Re: [PATCH] [RFC][POWERPC] Merge 32 and 64 bit pci_process_bridge_OF_ranges() instances

Hello Valentine,

On Tue, 18 Sep 2007 16:03:50 +0400
Valentine Barshak wrote:

Vitaly Bordug wrote:

quoted

+
+			hose->io_base_phys = cpu_phys_addr - pci_addr;

This is not gonna work on 32-bit platform (unless pci_addr == 0).
Should be
hose->io_base_phys = cpu_phys_addr;
The other way we should adjust io size like we do on 64-bit and rewrite 
resource fixup functions.

I think the second sounds like a plan then. We should not "assume" where we can make things to behave properly.

quoted

+			/* handle from 0 to top of I/O window */
+#ifdef CONFIG_PPC64
+			hose->pci_io_size = pci_addr + size;
+#endif
+			hose->io_base_virt = ioremap(hose->io_base_phys, size);

Do we need to ioremap on 64-bit? I think 64-bit uses different approach 
in handling io space.

Correct - 64 bit code does __get_vm_area() so the upper line is ppc32-specific.

quoted

+#ifdef CONFIG_PPC32
+			if (prim)
+				isa_io_base = (unsigned long)hose->io_base_virt;
+#endif

What's exactly the point of merging this single function?
If this was intended to add 64-bit physical address support to 32-bit 
platforms (like ppc440), then it does not seem sufficient to make pci 
stuff work right.
What about the 32-bit pcibios_fixup_resources(), 
pcibios_resource_to_bus(), pcibios_bus_to_resource() stuff?
There's still no 64-bit support. You'll get
"PCI Cannot allocate resource region" attempting to initialize resources 
at PCI start-up.

Because this function is critical to get the stuff going. You can have some devices working even without PCI resources initted
(what in fact I had with mpc8272).  I am in process of moving the mentioned to the common_... domain but I suspect there are other 32-bit-stick stuff still. So if you want to assist in cleaning this up, feel free to join the club...
-- 
Sincerely, Vitaly