From: Yinghai Lu <yinghai@kernel.org>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: David Miller <davem@davemloft.net>,
David Ahern <david.ahern@oracle.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"sparclinux@vger.kernel.org" <sparclinux@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCH 1/3] PCI: Introduce pci_bus_addr_t
Date: Fri, 3 Apr 2015 20:40:46 -0700 [thread overview]
Message-ID: <CAE9FiQX6Q4nPqZbCTfO+=obv6EGpeV4LRU-LkSsFWZQOaxOMrw@mail.gmail.com> (raw)
In-Reply-To: <20150403185939.GC10892@google.com>
On Fri, Apr 3, 2015 at 11:59 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> On Tue, Mar 31, 2015 at 07:57:47PM -0700, Yinghai Lu wrote:
>> David Ahern found commit d63e2e1f3df9 ("sparc/PCI: Clip bridge windows
>> to fit in upstream windows") broke booting on sparc/T5-8.
>>
>> In the boot log, there is
>> pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address
>> 0x110204000)
>> but that only could happen when dma_addr_t is 32-bit.
>>
>> According to David Miller, all DMA occurs behind an IOMMU and these
>> IOMMUs only support 32-bit addressing, therefore dma_addr_t is
>> 32-bit on sparc64.
>>
>> Let's introduce pci_bus_addr_t instead of using dma_addr_t,
>> and pci_bus_addr_t will be 64-bit on 64-bit platform or X86_PAE.
>
> I propose the following doc updates (I can just fold them into this patch
> if you approve):
>
>
> commit 13fca18e2f1d9dd078b8dfea965718cf13a4b600
> Author: Bjorn Helgaas <bhelgaas@google.com>
> Date: Fri Apr 3 12:39:35 2015 -0500
>
> pci-bus-addr-fixups
>
> diff --git a/include/linux/types.h b/include/linux/types.h
> index 6747247e3f9f..00a127e89752 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -139,12 +139,20 @@ typedef unsigned long blkcnt_t;
> */
> #define pgoff_t unsigned long
>
> -/* A dma_addr_t can hold any valid DMA or bus address for the platform */
> +/*
> + * A dma_addr_t can hold any valid DMA address, i.e., any address returned
> + * by the DMA API.
> + *
> + * If the DMA API only uses 32-bit addresses, dma_addr_t need only be 32
> + * bits wide. Bus addresses, e.g., PCI BARs, may be wider than 32 bits,
> + * but drivers do memory-mapped I/O to ioremapped kernel virtual addresses,
> + * so they don't care about the size of the actual bus addresses.
> + */
Good to me.
Thanks
Yinghai
next prev parent reply other threads:[~2015-04-04 3:40 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-01 2:57 [PATCH 0/3] PCI/sparc: Fix booting with T5-8 Yinghai Lu
2015-04-01 2:57 ` [PATCH 1/3] PCI: Introduce pci_bus_addr_t Yinghai Lu
2015-04-03 18:59 ` Bjorn Helgaas
2015-04-03 19:05 ` David Miller
2015-04-04 3:40 ` Yinghai Lu [this message]
2015-04-03 19:32 ` Bjorn Helgaas
2015-04-03 20:52 ` Bjorn Helgaas
2015-04-04 3:34 ` Yinghai Lu
2015-04-04 12:46 ` Bjorn Helgaas
2015-04-04 19:48 ` Rob Herring
2015-04-05 3:25 ` Bjorn Helgaas
2015-04-06 13:05 ` Rob Herring
2015-04-01 2:57 ` [PATCH 2/3] sparc/PCI: Add mem64 resource parsing for root bus Yinghai Lu
2015-04-03 20:46 ` Bjorn Helgaas
2015-04-01 2:57 ` [PATCH 3/3] PCI: Set pref for mem64 resource of pcie device Yinghai Lu
2015-04-06 22:06 ` Bjorn Helgaas
2015-04-06 22:35 ` Yinghai Lu
2015-04-06 22:49 ` Bjorn Helgaas
2015-04-07 1:13 ` Yinghai Lu
2015-04-07 3:43 ` Bjorn Helgaas
2015-04-07 5:23 ` Yinghai Lu
2015-04-07 12:18 ` Bjorn Helgaas
2015-04-07 0:35 ` David Miller
2015-04-07 16:48 ` Bjorn Helgaas
2015-04-08 15:47 ` Bjorn Helgaas
2015-04-08 16:08 ` David Miller
2015-04-08 21:12 ` Benjamin Herrenschmidt
2015-04-09 0:06 ` Yinghai Lu
2015-04-09 3:17 ` Benjamin Herrenschmidt
2015-04-09 4:11 ` Yinghai Lu
2015-04-09 8:56 ` Benjamin Herrenschmidt
2015-04-09 4:26 ` Bjorn Helgaas
2015-04-09 8:54 ` Benjamin Herrenschmidt
2015-04-09 18:31 ` Yinghai Lu
2015-04-09 23:31 ` Benjamin Herrenschmidt
2015-04-10 4:13 ` Yinghai Lu
2015-04-02 20:37 ` [PATCH 0/3] PCI/sparc: Fix booting with T5-8 David Miller
2015-04-02 22:07 ` Yinghai Lu
2015-04-02 22:13 ` Bjorn Helgaas
2015-04-03 0:42 ` David Miller
2015-05-16 15:25 ` Bjorn Helgaas
2015-05-16 15:28 ` Bjorn Helgaas
2015-05-27 23:27 ` Yinghai Lu
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