Re: [PATCH] x86/pci: do assign root bus res if _CRS is used

Bjorn Helgaas
2009-04-30T15:14:32Z

On Wednesday 29 April 2009 05:08:51 pm Bjorn Helgaas wrote:
> On Monday 27 April 2009 08:07:01 pm Yinghai Lu wrote:
> > On Mon, Apr 27, 2009 at 3:24 PM, Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:
> > > On Monday 27 April 2009 03:00:16 pm Yinghai Lu wrote:
> > >> On Mon, Apr 27, 2009 at 1:39 PM, Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:
> > >> >> other system may have broken _CRS.
> > >> >
> > >> > Do you have examples of problems here, or are you just worried that
> > >> > there *may* be problems?
> > >> one system with three chains... with pci=use_crs
> > >> [    9.365669] pci_bus 0000:00: resource 0 io:  [0x00-0x3af]
> > >> [    9.371065] pci_bus 0000:00: resource 1 io:  [0x3e0-0xcf7]
> > >> [    9.376551] pci_bus 0000:00: resource 2 io:  [0x3b0-0x3bb]
> > >> [    9.382028] pci_bus 0000:00: resource 3 io:  [0x3c0-0x3df]
> > >> [    9.387513] pci_bus 0000:00: resource 4 io:  [0xd00-0xefff]
> > >> [    9.393077] pci_bus 0000:00: resource 5 mem: [0x0a0000-0x0bffff]
> > >> [    9.399084] pci_bus 0000:00: resource 6 mem: [0x0d0000-0x0dffff]
> > >> [    9.405089] pci_bus 0000:00: resource 7 mem: [0xdd000000-0xdfffffff]
> > >> [    9.505332] pci_bus 0000:40: resource 0 io:  [0x5000-0x8fff]
> > >> [    9.510991] pci_bus 0000:40: resource 1 mem: [0xdb000000-0xdcffffff]
> > >> [    9.553378] pci_bus 0000:80: resource 0 io:  [0x1000-0x4fff]
> > >> [    9.559036] pci_bus 0000:80: resource 1 mem: [0xda000000-0xdaffffff]
> > >>
> > >> without that: amd_bus.c will read that from pci conf space
> > >> [    9.310965] pci_bus 0000:00: resource 0 io:  [0x9000-0xefff]
> > >> [    9.316621] pci_bus 0000:00: resource 1 io:  [0x00-0xfff]
> > >> [    9.322020] pci_bus 0000:00: resource 2 mem: [0xdd000000-0xdfffffff]
> > >> [    9.328373] pci_bus 0000:00: resource 3 mem: [0x0a0000-0x0bffff]
> > >> [    9.334378] pci_bus 0000:00: resource 4 mem: [0xc0000000-0xd9ffffff]
> > >> [    9.340731] pci_bus 0000:00: resource 5 mem: [0xf0000000-0xffffffff]
> > >> [    9.347084] pci_bus 0000:00: resource 6 mem: [0x840000000-0xfcffffffff]
> > >> [    9.444440] pci_bus 0000:40: resource 0 io:  [0x5000-0x8fff]
> > >> [    9.450099] pci_bus 0000:40: resource 1 io:  [0xf000-0xffff]
> > >> [    9.455757] pci_bus 0000:40: resource 2 mem: [0xdb000000-0xdcffffff]
> > >> [    9.498118] pci_bus 0000:80: resource 0 io:  [0x1000-0x4fff]
> > >> [    9.503777] pci_bus 0000:80: resource 1 mem: [0xda000000-0xdaffffff]
> > >
> > > It's interesting that many of the differences involve the legacy
> > > VGA I/O ports in the 0x3b0-0x3df range.  My guess is that the AMD
> > > chipset has special routing for those ranges.  If it didn't, it
> > > would be difficult to support VGA devices under the other two
> > > root bridges.  Maybe that VGA routing doesn't show up in the
> > > bridge's PCI config space.  Can you tell from the ASL whether the
> > > root bridge _SRS/_PRS/_CRS methods handle the VGA ranges specially?
> > >
> > > One of the differences is that PCI config space shows a 64-bit region
> > > (bus 0000:00 mem 0x840000000-0xfcffffffff) that doesn't show up in
> > > the _CRS info.  But the _CRS parsing depends on acpi_resource_to_address64(),
> > > which doesn't know about the ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64
> > > descriptors added in ACPI 3.0.  So this difference could be a result
> > > of that Linux bug.  It'd be interesting to see whether the test patch
> > > below makes a difference.
> > will check it.
>
> Did you learn anything about this? I have a PNPACPI patch to parse
> these new descriptors, but I don't have any machines where I can test
> it. If your box uses that descriptor, it'd be nice to test the patch
> there.

