From: Florian Fainelli <f.fainelli@gmail.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Jim Quinlan <jim2101024@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
linux-pci <linux-pci@vger.kernel.org>,
Florian Fainelli <f.fainelli@gmail.com>,
BCM Kernel Feedback <bcm-kernel-feedback-list@broadcom.com>,
Gregory Fong <gregory.0xf0@gmail.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Brian Norris <computersforpeace@gmail.com>,
Christoph Hellwig <hch@lst.de>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v5 04/12] PCI: brcmstb: add dma-range mapping for inbound traffic
Date: Thu, 20 Sep 2018 13:55:10 -0700 [thread overview]
Message-ID: <7fa897cf-4d58-c63f-afdd-a3ec5a6a56bf@gmail.com> (raw)
In-Reply-To: <CAKv+Gu_d-r0ubyqZcDzERYd5FVTSpjBk++iACHqVgtHrOK0F7A@mail.gmail.com>
On 09/19/2018 07:19 PM, Ard Biesheuvel wrote:
> On 19 September 2018 at 07:31, Jim Quinlan <jim2101024@gmail.com> wrote:
>> The Broadcom STB PCIe host controller is intimately related to the
>> memory subsystem. This close relationship adds complexity to how cpu
>> system memory is mapped to PCIe memory. Ideally, this mapping is an
>> identity mapping, or an identity mapping off by a constant. Not so in
>> this case.
>>
>> Consider the Broadcom reference board BCM97445LCC_4X8 which has 6 GB
>> of system memory. Here is how the PCIe controller maps the
>> system memory to PCIe memory:
>>
>> memc0-a@[ 0....3fffffff] <=> pci@[ 0....3fffffff]
>> memc0-b@[100000000...13fffffff] <=> pci@[ 40000000....7fffffff]
>> memc1-a@[ 40000000....7fffffff] <=> pci@[ 80000000....bfffffff]
>> memc1-b@[300000000...33fffffff] <=> pci@[ c0000000....ffffffff]
>> memc2-a@[ 80000000....bfffffff] <=> pci@[100000000...13fffffff]
>> memc2-b@[c00000000...c3fffffff] <=> pci@[140000000...17fffffff]
>>
>
> So is describing this as
>
> dma-ranges = <0x0 0x0 0x0 0x0 0x0 0x40000000>,
> <0x0 0x40000000 0x1 0x0 0x0 0x40000000>,
> <0x0 0x80000000 0x0 0x40000000 0x0 0x40000000>,
> <0x0 0xc0000000 0x3 0x0 0x0 0x40000000>,
> <0x1 0x0 0x0 0x80000000 0x0 0x40000000>,
> <0x1 0x40000000 0x0 0xc0000000 0x0 0x40000000>;
>
> not working for you? I haven't tried this myself, but since DT permits
> describing the inbound mappings this way, we should fix the code if it
> doesn't work at the moment.
You mean encoding the memory controller index in the first cell? If that
works, that's indeed a much cleaner solution, though is it standard
compliant in any form?
--
Florian
next prev parent reply other threads:[~2018-09-20 20:55 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-19 14:31 [PATCH v5 00/12] PCI: brcmstb: Add Broadcom Settopbox PCIe support (resend) Jim Quinlan
2018-09-19 14:31 ` [PATCH v5 01/12] soc: bcm: brcmstb: add memory API Jim Quinlan
2018-09-19 14:31 ` [PATCH v5 02/12] dt-bindings: pci: add DT docs for Brcmstb PCIe device Jim Quinlan
2018-09-19 14:31 ` Jim Quinlan
2018-09-20 9:06 ` Jonas Gorski
2018-09-21 18:00 ` Jim Quinlan
2018-09-19 14:31 ` [PATCH v5 03/12] PCI: brcmstb: add Broadcom STB PCIe host controller driver Jim Quinlan
2018-09-19 14:31 ` [PATCH v5 04/12] PCI: brcmstb: add dma-range mapping for inbound traffic Jim Quinlan
2018-09-19 14:31 ` Jim Quinlan
2018-09-20 2:19 ` Ard Biesheuvel
2018-09-20 20:55 ` Florian Fainelli [this message]
2018-09-20 21:04 ` Ard Biesheuvel
2018-09-20 21:31 ` Florian Fainelli
2018-09-20 21:33 ` Ard Biesheuvel
2018-09-20 21:39 ` Florian Fainelli
2018-09-21 17:40 ` Jim Quinlan
2018-09-24 8:25 ` Ard Biesheuvel
2018-09-24 15:01 ` Jim Quinlan
2018-09-26 2:59 ` Florian Fainelli
2018-09-26 7:59 ` Ard Biesheuvel
2018-09-26 10:56 ` Robin Murphy
2018-10-01 18:13 ` Florian Fainelli
2019-06-27 16:55 ` Stefan Wahren
2018-09-19 14:32 ` [PATCH v5 05/12] PCI: brcmstb: add MSI capability Jim Quinlan
2018-09-19 14:32 ` Jim Quinlan
2018-09-19 14:32 ` [PATCH v5 06/12] MIPS: BMIPS: add dma remap for BrcmSTB PCIe Jim Quinlan
2018-09-26 22:07 ` Paul Burton
2018-09-28 21:48 ` Jim Quinlan
2018-09-19 14:32 ` [PATCH v5 07/12] PCI/MSI: enable PCI_MSI_IRQ_DOMAIN support for MIPS Jim Quinlan
2018-09-19 14:32 ` [PATCH v5 08/12] MIPS: BMIPS: add PCI bindings for 7425, 7435 Jim Quinlan
2018-09-19 14:32 ` [PATCH v5 09/12] MIPS: BMIPS: enable PCI Jim Quinlan
2018-09-19 14:32 ` [PATCH v5 10/12] ARM64: declare __phys_to_dma on ARCH_HAS_PHYS_TO_DMA Jim Quinlan
2018-09-19 14:37 ` Christoph Hellwig
2018-09-19 14:32 ` [PATCH v5 11/12] ARM64: add dma remap for BrcmSTB PCIe Jim Quinlan
2018-09-19 14:32 ` Jim Quinlan
2018-09-19 14:41 ` Christoph Hellwig
2018-09-19 14:41 ` Christoph Hellwig
2018-09-21 18:29 ` Jim Quinlan
2018-09-19 14:32 ` [PATCH v5 12/12] ARM: " Jim Quinlan
2019-03-20 23:15 ` [PATCH v5 00/12] PCI: brcmstb: Add Broadcom Settopbox PCIe support (resend) Bjorn Helgaas
2019-03-20 23:22 ` Florian Fainelli
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