s390: remove broken hibernate / power management support

Hibernation is known to be broken for many years on s390. Given that
there aren't any real use cases, remove the code instead of spending
time to fix and maintain it.

Without hibernate support it doesn't make too much sense to keep power
management support; therefore remove it completely.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

4 files changed, 0 insertions, 548 deletions

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 2b1203cf7be6..10f80071f945 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -54,7 +54,6 @@ CFLAGS_REMOVE_nospec-branch.o	+= $(CC_FLAGS_EXPOLINE)
 
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_SCHED_TOPOLOGY)	+= topology.o
-obj-$(CONFIG_HIBERNATION)	+= suspend.o swsusp.o
 obj-$(CONFIG_AUDIT)		+= audit.o
 compat-obj-$(CONFIG_AUDIT)	+= compat_audit.o
 obj-$(CONFIG_COMPAT)		+= compat_linux.o compat_signal.o
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index cb8b1cc285c9..3a854cb5a4c6 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -14,7 +14,6 @@
 #include <linux/reboot.h>
 #include <linux/ftrace.h>
 #include <linux/debug_locks.h>
-#include <linux/suspend.h>
 #include <asm/cio.h>
 #include <asm/setup.h>
 #include <asm/pgtable.h>
@@ -39,36 +38,6 @@ extern const unsigned long long relocate_kernel_len;
 #ifdef CONFIG_CRASH_DUMP
 
