| Message ID | 20230223191140.4155012-10-usama.arif@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Parallel CPU bringup for x86_64 | expand |
From: Usama Arif <usama.arif@bytedance.com> Sent: Thursday, February 23, 2023 11:12 AM > > From: Brian Gerst <brgerst@gmail.com> > > Load RSP from current_task->thread.sp instead. > > Signed-off-by: Brian Gerst <brgerst@gmail.com> > Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> > Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> > Tested-by: Usama Arif <usama.arif@bytedance.com> > Signed-off-by: Usama Arif <usama.arif@bytedance.com> > --- > arch/x86/include/asm/processor.h | 6 +++++- > arch/x86/kernel/acpi/sleep.c | 2 +- > arch/x86/kernel/head_64.S | 35 ++++++++++++++++++-------------- > arch/x86/xen/xen-head.S | 2 +- > 4 files changed, 27 insertions(+), 18 deletions(-) > > diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h > index 4e35c66edeb7..9c4a5c4d46c1 100644 > --- a/arch/x86/include/asm/processor.h > +++ b/arch/x86/include/asm/processor.h > @@ -648,7 +648,11 @@ static inline void spin_lock_prefetch(const void *x) > #define KSTK_ESP(task) (task_pt_regs(task)->sp) > > #else > -#define INIT_THREAD { } > +extern unsigned long __end_init_task[]; > + > +#define INIT_THREAD { \ > + .sp = (unsigned long)&__end_init_task - PTREGS_SIZE, \ > +} I'm getting a compile error on the new reference to PTREGS_SIZE: In file included from ./arch/x86/include/asm/cpufeature.h:5:0, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:9, from ./include/linux/preempt.h:78, from ./include/linux/rcupdate.h:27, from ./include/linux/init_task.h:5, from init/init_task.c:2: ./arch/x86/include/asm/processor.h:654:42: error: 'PTREGS_SIZE' undeclared here (not in a function); did you mean 'TLS_SIZE'? .sp = (unsigned long)&__end_init_task - PTREGS_SIZE, \ ^ init/init_task.c:115:13: note: in expansion of macro 'INIT_THREAD' .thread = INIT_THREAD, ^~~~~~~~~~~ scripts/Makefile.build:252: recipe for target 'init/init_task.o' failed Michael
On Fri, 2023-02-24 at 18:24 +0000, Michael Kelley (LINUX) wrote:
> I'm getting a compile error on the new reference to PTREGS_SIZE:
Is it just that <asm/asm-offsets.h> is included conditionally, and not
in your build? What if you include it directly from <asm/processor.h>
On 24/02/2023 18:28, David Woodhouse wrote: > On Fri, 2023-02-24 at 18:24 +0000, Michael Kelley (LINUX) wrote: >> I'm getting a compile error on the new reference to PTREGS_SIZE: > > Is it just that <asm/asm-offsets.h> is included conditionally, and not > in your build? What if you include it directly from <asm/processor.h> This is fixed in the v2 patch that Brian sent. diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 9c4a5c4d46c1..bdde7316e75b 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -650,8 +650,8 @@ static inline void spin_lock_prefetch(const void *x) #else extern unsigned long __end_init_task[]; -#define INIT_THREAD { \ - .sp = (unsigned long)&__end_init_task - PTREGS_SIZE, \ +#define INIT_THREAD { \ + .sp = (unsigned long)&__end_init_task - sizeof(struct pt_regs), \ } extern unsigned long KSTK_ESP(struct task_struct *task);
