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From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 19/27] pci: PCIe driver for Marvell Armada 370/XP systems
Date: Fri, 1 Feb 2013 11:30:18 +0000	[thread overview]
Message-ID: <201302011130.18442.arnd@arndb.de> (raw)
In-Reply-To: <20130131224459.GA11846@obsidianresearch.com>

On Thursday 31 January 2013, Jason Gunthorpe wrote:
> On Thu, Jan 31, 2013 at 08:46:22PM +0000, Arnd Bergmann wrote:
> 
> > > If it is 0xDEAD0000, then Thomas has to keep what he has now, you
> > > can't mess with this address. Verify that the full 32 bit address
> > > exactly matching the MBUS window address is written to the PCI-PCI
> > > bridge IO base/limit registers.
> > 
> > If you do this, you break all sorts of expectations in the kernel and
> > I guess you'd have to set the io_offset value of that bus to 0x21530000
> > in order to make Linux I/O port 0 go to the first byte of the window
> > and come out as 0xDEAD0000 on the bus, but you still won't be able to
> > use legacy devices with hardcoded I/O port numbers.
> 
> I'm not sure exactly how the PCI core handles this, but it does look
> like pci_add_resource_offset via io_offset is the answer. I'm not sure
> what goes in the struct resource passed to the PCI core - the *bus* IO
> address range or the *kernel* IO address range..

IO Resources are always expressed in the kernel's view, so they are in
the range from 0 to IO_SPACE_LIMIT. The idea is that you can have multiple
buses that each have their own address space start at 0, but can put
them into the kernel address space at a different address.

Each device on any bus can still use I/O addresses starting at zero,
and you could have e.g. a VGA card on two buses each respond to I/O cycles
on port 0x3c0, but the PCI core will translate the resources to appear
in the kernel space at 0x103c0 for the second one.

> > > If it is 0x00000000 then the mmap scheme I outlined before must be
> > > used, and verify that only 0->0xFFFF is written to the PCI-PCI bridge
> > > IO base/limit registers..
> > 
> > For the primary bus, yes, but there are still two options for the
> > second one: you can either start at 0 again or you can continue
> 
> No, for *all* links. You use a mmap scheme with 4k granularity, I
> explained in a past email, but to quickly review..
> 
> - Each link gets 64k of reserved physical address space for IO,
>   this is just set aside, no MBUS windows are permantently assigned.
> - Linux is told to use a 64k IO range with bus IO address 0->0xFFFF
> - When the IO base/limit register in the link PCI-PCI bridge is programmed
>   the driver gets a 4k aligned region somewhere from 0->0xFFFF and then:
>     - Allocates a 64k MBUS window that translates physical address
>       0xZZZZxxxx to IO bus address 0x0000xxxx (goes in the TLP) for
>       that link
>     - Uses pci_ioremap_io to map the fraction of the link's 64k MBUS window
>       allocated to that bridge to the correct offset in the 
>       PCI_IO_VIRT_BASE region

We'd have to change pci_ioremap_io to allow mapping less than 64k, but
yes, that would work, too. I don't see an advantage to it though,
other than having io_offset always be zero.

> > at 0x10000 as we do for mv78xx0 and kirkwood for instance. Both
> > approaches probably have their merit.
> 
> Kirkwood uses the MBUS remapping registers to set the TLP address of
> link 0 to start at 0 and of link 1 to start at 0x10000 - so it is
> consistent with what you describe..

Right, so it also uses io_offset = 0 all the time, which means the
bus I/O port numbers are identical to the Linux I/O port numbers,
but they go beyond 64K on the bus on the second and later links.

> However, this is a suboptimal way to run the HW. It would be much
> better to place each link in a seperate PCI domain and have each link
> start its bus IO address at 0, and assign the kernel IO address in
> sequential 64k blocks as today.

I agree.

	Arnd

  reply	other threads:[~2013-02-01 11:30 UTC|newest]

