diff mbox

[1/1] x86: don't exclude low BIOS area when allocating address space for non-PCI cards

Message ID 53C63139.7000608@kristov.de
State Accepted
Headers show

Commit Message

Christoph Schulz July 16, 2014, 8 a.m. UTC 
From: Christoph Schulz <develop@kristov.de>

Commit 30919b0bf356a8ee0ef4f7d38ca8ad99b96820b2 ("x86: avoid low BIOS area when
allocating address space") moved the test for resource allocations that fall
within the first 1MB of address space from the PCI-specific path to a generic
path, such that all resource allocations will avoid this area. However, this
breaks ISA cards which need to allocate a memory region within the first 1MB.
An example is the i82365 PCMCIA controller and derivatives like the Ricoh
RF5C296/396 which map part of the PCMCIA socket memory address space into the
first 1MB of system memory address space. They do not work anymore as no usable
memory region exists due to this change:

Intel ISA PCIC probe: Ricoh RF5C296/396 ISA-to-PCMCIA at port 0x3e0 ofs 0x00, 2 sockets
host opts [0]: none
host opts [1]: none
ISA irqs (scanned) = 3,4,5,9,10 status change on irq 10
pcmcia_socket pcmcia_socket1: pccard: PCMCIA card inserted into slot 1
pcmcia_socket pcmcia_socket0: cs: IO port probe 0xc00-0xcff: excluding 0xcf8-0xcff
pcmcia_socket pcmcia_socket0: cs: IO port probe 0xa00-0xaff: clean.
pcmcia_socket pcmcia_socket0: cs: IO port probe 0x100-0x3ff: excluding 0x170-0x177 0x1f0-0x1f7 0x2f8-0x2ff 0x370-0x37f 0x3c0-0x3e7 0x3f0-0x3ff
pcmcia_socket pcmcia_socket0: cs: memory probe 0x0a0000-0x0affff: excluding 0xa0000-0xaffff
pcmcia_socket pcmcia_socket0: cs: memory probe 0x0b0000-0x0bffff: excluding 0xb0000-0xbffff
pcmcia_socket pcmcia_socket0: cs: memory probe 0x0c0000-0x0cffff: excluding 0xc0000-0xcbfff
pcmcia_socket pcmcia_socket0: cs: memory probe 0x0d0000-0x0dffff: clean.
pcmcia_socket pcmcia_socket0: cs: memory probe 0x0e0000-0x0effff: clean.
pcmcia_socket pcmcia_socket0: cs: memory probe 0x60000000-0x60ffffff: clean.
pcmcia_socket pcmcia_socket0: cs: memory probe 0xa0000000-0xa0ffffff: clean.
pcmcia_socket pcmcia_socket1: cs: IO port probe 0xc00-0xcff: excluding 0xcf8-0xcff
pcmcia_socket pcmcia_socket1: cs: IO port probe 0xa00-0xaff: clean.
pcmcia_socket pcmcia_socket1: cs: IO port probe 0x100-0x3ff: excluding 0x170-0x177 0x1f0-0x1f7 0x2f8-0x2ff 0x370-0x37f 0x3c0-0x3e7 0x3f0-0x3ff
pcmcia_socket pcmcia_socket1: cs: memory probe 0x0a0000-0x0affff: excluding 0xa0000-0xaffff
pcmcia_socket pcmcia_socket1: cs: memory probe 0x0b0000-0x0bffff: excluding 0xb0000-0xbffff
pcmcia_socket pcmcia_socket1: cs: memory probe 0x0c0000-0x0cffff: excluding 0xc0000-0xcbfff
pcmcia_socket pcmcia_socket1: cs: memory probe 0x0d0000-0x0dffff: clean.
pcmcia_socket pcmcia_socket1: cs: memory probe 0x0e0000-0x0effff: clean.
pcmcia_socket pcmcia_socket1: cs: memory probe 0x60000000-0x60ffffff: clean.
pcmcia_socket pcmcia_socket1: cs: memory probe 0xa0000000-0xa0ffffff: clean.
pcmcia_socket pcmcia_socket1: cs: memory probe 0x0cc000-0x0effff: excluding 0xe0000-0xeffff
pcmcia_socket pcmcia_socket1: cs: unable to map card memory!

If filtering out the first 1MB is reverted, everything works as expected.

