From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id DB5531A011E for ; Tue, 8 Mar 2016 16:10:53 +1100 (AEDT) Date: Tue, 8 Mar 2016 15:50:58 +1100 From: David Gibson To: Alexey Kardashevskiy Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras , Alex Williamson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH kernel 4/9] powerpc/powernv/iommu: Add real mode version of xchg() Message-ID: <20160308045058.GX22546@voom.fritz.box> References: <1457322077-26640-1-git-send-email-aik@ozlabs.ru> <1457322077-26640-5-git-send-email-aik@ozlabs.ru> <20160307060519.GM22546@voom.fritz.box> <56DD2E87.1010504@ozlabs.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="OtXN0xDA1zr/oUEL" In-Reply-To: <56DD2E87.1010504@ozlabs.ru> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --OtXN0xDA1zr/oUEL Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 07, 2016 at 06:32:23PM +1100, Alexey Kardashevskiy wrote: > On 03/07/2016 05:05 PM, David Gibson wrote: > >On Mon, Mar 07, 2016 at 02:41:12PM +1100, Alexey Kardashevskiy wrote: > >>In real mode, TCE tables are invalidated using different > >>cache-inhibited store instructions which is different from > >>the virtual mode. > >> > >>This defines and implements exchange_rm() callback. This does not > >>define set_rm/clear_rm/flush_rm callbacks as there is no user for those= - > >>exchange/exchange_rm are only to be used by KVM for VFIO. > >> > >>The exchange_rm callback is defined for IODA1/IODA2 powernv platforms. > >> > >>This replaces list_for_each_entry_rcu with its lockless version as > >>from now on pnv_pci_ioda2_tce_invalidate() can be called in > >>the real mode too. > >> > >>Signed-off-by: Alexey Kardashevskiy > >>--- > >> arch/powerpc/include/asm/iommu.h | 7 +++++++ > >> arch/powerpc/kernel/iommu.c | 15 +++++++++++++++ > >> arch/powerpc/platforms/powernv/pci-ioda.c | 28 ++++++++++++++++++++++= +++++- > >> 3 files changed, 49 insertions(+), 1 deletion(-) > >> > >>diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/as= m/iommu.h > >>index 7b87bab..3ca877a 100644 > >>--- a/arch/powerpc/include/asm/iommu.h > >>+++ b/arch/powerpc/include/asm/iommu.h > >>@@ -64,6 +64,11 @@ struct iommu_table_ops { > >> long index, > >> unsigned long *hpa, > >> enum dma_data_direction *direction); > >>+ /* Real mode */ > >>+ int (*exchange_rm)(struct iommu_table *tbl, > >>+ long index, > >>+ unsigned long *hpa, > >>+ enum dma_data_direction *direction); > >> #endif > >> void (*clear)(struct iommu_table *tbl, > >> long index, long npages); > >>@@ -208,6 +213,8 @@ extern void iommu_del_device(struct device *dev); > >> extern int __init tce_iommu_bus_notifier_init(void); > >> extern long iommu_tce_xchg(struct iommu_table *tbl, unsigned long ent= ry, > >> unsigned long *hpa, enum dma_data_direction *direction); > >>+extern long iommu_tce_xchg_rm(struct iommu_table *tbl, unsigned long e= ntry, > >>+ unsigned long *hpa, enum dma_data_direction *direction); > >> #else > >> static inline void iommu_register_group(struct iommu_table_group *tab= le_group, > >> int pci_domain_number, > >>diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c > >>index a8e3490..2fcc48b 100644 > >>--- a/arch/powerpc/kernel/iommu.c > >>+++ b/arch/powerpc/kernel/iommu.c > >>@@ -1062,6 +1062,21 @@ void iommu_release_ownership(struct iommu_table = *tbl) > >> } > >> EXPORT_SYMBOL_GPL(iommu_release_ownership); > >> > >>+long iommu_tce_xchg_rm(struct iommu_table *tbl, unsigned