From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lpp01m010-f46.google.com ([209.85.215.46]:33912 "EHLO mail-lpp01m010-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755019Ab2IFXV0 (ORCPT ); Thu, 6 Sep 2012 19:21:26 -0400 Received: by lagy9 with SMTP id y9so1477200lag.19 for ; Thu, 06 Sep 2012 16:21:24 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1345470395-17295-6-git-send-email-shangw@linux.vnet.ibm.com> References: <1345470395-17295-1-git-send-email-shangw@linux.vnet.ibm.com> <1345470395-17295-6-git-send-email-shangw@linux.vnet.ibm.com> From: Bjorn Helgaas Date: Thu, 6 Sep 2012 17:21:04 -0600 Message-ID: Subject: Re: [PATCH 5/8] pci: resource assignment based on p2p alignment To: Gavin Shan Cc: linux-pci@vger.kernel.org, benh@kernel.crashing.org, weiyang@linux.vnet.ibm.com, linuxram@us.ibm.com, yinghai@kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-pci-owner@vger.kernel.org List-ID: On Mon, Aug 20, 2012 at 7:46 AM, Gavin Shan wrote: > The patch changes function pbus_size_io() and pbus_size_mem() to > do resource (I/O, memory and prefetchable memory) reassignment > based on the minimal alignments for the p2p bridge, which was > retrieved by function window_alignment(). > > Signed-off-by: Gavin Shan > --- > drivers/pci/setup-bus.c | 16 ++++++++++++---- > 1 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 826a4f3..bb2eade 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -741,7 +741,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, > 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 min_align = 4096, align; > + resource_size_t io_align, min_align, align; > > if (!b_res) > return; > @@ -750,8 +750,14 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, > * Per spec, I/O windows are 4K-aligned, but some bridges have an > * extension to support 1K alignment. > */ > - if (bus->self->io_window_1k) > + if (bus->self->io_window_1k) { > + io_align = 4096; Why is io_align 4K instead of 1K here? > min_align = 1024; > + } else { > + io_align = window_alignment(bus, IORESOURCE_IO); This doesn't seem right. Only the non-1k path uses window_alignment(), so there's no way for the platform to influence the alignment of bridges that support 1k windows. I think the io_window_1k checking needs to be moved from pbus_size_io() to window_alignment(). Maybe you can then make the min_align handling in pbus_size_io() more similar to that in pbus_size_mem(), e.g., min_align = 0; ... min_align = max(min_align, window_alignment(bus, b_res->flags & mask)); > + min_align = io_align; > + } > + > list_for_each_entry(dev, &bus->devices, bus_list) { > int i; > > @@ -778,8 +784,8 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, > } > } > > - if (min_align > 4096) > - min_align = 4096; > + if (min_align > io_align) > + min_align = io_align; > > size0 = calculate_iosize(size, min_size, size1, > resource_size(b_res), min_align); > @@ -901,6 +907,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, > min_align = align1 >> 1; > align += aligns[order]; > } > + > + min_align = max(min_align, window_alignment(bus, b_res->flags & mask)); > size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align); > if (children_add_size > add_size) > add_size = children_add_size; > -- > 1.7.5.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html