Signed-off-by: Christoph Schulz <develop@kristov.de>
Tested-by: Robert Resch <fli4l@robert.reschpara.de>
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Comments

Bjorn Helgaas July 16, 2014, 7 p.m. UTC | #1 
On Wed, Jul 16, 2014 at 2:00 AM, Christoph Schulz <develop@kristov.de> wrote:
> From: Christoph Schulz <develop@kristov.de>
>
> Commit 30919b0bf356a8ee0ef4f7d38ca8ad99b96820b2 ("x86: avoid low BIOS area when
> allocating address space") moved the test for resource allocations that fall
> within the first 1MB of address space from the PCI-specific path to a generic
> path, such that all resource allocations will avoid this area. However, this
> breaks ISA cards which need to allocate a memory region within the first 1MB.
> An example is the i82365 PCMCIA controller and derivatives like the Ricoh
> RF5C296/396 which map part of the PCMCIA socket memory address space into the
> first 1MB of system memory address space. They do not work anymore as no usable
> memory region exists due to this change:
>
> Intel ISA PCIC probe: Ricoh RF5C296/396 ISA-to-PCMCIA at port 0x3e0 ofs 0x00, 2 sockets
> host opts [0]: none
> host opts [1]: none
> ISA irqs (scanned) = 3,4,5,9,10 status change on irq 10
> pcmcia_socket pcmcia_socket1: pccard: PCMCIA card inserted into slot 1
> pcmcia_socket pcmcia_socket0: cs: IO port probe 0xc00-0xcff: excluding 0xcf8-0xcff
> pcmcia_socket pcmcia_socket0: cs: IO port probe 0xa00-0xaff: clean.
> pcmcia_socket pcmcia_socket0: cs: IO port probe 0x100-0x3ff: excluding 0x170-0x177 0x1f0-0x1f7 0x2f8-0x2ff 0x370-0x37f 0x3c0-0x3e7 0x3f0-0x3ff
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x0a0000-0x0affff: excluding 0xa0000-0xaffff
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x0b0000-0x0bffff: excluding 0xb0000-0xbffff
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x0c0000-0x0cffff: excluding 0xc0000-0xcbfff
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x0d0000-0x0dffff: clean.
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x0e0000-0x0effff: clean.
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x60000000-0x60ffffff: clean.
> pcmcia_socket pcmcia_socket0: cs: memory probe 0xa0000000-0xa0ffffff: clean.
> pcmcia_socket pcmcia_socket1: cs: IO port probe 0xc00-0xcff: excluding 0xcf8-0xcff
> pcmcia_socket pcmcia_socket1: cs: IO port probe 0xa00-0xaff: clean.
> pcmcia_socket pcmcia_socket1: cs: IO port probe 0x100-0x3ff: excluding 0x170-0x177 0x1f0-0x1f7 0x2f8-0x2ff 0x370-0x37f 0x3c0-0x3e7 0x3f0-0x3ff
> pcmcia_socket pcmcia_socket1: cs: memory probe 0x0a0000-0x0affff: excluding 0xa0000-0xaffff
> pcmcia_socket pcmcia_socket1: cs: memory probe 0x0b0000-0x0bffff: excluding 0xb0000-0xbffff
> pcmcia_socket pcmcia_socket1: cs: memory probe 0x0c0000-0x0cffff: excluding 0xc0000-0xcbfff
> pcmcia_socket pcmcia_socket1: cs: memory probe 0x0d0000-0x0dffff: clean.
> pcmcia_socket pcmcia_socket1: cs: memory probe 0x0e0000-0x0effff: clean.
> pcmcia_socket pcmcia_socket1: cs: memory probe 0x60000000-0x60ffffff: clean.
> pcmcia_socket pcmcia_socket1: cs: memory probe 0xa0000000-0xa0ffffff: clean.
> pcmcia_socket pcmcia_socket1: cs: memory probe 0x0cc000-0x0effff: excluding 0xe0000-0xeffff
> pcmcia_socket pcmcia_socket1: cs: unable to map card memory!
>
> If filtering out the first 1MB is reverted, everything works as expected.
>
> Signed-off-by: Christoph Schulz <develop@kristov.de>
> Tested-by: Robert Resch <fli4l@robert.reschpara.de>

I applied this to pci/misc for v3.17, thanks.

This effectively reverts 30919b0bf356 ("x86: avoid low BIOS area when
allocating address space").  I don't see a reference there to a bug
fixed by 30919b0bf356, so hopefully reverting it won't reintroduce a
bug.

