From patchwork Tue Feb 16 03:33:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 1440812 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Dfmld1hNjz9sRN for ; Tue, 16 Feb 2021 14:33:33 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Dfmld0tQfz3cH2 for ; Tue, 16 Feb 2021 14:33:33 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.ru (client-ip=107.174.27.60; helo=ozlabs.ru; envelope-from=aik@ozlabs.ru; receiver=) Received: from ozlabs.ru (ozlabs.ru [107.174.27.60]) by lists.ozlabs.org (Postfix) with ESMTP id 4DfmlK3cTLz30Gv for ; Tue, 16 Feb 2021 14:33:17 +1100 (AEDT) Received: from fstn1-p1.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id DF05DAE80225; Mon, 15 Feb 2021 22:33:13 -0500 (EST) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH kernel 1/2] powerpc/iommu: Allocate it_map by vmalloc Date: Tue, 16 Feb 2021 14:33:06 +1100 Message-Id: <20210216033307.69863-2-aik@ozlabs.ru> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210216033307.69863-1-aik@ozlabs.ru> References: <20210216033307.69863-1-aik@ozlabs.ru> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , kvm-ppc@vger.kernel.org, David Gibson Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The IOMMU table uses the it_map bitmap to keep track of allocated DMA pages. This has always been a contiguous array allocated at either the boot time or when a passed through device is returned to the host OS. The it_map memory is allocated by alloc_pages() which allocates contiguous physical memory. Such allocation method occasionally creates a problem when there is no big chunk of memory available (no free memory or too fragmented). On powernv/ioda2 the default DMA window requires 16MB for it_map. This replaces alloc_pages_node() with vzalloc_node() which allocates contiguous block but in virtual memory. This should reduce changes of failure but should not cause other behavioral changes as it_map is only used by the kernel's DMA hooks/api when MMU is on. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Reviewed-by: Leonardo Bras --- arch/powerpc/kernel/iommu.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index c00214a4355c..8eb6eb0afa97 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -719,7 +719,6 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid, { unsigned long sz; static int welcomed = 0; - struct page *page; unsigned int i; struct iommu_pool *p; @@ -728,11 +727,9 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid, /* number of bytes needed for the bitmap */ sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); - page = alloc_pages_node(nid, GFP_KERNEL, get_order(sz)); - if (!page) + tbl->it_map = vzalloc_node(sz, nid); + if (!tbl->it_map) panic("iommu_init_table: Can't allocate %ld bytes\n", sz); - tbl->it_map = page_address(page); - memset(tbl->it_map, 0, sz); iommu_table_reserve_pages(tbl, res_start, res_end); @@ -774,8 +771,6 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid, static void iommu_table_free(struct kref *kref) { - unsigned long bitmap_sz; - unsigned int order; struct iommu_table *tbl; tbl = container_of(kref, struct iommu_table, it_kref); @@ -796,12 +791,8 @@ static void iommu_table_free(struct kref *kref) if (!bitmap_empty(tbl->it_map, tbl->it_size)) pr_warn("%s: Unexpected TCEs\n", __func__); - /* calculate bitmap size in bytes */ - bitmap_sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); - /* free bitmap */ - order = get_order(bitmap_sz); - free_pages((unsigned long) tbl->it_map, order); + vfree(tbl->it_map); /* free table */ kfree(tbl); From patchwork Tue Feb 16 03:33:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 1440814 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DfmmS5qWzz9sRN for ; Tue, 16 Feb 2021 14:34:16 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4DfmmS54vmz3cYd for ; Tue, 16 Feb 2021 14:34:16 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.ru (client-ip=107.174.27.60; helo=ozlabs.ru; envelope-from=aik@ozlabs.ru; receiver=) Received: from ozlabs.ru (ozlabs.ru [107.174.27.60]) by lists.ozlabs.org (Postfix) with ESMTP id 4Dfmlz6pVjz30R0 for ; Tue, 16 Feb 2021 14:33:51 +1100 (AEDT) Received: from fstn1-p1.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id 77AE6AE8022A; Mon, 15 Feb 2021 22:33:17 -0500 (EST) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH kernel 2/2] powerpc/iommu: Do not immediately panic when failed IOMMU table allocation Date: Tue, 16 Feb 2021 14:33:07 +1100 Message-Id: <20210216033307.69863-3-aik@ozlabs.ru> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210216033307.69863-1-aik@ozlabs.ru> References: <20210216033307.69863-1-aik@ozlabs.ru> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , kvm-ppc@vger.kernel.org, David Gibson Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Most platforms allocate IOMMU table structures (specifically it_map) at the boot time and when this fails - it is a valid reason for panic(). However the powernv platform allocates it_map after a device is returned to the host OS after being passed through and this happens long after the host OS booted. It is quite possible to trigger the it_map allocation panic() and kill the host even though it is not necessary - the host OS can still use the DMA bypass mode (requires a tiny fraction of it_map's memory) and even if that fails, the host OS is runnnable as it was without the device for which allocating it_map causes the panic. Instead of immediately crashing in a powernv/ioda2 system, this prints an error and continues. All other platforms still call panic(). Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Reviewed-by: Leonardo Bras --- arch/powerpc/kernel/iommu.c | 6 ++++-- arch/powerpc/platforms/cell/iommu.c | 3 ++- arch/powerpc/platforms/pasemi/iommu.c | 4 +++- arch/powerpc/platforms/powernv/pci-ioda.c | 15 ++++++++------- arch/powerpc/platforms/pseries/iommu.c | 10 +++++++--- arch/powerpc/sysdev/dart_iommu.c | 3 ++- 6 files changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 8eb6eb0afa97..c1a5c366a664 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -728,8 +728,10 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid, sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); tbl->it_map = vzalloc_node(sz, nid); - if (!tbl->it_map) - panic("iommu_init_table: Can't allocate %ld bytes\n", sz); + if (!tbl->it_map) { + pr_err("%s: Can't allocate %ld bytes\n", __func__, sz); + return NULL; + } iommu_table_reserve_pages(tbl, res_start, res_end); diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c index 2124831cf57c..fa08699aedeb 100644 --- a/arch/powerpc/platforms/cell/iommu.c +++ b/arch/powerpc/platforms/cell/iommu.c @@ -486,7 +486,8 @@ cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np, window->table.it_size = size >> window->table.it_page_shift; window->table.it_ops = &cell_iommu_ops; - iommu_init_table(&window->table, iommu->nid, 0, 0); + if (!iommu_init_table(&window->table, iommu->nid, 0, 0)) + panic("Failed to initialize iommu table"); pr_debug("\tioid %d\n", window->ioid); pr_debug("\tblocksize %ld\n", window->table.it_blocksize); diff --git a/arch/powerpc/platforms/pasemi/iommu.c b/arch/powerpc/platforms/pasemi/iommu.c index b500a6e47e6b..5be7242fbd86 100644 --- a/arch/powerpc/platforms/pasemi/iommu.c +++ b/arch/powerpc/platforms/pasemi/iommu.c @@ -146,7 +146,9 @@ static void iommu_table_iobmap_setup(void) */ iommu_table_iobmap.it_blocksize = 4; iommu_table_iobmap.it_ops = &iommu_table_iobmap_ops; - iommu_init_table(&iommu_table_iobmap, 0, 0, 0); + if (!iommu_init_table(&iommu_table_iobmap, 0, 0, 0)) + panic("Failed to initialize iommu table"); + pr_debug(" <- %s\n", __func__); } diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index f0f901683a2f..66c3c3337334 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1762,7 +1762,8 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb, tbl->it_ops = &pnv_ioda1_iommu_ops; pe->table_group.tce32_start = tbl->it_offset << tbl->it_page_shift; pe->table_group.tce32_size = tbl->it_size << tbl->it_page_shift; - iommu_init_table(tbl, phb->hose->node, 0, 0); + if (!iommu_init_table(tbl, phb->hose->node, 0, 0)) + panic("Failed to initialize iommu table"); pe->dma_setup_done = true; return; @@ -1930,16 +1931,16 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe) res_start = pe->phb->ioda.m32_pci_base >> tbl->it_page_shift; res_end = min(window_size, SZ_4G) >> tbl->it_page_shift; } - iommu_init_table(tbl, pe->phb->hose->node, res_start, res_end); - rc = pnv_pci_ioda2_set_window(&pe->table_group, 0, tbl); + if (iommu_init_table(tbl, pe->phb->hose->node, res_start, res_end)) + rc = pnv_pci_ioda2_set_window(&pe->table_group, 0, tbl); + else + rc = -ENOMEM; if (rc) { - pe_err(pe, "Failed to configure 32-bit TCE table, err %ld\n", - rc); + pe_err(pe, "Failed to configure 32-bit TCE table, err %ld\n", rc); iommu_tce_table_put(tbl); - return rc; + tbl = NULL; /* This clears iommu_table_base below */ } - if (!pnv_iommu_bypass_disabled) pnv_pci_ioda2_set_bypass(pe, true); diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 9fc5217f0c8e..4d9ac1f181c2 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -638,7 +638,8 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus) iommu_table_setparms(pci->phb, dn, tbl); tbl->it_ops = &iommu_table_pseries_ops; - iommu_init_table(tbl, pci->phb->node, 0, 0); + if (!iommu_init_table(tbl, pci->phb->node, 0, 0)) + panic("Failed to initialize iommu table"); /* Divide the rest (1.75GB) among the children */ pci->phb->dma_window_size = 0x80000000ul; @@ -720,7 +721,8 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus) iommu_table_setparms_lpar(ppci->phb, pdn, tbl, ppci->table_group, dma_window); tbl->it_ops = &iommu_table_lpar_multi_ops; - iommu_init_table(tbl, ppci->phb->node, 0, 0); + if (!iommu_init_table(tbl, ppci->phb->node, 0, 0)) + panic("Failed to initialize iommu table"); iommu_register_group(ppci->table_group, pci_domain_nr(bus), 0); pr_debug(" created table: %p\n", ppci->table_group); @@ -749,7 +751,9 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev) tbl = PCI_DN(dn)->table_group->tables[0]; iommu_table_setparms(phb, dn, tbl); tbl->it_ops = &iommu_table_pseries_ops; - iommu_init_table(tbl, phb->node, 0, 0); + if (!iommu_init_table(tbl, phb->node, 0, 0)) + panic("Failed to initialize iommu table"); + set_iommu_table_base(&dev->dev, tbl); return; } diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c index 6b4a34b36d98..1d33b7a5ea83 100644 --- a/arch/powerpc/sysdev/dart_iommu.c +++ b/arch/powerpc/sysdev/dart_iommu.c @@ -344,7 +344,8 @@ static void iommu_table_dart_setup(void) iommu_table_dart.it_index = 0; iommu_table_dart.it_blocksize = 1; iommu_table_dart.it_ops = &iommu_dart_ops; - iommu_init_table(&iommu_table_dart, -1, 0, 0); + if (!iommu_init_table(&iommu_table_dart, -1, 0, 0)) + panic("Failed to initialize iommu table"); /* Reserve the last page of the DART to avoid possible prefetch * past the DART mapped area