From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com [IPv6:2607:f8b0:400e:c00::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 7F5771A0B6C for ; Mon, 7 Mar 2016 18:32:33 +1100 (AEDT) Received: by mail-pf0-x244.google.com with SMTP id 63so7583144pfe.0 for ; Sun, 06 Mar 2016 23:32:33 -0800 (PST) Subject: Re: [PATCH kernel 4/9] powerpc/powernv/iommu: Add real mode version of xchg() To: David Gibson References: <1457322077-26640-1-git-send-email-aik@ozlabs.ru> <1457322077-26640-5-git-send-email-aik@ozlabs.ru> <20160307060519.GM22546@voom.fritz.box> Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras , Alex Williamson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org From: Alexey Kardashevskiy Message-ID: <56DD2E87.1010504@ozlabs.ru> Date: Mon, 7 Mar 2016 18:32:23 +1100 MIME-Version: 1.0 In-Reply-To: <20160307060519.GM22546@voom.fritz.box> Content-Type: text/plain; charset=koi8-r; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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/asm/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 entry, >> unsigned long *hpa, enum dma_data_direction *direction); >> +extern long iommu_tce_xchg_rm(struct iommu_table *tbl, unsigned long entry, >> + unsigned long *hpa, enum dma_data_direction *direction); >> #else >> static inline void iommu_register_group(struct iommu_table_group *table_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 = tbl->it_ops->exchange_rm(tbl, entry, hpa, direction); >> + >> + if (!ret && ((*direction == DMA_FROM_DEVICE) || >> + (*direction == 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/platforms/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 = 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. The last parameter - "rm" - to pnv_pci_ioda1_tce_invalidate() is different. > >> 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 = { >> .set = pnv_ioda1_tce_build, >> #ifdef CONFIG_IOMMU_API >> .exchange = pnv_ioda1_tce_xchg, >> + .exchange_rm = pnv_ioda1_tce_xchg_rm, >> #endif >> .clear = pnv_ioda1_tce_free, >> .get = pnv_tce_get, >> @@ -1866,7 +1879,7 @@ static void pnv_pci_ioda2_tce_invalidate(struct iommu_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 = 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 = 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 = { >> .set = pnv_ioda2_tce_build, >> #ifdef CONFIG_IOMMU_API >> .exchange = pnv_ioda2_tce_xchg, >> + .exchange_rm = pnv_ioda2_tce_xchg_rm, >> #endif >> .clear = pnv_ioda2_tce_free, >> .get = pnv_tce_get, > -- Alexey