Oops, I should have just attached the PNPACPI patch in case anybody
has a box where it can be tested. One way to test it would be to
compare the output of "grep . /sys/devices/pnp*/*/{id,resources,options}"
before and after the patch. If a BIOS uses the new descriptors, we
should see some new resources after the patch.

PNPACPI: parse Extended Address Space Descriptors

From: Bjorn Helgaas <bjorn.helgaas@hp.com>

Extended Address Space Descriptors are new in ACPI 3.0 and allow the
BIOS to communicate device resource cacheability attributes (write-back,
write-through, uncacheable, etc) to the OS.

Previously, PNPACPI ignored these descriptors, so if a BIOS used them,
a device could be responding at addresses the OS doesn't know about.
This patch adds support for these descriptors in _CRS and _PRS. We
don't attempt to encode them for _SRS (just like we don't attempt to
encode the existing 16-, 32-, and 64-bit Address Space Descriptors).

Unfortunately, I don't have a way to test this.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
---
drivers/pnp/pnpacpi/rsparser.c | 45 ++++++++++++++++++++++++++++++++++++++--
1 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c
index adf1785..0864242 100644
--- a/drivers/pnp/pnpacpi/rsparser.c
+++ b/drivers/pnp/pnpacpi/rsparser.c
@@ -287,6 +287,25 @@ static void pnpacpi_parse_allocated_address_space(struct pnp_dev *dev,
ACPI_DECODE_16);
}

+static void pnpacpi_parse_allocated_ext_address_space(struct pnp_dev *dev,
+ struct acpi_resource *res)
+{
+ struct acpi_resource_extended_address64 *p = &res->data.ext_address64;
+
+ if (p->producer_consumer == ACPI_PRODUCER)
+ return;
+
+ if (p->resource_type == ACPI_MEMORY_RANGE)
+ pnpacpi_parse_allocated_memresource(dev,
+ p->minimum, p->address_length,
+ p->info.mem.write_protect);
+ else if (p->resource_type == ACPI_IO_RANGE)
+ pnpacpi_parse_allocated_ioresource(dev,
+ p->minimum, p->address_length,
+ p->granularity == 0xfff ? ACPI_DECODE_10 :
+ ACPI_DECODE_16);
+}
+
static acpi_status pnpacpi_allocated_resource(struct acpi_resource *res,
void *data)
{
@@ -400,8 +419,7 @@ static acpi_status pnpacpi_allocated_resource(struct acpi_resource *res,
break;

case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
- if (res->data.ext_address64.producer_consumer == ACPI_PRODUCER)
- return AE_OK;
+ pnpacpi_parse_allocated_ext_address_space(dev, res);
break;

case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
@@ -630,6 +648,28 @@ static __init void pnpacpi_parse_address_option(struct pnp_dev *dev,
IORESOURCE_IO_FIXED);
}

+static __init void pnpacpi_parse_ext_address_option(struct pnp_dev *dev,
+ unsigned int option_flags,
+ struct acpi_resource *r)
+{
+ struct acpi_resource_extended_address64 *p = &r->data.ext_address64;
+ unsigned char flags = 0;
+
+ if (p->address_length == 0)
+ return;
+
+ if (p->resource_type == ACPI_MEMORY_RANGE) {
+ if (p->info.mem.write_protect == ACPI_READ_WRITE_MEMORY)
+ flags = IORESOURCE_MEM_WRITEABLE;
+ pnp_register_mem_resource(dev, option_flags, p->minimum,
+ p->minimum, 0, p->address_length,
+ flags);
+ } else if (p->resource_type == ACPI_IO_RANGE)
+ pnp_register_port_resource(dev, option_flags, p->minimum,
+ p->minimum, 0, p->address_length,
+ IORESOURCE_IO_FIXED);
+}
+
struct acpipnp_parse_option_s {
struct pnp_dev *dev;
unsigned int option_flags;
@@ -711,6 +751,7 @@ static __init acpi_status pnpacpi_option_resource(struct acpi_resource *res,
break;

case ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64:
+ pnpacpi_parse_ext_address_option(dev, option_flags, res);
break;

case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html