[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [XEN PATCH 7/9] x86/smp: drop booting_cpu variable
CPU id is obtained as a side effect of searching for appropriate stack for AP. It can be used as a parameter to start_secondary(). Coincidentally this also makes further work on making AP bring-up code parallel easier. Signed-off-by: Krystian Hebel <krystian.hebel@xxxxxxxxx> --- xen/arch/x86/boot/x86_64.S | 13 +++++++++---- xen/arch/x86/smpboot.c | 15 +++++---------- 2 files changed, 14 insertions(+), 14 deletions(-) diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S index 8d61f270761f..ad01f20d548d 100644 --- a/xen/arch/x86/boot/x86_64.S +++ b/xen/arch/x86/boot/x86_64.S @@ -20,20 +20,24 @@ ENTRY(__high_start) jz .L_stack_set /* APs only: get stack base from APIC ID saved in %esp. */ - mov $0, %rax + mov $0, %rbx lea cpu_data(%rip), %rcx /* cpu_data[0] is BSP, skip it. */ 1: - add $1, %rax + add $1, %rbx add $CPUINFO_X86_sizeof, %rcx - cmp $NR_CPUS, %eax + cmp $NR_CPUS, %rbx jb 2f hlt 2: cmp %esp, CPUINFO_X86_apicid(%rcx) jne 1b - /* %rcx is now cpu_data[cpu], read stack base from it. */ + /* + * At this point: + * - %rcx is cpu_data[cpu], read stack base from it, + * - %rbx (callee-save) is Xen cpu number, pass it to start_secondary(). + */ mov CPUINFO_X86_stack_base(%rcx), %rsp test %rsp,%rsp @@ -101,6 +105,7 @@ ENTRY(__high_start) .L_ap_cet_done: #endif /* CONFIG_XEN_SHSTK || CONFIG_XEN_IBT */ + mov %rbx, %rdi tailcall start_secondary .L_bsp: diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c index a3895dafa267..39ffd356dbbc 100644 --- a/xen/arch/x86/smpboot.c +++ b/xen/arch/x86/smpboot.c @@ -222,8 +222,6 @@ static void smp_callin(void) cpu_relax(); } -static int booting_cpu; - /* CPUs for which sibling maps can be computed. */ static cpumask_t cpu_sibling_setup_map; @@ -311,15 +309,14 @@ static void set_cpu_sibling_map(unsigned int cpu) } } -void start_secondary(void *unused) +void start_secondary(unsigned int cpu) { struct cpu_info *info = get_cpu_info(); /* - * Dont put anything before smp_callin(), SMP booting is so fragile that we + * Don't put anything before smp_callin(), SMP booting is so fragile that we * want to limit the things done here to the most necessary things. */ - unsigned int cpu = booting_cpu; /* Critical region without IDT or TSS. Any fault is deadly! */ @@ -346,9 +343,9 @@ void start_secondary(void *unused) */ spin_debug_disable(); - get_cpu_info()->use_pv_cr3 = false; - get_cpu_info()->xen_cr3 = 0; - get_cpu_info()->pv_cr3 = 0; + info->use_pv_cr3 = false; + info->xen_cr3 = 0; + info->pv_cr3 = 0; /* * BUG_ON() used in load_system_tables() and later code may end up calling @@ -575,8 +572,6 @@ static int do_boot_cpu(int apicid, int cpu) */ mtrr_save_state(); - booting_cpu = cpu; - start_eip = bootsym_phys(trampoline_realmode_entry); /* start_eip needs be page aligned, and below the 1M boundary. */ -- 2.41.0
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