Re: pci: Arch hook to determine config space size

[Brian King]

Matthew Wilcox wrote:
> Basically, ppc64's config ops are broken and need to check the offset
> being read.  Here's i386:
>
> static int pci_conf1_write (int seg, int bus, int devfn, int reg, int len, u32 v
> alue)
> {
>         unsigned long flags;
>
>         if ((bus > 255) || (devfn > 255) || (reg > 255)) 
>                 return -EINVAL;

Here is a pure ppc64 implementation that does this.

> I think all the config ops in ppc64 are broken and need to check for these
> limits.  Also, it does some checks that are already performed by upper layers:
>
>         if (where & (size - 1))
>                 return PCIBIOS_BAD_REGISTER_NUMBER;
>
> is checked for in drivers/pci/access.c

I can submit a separate patch to clean that up.

--
Brian King
eServer Storage I/O
IBM Linux Technology Center


When working with a PCI-X Mode 2 adapter on a PCI-X Mode 1 PPC64
system, the current code used to determine the config space size
of a device results in a PCI Master abort and an EEH error, resulting
in the device being taken offline. This patch checks OF to see if
the PCI bridge supports PCI-X Mode 2 and fails config accesses beyond
256 bytes if it does not.

Signed-off-by: Brian King <brking@xxxxxxxxxx>
---

 linux-2.6.11-rc2-bk9-bjking1/arch/ppc64/kernel/pSeries_pci.c |   25 +++++++++++
 linux-2.6.11-rc2-bk9-bjking1/include/asm-ppc64/prom.h        |    1 
 2 files changed, 26 insertions(+)

diff -puN arch/ppc64/kernel/pSeries_pci.c~ppc64_pcix_mode2_cfg arch/ppc64/kernel/pSeries_pci.c
--- linux-2.6.11-rc2-bk9/arch/ppc64/kernel/pSeries_pci.c~ppc64_pcix_mode2_cfg	2005-01-31 14:32:01.000000000 -0600
+++ linux-2.6.11-rc2-bk9-bjking1/arch/ppc64/kernel/pSeries_pci.c	2005-01-31 15:09:53.000000000 -0600
@@ -52,6 +52,16 @@ static int s7a_workaround;
 
 extern struct mpic *pSeries_mpic;
 
+static int config_access_valid(struct device_node *dn, int where)
+{
+	struct device_node *hose_dn = dn->phb->arch_data;
+
+	if (where < 256 || hose_dn->pci_ext_config_space)
+		return 1;
+
+	return 0;
+}
+
 static int rtas_read_config(struct device_node *dn, int where, int size, u32 *val)
 {
 	int returnval = -1;
@@ -62,6 +72,8 @@ static int rtas_read_config(struct devic
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	if (where & (size - 1))
 		return PCIBIOS_BAD_REGISTER_NUMBER;
+	if (!config_access_valid(dn, where))
+		return PCIBIOS_BAD_REGISTER_NUMBER;
 
 	addr = (dn->busno << 16) | (dn->devfn << 8) | where;
 	buid = dn->phb->buid;
@@ -110,6 +122,8 @@ static int rtas_write_config(struct devi
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	if (where & (size - 1))
 		return PCIBIOS_BAD_REGISTER_NUMBER;
+	if (!config_access_valid(dn, where))
+		return PCIBIOS_BAD_REGISTER_NUMBER;
 
 	addr = (dn->busno << 16) | (dn->devfn << 8) | where;
 	buid = dn->phb->buid;
@@ -270,6 +284,16 @@ static int phb_set_bus_ranges(struct dev
 	return 0;
 }
 
+static void __devinit get_phb_config_space_type(struct device_node *dn)
+{
+	int *type = (int *)get_property(dn, "ibm,pci-config-space-type", NULL);
+
+	if (type && *type == 1)
+		dn->pci_ext_config_space = 1;
+	else
+		dn->pci_ext_config_space = 0;
+}
+
 static int __devinit setup_phb(struct device_node *dev,
 			       struct pci_controller *phb,
 			       unsigned int addr_size_words)
@@ -285,6 +309,7 @@ static int __devinit setup_phb(struct de
 	phb->arch_data = dev;
 	phb->ops = &rtas_pci_ops;
 	phb->buid = get_phb_buid(dev);
+	get_phb_config_space_type(dev);
 
 	return 0;
 }
diff -puN include/asm-ppc64/prom.h~ppc64_pcix_mode2_cfg include/asm-ppc64/prom.h
--- linux-2.6.11-rc2-bk9/include/asm-ppc64/prom.h~ppc64_pcix_mode2_cfg	2005-01-31 14:32:01.000000000 -0600
+++ linux-2.6.11-rc2-bk9-bjking1/include/asm-ppc64/prom.h	2005-01-31 14:32:01.000000000 -0600
@@ -137,6 +137,7 @@ struct device_node {
 	int	devfn;			/* for pci devices */
 	int	eeh_mode;		/* See eeh.h for possible EEH_MODEs */
 	int	eeh_config_addr;
+	int	pci_ext_config_space;	/* for phb's or bridges */
 	struct  pci_controller *phb;	/* for pci devices */
 	struct	iommu_table *iommu_table;	/* for phb's or bridges */
 
_