 /*
- * PM notifier callback for kdump
- */
-static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
-			       void *ptr)
-{
-	switch (action) {
-	case PM_SUSPEND_PREPARE:
-	case PM_HIBERNATION_PREPARE:
-		if (kexec_crash_image)
-			arch_kexec_unprotect_crashkres();
-		break;
-	case PM_POST_SUSPEND:
-	case PM_POST_HIBERNATION:
-		if (kexec_crash_image)
-			arch_kexec_protect_crashkres();
-		break;
-	default:
-		return NOTIFY_DONE;
-	}
-	return NOTIFY_OK;
-}
-
-static int __init machine_kdump_pm_init(void)
-{
-	pm_notifier(machine_kdump_pm_cb, 0);
-	return 0;
-}
-arch_initcall(machine_kdump_pm_init);
-
-/*
  * Reset the system, copy boot CPU registers to absolute zero,
  * and jump to the kdump image
  */
diff --git a/arch/s390/kernel/suspend.c b/arch/s390/kernel/suspend.c
deleted file mode 100644
index 75b7b307946e..000000000000
--- a/arch/s390/kernel/suspend.c
+++ /dev/null
@@ -1,240 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Suspend support specific for s390.
- *
- * Copyright IBM Corp. 2009
- *
- * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
- */
-
-#include <linux/pfn.h>
-#include <linux/suspend.h>
-#include <linux/mm.h>
-#include <linux/pci.h>
-#include <asm/ctl_reg.h>
-#include <asm/ipl.h>
-#include <asm/cio.h>
-#include <asm/sections.h>
-#include "entry.h"
-
-/*
- * The restore of the saved pages in an hibernation image will set
- * the change and referenced bits in the storage key for each page.
- * Overindication of the referenced bits after an hibernation cycle
- * does not cause any harm but the overindication of the change bits
- * would cause trouble.
- * Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each
- * page to the most significant byte of the associated page frame
- * number in the hibernation image.
- */
-
-/*
- * Key storage is allocated as a linked list of pages.
- * The size of the keys array is (PAGE_SIZE - sizeof(long))
- */
-struct page_key_data {
-	struct page_key_data *next;
-	unsigned char data[];
-};
-
-#define PAGE_KEY_DATA_SIZE	(PAGE_SIZE - sizeof(struct page_key_data *))
-
-static struct page_key_data *page_key_data;
-static struct page_key_data *page_key_rp, *page_key_wp;
-static unsigned long page_key_rx, page_key_wx;
-unsigned long suspend_zero_pages;
-
-/*
- * For each page in the hibernation image one additional byte is
- * stored in the most significant byte of the page frame number.
- * On suspend no additional memory is required but on resume the
- * keys need to be memorized until the page data has been restored.
- * Only then can the storage keys be set to their old state.
- */
-unsigned long page_key_additional_pages(unsigned long pages)
-{
-	return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
-}
-
-/*
- * Free page_key_data list of arrays.
- */
-void page_key_free(void)
-{
-	struct page_key_data *pkd;
-
-	while (page_key_data) {
-		pkd = page_key_data;
-		page_key_data = pkd->next;
-		free_page((unsigned long) pkd);
-	}
-}
-
-/*
- * Allocate page_key_data list of arrays with enough room to store
- * one byte for each page in the hibernation image.
- */
-int page_key_alloc(unsigned long pages)
-{
-	struct page_key_data *pk;
-	unsigned long size;
-
-	size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
-	while (size--) {
-		pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL);
-		if (!pk) {
-			page_key_free();
-			return -ENOMEM;
-		}
-		pk->next = page_key_data;
-		page_key_data = pk;
-	}
-	page_key_rp = page_key_wp = page_key_data;
-	page_key_rx = page_key_wx = 0;
-	return 0;
-}
-
-/*
- * Save the storage key into the upper 8 bits of the page frame number.
- */
-void page_key_read(unsigned long *pfn)
-{
-	struct page *page;
-	unsigned long addr;
-	unsigned char key;
-
-	page = pfn_to_page(*pfn);
-	addr = (unsigned long) page_address(page);
-	key = (unsigned char) page_get_storage_key(addr) & 0x7f;
-	if (arch_test_page_nodat(page))
-		key |= 0x80;
-	*(unsigned char *) pfn = key;
-}
-
-/*
- * Extract the storage key from the upper 8 bits of the page frame number
- * and store it in the page_key_data list of arrays.
- */
-void page_key_memorize(unsigned long *pfn)
-{
-	page_key_wp->data[page_key_wx] = *(unsigned char *) pfn;
-	*(unsigned char *) pfn = 0;
-	if (++page_key_wx < PAGE_KEY_DATA_SIZE)
-		return;
-	page_key_wp = page_key_wp->next;
-	page_key_wx = 0;
-}
-
-/*
- * Get the next key from the page_key_data list of arrays and set the
- * storage key of the page referred by @address. If @address refers to
- * a "safe" page the swsusp_arch_resume code will transfer the storage
- * key from the buffer page to the original page.
- */
-void page_key_write(void *address)
-{
-	struct page *page;
-	unsigned char key;
-
-	key = page_key_rp->data[page_key_rx];
-	page_set_storage_key((unsigned long) address, key & 0x7f, 0);
-	page = virt_to_page(address);
-	if (key & 0x80)
