Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031265AbbDYMTz (ORCPT ); Sat, 25 Apr 2015 08:19:55 -0400 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:48094 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759242AbbDYMQ1 (ORCPT ); Sat, 25 Apr 2015 08:16:27 -0400 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Benjamin Herrenschmidt , Paul Mackerras , Alex Williamson , Gavin Shan , David Gibson , linux-kernel@vger.kernel.org Subject: [PATCH kernel v9 13/32] vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control Date: Sat, 25 Apr 2015 22:14:37 +1000 Message-Id: <1429964096-11524-14-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1429964096-11524-1-git-send-email-aik@ozlabs.ru> References: <1429964096-11524-1-git-send-email-aik@ozlabs.ru> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15042512-0021-0000-0000-00000126CBF7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9903 Lines: 294 This adds tce_iommu_take_ownership() and tce_iommu_release_ownership which call in a loop iommu_take_ownership()/iommu_release_ownership() for every table on the group. As there is just one now, no change in behaviour is expected. At the moment the iommu_table struct has a set_bypass() which enables/ disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code which calls this callback when external IOMMU users such as VFIO are about to get over a PHB. The set_bypass() callback is not really an iommu_table function but IOMMU/PE function. This introduces a iommu_table_group_ops struct and adds take_ownership()/release_ownership() callbacks to it which are called when an external user takes/releases control over the IOMMU. This replaces set_bypass() with ownership callbacks as it is not necessarily just bypass enabling, it can be something else/more so let's give it more generic name. The callbacks is implemented for IODA2 only. Other platforms (P5IOC2, IODA1) will use the old iommu_take_ownership/iommu_release_ownership API. The following patches will replace iommu_take_ownership/ iommu_release_ownership calls in IODA2 with full IOMMU table release/ create. Signed-off-by: Alexey Kardashevskiy [aw: for the vfio related changes] Acked-by: Alex Williamson --- Changes: v9: * squashed "vfio: powerpc/spapr: powerpc/iommu: Rework IOMMU ownership control" and "vfio: powerpc/spapr: powerpc/powernv/ioda2: Rework IOMMU ownership control" into a single patch * moved helpers with a loop through tables in a group to vfio_iommu_spapr_tce.c to keep the platform code free of IOMMU table groups as much as possible * added missing tce_iommu_clear() to tce_iommu_release_ownership() * replaced the set_ownership(enable) callback with take_ownership() and release_ownership() --- arch/powerpc/include/asm/iommu.h | 13 +++++- arch/powerpc/kernel/iommu.c | 11 ------ arch/powerpc/platforms/powernv/pci-ioda.c | 40 +++++++++++++++---- drivers/vfio/vfio_iommu_spapr_tce.c | 66 +++++++++++++++++++++++++++---- 4 files changed, 103 insertions(+), 27 deletions(-) diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h index fa37519..e63419e 100644 --- a/arch/powerpc/include/asm/iommu.h +++ b/arch/powerpc/include/asm/iommu.h @@ -93,7 +93,6 @@ struct iommu_table { unsigned long it_page_shift;/* table iommu page size */ struct iommu_table_group *it_table_group; struct iommu_table_ops *it_ops; - void (*set_bypass)(struct iommu_table *tbl, bool enable); }; /* Pure 2^n version of get_order */ @@ -128,11 +127,23 @@ extern struct iommu_table *iommu_init_table(struct iommu_table * tbl, #define IOMMU_TABLE_GROUP_MAX_TABLES 1 +struct iommu_table_group; + +struct iommu_table_group_ops { + /* + * Switches ownership from the kernel itself to an external + * user. While onwership is taken, the kernel cannot use IOMMU itself. + */ + void (*take_ownership)(struct iommu_table_group *table_group); + void (*release_ownership)(struct iommu_table_group *table_group); +}; + struct iommu_table_group { #ifdef CONFIG_IOMMU_API struct iommu_group *group; #endif struct iommu_table tables[IOMMU_TABLE_GROUP_MAX_TABLES]; + struct iommu_table_group_ops *ops; }; #ifdef CONFIG_IOMMU_API diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 005146b..2856d27 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1057,13 +1057,6 @@ int iommu_take_ownership(struct iommu_table *tbl) memset(tbl->it_map, 0xff, sz); - /* - * Disable iommu bypass, otherwise the user can DMA to all of - * our physical memory via the bypass window instead of just - * the pages that has been explicitly mapped into the iommu - */ - if (tbl->set_bypass) - tbl->set_bypass(tbl, false); return 0; } @@ -1078,10 +1071,6 @@ void iommu_release_ownership(struct iommu_table *tbl) /* Restore bit#0 set by iommu_init_table() */ if (tbl->it_offset == 0) set_bit(0, tbl->it_map); - - /* The kernel owns the device now, we can restore the iommu bypass */ - if (tbl->set_bypass) - tbl->set_bypass(tbl, true); } EXPORT_SYMBOL_GPL(iommu_release_ownership); diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 