Thread overview: 216+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-28 18:56 [PATCH v2] PCIe support for the Armada 370 and Armada XP SoCs Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 01/27] of/pci: Provide support for parsing PCI DT ranges property Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 02/27] of/pci: Add of_pci_get_devfn() function Thomas Petazzoni
2013-01-28 22:00   ` Stephen Warren
2013-01-28 22:16     ` Thierry Reding
2013-01-29 10:04       ` Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 03/27] of/pci: Add of_pci_parse_bus_range() function Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 04/27] ARM: pci: Allow passing per-controller private data Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 05/27] arm: pci: add a align_resource hook Thomas Petazzoni
2013-01-29 15:12   ` Thomas Petazzoni
2013-01-29 15:15     ` Russell King - ARM Linux
2013-01-29 15:23       ` Thomas Petazzoni
2013-01-29 15:25         ` Russell King - ARM Linux
2013-01-29 15:28           ` Thomas Petazzoni
2013-01-29 15:58     ` Russell King - ARM Linux
2013-01-29 16:20       ` Thomas Petazzoni
2013-01-29 16:45         ` Arnd Bergmann
2013-01-29 17:09           ` Thomas Petazzoni
2013-01-29 20:15             ` Arnd Bergmann
2013-01-29 20:33               ` Thomas Petazzoni
2013-01-29 21:59                 ` Thomas Petazzoni
2013-01-29 22:17                   ` Stephen Warren
2013-01-30  4:49                   ` Jason Gunthorpe
2013-01-29 22:54                 ` Arnd Bergmann
2013-01-30  4:21                   ` Jason Gunthorpe
2013-01-30  9:55                     ` Arnd Bergmann
2013-01-30 11:47                       ` Thomas Petazzoni
2013-01-30 16:17                         ` Arnd Bergmann
2013-01-30 16:38                           ` Thomas Petazzoni
2013-01-30 20:48                         ` Bjorn Helgaas
2013-01-30 21:06                           ` Jason Gunthorpe
2013-01-30  4:56           ` Jason Gunthorpe
2013-01-30  8:19             ` Thomas Petazzoni
2013-01-30  9:46             ` Arnd Bergmann
2013-01-30  9:54               ` Thomas Petazzoni
2013-01-30 10:03                 ` Arnd Bergmann
2013-01-30 11:42                   ` Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 06/27] lib: devres: don't enclose pcim_*() functions in CONFIG_HAS_IOPORT Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 07/27] PCI: Add software-emulated host bridge Thomas Petazzoni
2013-01-28 20:18   ` Arnd Bergmann
2013-01-28 22:03     ` Stephen Warren
2013-01-28 22:09       ` Jason Gunthorpe
2013-01-28 22:18         ` Thomas Petazzoni
2013-01-28 22:23           ` Jason Gunthorpe
2013-01-28 22:30             ` Thomas Petazzoni
2013-01-28 22:51               ` Jason Gunthorpe
2013-01-29 10:01                 ` Thomas Petazzoni
2013-01-29 17:42                   ` Jason Gunthorpe
2013-01-29 17:43                     ` Thomas Petazzoni
2013-01-29  2:40         ` Bjorn Helgaas
2013-01-29  6:16           ` Jason Gunthorpe
2013-01-28 22:09     ` Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 08/27] pci: implement an emulated PCI-to-PCI bridge Thomas Petazzoni
2013-01-28 19:35   ` Jason Gunthorpe
2013-01-28 19:39     ` Thomas Petazzoni
2013-01-28 19:55       ` Jason Gunthorpe
2013-01-28 22:06         ` Stephen Warren
2013-01-28 22:16           ` Jason Gunthorpe
2013-01-29 22:35   ` Bjorn Helgaas
2013-01-29 23:06     ` Arnd Bergmann
2013-01-30  4:12       ` Jason Gunthorpe
2013-01-28 18:56 ` [PATCH v2 09/27] pci: infrastructure to add drivers in drivers/pci/host Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 10/27] arm: mvebu: fix address-cells in mpic DT node Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 11/27] clk: mvebu: create parent-child relation for PCIe clocks on Armada 370 Thomas Petazzoni
2013-01-28 22:08   ` Stephen Warren
2013-01-28 22:21     ` Thomas Petazzoni
2013-01-28 22:27       ` Stephen Warren
2013-01-28 22:44         ` Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 12/27] clk: mvebu: add more PCIe clocks for Armada XP Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 13/27] arm: plat-orion: introduce WIN_CTRL_ENABLE in address mapping code Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 14/27] arm: plat-orion: refactor the orion_disable_wins() function Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 15/27] arm: plat-orion: introduce orion_{alloc, free}_cpu_win() functions Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 16/27] arm: mvebu: add functions to alloc/free PCIe decoding windows Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 17/27] arm: plat-orion: make common PCIe code usable on mvebu Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 18/27] arm: plat-orion: add more flexible PCI configuration space read/write functions Thomas Petazzoni
