diff options
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 49 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 8 | ||||
| -rw-r--r-- | arch/x86/mm/init.c | 34 |
4 files changed, 50 insertions, 46 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index fb1d3358a4af..775f10100d7f 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -169,21 +169,21 @@ static int __init x86_mpx_setup(char *s) __setup("nompx", x86_mpx_setup); #ifdef CONFIG_X86_64 -static int __init x86_pcid_setup(char *s) +static int __init x86_nopcid_setup(char *s) { - /* require an exact match without trailing characters */ - if (strlen(s)) - return 0; + /* nopcid doesn't accept parameters */ + if (s) + return -EINVAL; /* do not emit a message if the feature is not present */ if (!boot_cpu_has(X86_FEATURE_PCID)) - return 1; + return 0; setup_clear_cpu_cap(X86_FEATURE_PCID); pr_info("nopcid: PCID feature disabled\n"); - return 1; + return 0; } -__setup("nopcid", x86_pcid_setup); +early_param("nopcid", x86_nopcid_setup); #endif static int __init x86_noinvpcid_setup(char *s) @@ -329,38 +329,6 @@ static __always_inline void setup_smap(struct cpuinfo_x86 *c) } } -static void setup_pcid(struct cpuinfo_x86 *c) -{ - if (cpu_has(c, X86_FEATURE_PCID)) { - if (cpu_has(c, X86_FEATURE_PGE)) { - /* - * We'd like to use cr4_set_bits_and_update_boot(), - * but we can't. CR4.PCIDE is special and can only - * be set in long mode, and the early CPU init code - * doesn't know this and would try to restore CR4.PCIDE - * prior to entering long mode. - * - * Instead, we rely on the fact that hotplug, resume, - * etc all fully restore CR4 before they write anything - * that could have nonzero PCID bits to CR3. CR4.PCIDE - * has no effect on the page tables themselves, so we - * don't need it to be restored early. - */ - cr4_set_bits(X86_CR4_PCIDE); - } else { - /* - * flush_tlb_all(), as currently implemented, won't - * work if PCID is on but PGE is not. Since that - * combination doesn't exist on real hardware, there's - * no reason to try to fully support it, but it's - * polite to avoid corrupting data if we're on - * an improperly configured VM. - */ - clear_cpu_cap(c, X86_FEATURE_PCID); - } - } -} - /* * Protection Keys are not available in 32-bit mode. */ @@ -1175,9 +1143,6 @@ static void identify_cpu(struct cpuinfo_x86 *c) setup_smep(c); setup_smap(c); - /* Set up PCID */ - setup_pcid(c); - /* * The vendor-specific functions might have changed features. * Now we do "generic changes." diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d84afb0a322d..0957dd73d127 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1178,8 +1178,11 @@ void __init setup_arch(char **cmdline_p) * with the current CR4 value. This may not be necessary, but * auditing all the early-boot CR4 manipulation would be needed to * rule it out. + * + * Mask off features that don't work outside long mode (just + * PCIDE for now). */ - mmu_cr4_features = __read_cr4(); + mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE; memblock_set_current_limit(get_max_mapped()); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index cd6622c3204e..0854ff169274 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -226,10 +226,12 @@ static int enable_start_cpu0; static void notrace start_secondary(void *unused) { /* - * Don't put *anything* before cpu_init(), SMP booting is too - * fragile that we want to limit the things done here to the - * most necessary things. + * Don't put *anything* except direct CPU state initialization + * before cpu_init(), SMP booting is too fragile that we want to + * limit the things done here to the most necessary things. */ + if (boot_cpu_has(X86_FEATURE_PCID)) + __write_cr4(__read_cr4() | X86_CR4_PCIDE); cpu_init(); x86_cpuinit.early_percpu_clock_init(); preempt_disable(); diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 7777ccc0e9f9..af5c1ed21d43 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -19,6 +19,7 @@ #include <asm/microcode.h> #include <asm/kaslr.h> #include <asm/hypervisor.h> +#include <asm/cpufeature.h> /* * We need to define the tracepoints somewhere, and tlb.c @@ -193,6 +194,38 @@ static void __init probe_page_size_mask(void) } } +static void setup_pcid(void) +{ +#ifdef CONFIG_X86_64 + if (boot_cpu_has(X86_FEATURE_PCID)) { + if (boot_cpu_has(X86_FEATURE_PGE)) { + /* + * This can't be cr4_set_bits_and_update_boot() -- + * the trampoline code can't handle CR4.PCIDE and + * it wouldn't do any good anyway. Despite the name, + * cr4_set_bits_and_update_boot() doesn't actually + * cause the bits in question to remain set all the + * way through the secondary boot asm. + * + * Instead, we brute-force it and set CR4.PCIDE + * manually in start_secondary(). + */ + cr4_set_bits(X86_CR4_PCIDE); + } else { + /* + * flush_tlb_all(), as currently implemented, won't + * work if PCID is on but PGE is not. Since that + * combination doesn't exist on real hardware, there's + * no reason to try to fully support it, but it's + * polite to avoid corrupting data if we're on + * an improperly configured VM. + */ + setup_clear_cpu_cap(X86_FEATURE_PCID); + } + } +#endif +} + #ifdef CONFIG_X86_32 #define NR_RANGE_MR 3 #else /* CONFIG_X86_64 */ @@ -592,6 +625,7 @@ void __init init_mem_mapping(void) unsigned long end; probe_page_size_mask(); + setup_pcid(); #ifdef CONFIG_X86_64 end = max_pfn << PAGE_SHIFT; |