[PATCH] x86, pci-hotplug, calgary / rio: fix EBDA ioremap()

[Ingo Molnar]

* Ingo Molnar <mingo@xxxxxxx> wrote:

> ibmphpd: IBM Hot Plug PCI Controller Driver version: 0.6
> resource map sanity check conflict: 0x9f800 0xaf5e7 0x9f800 0x9ffff reserved
> ------------[ cut here ]------------
> WARNING: at arch/x86/mm/ioremap.c:175 __ioremap_caller+0x5c/0x226()
> Pid: 1, comm: swapper Not tainted 2.6.27-rc7-tip-00914-g347b10f-dirty #36037
>  [<c013a72d>] warn_on_slowpath+0x41/0x68
>  [<c0156f00>] ? __lock_acquire+0x9ba/0xa7f
>  [<c012158c>] ? do_flush_tlb_all+0x0/0x59
>  [<c015ac31>] ? smp_call_function_mask+0x74/0x17d
>  [<c012158c>] ? do_flush_tlb_all+0x0/0x59
>  [<c013b228>] ? printk+0x1a/0x1c
>  [<c013f302>] ? iomem_map_sanity_check+0x82/0x8c
>  [<c0a773e8>] ? _read_unlock+0x22/0x25
>  [<c013f302>] ? iomem_map_sanity_check+0x82/0x8c
>  [<c0154e17>] ? trace_hardirqs_off+0xb/0xd
>  [<c0127731>] __ioremap_caller+0x5c/0x226
>  [<c0156158>] ? trace_hardirqs_on+0xb/0xd
>  [<c012767d>] ? iounmap+0x9d/0xa5
>  [<c01279dd>] ioremap_nocache+0x15/0x17
>  [<c0403c42>] ? ioremap+0xd/0xf
>  [<c0403c42>] ioremap+0xd/0xf
>  [<c0f1928f>] ibmphp_access_ebda+0x60/0xa0e
>  [<c0f17f64>] ibmphp_init+0xb5/0x360
>  [<c0101057>] do_one_initcall+0x57/0x138
>  [<c0f17eaf>] ? ibmphp_init+0x0/0x360
>  [<c0156158>] ? trace_hardirqs_on+0xb/0xd
>  [<c0148d75>] ? __queue_work+0x2b/0x30
>  [<c0f17eaf>] ? ibmphp_init+0x0/0x360
>  [<c0f015a0>] kernel_init+0x17b/0x1e2
>  [<c0f01425>] ? kernel_init+0x0/0x1e2
>  [<c01178b3>] kernel_thread_helper+0x7/0x10
>  =======================
> ---[ end trace a7919e7f17c0a725 ]---
> initcall ibmphp_init+0x0/0x360 returned -19 after 144 msecs
> calling  zt5550_init+0x0/0x6a @ 1
> 
> mapping the EBDA is rather ... un-nice from that driver, so i guess 
> you check does the right thing in flagging possible crap.

it does:

    addr:  0x9f800
     end:  0xaf5e7
p->start:  0x9f800
  p->end:  0x9ffff

resources are laid out like this:

  0009f800-0009ffff : reserved
  000a0000-000bffff : Video RAM area

so the driver over-maps into the Video RAM...

and drivers/pci/hotplug/ibmphp_ebda.c seems to be under the 
misunderstanding that the EBDA is up to 65000 bytes large:

        io_mem = ioremap (ebda_seg<<4, 65000);

in reality the EBDA is at most 4K on a normal PC. So i think the right 
fix is the patch below - crop the range to 4K.

_Maybe_ we could remap io_mem to 64K window once we detected a RIO 
signature - but looking at the bogus 65000 number above i think it was 
just added in randomly as a "should be enough, doesnt cause problems" 
thing.

	Ingo

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