percpu: active_stack with gs

Message-Id: <20230925002417.467022-1-damien@zamaudio.com>

9 files changed, 17 insertions, 23 deletions

diff --git a/i386/i386/cswitch.S b/i386/i386/cswitch.S
index 598e32cf..2dee309b 100644
--- a/i386/i386/cswitch.S
+++ b/i386/i386/cswitch.S
@@ -41,7 +41,7 @@ ENTRY(Load_context)
 	lea	KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%edx
 						/* point to stack top */
 	CPU_NUMBER(%eax)
-	movl	%ecx,CX(EXT(active_stacks),%eax)	/* store stack address */
+	movl	%ecx,MY(ACTIVE_STACK)		/* store stack address */
 	movl	%edx,CX(EXT(kernel_stack),%eax)	/* store stack top */
 
 	movl	KSS_ESP(%ecx),%esp		/* switch stacks */
@@ -58,8 +58,7 @@ ENTRY(Load_context)
  */
 
 ENTRY(Switch_context)
-	CPU_NUMBER(%edx)
-	movl	CX(EXT(active_stacks),%edx),%ecx	/* get old kernel stack */
+	movl	MY(ACTIVE_STACK),%ecx		/* get old kernel stack */
 
 	movl	%ebx,KSS_EBX(%ecx)		/* save registers */
 	movl	%ebp,KSS_EBP(%ecx)
@@ -79,8 +78,9 @@ ENTRY(Switch_context)
 	lea	KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%ebx
 						/* point to stack top */
 
+	CPU_NUMBER(%edx)
 	movl	%esi,MY(ACTIVE_THREAD)		/* new thread is active */
-	movl	%ecx,CX(EXT(active_stacks),%edx)	/* set current stack */
+	movl	%ecx,MY(ACTIVE_STACK)		/* set current stack */
 	movl	%ebx,CX(EXT(kernel_stack),%edx)	/* set stack top */
 
 	movl	KSS_ESP(%ecx),%esp		/* switch stacks */
@@ -110,8 +110,7 @@ ENTRY(Thread_continue)
  * has no FPU state)
  */
 ENTRY(switch_to_shutdown_context)
-	CPU_NUMBER(%edx)
-	movl	CX(EXT(active_stacks),%edx),%ecx	/* get old kernel stack */
+	movl	MY(ACTIVE_STACK),%ecx		/* get old kernel stack */
 	movl	%ebx,KSS_EBX(%ecx)		/* save registers */
 	movl	%ebp,KSS_EBP(%ecx)
 	movl	%edi,KSS_EDI(%ecx)
@@ -125,6 +124,7 @@ ENTRY(switch_to_shutdown_context)
 	movl	4(%esp),%ebx			/* get routine to run next */
 	movl	8(%esp),%esi			/* get its argument */
 
+	CPU_NUMBER(%edx)
 	movl	CX(EXT(int_stack_base),%edx),%ecx	/* point to its interrupt stack */
 	lea	-4+INTSTACK_SIZE(%ecx),%esp	/* switch to it (top) */
 
diff --git a/i386/i386/i386asm.sym b/i386/i386/i386asm.sym
index e9a792c3..e1f5c6bb 100644
--- a/i386/i386/i386asm.sym
+++ b/i386/i386/i386asm.sym
@@ -55,6 +55,7 @@ offset	ApicLocalUnit		lu	apic_id		APIC_ID
 
 offset	percpu			pc	cpu_id		PERCPU_CPU_ID
 offset	percpu			pc	active_thread	PERCPU_ACTIVE_THREAD
+offset	percpu			pc	active_stack	PERCPU_ACTIVE_STACK
 
 offset	pcb			pcb	iss
 
diff --git a/i386/i386/locore.S b/i386/i386/locore.S
index 8fba7638..d3986793 100644
--- a/i386/i386/locore.S
+++ b/i386/i386/locore.S
@@ -555,7 +555,7 @@ trap_from_kernel:
 	cmpl	CX(EXT(kernel_stack),%edx),%esp
 					/* already on kernel stack? */
 	ja	0f
-	cmpl	CX(EXT(active_stacks),%edx),%esp
+	cmpl	MY(ACTIVE_STACK),%esp
 	ja	1f			/* switch if not */
 0:
 	movl	CX(EXT(kernel_stack),%edx),%esp
diff --git a/i386/i386/percpu.h b/i386/i386/percpu.h
index ad4836ce..d73cfc8d 100644
--- a/i386/i386/percpu.h
+++ b/i386/i386/percpu.h
@@ -59,10 +59,10 @@ struct percpu {
     int			cpu_id;
     struct processor	processor;
     thread_t		active_thread;
+    vm_offset_t		active_stack;
 /*
     struct machine_slot	machine_slot;
     struct mp_desc_table mp_desc_table;
-    vm_offset_t		active_stack;
     vm_offset_t		int_stack_top;
     vm_offset_t		int_stack_base;
     ast_t		need_ast;
diff --git a/kern/startup.c b/kern/startup.c
index 177232fc..e72cf6f4 100644
--- a/kern/startup.c
+++ b/kern/startup.c
@@ -301,7 +301,7 @@ void cpu_launch_first_thread(thread_t th)
 	PMAP_ACTIVATE_KERNEL(mycpu);
 
 	percpu_assign(active_thread, th);
-	active_stacks[mycpu] = th->kernel_stack;
+	percpu_assign(active_stack, th->kernel_stack);
 	thread_lock(th);
 	th->state &= ~TH_UNINT;
 	thread_unlock(th);
diff --git a/kern/thread.c b/kern/thread.c
index c397de84..38287581 100644
--- a/kern/thread.c
+++ b/kern/thread.c
@@ -69,8 +69,6 @@
 #include <machine/pcb.h>
 #include <machine/thread.h>		/* for MACHINE_STACK */
 
