> static void get_smca_bank_info(unsigned int bank)
> {
> unsigned int i, hwid_mcatype, cpu = smp_processor_id();
> - struct smca_hwid_mcatype *type;
> + struct smca_hwid *s_hwid;
> u32 high, instance_id;
> - u16 hwid, mcatype;
>
> /* Collect bank_info using CPU 0 for now. */
> if (cpu)
> @@ -162,14 +157,13 @@ static void get_smca_bank_info(unsigned int bank)
> return;
> }
>
> - hwid = high & MCI_IPID_HWID;
> - mcatype = (high & MCI_IPID_MCATYPE) >> 16;
> - hwid_mcatype = HWID_MCATYPE(hwid, mcatype);
> + hwid_mcatype = HWID_MCATYPE(high & MCI_IPID_HWID,
> + (high & MCI_IPID_MCATYPE) >> 16);
>
Sorry for catching this late, but it seems this change doesn't compile
correctly. This causes the value of hwid_mcatype to be incorrect, so we
will never match a bank to its type.
I see this with GCC 4.8.5 and 5.4.0.
There are no warnings or issues when building or booting just
that the behavior is incorrect.
Disassembly of above change:
db: 8b 45 e0 mov -0x20(%rbp),%eax
de: 41 89 c4 mov %eax,%r12d
e1: 25 00 00 ff 0f and $0xfff0000,%eax
e6: 41 c1 ec 10 shr $0x10,%r12d
ea: 41 09 c4 or %eax,%r12d
Disassembly of original code:
286: 8b 45 d0 mov -0x30(%rbp),%eax
289: 41 89 c5 mov %eax,%r13d
28c: c1 e8 10 shr $0x10,%eax
28f: 41 81 e5 ff 0f 00 00 and $0xfff,%r13d
296: 41 c1 e5 10 shl $0x10,%r13d
29a: 41 09 c5 or %eax,%r13d
Adding extra parentheses in HWID_MCATYPE() gives the same assembly as the
original code and fixes the behavior.
> + hwid_mcatype = HWID_MCATYPE((high & MCI_IPID_HWID)),
> + ((high & MCI_IPID_MCATYPE) >> 16));
Thanks,
Yazen