88472cb..718d5cc 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1870,10 +1870,8 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb, __free_pages(tce_mem, get_order(TCE32_TABLE_SIZE * segs)); } -static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable) +static void pnv_pci_ioda2_set_bypass(struct pnv_ioda_pe *pe, bool enable) { - struct pnv_ioda_pe *pe = container_of(tbl->it_table_group, - struct pnv_ioda_pe, table_group); uint16_t window_id = (pe->pe_number << 1 ) + 1; int64_t rc; @@ -1901,7 +1899,8 @@ static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable) * host side. */ if (pe->pdev) - set_iommu_table_base(&pe->pdev->dev, tbl); + set_iommu_table_base(&pe->pdev->dev, + &pe->table_group.tables[0]); else pnv_ioda_setup_bus_dma(pe, pe->pbus, false); } @@ -1917,13 +1916,35 @@ static void pnv_pci_ioda2_setup_bypass_pe(struct pnv_phb *phb, /* TVE #1 is selected by PCI address bit 59 */ pe->tce_bypass_base = 1ull << 59; - /* Install set_bypass callback for VFIO */ - pe->table_group.tables[0].set_bypass = pnv_pci_ioda2_set_bypass; - /* Enable bypass by default */ - pnv_pci_ioda2_set_bypass(&pe->table_group.tables[0], true); + pnv_pci_ioda2_set_bypass(pe, true); } +#ifdef CONFIG_IOMMU_API +static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group) +{ + struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe, + table_group); + + iommu_take_ownership(&table_group->tables[0]); + pnv_pci_ioda2_set_bypass(pe, false); +} + +static void pnv_ioda2_release_ownership(struct iommu_table_group *table_group) +{ + struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe, + table_group); + + iommu_release_ownership(&table_group->tables[0]); + pnv_pci_ioda2_set_bypass(pe, true); +} + +static struct iommu_table_group_ops pnv_pci_ioda2_ops = { + .take_ownership = pnv_ioda2_take_ownership, + .release_ownership = pnv_ioda2_release_ownership, +}; +#endif + static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb, struct pnv_ioda_pe *pe) { @@ -1991,6 +2012,9 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb, } tbl->it_ops = &pnv_ioda2_iommu_ops; iommu_init_table(tbl, phb->hose->node); +#ifdef CONFIG_IOMMU_API + pe->table_group.ops = &pnv_pci_ioda2_ops; +#endif if (pe->flags & PNV_IODA_PE_DEV) { iommu_register_group(&pe->table_group, phb->hose->global_number, diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 17e884a..dacc738 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -483,6 +483,43 @@ static long tce_iommu_ioctl(void *iommu_data, return -ENOTTY; } +static void tce_iommu_release_ownership(struct tce_container *container, + struct iommu_table_group *table_group) +{ + int i; + + for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { + struct iommu_table *tbl = &table_group->tables[i]; + + tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); + if (tbl->it_map) + iommu_release_ownership(tbl); + } +} + +static int tce_iommu_take_ownership(struct iommu_table_group *table_group) +{ + int i, j, rc = 0; + + for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { + struct iommu_table *tbl = &table_group->tables[i]; + + if (!tbl->it_map) + continue; + + rc = iommu_take_ownership(tbl); + if (rc) { + for (j = 0; j < i; ++j) + iommu_release_ownership( + &table_group->tables[j]); + + return rc; + } + } + + return 0; +} + static int tce_iommu_attach_group(void *iommu_data, struct iommu_group *iommu_group) { @@ -515,9 +552,23 @@ static int tce_iommu_attach_group(void *iommu_data, goto unlock_exit; } - ret = iommu_take_ownership(&table_group->tables[0]); - if (!ret) - container->grp = iommu_group; + if (!table_group->ops || !table_group->ops->take_ownership || + !table_group->ops->release_ownership) { + ret = tce_iommu_take_ownership(table_group); + } else { + /* + * Disable iommu bypass, otherwise the user can DMA to all of + * our physical memory via the bypass window instead of just + * the pages that has been explicitly mapped into the iommu + */ + table_group->ops->take_ownership(table_group); + ret = 0; + } + + if (ret) + goto unlock_exit; + + container->grp = iommu_group; unlock_exit: mutex_unlock(&container->lock); @@ -530,7 +581,6 @@ static void tce_iommu_detach_group(void *iommu_data, { struct tce_container *container = iommu_data; struct iommu_table_group *table_group; - struct iommu_table *tbl; mutex_lock(&container->lock); if (iommu_group != container->grp) { @@ -553,9 +603,11 @@ static void tce_iommu_detach_group(void *iommu_data, table_group = iommu_group_get_iommudata(iommu_group); BUG_ON(!table_group); - tbl = &table_group->tables[0]; - tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size); - iommu_release_ownership(tbl); + /* Kernel owns the device now, we can restore bypass */ + if (!table_group->ops || !table_group->ops->release_ownership) + tce_iommu_release_ownership(container, table_group); + else + table_group->ops->release_ownership(table_group); unlock_exit: mutex_unlock(&container->lock); -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/