-vm_offset_t active_stacks[NCPUS];
-
 struct kmem_cache thread_cache;
 struct kmem_cache thread_stack_cache;
 
@@ -2572,7 +2570,7 @@ kern_return_t processor_set_stack_usage(
 
 			for (cpu = 0; cpu < smp_get_numcpus(); cpu++)
 				if (percpu_array[cpu].active_thread == thread) {
-					stack = active_stacks[cpu];
+					stack = percpu_array[cpu].active_stack;
 					break;
 				}
 		}
diff --git a/kern/thread.h b/kern/thread.h
index 144160d5..7bfe2e89 100644
--- a/kern/thread.h
+++ b/kern/thread.h
@@ -268,9 +268,6 @@ typedef struct thread *thread_t;
 typedef	mach_port_t *thread_array_t;
 #endif	/* _KERN_KERN_TYPES_H_ */
 
-
-extern vm_offset_t	active_stacks[NCPUS];	/* active kernel stacks */
-
 #ifdef KERNEL
 /*
  *	User routines
@@ -417,7 +414,7 @@ extern void		thread_unfreeze(
 #define current_thread()	(percpu_get(thread_t, active_thread))
 #endif	/* CURRENT_THREAD */
 
-#define	current_stack()		(active_stacks[cpu_number()])
+#define	current_stack()		(percpu_get(vm_offset_t, active_stack))
 
 #define	current_task()		(current_thread()->task)
 #define	current_space()		(current_task()->itk_space)
diff --git a/x86_64/cswitch.S b/x86_64/cswitch.S
index 29dae62c..9c4640fd 100644
--- a/x86_64/cswitch.S
+++ b/x86_64/cswitch.S
@@ -40,7 +40,7 @@ ENTRY(Load_context)
 	lea	KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%rcx),%rdx
 						/* point to stack top */
 	CPU_NUMBER(%eax)
-	movq	%rcx,CX(EXT(active_stacks),%rax)	/* store stack address */
+	movq	%rcx,MY(ACTIVE_STACK)		/* store stack address */
 	movq	%rdx,CX(EXT(kernel_stack),%rax)	/* store stack top */
 
 /* XXX complete */
@@ -61,8 +61,7 @@ ENTRY(Load_context)
  */
 
 ENTRY(Switch_context)
-	CPU_NUMBER(%eax)
-	movq	CX(EXT(active_stacks),%rax),%rcx	/* get old kernel stack */
+	movq	MY(ACTIVE_STACK),%rcx		/* get old kernel stack */
 
 	movq	%r12,KSS_R12(%rcx)		/* save registers */
 	movq	%r13,KSS_R13(%rcx)
@@ -86,7 +85,7 @@ ENTRY(Switch_context)
 
 	CPU_NUMBER(%eax)
 	movq	%rsi,MY(ACTIVE_THREAD)		/* new thread is active */
-	movq	%rcx,CX(EXT(active_stacks),%rax)	/* set current stack */
+	movq	%rcx,MY(ACTIVE_STACK)		/* set current stack */
 	movq	%rbx,CX(EXT(kernel_stack),%rax)	/* set stack top */
 
 	movq	KSS_ESP(%rcx),%rsp		/* switch stacks */
@@ -119,8 +118,7 @@ ENTRY(Thread_continue)
  */
 ENTRY(switch_to_shutdown_context)
 ud2
-	CPU_NUMBER(%eax)
-	movq	CX(EXT(active_stacks),%rax),%rcx	/* get old kernel stack */
+	movq	MY(ACTIVE_STACK),%rcx		/* get old kernel stack */
 	movq	%r12,KSS_R12(%rcx)		/* save registers */
 	movq	%r13,KSS_R13(%rcx)
 	movq	%r14,KSS_R14(%rcx)
diff --git a/x86_64/locore.S b/x86_64/locore.S
index 55dc4d27..7eaeda3b 100644
--- a/x86_64/locore.S
+++ b/x86_64/locore.S
@@ -673,7 +673,7 @@ trap_from_kernel:
 	cmpq	CX(EXT(kernel_stack),%rdx),%rsp
 					/* already on kernel stack? */
 	ja	0f
-	cmpq	CX(EXT(active_stacks),%rdx),%rsp
+	cmpq	MY(ACTIVE_STACK),%rsp
 	ja	1f			/* switch if not */
 0:
 	movq	CX(EXT(kernel_stack),%rdx),%rsp