Re: [PATCH] powerpc: enable access to HT Host-Bridge on Maple
From: Segher Boessenkool <hidden>
Date: 2011-07-01 16:41:06
CPC925/CPC945 use special window to access host bridge functionality of u3-ht. Provide a way to access this device.
Why? Is anything going to use it?
+static int u3_ht_root_read_config(struct pci_controller *hose, u8
offset,
+ int len, u32 *val)
+{
+ volatile void __iomem *addr;
+
+ addr = hose->cfg_addr;
+ addr += ((offset & ~3) << 2) + (4 - len - (offset & 3));This will only work for len 1,2,4 with offset a multiple of len, is that guaranteed here?
+static int u3_ht_root_write_config(struct pci_controller *hose, u8
offset,
+ int len, u32 val)
+{
+ volatile void __iomem *addr;
+
+ addr = hose->cfg_addr + ((offset & ~3) << 2) + (4 - len - (offset
& 3));
+
+ if (offset >= PCI_BASE_ADDRESS_0 && offset < PCI_CAPABILITY_LIST)
+ return PCIBIOS_SUCCESSFUL;This is a workaround for something; at the very least it needs a comment, but probably it shouldn't be here at all.
quoted hunk ↗ jump to hunk
static int u3_ht_read_config(struct pci_bus *bus, unsigned int devfn, int offset, int len, u32 *val) {@@ -217,6 +265,9 @@ static int u3_ht_read_config(struct pci_bus*bus, unsigned int devfn, if (hose == NULL) return PCIBIOS_DEVICE_NOT_FOUND; + if (bus->number == hose->first_busno && devfn == PCI_DEVFN(0, 0)) + return u3_ht_root_read_config(hose, offset, len, val); + if (offset > 0xff) return PCIBIOS_BAD_REGISTER_NUMBER;
u3_ht_root_read_config() can get an offset out of range this way.
hose->cfg_data = ioremap(0xf2000000, 0x02000000); + hose->cfg_addr = ioremap(0xf8070000, 0x1000);
Eww. You could just make a global instead of abusing existing fields, there can be only one CPC9x5 in a system anyway. Segher