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| author | Michael Ellerman <mpe@ellerman.id.au> | 2016-08-05 08:40:56 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-08-09 08:52:03 +0200 |
| commit | 61e8a0d5a0270b91581f6c715036844b2ea98da1 (patch) | |
| tree | 8ce81771a18b73cbb1fd45a349944a2c31350597 /arch/powerpc | |
| parent | powerpc/eeh: Switch to conventional PCI address output in EEH log (diff) | |
| download | linux-61e8a0d5a0270b91581f6c715036844b2ea98da1.tar.xz linux-61e8a0d5a0270b91581f6c715036844b2ea98da1.zip | |
powerpc/pci: Fix endian bug in fixed PHB numbering
The recent commit 63a72284b159 ("powerpc/pci: Assign fixed PHB number
based on device-tree properties"), added code to read a 64-bit property
from the device tree, and if not found read a 32-bit property (reg).
There was a bug in the 32-bit case, on big endian machines, due to the
use of the 64-bit value to read the 32-bit property. The cast of &prop
means we end up writing to the high 32-bit of prop, leaving the low
32-bits containing whatever junk was on the stack.
If that junk value was non-zero, and < MAX_PHBS, we would end up using
it as the PHB id. This results in users seeing what appear to be random
PHB ids.
Fix it by reading into a u32 property and then assigning that to the
u64 value, letting the CPU do the correct conversions for us.
Fixes: 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/pci-common.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index a5c0153ede37..7fdf324d5b51 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -78,6 +78,7 @@ EXPORT_SYMBOL(get_pci_dma_ops); static int get_phb_number(struct device_node *dn) { int ret, phb_id = -1; + u32 prop_32; u64 prop; /* @@ -86,8 +87,10 @@ static int get_phb_number(struct device_node *dn) * reading "ibm,opal-phbid", only present in OPAL environment. */ ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop); - if (ret) - ret = of_property_read_u32_index(dn, "reg", 1, (u32 *)&prop); + if (ret) { + ret = of_property_read_u32_index(dn, "reg", 1, &prop_32); + prop = prop_32; + } if (!ret) phb_id = (int)(prop & (MAX_PHBS - 1)); |