2013-01-28 19:51   ` Jason Gunthorpe
2013-01-29  8:40     ` Thomas Petazzoni
2013-01-29 17:40       ` Jason Gunthorpe
2013-01-28 18:56 ` [PATCH v2 19/27] pci: PCIe driver for Marvell Armada 370/XP systems Thomas Petazzoni
2013-01-28 22:21   ` Stephen Warren
2013-01-29  8:41     ` Thomas Petazzoni
2013-01-29  9:20       ` Thierry Reding
2013-01-29  9:21         ` Thomas Petazzoni
2013-02-07 10:24         ` Thomas Petazzoni
2013-02-07 15:46           ` Bjorn Helgaas
2013-02-07 16:00             ` Thomas Petazzoni
2013-02-07 18:08               ` Bjorn Helgaas
2013-02-07 18:15                 ` Jason Gunthorpe
2013-02-07 18:30                   ` Bjorn Helgaas
2013-02-07 18:43                 ` Thierry Reding
2013-01-29 19:47       ` Stephen Warren
2013-01-29  3:29   ` Bjorn Helgaas
2013-01-29  5:55     ` Jason Gunthorpe
2013-01-29  8:00       ` Thomas Petazzoni
2013-01-29 17:47       ` Bjorn Helgaas
2013-01-29 18:14         ` Thomas Petazzoni
2013-01-29 18:41         ` Jason Gunthorpe
2013-01-29 19:07           ` Bjorn Helgaas
2013-01-29 19:18             ` Jason Gunthorpe
2013-01-29 19:38               ` Bjorn Helgaas
2013-01-29 22:27                 ` Bjorn Helgaas
2013-01-30  4:24                   ` Jason Gunthorpe
2013-01-30  9:35                   ` Thomas Petazzoni
2013-01-30 18:52                     ` Bjorn Helgaas
2013-01-30 22:28                       ` Thomas Petazzoni
2013-01-30 23:10                         ` Jason Gunthorpe
2013-01-30 23:48                         ` Bjorn Helgaas
2013-01-31 16:04                       ` Thomas Petazzoni
2013-01-31 16:30                         ` Bjorn Helgaas
2013-01-31 16:33                           ` Thomas Petazzoni
2013-01-31 17:03                             ` Bjorn Helgaas
2013-01-31 16:42                           ` Russell King - ARM Linux
2013-01-29 13:22   ` Andrew Murray
2013-01-29 13:45     ` Thomas Petazzoni
2013-01-29 14:05       ` Andrew Murray
2013-01-29 14:20         ` Thierry Reding
2013-01-29 14:29           ` Thomas Petazzoni
2013-01-29 15:02             ` Thierry Reding
2013-01-29 15:08               ` Andrew Murray
2013-01-29 15:10               ` Thomas Petazzoni
2013-02-07 14:37     ` Thomas Petazzoni
2013-02-07 15:51       ` Andrew Murray
2013-02-07 16:19         ` Thomas Petazzoni
2013-02-07 16:40           ` Thomas Petazzoni
2013-02-07 16:53             ` Andrew Murray
2013-02-07 17:14               ` Thomas Petazzoni
2013-02-07 17:29                 ` Andrew Murray
2013-02-07 17:37                   ` Thomas Petazzoni
2013-02-07 18:21                     ` Jason Gunthorpe
2013-02-07 23:25                       ` Arnd Bergmann
2013-02-08  0:44                         ` Jason Gunthorpe
2013-02-09 22:23                           ` Arnd Bergmann
2013-02-12 19:26                             ` Jason Gunthorpe
2013-02-07 18:30                     ` Andrew Murray
2013-02-07 23:27                       ` Arnd Bergmann
2013-01-30 11:32   ` Russell King - ARM Linux
2013-01-30 11:37     ` Thomas Petazzoni
2013-01-30 12:03     ` Thierry Reding
2013-01-30 13:07       ` Thomas Petazzoni
2013-01-30 15:08       ` Russell King - ARM Linux
2013-01-30 15:19         ` Russell King - ARM Linux
2013-01-30 15:36           ` Thomas Petazzoni
2013-01-30 15:46             ` Russell King - ARM Linux
2013-01-31 14:30               ` Thomas Petazzoni
2013-01-31 14:50                 ` Russell King - ARM Linux
2013-01-31 14:57                   ` Thomas Petazzoni
2013-01-31 15:08                     ` Russell King - ARM Linux
2013-01-31 15:22                       ` Thomas Petazzoni
2013-01-31 15:36                         ` Russell King - ARM Linux
2013-01-31 15:47                           ` Thomas Petazzoni
2013-01-31 15:48                             ` Russell King - ARM Linux
2013-01-31 16:18                           ` Arnd Bergmann
2013-01-31 18:02                             ` Jason Gunthorpe
2013-01-31 20:46                               ` Arnd Bergmann
2013-01-31 22:44                                 ` Jason Gunthorpe
2013-02-01 11:30                                   ` Arnd Bergmann [this message]
2013-02-01 19:52                                     ` Jason Gunthorpe
