s390/sysctl: Remove "vm/allocate_pgste" sysctl

JIRA: https://issues.redhat.com/browse/RHEL-113440

commit 46ba4d0
Author: Heiko Carstens <hca@linux.ibm.com>
Date:   Mon Mar 10 12:43:01 2025 +0100

    s390/sysctl: Remove "vm/allocate_pgste" sysctl

    Remove the not needed "vm/allocate_pgste" sysctl. It has no effect
    anymore. However this is a user space visible change. It shouldn't cause
    any problems, however if it does this needs to be partially reverted.

    Note that some distributions set
    vm/allocate_pgste=1

    in one of the various sysctl configuration files. Besides a warning about
    the (now) non-existent procfs file this doesn't cause any problems.

    Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
    Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
    Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

Conflicts:
    arch/s390/mm/pgalloc.c
    (missing patch "treewide: const qualify ctl_tables where applicable"
     in downstream)
Signed-off-by: Thomas Huth <thuth@redhat.com>

Author: huth

arch/s390/include/asm/pgalloc.h

@@ -26,7 +26,6 @@ unsigned long *page_table_alloc(struct mm_struct *);
 struct ptdesc *page_table_alloc_pgste(struct mm_struct *mm);
 void page_table_free(struct mm_struct *, unsigned long *);
 void page_table_free_pgste(struct ptdesc *ptdesc);
-extern int page_table_allocate_pgste;
 
 static inline void crst_table_init(unsigned long *crst, unsigned long entry)
 {

arch/s390/mm/pgalloc.c

@@ -16,31 +16,6 @@
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
 
-#ifdef CONFIG_PGSTE
-
-int page_table_allocate_pgste = 0;
-EXPORT_SYMBOL(page_table_allocate_pgste);
-
-static struct ctl_table page_table_sysctl[] = {
-	{
-		.procname	= "allocate_pgste",
-		.data		= &page_table_allocate_pgste,
-		.maxlen		= sizeof(int),
-		.mode		= S_IRUGO | S_IWUSR,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE,
-	},
-};
-
-static int __init page_table_register_sysctl(void)
-{
-	return register_sysctl("vm", page_table_sysctl) ? 0 : -ENOMEM;
-}
-__initcall(page_table_register_sysctl);
-
-#endif /* CONFIG_PGSTE */
-
 unsigned long *crst_table_alloc(struct mm_struct *mm)
 {
 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);