From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55637) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aP0Kb-0000cn-TB for qemu-devel@nongnu.org; Thu, 28 Jan 2016 23:06:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aP0Ka-0002kh-Nd for qemu-devel@nongnu.org; Thu, 28 Jan 2016 23:06:45 -0500 Date: Fri, 29 Jan 2016 13:31:02 +1100 From: David Gibson Message-ID: <20160129023102.GE23043@voom.redhat.com> References: <1453889591-30968-1-git-send-email-david@gibson.dropbear.id.au> <1453889591-30968-7-git-send-email-david@gibson.dropbear.id.au> <56AA3791.1030905@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="LSp5EJdfMPwZcMS1" Content-Disposition: inline In-Reply-To: <56AA3791.1030905@redhat.com> Subject: Re: [Qemu-devel] [PATCHv2 06/10] target-ppc: Remove unused mmu models from ppc_tlb_invalidate_one List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: lvivier@redhat.com, aik@ozlabs.ru, agraf@suse.de, qemu-devel@nongnu.org, qemu-ppc@nongnu.org --LSp5EJdfMPwZcMS1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jan 28, 2016 at 04:45:21PM +0100, Thomas Huth wrote: > On 27.01.2016 11:13, David Gibson wrote: > > ppc_tlb_invalidate_one() has a big switch handling many different MMU > > types. However, most of those branches can never be reached: > >=20 > > It is called from 3 places: from remove_hpte() and h_protect() in > > spapr_hcall.c (which always has a 64-bit hash MMU type), and from > > helper_tlbie() in mmu_helper.c. > >=20 > > Calls to helper_tlbie() are generated from gen_tlbiel, gen_tlbiel and > > gen_tlbiva. The first two are only used with the PPC_MEM_TLBIE flag, > > set only with 32-bit or 64-bit hash MMU models, and gen_tlbiva() is > > used only on 440 and 460 models with the BookE mmu model. > >=20 > > These means the exhaustive list of MMU types which may call > > ppc_tlb_invalidate_one() is: POWERPC_MMU_SOFT_6xx, POWERPC_MMU_601, > > POWERPC_MMU_32B, POWERPC_MMU_SOFT_74xx, POWERPC_MMU_64B, POWERPC_MMU_2_= 03, > > POWERPC_MMU_2_06, POWERPC_MMU_2_07 and POWERPC_MMU_BOOKE. > >=20 > > Clean up by removing logic for all other MMU types from > > ppc_tlb_invalidate_one(). > >=20 > > Signed-off-by: David Gibson > > --- > ... > > @@ -2031,9 +2016,8 @@ void ppc_tlb_invalidate_one(CPUPPCState *env, tar= get_ulong addr) > > break; > > #endif /* defined(TARGET_PPC64) */ > > default: > > - /* XXX: TODO */ > > - cpu_abort(CPU(cpu), "Unknown MMU model\n"); > > - break; > > + /* Should never reach here with other MMU models */ > > + assert(0); > > } >=20 > May I suggest to simply use "abort()" instead of "assert(0)" ? I actually prefer assert(0), because it documents that this is really a "can't happen" rather than just "we can't cope". It also means it can be elided with -DNDEBUG. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --LSp5EJdfMPwZcMS1 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJWqs7mAAoJEGw4ysog2bOS1dcQAJT0+YY7VARs6iQFruEspMqA 6yWhSWTo2SI80FwdyDgYuOZ2y4nqJ/nYrSqmGQ8UuK4uW+pujpzmcMjuh4xKIQfy 1rh1owj19a9XbUX5Su4+wI2isvzYan4AZZBhHbbpj/ZYv+C5XI56I/wMbOxb63h8 JP3gXeDY6EYTau+byCorcOfO1Yko1mIxawj6iBg/GZBK2SK/gPJSKyv+b5SGve3c i5rVl0o0dzXOYnRv9D7STbTgYG2SOKQsp2KR+omhFv7RqkQncX9Km0N7iAnHMrjQ 6HA3ekaCM6ccfx18hMMLomXhVKUqKS8SwFkTrY0KzhCKBPHtfHXVuWBpFwIrI6OM VTOO6ooyYSewoHvFPZsq6tgP2gYjYM58XflG9/4HBPSn5BIS0sKrO+rOSCwSdwzv C5qdGLX+S5jVSCTw/k2lRy95b7Mob+M1cfnEqcUXlVThSTNZ890PGSHzhgXcYyyF 8Hzj8uYh7lsRFHds9Il6vwUBD4ijlzTNzWe+r/HEgPnH6Z5s8GDZtUoHFpph5/36 MEiqWdi1/xxs+NQggs7h9cIwMgCwoYl3MGw4I8gTxCAufWsfTsTkZdpt1oV4v0aM 2/Xi7fDjzOGH8zgMrvevdfAHFCiv7SIDg2wMI39iVu/JN5sVL4AfpxniB092DJXD AWdENs31qPY+1eS5L2jY =EdC1 -----END PGP SIGNATURE----- --LSp5EJdfMPwZcMS1--