| Message ID | 1363757079-23550-4-git-send-email-lucaskt@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 2013-03-20 at 02:24 -0300, Lucas Kannebley Tavares wrote: > Implementation of a architecture-specific pcibios_get_speed_cap_mask. > This implementation detects bus capabilities based on OF > ibm,pcie-link-speed-stats property. The problem with your approach is that it's not a runtime detection... If the pseries machine is compiled into the kernel binary, it will override pcibios_get_speed_cap_mask() using the device-tree, regardless of whether the machine is currently booted on a pseries machine or not. This wouldn't be a big problem if the pseries pcibios_get_speed_cap_mask() was capable of doing a fallback to the generic one if the device-tree property is absent but that isn't the case. I think what you need to do is: - Make it so the generic one can be called by the override. This can look a bit tricky but it's better that way. One way to do it is to have the actual implementation be in a __pci_* variant called by the weak pcibios_* variant - Move the powerpc on to arch/powerpc/kernel/pci-common.c and make it call a ppc_md.pcibios_get_speed_cap_mask(). If the hook is absent (NULL), make it call the generic one - pseries can then populate the hook in ppc_md. with its custom variant. Cheers, Ben.
diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c index 0b580f4..4da8deb 100644 --- a/arch/powerpc/platforms/pseries/pci.c +++ b/arch/powerpc/platforms/pseries/pci.c @@ -24,6 +24,7 @@ #include <linux/kernel.h> #include <linux/pci.h> #include <linux/string.h> +#include <linux/device.h> #include <asm/eeh.h> #include <asm/pci-bridge.h> @@ -108,3 +109,37 @@ static void fixup_winbond_82c105(struct pci_dev* dev) } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_82C105, fixup_winbond_82c105); + +int pcibios_get_speed_cap_mask(struct pci_dev *dev, u32 *mask) +{ + struct device_node *dn, *pdn; + const uint32_t *pcie_link_speed_stats = NULL; + + *mask = 0; + dn = pci_bus_to_OF_node(dev->bus); + + /* Find nearest ibm,pcie-link-speed-stats, walking up the device tree */ + for (pdn = dn; pdn != NULL; pdn = pdn->parent) { + pcie_link_speed_stats = (const uint32_t *) of_get_property(pdn, + "ibm,pcie-link-speed-stats", NULL); + if (pcie_link_speed_stats != NULL) + break; + } + + if (pcie_link_speed_stats == NULL) { + dev_info(&dev->dev, "no ibm,pcie-link-speed-stats property\n"); + return -EINVAL; + } + + switch (pcie_link_speed_stats[0]) { + case 0x02: + *mask |= PCIE_SPEED_50; + case 0x01: + *mask |= PCIE_SPEED_25; + case 0x00: + default: + return -EINVAL; + } + + return 0; +}
Implementation of a architecture-specific pcibios_get_speed_cap_mask. This implementation detects bus capabilities based on OF ibm,pcie-link-speed-stats property. Signed-off-by: Lucas Kannebley Tavares <lucaskt@linux.vnet.ibm.com> --- arch/powerpc/platforms/pseries/pci.c | 35 ++++++++++++++++++++++++++++++++++ 1 files changed, 35 insertions(+), 0 deletions(-)