Date: Mon, 23 Feb 2015 09:52:43 -0500 From: John Baldwin <jhb@freebsd.org> To: Nathan Whitehorn <nwhitehorn@freebsd.org> Cc: Konstantin Belousov <kostikbel@gmail.com>, svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r279189 - in head/sys/powerpc: aim fpu include powerpc Message-ID: <1832257.41OqWDsdB6@ralph.baldwin.cx> In-Reply-To: <54EA9EC6.3070304@freebsd.org> References: <201502222140.t1MLeSFg075690@svn.freebsd.org> <20150223012148.GN74514@kib.kiev.ua> <54EA9EC6.3070304@freebsd.org>
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On Sunday, February 22, 2015 07:30:14 PM Nathan Whitehorn wrote: > On 02/22/15 17:21, Konstantin Belousov wrote: > > On Sun, Feb 22, 2015 at 09:40:28PM +0000, Nathan Whitehorn wrote: > >> Author: nwhitehorn > >> Date: Sun Feb 22 21:40:27 2015 > >> New Revision: 279189 > >> URL: https://svnweb.freebsd.org/changeset/base/279189 > >> > >> Log: > >> Kernel support for the Vector-Scalar eXtension (VSX) found on the > >> POWER7 > >> and POWER8. This instruction set unifies the 32 64-bit scalar floating > >> point registers with the 32 128-bit vector registers into a single > >> bank > >> of 64 128-bit registers. Kernel support mostly amounts to saving and > >> restoring the wider version of the floating point registers and making > >> sure that both scalar FP and vector registers are enabled once a VSX > >> instruction is executed. get_mcontext() and friends currently cannot > >> see the high bits, which will require a little more work. > >> > >> As the system compiler (GCC 4.2) does not support VSX, making use of > >> this > >> from userland requires either newer GCC or clang. > > > > Handling the similar issue (exploding of the machine state size) for x86 > > resulted in the creation of the getcontextx(3) API. It is both get/set > > context(2) syscalls and signal handling which require modifications. > > > > For signal handlers and sigreturn(2), it is possible to make it > > transparent > > for the consumers, but not for *context(2), since mcontext_t is explicit > > type allocated by callers. > > Thanks! I had forgotten about the signal handling issue. Will look into > this tomorrow. Don't forget to include the info in cores as well so debuggers can see them (as well as ptrace access if that needs changes). -- John Baldwin
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