Messages in this thread | | | Date | Wed, 12 Apr 2023 12:25:01 +0200 | Subject | Re: [PATCH v5 07/15] x86/mtrr: replace vendor tests in MTRR code | From | Juergen Gross <> |
| |
On 12.04.23 10:45, Borislav Petkov wrote: > On Sat, Apr 01, 2023 at 08:36:44AM +0200, Juergen Gross wrote: >> Modern CPUs all share the same MTRR interface implemented via >> generic_mtrr_ops. >> >> At several places in MTRR code this generic interface is deduced via >> is_cpu(INTEL) tests, which is only working due to X86_VENDOR_INTEL >> being 0 (the is_cpu() macro is testing mtrr_if->vendor, which isn't >> explicitly set in generic_mtrr_ops). >> >> Fix that by replacing the is_cpu(INTEL) tests with testing for mtrr_if >> to be &generic_mtrr_ops. > > Replace with: > > "Test the generic CPU feature X86_FEATURE_MTRR instead." > >> diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c >> index 1c19d67ddab3..46aae69d259e 100644 >> --- a/arch/x86/kernel/cpu/mtrr/mtrr.c >> +++ b/arch/x86/kernel/cpu/mtrr/mtrr.c >> @@ -108,14 +108,12 @@ static int have_wrcomb(void) >> /* This function returns the number of variable MTRRs */ >> static void __init set_num_var_ranges(bool use_generic) >> { >> - unsigned long config = 0, dummy; >> + unsigned long config, dummy; >> >> if (use_generic) >> rdmsr(MSR_MTRRcap, config, dummy); >> - else if (is_cpu(AMD) || is_cpu(HYGON)) >> - config = 2; >> - else if (is_cpu(CYRIX) || is_cpu(CENTAUR)) >> - config = 8; >> + else >> + config = mtrr_if->var_regs; >> >> num_var_ranges = config & MTRR_CONFIG_NUM_VAR_MASK; >> } > > From previous review which you've missed to incorporate: > > "Since you're touching this function, you might simply expand its body in > its only call site in mtrr_bp_init(), put a comment above the expanded > code and remove that function. > > That is, if we're going to do the ->var_regs thing." >
Oh, sorry. Will do it.
Juergen [unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature] | |