diff options
| author | Thomas Gleixner <[email protected]> | 2022-09-15 13:10:42 +0200 |
|---|---|---|
| committer | Peter Zijlstra <[email protected]> | 2022-10-17 16:40:56 +0200 |
| commit | 1f19e2d50baf6515991844eaa8a84a0b0037da70 (patch) | |
| tree | 6d84eb4e93ff86a34b3678b284f802cf696db10c /arch/x86/kernel/cpu/common.c | |
| parent | b5636d45aae42aa345b4c7918bdef245ed63da68 (diff) | |
x86/cpu: Get rid of redundant switch_to_new_gdt() invocations
The only place where switch_to_new_gdt() is required is early boot to
switch from the early GDT to the direct GDT. Any other invocation is
completely redundant because it does not change anything.
Secondary CPUs come out of the ASM code with GDT and GSBASE correctly set
up. The same is true for XEN_PV.
Remove all the voodoo invocations which are left overs from the ancient
past, rename the function to switch_gdt_and_percpu_base() and mark it init.
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c09abee6f4d5..f51928dd275a 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -729,14 +729,15 @@ void load_fixmap_gdt(int cpu) EXPORT_SYMBOL_GPL(load_fixmap_gdt); /** - * switch_to_new_gdt - Switch form early GDT to the direct one + * switch_gdt_and_percpu_base - Switch to direct GDT and runtime per CPU base * @cpu: The CPU number for which this is invoked * - * Invoked during early boot to switch from early GDT and early per CPU - * (%fs on 32bit, GS_BASE on 64bit) to the direct GDT and the runtime per - * CPU area. + * Invoked during early boot to switch from early GDT and early per CPU to + * the direct GDT and the runtime per CPU area. On 32-bit the percpu base + * switch is implicit by loading the direct GDT. On 64bit this requires + * to update GSBASE. */ -void switch_to_new_gdt(int cpu) +void __init switch_gdt_and_percpu_base(int cpu) { load_direct_gdt(cpu); @@ -2263,12 +2264,6 @@ void cpu_init(void) boot_cpu_has(X86_FEATURE_TSC) || boot_cpu_has(X86_FEATURE_DE)) cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE); - /* - * Initialize the per-CPU GDT with the boot GDT, - * and set up the GDT descriptor: - */ - switch_to_new_gdt(cpu); - if (IS_ENABLED(CONFIG_X86_64)) { loadsegment(fs, 0); memset(cur->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8); |