Hello. James Bottomley wrote:
The driver stores the the PCI resource address into 'u_long' variable before calling ioremap_nocache() on it. This warrants kernel oops when the registers are accessed on PPC 44x platforms which (being 32-bit) have PCI memory space mapped beyond 4 GB.
The arch/ppc/ kernel has a fixup in ioremap() that creates an illusion of the PCI I/O and memory resources are mapped below 4 GB, but arch/powerpc/ code got
Not I/O, just memory, of course. :-] Although PCI I/O space is mapped beyond 4 GB...
rid of this trick, having instead CONFIG_RESOURCES_64BIT enabled.
Signed-off-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
Well, all I can say about the architecture is: yuk!
It's not alone, there's also Alchemy MIPS SOCs -- arch/mips/ still uses the ioremap() trick for their PCI space.
However, if this is truly a problem, you only fixed half of it:
A nice machine check occurs in the siimage driver on 44x due to the same issue.
aic79xx_osm.h and aic79xx_osm_pci.c have the same problems.
Yes, I can fix it in a separate patch.
Also, your fixes don't look complete. This statement in ahc_pci_map_registers(struct ahc_softc *ahc)
ahc->bsh.ioport = base;
Should be warning because bsh.ioport is still u_long and base should be u64 (so a truncation warning).
No warnings, just silent truncation (as it was before the patch when the 64-bit 'resource_size_t' result of pci_resource_start() was put into 'u_long' variable). And since when C compilers warn about truncations due to implicit type converions? :-O
I think the correct fix (unless you also have a ludicrous port space?) is simply to cast to (u_long).
There's nothing to fix here I think. But if you insist I may add an explicit type cast...
- printf("aic7xxx: PCI%d:%d:%d MEM region 0x%lx " + printf("aic7xxx: PCI%d:%d:%d MEM region 0x%llx " "unavailable. Cannot memory map device.\n", ahc_get_pci_bus(ahc->dev_softc), ahc_get_pci_slot(ahc->dev_softc), ahc_get_pci_function(ahc->dev_softc), - base); + (uint64_t)base);
This isn't quite right: uint64_t is unsigned long on 64 bit platforms,
However, 'unsigned long long' and 'unsigned long' are both 64-bit there.
so it won't match %llx (you need it to be unsigned long long explicitly).
OK.
@@ -398,7 +398,7 @@ ahc_pci_map_registers(struct ahc_softc * ahc_get_pci_bus(ahc->dev_softc), ahc_get_pci_slot(ahc->dev_softc), ahc_get_pci_function(ahc->dev_softc), - base); + (u_long)base);
This also isn't right ... you need to cast it to unsigned long long and use %llx in the printf.
I can do that if you insist but truncation to u_long is safe for I/O ports...
James
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