From patchwork Wed Jun 27 14:48:45 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 167659 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B59301007D2 for ; Thu, 28 Jun 2012 00:49:26 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756543Ab2F0OtZ (ORCPT ); Wed, 27 Jun 2012 10:49:25 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:58759 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756563Ab2F0OtY (ORCPT ); Wed, 27 Jun 2012 10:49:24 -0400 Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 27 Jun 2012 10:49:03 -0400 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 19C746E8066 for ; Wed, 27 Jun 2012 10:49:02 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q5REn1Mf050070 for ; Wed, 27 Jun 2012 10:49:01 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q5RKJmhK003339 for ; Wed, 27 Jun 2012 16:19:53 -0400 Received: from shangw ([9.77.180.236]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q5RKJkIa002715; Wed, 27 Jun 2012 16:19:47 -0400 Received: by shangw (Postfix, from userid 1000) id 6243F3818B0; Wed, 27 Jun 2012 22:48:51 +0800 (CST) From: Gavin Shan To: linux-pci@vger.kernel.org, linuxppc-dev@ozlabs.org Cc: yinghai@kernel.org, bhelgaas@google.com, benh@kernel.crashing.org, Gavin Shan Subject: [PATCH V4 2/2] PCI: minimal alignment for bars of P2P bridges Date: Wed, 27 Jun 2012 22:48:45 +0800 Message-Id: <1340808525-24996-2-git-send-email-shangw@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1340808525-24996-1-git-send-email-shangw@linux.vnet.ibm.com> References: <1340808525-24996-1-git-send-email-shangw@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12062714-9360-0000-0000-000007D30ABE Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On some powerpc platforms, device BARs need to be assigned to separate "segments" of the address space in order for the error isolation and HW virtualization mechanisms (EEH) to work properly. Those "segments" have a minimum size that can be fairly large (16M). In order to be able to use the generic resource assignment code rather than re-inventing our own, we chose to group devices by bus. That way, a simple change of the minimum alignment requirements of resources assigned to PCI to PCI (P2P) bridges is enough to ensure that all BARs for devices below those bridges will fit into contiguous sets of segments and there will be no overlap. This patch provides a way for the host bridge to override the default alignment values used by the resource allocation code for that purpose. Signed-off-by: Gavin Shan Reviewed-by: Ram Pai Reviewed-by: Richard Yang --- drivers/pci/probe.c | 5 +++++ drivers/pci/setup-bus.c | 28 +++++++++++++++++++++------- include/linux/pci.h | 8 ++++++++ 3 files changed, 34 insertions(+), 7 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 658ac97..a196529 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -431,6 +431,11 @@ static struct pci_host_bridge *pci_alloc_host_bridge(struct pci_bus *b) if (bridge) { INIT_LIST_HEAD(&bridge->windows); bridge->bus = b; + + /* Set minimal alignment shift of P2P bridges */ + bridge->io_align_shift = PCI_DEFAULT_IO_ALIGN_SHIFT; + bridge->mem_align_shift = PCI_DEFAULT_MEM_ALIGN_SHIFT; + bridge->pmem_align_shift = PCI_DEFAULT_PMEM_ALIGN_SHIFT; } return bridge; diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 8fa2d4b..caebe98 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -706,10 +706,12 @@ static resource_size_t calculate_memsize(resource_size_t size, static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, resource_size_t add_size, struct list_head *realloc_head) { + struct pci_host_bridge *phb; struct pci_dev *dev; struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO); unsigned long size = 0, size0 = 0, size1 = 0; resource_size_t children_add_size = 0; + resource_size_t io_align; if (!b_res) return; @@ -735,13 +737,17 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, children_add_size += get_res_add_size(realloc_head, r); } } + + phb = find_pci_host_bridge(bus); + io_align = (1 << phb->io_align_shift); + size0 = calculate_iosize(size, min_size, size1, - resource_size(b_res), 4096); + resource_size(b_res), io_align); if (children_add_size > add_size) add_size = children_add_size; size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 : calculate_iosize(size, min_size, add_size + size1, - resource_size(b_res), 4096); + resource_size(b_res), io_align); if (!size0 && !size1) { if (b_res->start || b_res->end) dev_info(&bus->self->dev, "disabling bridge window " @@ -751,11 +757,11 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, return; } /* Alignment of the IO window is always 4K */ - b_res->start = 4096; + b_res->start = io_align; b_res->end = b_res->start + size0 - 1; b_res->flags |= IORESOURCE_STARTALIGN; if (size1 > size0 && realloc_head) { - add_to_list(realloc_head, bus->self, b_res, size1-size0, 4096); + add_to_list(realloc_head, bus->self, b_res, size1-size0, io_align); dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window " "%pR to [bus %02x-%02x] add_size %lx\n", b_res, bus->secondary, bus->subordinate, size1-size0); @@ -778,6 +784,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, resource_size_t add_size, struct list_head *realloc_head) { + struct pci_host_bridge *phb; struct pci_dev *dev; resource_size_t min_align, align, size, size0, size1; resource_size_t aligns[12]; /* Alignments from 1Mb to 2Gb */ @@ -785,10 +792,17 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, struct resource *b_res = find_free_bus_resource(bus, type); unsigned int mem64_mask = 0; resource_size_t children_add_size = 0; + int mem_align_shift; if (!b_res) return 0; + phb = find_pci_host_bridge(bus); + if (type & IORESOURCE_PREFETCH) + mem_align_shift = phb->pmem_align_shift; + else + mem_align_shift = phb->mem_align_shift; + memset(aligns, 0, sizeof(aligns)); max_order = 0; size = 0; @@ -818,8 +832,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, #endif /* For bridges size != alignment */ align = pci_resource_alignment(dev, r); - order = __ffs(align) - 20; - if (order > 11) { + order = __ffs(align) - mem_align_shift; + if (order > (11 - (mem_align_shift - 20))) { dev_warn(&dev->dev, "disabling BAR %d: %pR " "(bad alignment %#llx)\n", i, r, (unsigned long long) align); @@ -846,7 +860,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, for (order = 0; order <= max_order; order++) { resource_size_t align1 = 1; - align1 <<= (order + 20); + align1 <<= (order + mem_align_shift); if (!align) min_align = align1; diff --git a/include/linux/pci.h b/include/linux/pci.h index 2b559f1..879de4e 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -376,9 +376,17 @@ struct pci_host_bridge_window { resource_size_t offset; /* bus address + offset = CPU address */ }; +/* Default shits for P2P I/O and MMIO bar minimal alignment shifts */ +#define PCI_DEFAULT_IO_ALIGN_SHIFT 12 /* 4KB */ +#define PCI_DEFAULT_MEM_ALIGN_SHIFT 20 /* 1MB */ +#define PCI_DEFAULT_PMEM_ALIGN_SHIFT 20 /* 1MB */ + struct pci_host_bridge { struct device dev; struct pci_bus *bus; /* root bus */ + int io_align_shift; /* P2P I/O bar minimal alignment shift */ + int mem_align_shift; /* P2P MMIO bar minimal alignment shift */ + int pmem_align_shift; /* P2P prefetchable MMIO bar minimal alignment shift */ struct list_head windows; /* pci_host_bridge_windows */ void (*release_fn)(struct pci_host_bridge *); void *release_data;