > >  { > >   asm_volatile_goto("1:\n\t" > >    WASM(nop) "\n\t" > > -  ".pushsection __jump_table,  \"aw\"\n\t" > > +  push_section_tbl_any(.data, __jump_table, aw) > >    ".word 1b, %l[l_yes], %c0\n\t" > >    ".popsection\n\t" > >    : :  "i" (&((char *)key)[branch]) :  : l_yes); > > @@ -26,7 +28,7 @@ static __always_inline bool > > arch_static_branch_jump(struct static_key *key, bool > >  { > >   asm_volatile_goto("1:\n\t" > >    WASM(b) " %l[l_yes]\n\t" > > -  ".pushsection __jump_table,  \"aw\"\n\t" > > +  push_section_tbl_any(.data, __jump_table, aw) > >    ".word 1b, %l[l_yes], %c0\n\t" > >    ".popsection\n\t" > > Does it make sense to introduce something like > > #define pop_section_tbl ".popsection\n\t" > #define pop_section_tbl_any pop_section_tbl Absolutely ! However this would be an evolution, and I would much prefer to add this later as an atomic step later to enable other users to also be using this shared macro. I did not have an immediate need for a pop_section_tbl() macro as its not section specific. Luis