From: Vasily Gorbik <gor@linux.ibm.com>
Date: Tue, 18 Sep 2018 18:23:40 +0200
Subject: s390: unify stack size definitions
Git-commit: 32ce55a6592fc3e117e70953001a9ea1931f7941
Patch-mainline: v4.20-rc1
References: jsc#SLE-11178

Remove STACK_ORDER and STACK_SIZE in favour of identical THREAD_SIZE_ORDER
and THREAD_SIZE definitions. THREAD_SIZE and THREAD_SIZE_ORDER naming is
misleading since it is used as general kernel stack size information. But
both those definitions are used in the common code and throughout
architectures specific code, so changing the naming is problematic.

Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
---
 arch/s390/include/asm/processor.h   |    8 --------
 arch/s390/include/asm/thread_info.h |    5 ++++-
 arch/s390/kernel/dumpstack.c        |    4 ++--
 arch/s390/kernel/irq.c              |    2 +-
 arch/s390/kernel/setup.c            |   12 ++++++------
 arch/s390/kernel/smp.c              |    6 +++---
 6 files changed, 16 insertions(+), 21 deletions(-)

--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -162,14 +162,6 @@ struct thread_struct {
 typedef struct thread_struct thread_struct;
 
 /*
- * General size of a stack
- */
-#define STACK_ORDER 2
-#define STACK_SIZE (PAGE_SIZE << STACK_ORDER)
-#define STACK_INIT_OFFSET \
-	(STACK_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs))
-
-/*
  * Stack layout of a C stack frame.
  */
 #ifndef __PACK_STACK
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -10,7 +10,7 @@
 #include <linux/const.h>
 
 /*
- * Size of kernel stack for each process
+ * General size of kernel stacks
  */
 #define THREAD_SIZE_ORDER 2
 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
@@ -20,6 +20,9 @@
 #include <asm/page.h>
 #include <asm/processor.h>
 
+#define STACK_INIT_OFFSET \
+	(THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs))
+
 /*
  * low level task data that entry.S needs immediate access to
  * - this struct should fit entirely inside of one cache line
--- a/arch/s390/kernel/dumpstack.c
+++ b/arch/s390/kernel/dumpstack.c
@@ -76,11 +76,11 @@ void dump_trace(dump_trace_func_t func,
 	frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
 #ifdef CONFIG_CHECK_STACK
 	sp = __dump_trace(func, data, sp,
-			  S390_lowcore.nodat_stack + frame_size - STACK_SIZE,
+			  S390_lowcore.nodat_stack + frame_size - THREAD_SIZE,
 			  S390_lowcore.nodat_stack + frame_size);
 #endif
 	sp = __dump_trace(func, data, sp,
-			  S390_lowcore.async_stack + frame_size - STACK_SIZE,
+			  S390_lowcore.async_stack + frame_size - THREAD_SIZE,
 			  S390_lowcore.async_stack + frame_size);
 	task = task ?: current;
 	__dump_trace(func, data, sp,
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -170,7 +170,7 @@ void do_softirq_own_stack(void)
 	old = current_stack_pointer();
 	/* Check against async. stack address range. */
 	new = S390_lowcore.async_stack;
-	if (((new - old) >> (PAGE_SHIFT + STACK_ORDER)) != 0) {
+	if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) {
 		CALL_ON_STACK(__do_softirq, new, 0);
 	} else {
 		/* We are already on the async stack. */
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -307,13 +307,13 @@ unsigned long stack_alloc(void)
 {
 #ifdef CONFIG_VMAP_STACK
 	return (unsigned long)
-		__vmalloc_node_range(STACK_SIZE, STACK_SIZE,
+		__vmalloc_node_range(THREAD_SIZE, THREAD_SIZE,
 				     VMALLOC_START, VMALLOC_END,
 				     THREADINFO_GFP,
 				     PAGE_KERNEL, 0, NUMA_NO_NODE,
 				     __builtin_return_address(0));
 #else
-	return __get_free_pages(GFP_KERNEL, STACK_ORDER);
+	return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 #endif
 }
 
@@ -322,7 +322,7 @@ void stack_free(unsigned long stack)
 #ifdef CONFIG_VMAP_STACK
 	vfree((void *) stack);
 #else
-	free_pages(stack, STACK_ORDER);
+	free_pages(stack, THREAD_SIZE_ORDER);
 #endif
 }
 
@@ -330,7 +330,7 @@ int __init arch_early_irq_init(void)
 {
 	unsigned long stack;
 
-	stack = __get_free_pages(GFP_KERNEL, STACK_ORDER);
+	stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 	if (!stack)
 		panic("Couldn't allocate async stack");
 	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
@@ -346,7 +346,7 @@ static int __init async_stack_realloc(vo
 	if (!new)
 		panic("Couldn't allocate async stack");
 	S390_lowcore.async_stack = new + STACK_INIT_OFFSET;
-	free_pages(old, STACK_ORDER);
+	free_pages(old, THREAD_SIZE_ORDER);
 	return 0;
 }
 early_initcall(async_stack_realloc);
@@ -435,7 +435,7 @@ static void __init setup_lowcore(void)
 	 * Allocate the global restart stack which is the same for
 	 * all CPUs in cast *one* of them does a PSW restart.
 	 */
-	restart_stack = memblock_virt_alloc(STACK_SIZE, STACK_SIZE);
+	restart_stack = memblock_virt_alloc(THREAD_SIZE, THREAD_SIZE);
 	restart_stack += STACK_INIT_OFFSET;
 
 	/*
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -195,7 +195,7 @@ static int pcpu_alloc_lowcore(struct pcp
 	if (pcpu != &pcpu_devices[0]) {
 		pcpu->lowcore =	(struct lowcore *)
 			__get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
-		nodat_stack = __get_free_pages(GFP_KERNEL, STACK_ORDER);
+		nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 		if (!pcpu->lowcore || !nodat_stack)
 			goto out;
 		if (MACHINE_HAS_VX || MACHINE_HAS_GS) {
@@ -234,7 +234,7 @@ out:
 		if (mcesa_origin)
 			kmem_cache_free(pcpu_mcesa_cache,
 					(void *) mcesa_origin);
-		free_pages(nodat_stack, STACK_ORDER);
+		free_pages(nodat_stack, THREAD_SIZE_ORDER);
 		free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
 	}
 	return -ENOMEM;
@@ -261,7 +261,7 @@ static void pcpu_free_lowcore(struct pcp
 		mcesa_origin = pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK;
 		kmem_cache_free(pcpu_mcesa_cache, (void *) mcesa_origin);
 	}
-	free_pages(nodat_stack, STACK_ORDER);
+	free_pages(nodat_stack, THREAD_SIZE_ORDER);
 	free_pages(lowcore, LC_ORDER);
 }