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 4e35c66edeb7..9c4a5c4d46c1 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -648,7 +648,11 @@ static inline void spin_lock_prefetch(const void *x) #define KSTK_ESP(task) (task_pt_regs(task)->sp) #else -#define INIT_THREAD { } +extern unsigned long __end_init_task[]; + +#define INIT_THREAD { \ + .sp = (unsigned long)&__end_init_task - PTREGS_SIZE, \ +} extern unsigned long KSTK_ESP(struct task_struct *task); diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 47e75c056cb5..008fda8b1982 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -113,7 +113,7 @@ int x86_acpi_suspend_lowlevel(void) saved_magic = 0x12345678; #else /* CONFIG_64BIT */ #ifdef CONFIG_SMP - initial_stack = (unsigned long)temp_stack + sizeof(temp_stack); + current->thread.sp = (unsigned long)temp_stack + sizeof(temp_stack); early_gdt_descr.address = (unsigned long)get_cpu_gdt_rw(smp_processor_id()); initial_gs = per_cpu_offset(smp_processor_id()); diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index c32e5b06a9ce..f7905ba4b992 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -62,8 +62,8 @@ SYM_CODE_START_NOALIGN(startup_64) * tables and then reload them. */ - /* Set up the stack for verify_cpu(), similar to initial_stack below */ - leaq (__end_init_task - FRAME_SIZE)(%rip), %rsp + /* Set up the stack for verify_cpu() */ + leaq (__end_init_task - PTREGS_SIZE)(%rip), %rsp leaq _text(%rip), %rdi @@ -245,11 +245,11 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) #ifdef CONFIG_SMP /* * Is this the boot CPU coming up? If so everything is available - * in initial_gs, initial_stack and early_gdt_descr. + * in initial_gs and early_gdt_descr. */ movl smpboot_control(%rip), %edx testl $STARTUP_SECONDARY, %edx - jz .Lsetup_cpu + jz .Linit_cpu0_data /* * For parallel boot, the APIC ID is retrieved from CPUID, and then @@ -302,6 +302,10 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) hlt jmp 1b +.Linit_cpu0_data: + movq __per_cpu_offset(%rip), %rdx + jmp .Lsetup_cpu + .Linit_cpu_data: /* Get the per cpu offset for the given CPU# which is in ECX */ leaq __per_cpu_offset(%rip), %rbx @@ -314,13 +318,21 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) addq %rbx, %rcx movq %rcx, early_gdt_descr_base(%rip) - /* Find the idle task stack */ - movq pcpu_hot + X86_current_task(%rbx), %rcx - movq TASK_threadsp(%rcx), %rcx - movq %rcx, initial_stack(%rip) + movq %rbx, %rdx +#else + xorl %edx, %edx #endif /* CONFIG_SMP */ .Lsetup_cpu: + /* + * Setup a boot time stack - Any secondary CPU will have lost its stack + * by now because the cr3-switch above unmaps the real-mode stack + * + * RDX contains the per-cpu offset + */ + movq pcpu_hot + X86_current_task(%rdx), %rax + movq TASK_threadsp(%rax), %rsp + /* * We must switch to a new descriptor in kernel space for the GDT * because soon the kernel won't have access anymore to the userspace @@ -355,12 +367,6 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) movl initial_gs+4(%rip),%edx wrmsr - /* - * Setup a boot time stack - Any secondary CPU will have lost its stack - * by now because the cr3-switch above unmaps the real-mode stack - */ - movq initial_stack(%rip), %rsp - /* Drop the realmode protection. For the boot CPU the pointer is NULL! */ movq trampoline_lock(%rip), %rax testq %rax, %rax @@ -517,7 +523,6 @@ SYM_DATA(initial_vc_handler, .quad handle_vc_boot_ghcb) * The FRAME_SIZE gap is a convention which helps the in-kernel unwinder * reliably detect the end of the stack. */ -SYM_DATA(initial_stack, .quad init_thread_union + THREAD_SIZE - FRAME_SIZE) SYM_DATA(trampoline_lock, .quad 0); __FINITDATA diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index ffaa62167f6e..6bd391476656 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -49,7 +49,7 @@ SYM_CODE_START(startup_xen) ANNOTATE_NOENDBR cld - mov initial_stack(%rip), %rsp + leaq (__end_init_task - PTREGS_SIZE)(%rip), %rsp /* Set up %gs. *