2013-02-06 16:51                                   ` Thomas Petazzoni
2013-02-06 17:09                                     ` Jason Gunthorpe
2013-02-06 17:18                                       ` Thomas Petazzoni
2013-02-06 17:50                                         ` Jason Gunthorpe
2013-02-06 18:02                                           ` Thomas Petazzoni
2013-02-06 18:22                                           ` Stephen Warren
2013-02-06 18:39                                             ` Jason Gunthorpe
2013-02-06 18:42                                             ` Thomas Petazzoni
2013-02-06 22:04                                               ` Arnd Bergmann
     [not found]                                           ` <20130207165009.73b1f340@skate>
2013-02-07 23:33                                             ` Giving special alignment/size constraints to the Linux PCI core? Arnd Bergmann
2013-02-08  4:21                                             ` Bjorn Helgaas
2013-02-08  8:14                                               ` Thomas Petazzoni
2013-02-12 16:00                                                 ` Arnd Bergmann
2013-02-12 18:41                                                   ` Jason Gunthorpe
2013-02-12 19:02                                                     ` Arnd Bergmann
2013-02-12 19:38                                                       ` Jason Gunthorpe
2013-02-12 23:05                                                         ` Arnd Bergmann
2013-02-13  0:32                                                           ` Jason Gunthorpe
2013-02-13 18:53                                                             ` Arnd Bergmann
2013-02-13 19:12                                                               ` Jason Gunthorpe
2013-02-13 19:51                                                                 ` Thomas Petazzoni
2013-02-13 21:10                                                                 ` Arnd Bergmann
2013-02-13 21:20                                                                   ` Yinghai Lu
2013-02-13 22:24                                                                     ` Arnd Bergmann
2013-02-13 21:02                                                             ` Yinghai Lu
2013-01-31  7:10           ` [PATCH v2 19/27] pci: PCIe driver for Marvell Armada 370/XP systems Thierry Reding
2013-02-01  0:34   ` Stephen Warren
2013-02-01  1:41     ` Jason Gunthorpe
2013-02-01  2:21       ` Stephen Warren
2013-02-01  3:51         ` Jason Gunthorpe
2013-02-01  9:03           ` Thomas Petazzoni
2013-02-01 16:07             ` Arnd Bergmann
2013-02-01 16:26               ` Russell King - ARM Linux
2013-02-01 17:45                 ` Arnd Bergmann
2013-02-01 19:58                   ` Jason Gunthorpe
2013-02-01  8:46         ` Thomas Petazzoni
2013-02-01 16:02           ` Arnd Bergmann
2013-02-01 17:57           ` Stephen Warren
2013-02-01 19:39             ` Jason Gunthorpe
2013-02-01 20:30               ` Stephen Warren
2013-01-28 18:56 ` [PATCH v2 20/27] arm: mvebu: PCIe support is now available on mvebu Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 21/27] arm: mvebu: add PCIe Device Tree informations for Armada 370 Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 22/27] arm: mvebu: add PCIe Device Tree informations for Armada XP Thomas Petazzoni
2013-02-06 22:41   ` Arnd Bergmann
2013-02-06 23:07     ` Thomas Petazzoni
2013-02-07  8:04       ` Arnd Bergmann
2013-02-07  8:45         ` Thomas Petazzoni
2013-02-07  9:09           ` Arnd Bergmann
2013-02-07  1:05     ` Jason Gunthorpe
2013-02-07  7:28       ` Thierry Reding
2013-02-07 17:49         ` Jason Gunthorpe
2013-02-07  8:24       ` Arnd Bergmann
2013-02-07 17:00         ` Jason Gunthorpe
2013-02-07 23:44           ` Arnd Bergmann
2013-01-28 18:56 ` [PATCH v2 23/27] arm: mvebu: PCIe Device Tree informations for OpenBlocks AX3-4 Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 24/27] arm: mvebu: PCIe Device Tree informations for Armada XP DB Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 25/27] arm: mvebu: PCIe Device Tree informations for Armada 370 Mirabox Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 26/27] arm: mvebu: PCIe Device Tree informations for Armada 370 DB Thomas Petazzoni
2013-01-28 18:56 ` [PATCH v2 27/27] arm: mvebu: update defconfig with PCI and USB support Thomas Petazzoni

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