long entry, > >>+ unsigned long *hpa, enum dma_data_direction *direction) > >>+{ > >>+ long ret; > >>+ > >>+ ret =3D tbl->it_ops->exchange_rm(tbl, entry, hpa, direction); > >>+ > >>+ if (!ret && ((*direction =3D=3D DMA_FROM_DEVICE) || > >>+ (*direction =3D=3D DMA_BIDIRECTIONAL))) > >>+ SetPageDirty(realmode_pfn_to_page(*hpa >> PAGE_SHIFT)); > >>+ > >>+ return ret; > >>+} > >>+EXPORT_SYMBOL_GPL(iommu_tce_xchg_rm); > > > >> int iommu_add_device(struct device *dev) > >> { > >> struct iommu_table *tbl; > >>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/p= latforms/powernv/pci-ioda.c > >>index c5baaf3..bed1944 100644 > >>--- a/arch/powerpc/platforms/powernv/pci-ioda.c > >>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c > >>@@ -1791,6 +1791,18 @@ static int pnv_ioda1_tce_xchg(struct iommu_table= *tbl, long index, > >> > >> return ret; > >> } > >>+ > >>+static int pnv_ioda1_tce_xchg_rm(struct iommu_table *tbl, long index, > >>+ unsigned long *hpa, enum dma_data_direction *direction) > >>+{ > >>+ long ret =3D pnv_tce_xchg(tbl, index, hpa, direction); > >>+ > >>+ if (!ret && (tbl->it_type & > >>+ (TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE))) > >>+ pnv_pci_ioda1_tce_invalidate(tbl, index, 1, true); > >>+ > >>+ return ret; > >>+} > >> #endif > > > >Both your _rm variants are identical to the non _rm versions. Why not > >just set the function poiinter to the same thing, rather than copying > >the whole function. >=20 >=20 > The last parameter - "rm" - to pnv_pci_ioda1_tce_invalidate() is > different. Ah, missed that, sorry. >=20 >=20 > > > >> static void pnv_ioda1_tce_free(struct iommu_table *tbl, long index, > >>@@ -1806,6 +1818,7 @@ static struct iommu_table_ops pnv_ioda1_iommu_ops= =3D { > >> .set =3D pnv_ioda1_tce_build, > >> #ifdef CONFIG_IOMMU_API > >> .exchange =3D pnv_ioda1_tce_xchg, > >>+ .exchange_rm =3D pnv_ioda1_tce_xchg_rm, > >> #endif > >> .clear =3D pnv_ioda1_tce_free, > >> .get =3D pnv_tce_get, > >>@@ -1866,7 +1879,7 @@ static void pnv_pci_ioda2_tce_invalidate(struct i= ommu_table *tbl, > >> { > >> struct iommu_table_group_link *tgl; > >> > >>- list_for_each_entry_rcu(tgl, &tbl->it_group_list, next) { > >>+ list_for_each_entry_lockless(tgl, &tbl->it_group_list, next) { > >> struct pnv_ioda_pe *npe; > >> struct pnv_ioda_pe *pe =3D container_of(tgl->table_group, > >> struct pnv_ioda_pe, table_group); > >>@@ -1918,6 +1931,18 @@ static int pnv_ioda2_tce_xchg(struct iommu_table= *tbl, long index, > >> > >> return ret; > >> } > >>+ > >>+static int pnv_ioda2_tce_xchg_rm(struct iommu_table *tbl, long index, > >>+ unsigned long *hpa, enum dma_data_direction *direction) > >>+{ > >>+ long ret =3D pnv_tce_xchg(tbl, index, hpa, direction); > >>+ > >>+ if (!ret && (tbl->it_type & > >>+ (TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE))) > >>+ pnv_pci_ioda2_tce_invalidate(tbl, index, 1, true); > >>+ > >>+ return ret; > >>+} > >> #endif > >> > >> static void pnv_ioda2_tce_free(struct iommu_table *tbl, long index, > >>@@ -1939,6 +1964,7 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops= =3D { > >> .set =3D pnv_ioda2_tce_build, > >> #ifdef CONFIG_IOMMU_API > >> .exchange =3D pnv_ioda2_tce_xchg, > >>+ .exchange_rm =3D pnv_ioda2_tce_xchg_rm, > >> #endif > >> .clear =3D pnv_ioda2_tce_free, > >> .get =3D pnv_tce_get, > > >=20 >=20 --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. 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