Commit 01c7bc51 authored by Brian Gerst's avatar Brian Gerst Committed by Ingo Molnar
Browse files

x86/smp: Move cpu number to percpu hot section 



No functional change.

Signed-off-by: default avatarBrian Gerst <brgerst@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarUros Bizjak <ubizjak@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250303165246.2175811-5-brgerst@gmail.com
parent 46e8fff6

arch/x86/include/asm/current.h

+0 −1
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ struct task_struct; 


struct pcpu_hot {

	struct task_struct	*current_task;

	int			cpu_number;

#ifdef CONFIG_MITIGATION_CALL_DEPTH_TRACKING

	u64			call_depth;

#endif

arch/x86/include/asm/smp.h

+4 −3
Original line number Diff line number Diff line
@@ -6,7 +6,8 @@ 
#include <linux/thread_info.h>



#include <asm/cpumask.h>

#include <asm/current.h>



DECLARE_PER_CPU_CACHE_HOT(int, cpu_number);



DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);

DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
@@ -132,8 +133,8 @@ __visible void smp_call_function_single_interrupt(struct pt_regs *r); 
 * This function is needed by all SMP systems. It must _always_ be valid

 * from the initial startup.

 */

#define raw_smp_processor_id()  this_cpu_read(pcpu_hot.cpu_number)

#define __smp_processor_id() __this_cpu_read(pcpu_hot.cpu_number)

#define raw_smp_processor_id()  this_cpu_read(cpu_number)

#define __smp_processor_id() __this_cpu_read(cpu_number)



static inline struct cpumask *cpu_llc_shared_mask(int cpu)

{

arch/x86/kernel/setup_percpu.c

+4 −1
Original line number Diff line number Diff line
@@ -23,6 +23,9 @@ 
#include <asm/cpumask.h>

#include <asm/cpu.h>



DEFINE_PER_CPU_CACHE_HOT(int, cpu_number);

EXPORT_PER_CPU_SYMBOL(cpu_number);



DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);

EXPORT_PER_CPU_SYMBOL(this_cpu_off);
@@ -161,7 +164,7 @@ void __init setup_per_cpu_areas(void) 
	for_each_possible_cpu(cpu) {

		per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu];

		per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);

		per_cpu(pcpu_hot.cpu_number, cpu) = cpu;

		per_cpu(cpu_number, cpu) = cpu;

		setup_percpu_segment(cpu);

		/*

		 * Copy data used in early init routines from the

kernel/bpf/verifier.c

+2 −2
Original line number Diff line number Diff line
@@ -21702,12 +21702,12 @@ static int do_misc_fixups(struct bpf_verifier_env *env) 
		if (insn->imm == BPF_FUNC_get_smp_processor_id &&

		    verifier_inlines_helper_call(env, insn->imm)) {

			/* BPF_FUNC_get_smp_processor_id inlining is an

			 * optimization, so if pcpu_hot.cpu_number is ever

			 * optimization, so if cpu_number is ever

			 * changed in some incompatible and hard to support

			 * way, it's fine to back out this inlining logic

			 */

#ifdef CONFIG_SMP

			insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, (u32)(unsigned long)&pcpu_hot.cpu_number);

			insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, (u32)(unsigned long)&cpu_number);

			insn_buf[1] = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0);

			insn_buf[2] = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0);

			cnt = 3;