Quark X1000 requires CR3 to be rewritten to flush TLB entries irrespective of the PGE bits in CR4 or PTE.PGE
Add a comment to setup_arch to indicate that the code load_cr3(swapper_pg_dir); __flush_tlb_all(); Will already have flushed the TLB @ the CR3 reload allowing us to skip over a potential if/else for Quark. This comment clearly states the bug, the behaviour we rely on and the reason why we only do it this way - one time. Later on cpu_has_pge() will be false due to a fixup in intel_init_early() and __flush_tlb_all() will work as expected from that point onwards Signed-off-by: Bryan O'Donoghue <[email protected]> --- arch/x86/kernel/setup.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 41ead8d..235cfd3 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -879,6 +879,15 @@ void __init setup_arch(char **cmdline_p) KERNEL_PGD_PTRS); load_cr3(swapper_pg_dir); + /* + * Note: Quark X1000 CPUs advertise PGE incorrectly and require + * a cr3 based tlb flush, so the following __flush_tlb_all() + * will not flush anything because the cpu quirk which clears + * X86_FEATURE_PGE has not been invoked yet. Though due to the + * load_cr3() above the TLB has been flushed already. The + * quirk is invoked before subsequent calls to __flush_tlb_all() + * so proper operation is guaranteed. + */ __flush_tlb_all(); #else printk(KERN_INFO "Command line: %s\n", boot_command_line); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
