[coreboot] pci_read_config8 crash in mainboard.c
Carl-Daniel Hailfinger
c-d.hailfinger.devel.2006 at gmx.net
Wed Mar 4 01:46:53 CET 2009
On 03.03.2009 19:22, Marc Jones wrote:
> I think I see the problem. The mainboard.c code is called during the
> chip_operations enable_dev stage very early before the static tree is
> setup with the device function pointers. The reason for this is to do
> chip device setup before the devices are scanned. For example the
> device may need to be enabled in the southbridge before it will be
> found in the normal scan or it may need to be hidden etc.
>
> If you look at static.c you will see that the .ops = 0 for all the
> devices. That field gets updated in set_pci_ops() (or other device ops
> setup functions) which happens later in the device scan, after the
> chip enable_dev.
>
> That is why we need to use the direct access pci functions and not the
> static tree pointer functions. I think that the fix is to add a
> comment explaining why you need to use the direct access functions at
> in the enable_dev function.
>
To be honest, I prefer a fix which is not an easily overlooked "don't do
this" comment.
> I hope that was clear. It is a bit easier to understand in V3 where
> the stages/phases are numbered.
>
Thanks for your explanation.
A lot (all?) of the DBM690T mainboard setup code does not muck with
device visibility or bus setup and could easily be called at a time when
the static device tree has been prepared sufficiently well.
Until someone can tell me how to call the mainboard specific setup code
at a more opportune time, the following bandaid works well enough to
boot without problems.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net>
Index: LinuxBIOSv2-asus_m2a-vm/src/mainboard/amd/dbm690t/mainboard.c
===================================================================
--- LinuxBIOSv2-asus_m2a-vm/src/mainboard/amd/dbm690t/mainboard.c (Revision 3967)
+++ LinuxBIOSv2-asus_m2a-vm/src/mainboard/amd/dbm690t/mainboard.c (Arbeitskopie)
@@ -89,6 +89,31 @@
outb(byte, 0xC52);
}
+/*
+ * This is a totally gross hack to be able to use pci_{read,write}_config*
+ * early during boot when the device tree is not yet set up completely.
+ */
+void devicetree_early_fixup(struct device *dev)
+{
+ struct bus *pbus = dev->bus;
+ while(pbus && pbus->dev && !ops_pci_bus(pbus)) {
+ if (pbus == pbus->dev->bus)
+ break;
+ pbus = pbus->dev->bus;
+ }
+ if (ops_pci_bus(pbus)) {
+ printk_info("%s not needed\n", __func__);
+ return;
+ }
+ if (pbus && pbus->dev && pbus->dev->ops) {
+ printk_info("%s fixing up root bus pci ops\n", __func__);
+ pbus->dev->ops->ops_pci_bus = &pci_cf8_conf1;
+ return;
+ }
+ printk_info("%s failed\n", __func__);
+ return;
+}
+
/********************************************************
* dbm690t uses SB600 GPIO9 to detect IDE_DMA66.
* IDE_DMA66 is routed to GPIO 9. So we read Gpio 9 to
@@ -97,32 +122,25 @@
static void get_ide_dma66()
{
u8 byte;
- /*u32 sm_dev, ide_dev; */
- device_t sm_dev, ide_dev;
- struct bus pbus;
+ struct device *sm_dev;
+ struct device *ide_dev;
+ printk_info("%s.\n", __func__);
sm_dev = dev_find_slot(0, PCI_DEVFN(0x14, 0));
+ devicetree_early_fixup(sm_dev);
- byte =
- pci_cf8_conf1.read8(&pbus, sm_dev->bus->secondary,
- sm_dev->path.pci.devfn, 0xA9);
+ byte = pci_read_config8(sm_dev, 0xA9);
byte |= (1 << 5); /* Set Gpio9 as input */
- pci_cf8_conf1.write8(&pbus, sm_dev->bus->secondary,
- sm_dev->path.pci.devfn, 0xA9, byte);
+ pci_write_config8(sm_dev, 0xA9, byte);
ide_dev = dev_find_slot(0, PCI_DEVFN(0x14, 1));
- byte =
- pci_cf8_conf1.read8(&pbus, ide_dev->bus->secondary,
- ide_dev->path.pci.devfn, 0x56);
+ byte = pci_read_config8(ide_dev, 0x56);
byte &= ~(7 << 0);
- if ((1 << 5) & pci_cf8_conf1.
- read8(&pbus, sm_dev->bus->secondary, sm_dev->path.pci.devfn,
- 0xAA))
+ if ((1 << 5) & pci_read_config8(sm_dev, 0xAA))
byte |= 2 << 0; /* mode 2 */
else
byte |= 5 << 0; /* mode 5 */
- pci_cf8_conf1.write8(&pbus, ide_dev->bus->secondary,
- ide_dev->path.pci.devfn, 0x56, byte);
+ pci_write_config8(ide_dev, 0x56, byte);
}
/*
@@ -133,7 +151,6 @@
u8 byte;
u16 word;
device_t sm_dev;
- struct bus pbus;
/* set ADT 7461 */
ADT7461_write_byte(0x0B, 0x50); /* Local Temperature Hight limit */
@@ -156,12 +173,9 @@
/* set GPIO 64 to input */
sm_dev = dev_find_slot(0, PCI_DEVFN(0x14, 0));
- word =
- pci_cf8_conf1.read16(&pbus, sm_dev->bus->secondary,
- sm_dev->path.pci.devfn, 0x56);
+ word = pci_read_config16(sm_dev, 0x56);
word |= 1 << 7;
- pci_cf8_conf1.write16(&pbus, sm_dev->bus->secondary,
- sm_dev->path.pci.devfn, 0x56, word);
+ pci_write_config16(sm_dev, 0x56, word);
/* set GPIO 64 internal pull-up */
byte = pm2_ioread(0xf0);
--
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