> ---
> diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c
> index 2a26819..80eab01 100644
> --- a/arch/x86/kernel/resource.c
> +++ b/arch/x86/kernel/resource.c
> @@ -37,10 +37,12 @@ static void remove_e820_regions(struct resource *avail)
>
>  void arch_remove_reservations(struct resource *avail)
>  {
> -       /* Trim out BIOS areas (low 1MB and high 2MB) and E820 regions */
> +       /*
> +        * Trim out BIOS area (high 2MB) and E820 regions. We do not remove
> +        * the low 1MB unconditionally, as this area is needed for some ISA
> +        * cards requiring a memory range, e.g. the i82365 PCMCIA controller.
> +        */
>         if (avail->flags & IORESOURCE_MEM) {
> -               if (avail->start < BIOS_END)
> -                       avail->start = BIOS_END;
>                 resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END);
>
>                 remove_e820_regions(avail);
> diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
> index a19ed92..2ae525e 100644
> --- a/arch/x86/pci/i386.c
> +++ b/arch/x86/pci/i386.c
> @@ -162,6 +162,10 @@ pcibios_align_resource(void *data, const struct resource *res,
>                         return start;
>                 if (start & 0x300)
>                         start = (start + 0x3ff) & ~0x3ff;
> +       } else if (res->flags & IORESOURCE_MEM) {
> +               /* The low 1MB range is reserved for ISA cards */
> +               if (start < BIOS_END)
> +                       start = BIOS_END;
>         }
>         return start;
>  }
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Christoph Schulz July 16, 2014, 7:35 p.m. UTC | #2 
Hello!

Bjorn Helgaas schrieb am Wed, 16 Jul 2014 13:00:21 -0600:

> I applied this to pci/misc for v3.17, thanks.

Thank you very much. What do you think about queuing it up to -stable?  
Commit 30919b0bf356 is in the tree since 2.6.37-rc7. We have used the  
proposed patch for over a year (since 3.2.42 / 3.7.10 / 3.8.5, to be  
exact) without any regressions. I *think* it meets the criteria for  
-stable, but I don't have much experience of Linux kernel development  
processes, so it's your decision, of course.

> This effectively reverts 30919b0bf356 ("x86: avoid low BIOS area when
> allocating address space").  I don't see a reference there to a bug
> fixed by 30919b0bf356, so hopefully reverting it won't reintroduce a
> bug.

Well, for PCI, the current behaviour does not change effectively, and  
for ISA, the proposed patch fixes a bug. What memory allocations  
beyond ISA and PCI could be adversely affected?


Best regards,

Christoph Schulz

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Bjorn Helgaas July 16, 2014, 8:26 p.m. UTC | #3 
On Wed, Jul 16, 2014 at 1:35 PM, Christoph Schulz <develop@kristov.de> wrote:
> Hello!
>
> Bjorn Helgaas schrieb am Wed, 16 Jul 2014 13:00:21 -0600:
>
>
>> I applied this to pci/misc for v3.17, thanks.
>
>
> Thank you very much. What do you think about queuing it up to -stable?
> Commit 30919b0bf356 is in the tree since 2.6.37-rc7. We have used the
> proposed patch for over a year (since 3.2.42 / 3.7.10 / 3.8.5, to be exact)
> without any regressions. I *think* it meets the criteria for -stable, but I
> don't have much experience of Linux kernel development processes, so it's
> your decision, of course.

Good point, I added:

CC: stable@vger.kernel.org  # v2.6.37+

>> This effectively reverts 30919b0bf356 ("x86: avoid low BIOS area when
>> allocating address space").  I don't see a reference there to a bug
>> fixed by 30919b0bf356, so hopefully reverting it won't reintroduce a
>> bug.
>
>
> Well, for PCI, the current behaviour does not change effectively, and for
> ISA, the proposed patch fixes a bug. What memory allocations beyond ISA and
> PCI could be adversely affected?

There aren't very many, I guess, but I don't want to build things on
the assumption that ISA and PCI are the only possibilities.  ISA was
once the only possibility :)

Bjorn
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diff mbox

Patch

diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c
index 2a26819..80eab01 100644
--- a/arch/x86/kernel/resource.c
+++ b/arch/x86/kernel/resource.c
@@ -37,10 +37,12 @@  static void remove_e820_regions(struct resource *avail)
 
 void arch_remove_reservations(struct resource *avail)
 {
-	/* Trim out BIOS areas (low 1MB and high 2MB) and E820 regions */
+	/*
+	 * Trim out BIOS area (high 2MB) and E820 regions. We do not remove
+	 * the low 1MB unconditionally, as this area is needed for some ISA
+	 * cards requiring a memory range, e.g. the i82365 PCMCIA controller.
+	 */
 	if (avail->flags & IORESOURCE_MEM) {
-		if (avail->start < BIOS_END)
-			avail->start = BIOS_END;
 		resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END);
 
 		remove_e820_regions(avail);
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index a19ed92..2ae525e 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -162,6 +162,10 @@  pcibios_align_resource(void *data, const struct resource *res,
 			return start;
 		if (start & 0x300)
 			start = (start + 0x3ff) & ~0x3ff;
+	} else if (res->flags & IORESOURCE_MEM) {
+		/* The low 1MB range is reserved for ISA cards */
+		if (start < BIOS_END)
+			start = BIOS_END;
 	}
 	return start;
 }