s390: remove 31 bit support

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 0 insertions, 72 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index a5ea8bc17cb3..7262fe438c99 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -92,10 +92,8 @@ EXPORT_SYMBOL(VMALLOC_END);
 struct page *vmemmap;
 EXPORT_SYMBOL(vmemmap);
 
-#ifdef CONFIG_64BIT
 unsigned long MODULES_VADDR;
 unsigned long MODULES_END;
-#endif
 
 /* An array with a pointer to the lowcore of every CPU. */
 struct _lowcore *lowcore_ptr[NR_CPUS];
@@ -334,19 +332,10 @@ static void __init setup_lowcore(void)
 	lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
 	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
 	       MAX_FACILITY_BIT/8);
-#ifndef CONFIG_64BIT
-	if (MACHINE_HAS_IEEE) {
-		lc->extended_save_area_addr = (__u32)
-			__alloc_bootmem_low(PAGE_SIZE, PAGE_SIZE, 0);
-		/* enable extended save area */
-		__ctl_set_bit(14, 29);
-	}
-#else
 	if (MACHINE_HAS_VX)
 		lc->vector_save_area_addr =
 			(unsigned long) &lc->vector_save_area;
 	lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
-#endif
 	lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
 	lc->async_enter_timer = S390_lowcore.async_enter_timer;
 	lc->exit_timer = S390_lowcore.exit_timer;
@@ -450,7 +439,6 @@ static void __init setup_memory_end(void)
 	unsigned long vmax, vmalloc_size, tmp;
 
 	/* Choose kernel address space layout: 2, 3, or 4 levels. */
-#ifdef CONFIG_64BIT
 	vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
 	tmp = (memory_end ?: max_physmem_end) / PAGE_SIZE;
 	tmp = tmp * (sizeof(struct page) + PAGE_SIZE);
@@ -462,12 +450,6 @@ static void __init setup_memory_end(void)
 	MODULES_END = vmax;
 	MODULES_VADDR = MODULES_END - MODULES_LEN;
 	VMALLOC_END = MODULES_VADDR;
-#else
-	vmalloc_size = VMALLOC_END ?: 96UL << 20;
-	vmax = 1UL << 31;		/* 2-level kernel page table */
-	/* vmalloc area is at the end of the kernel address space. */
-	VMALLOC_END = vmax;
-#endif
 	VMALLOC_START = vmax - vmalloc_size;
 
 	/* Split remaining virtual space between 1:1 mapping & vmemmap array */
@@ -754,7 +736,6 @@ static void __init setup_hwcaps(void)
 	if (MACHINE_HAS_HPAGE)
 		elf_hwcap |= HWCAP_S390_HPAGE;
 
-#if defined(CONFIG_64BIT)
 	/*
 	 * 64-bit register support for 31-bit processes
 	 * HWCAP_S390_HIGH_GPRS is bit 9.
@@ -772,22 +753,15 @@ static void __init setup_hwcaps(void)
 	 */
 	if (test_facility(129))
 		elf_hwcap |= HWCAP_S390_VXRS;
-#endif
-
 	get_cpu_id(&cpu_id);
 	add_device_randomness(&cpu_id, sizeof(cpu_id));
 	switch (cpu_id.machine) {
 	case 0x9672:
-#if !defined(CONFIG_64BIT)
-	default:	/* Use "g5" as default for 31 bit kernels. */
-#endif
 		strcpy(elf_platform, "g5");
 		break;
 	case 0x2064:
 	case 0x2066:
-#if defined(CONFIG_64BIT)
 	default:	/* Use "z900" as default for 64 bit kernels. */
-#endif
 		strcpy(elf_platform, "z900");
 		break;
 	case 0x2084:
@@ -839,19 +813,6 @@ void __init setup_arch(char **cmdline_p)
         /*
          * print what head.S has found out about the machine
          */
-#ifndef CONFIG_64BIT
-	if (MACHINE_IS_VM)
-		pr_info("Linux is running as a z/VM "
-			"guest operating system in 31-bit mode\n");
-	else if (MACHINE_IS_LPAR)
-		pr_info("Linux is running natively in 31-bit mode\n");
-	if (MACHINE_HAS_IEEE)
-		pr_info("The hardware system has IEEE compatible "
-			"floating point units\n");
-	else
-		pr_info("The hardware system has no IEEE compatible "
-			"floating point units\n");
-#else /* CONFIG_64BIT */
 	if (MACHINE_IS_VM)
 		pr_info("Linux is running as a z/VM "
 			"guest operating system in 64-bit mode\n");
@@ -859,7 +820,6 @@ void __init setup_arch(char **cmdline_p)
 		pr_info("Linux is running under KVM in 64-bit mode\n");
 	else if (MACHINE_IS_LPAR)
 		pr_info("Linux is running natively in 64-bit mode\n");
-#endif /* CONFIG_64BIT */
 
 	/* Have one command line that is parsed and saved in /proc/cmdline */
 	/* boot_command_line has been already set up in early.c */
@@ -930,35 +890,3 @@ void __init setup_arch(char **cmdline_p)
 	/* Add system specific data to the random pool */
 	setup_randomness();
 }
-
-#ifdef CONFIG_32BIT
-static int no_removal_warning __initdata;
-
-static int __init parse_no_removal_warning(char *str)
-{
-	no_removal_warning = 1;
-	return 0;
-}
-__setup("no_removal_warning", parse_no_removal_warning);
-
-static int __init removal_warning(void)
-{
-	if (no_removal_warning)
-		return 0;
-	printk(KERN_ALERT "\n\n");
-	printk(KERN_CONT "Warning - you are using a 31 bit kernel!\n\n");
-	printk(KERN_CONT "We plan to remove 31 bit kernel support from the kernel sources in March 2015.\n");
-	printk(KERN_CONT "Currently we assume that nobody is using the 31 bit kernel on old 31 bit\n");
-	printk(KERN_CONT "hardware anymore. If you think that the code should not be removed and also\n");
-	printk(KERN_CONT "future versions of the Linux kernel should be able to run in 31 bit mode\n");
-	printk(KERN_CONT "please let us know. Please write to:\n");
-	printk(KERN_CONT "linux390@de.ibm.com (mail address) and/or\n");
-	printk(KERN_CONT "linux-s390@vger.kernel.org (mailing list).\n\n");
-	printk(KERN_CONT "Thank you!\n\n");
-	printk(KERN_CONT "If this kernel runs on a 64 bit machine you may consider using a 64 bit kernel.\n");
-	printk(KERN_CONT "This message can be disabled with the \"no_removal_warning\" kernel parameter.\n");
-	schedule_timeout_uninterruptible(300 * HZ);
-	return 0;
-}
-early_initcall(removal_warning);
-#endif