-		arch_set_page_nodat(page, 0);
-	else
-		arch_set_page_dat(page, 0);
-	if (++page_key_rx >= PAGE_KEY_DATA_SIZE)
-		return;
-	page_key_rp = page_key_rp->next;
-	page_key_rx = 0;
-}
-
-int pfn_is_nosave(unsigned long pfn)
-{
-	unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));
-	unsigned long nosave_end_pfn = PFN_DOWN(__pa(&__nosave_end));
-	unsigned long end_rodata_pfn = PFN_DOWN(__pa(__end_rodata)) - 1;
-	unsigned long stext_pfn = PFN_DOWN(__pa(_stext));
-
-	/* Always save lowcore pages (LC protection might be enabled). */
-	if (pfn <= LC_PAGES)
-		return 0;
-	if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn)
-		return 1;
-	/* Skip memory holes and read-only pages (DCSS, ...). */
-	if (pfn >= stext_pfn && pfn <= end_rodata_pfn)
-		return 0;
-	if (tprot(PFN_PHYS(pfn)))
-		return 1;
-	return 0;
-}
-
-/*
- * PM notifier callback for suspend
- */
-static int suspend_pm_cb(struct notifier_block *nb, unsigned long action,
-			 void *ptr)
-{
-	switch (action) {
-	case PM_SUSPEND_PREPARE:
-	case PM_HIBERNATION_PREPARE:
-		suspend_zero_pages = __get_free_pages(GFP_KERNEL, LC_ORDER);
-		if (!suspend_zero_pages)
-			return NOTIFY_BAD;
-		break;
-	case PM_POST_SUSPEND:
-	case PM_POST_HIBERNATION:
-		free_pages(suspend_zero_pages, LC_ORDER);
-		break;
-	default:
-		return NOTIFY_DONE;
-	}
-	return NOTIFY_OK;
-}
-
-static int __init suspend_pm_init(void)
-{
-	pm_notifier(suspend_pm_cb, 0);
-	return 0;
-}
-arch_initcall(suspend_pm_init);
-
-void save_processor_state(void)
-{
-	/* swsusp_arch_suspend() actually saves all cpu register contents.
-	 * Machine checks must be disabled since swsusp_arch_suspend() stores
-	 * register contents to their lowcore save areas. That's the same
-	 * place where register contents on machine checks would be saved.
-	 * To avoid register corruption disable machine checks.
-	 * We must also disable machine checks in the new psw mask for
-	 * program checks, since swsusp_arch_suspend() may generate program
-	 * checks. Disabling machine checks for all other new psw masks is
-	 * just paranoia.
-	 */
-	local_mcck_disable();
-	/* Disable lowcore protection */
-	__ctl_clear_bit(0,28);
-	S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK;
-	S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK;
-	S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK;
-	S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK;
-}
-
-void restore_processor_state(void)
-{
-	S390_lowcore.external_new_psw.mask |= PSW_MASK_MCHECK;
-	S390_lowcore.svc_new_psw.mask |= PSW_MASK_MCHECK;
-	S390_lowcore.io_new_psw.mask |= PSW_MASK_MCHECK;
-	S390_lowcore.program_new_psw.mask |= PSW_MASK_MCHECK;
-	/* Enable lowcore protection */
-	__ctl_set_bit(0,28);
-	local_mcck_enable();
-}
-
-/* Called at the end of swsusp_arch_resume */
-void s390_early_resume(void)
-{
-	lgr_info_log();
-	channel_subsystem_reinit();
-	zpci_rescan();
-}
diff --git a/arch/s390/kernel/swsusp.S b/arch/s390/kernel/swsusp.S
deleted file mode 100644
index a7baf0b5f818..000000000000
--- a/arch/s390/kernel/swsusp.S
+++ /dev/null
@@ -1,276 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * S390 64-bit swsusp implementation
- *
- * Copyright IBM Corp. 2009
- *
- * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
- *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
- */
-
-#include <linux/linkage.h>
-#include <asm/page.h>
-#include <asm/ptrace.h>
-#include <asm/thread_info.h>
-#include <asm/asm-offsets.h>
-#include <asm/nospec-insn.h>
-#include <asm/sigp.h>
-
-/*
- * Save register context in absolute 0 lowcore and call swsusp_save() to
- * create in-memory kernel image. The context is saved in the designated
- * "store status" memory locations (see POP).
- * We return from this function twice. The first time during the suspend to
- * disk process. The second time via the swsusp_arch_resume() function
- * (see below) in the resume process.
- * This function runs with disabled interrupts.
- */
-	GEN_BR_THUNK %r14
-
-	.section .text
-ENTRY(swsusp_arch_suspend)
-	lg	%r1,__LC_NODAT_STACK
-	stmg	%r6,%r15,__SF_GPRS(%r1)
-	aghi	%r1,-STACK_FRAME_OVERHEAD
-	stg	%r15,__SF_BACKCHAIN(%r1)
-	lgr	%r15,%r1
-
-	/* Store FPU registers */
-	brasl	%r14,save_fpu_regs
-
-	/* Deactivate DAT */
-	stnsm	__SF_EMPTY(%r15),0xfb
-
-	/* Store prefix register on stack */
-	stpx	__SF_EMPTY(%r15)
-
-	/* Save prefix register contents for lowcore copy */
-	llgf	%r10,__SF_EMPTY(%r15)
-
-	/* Get pointer to save area */
-	lghi	%r1,0x1000
-
-	/* Save CPU address */
-	stap	__LC_EXT_CPU_ADDR(%r0)
-
-	/* Store registers */
-	mvc	0x318(4,%r1),__SF_EMPTY(%r15)	/* move prefix to lowcore */
-	stam	%a0,%a15,0x340(%r1)		/* store access registers */
-	stctg	%c0,%c15,0x380(%r1)		/* store control registers */
-	stmg	%r0,%r15,0x280(%r1)		/* store general registers */
-
-	stpt	0x328(%r1)			/* store timer */
-	stck	__SF_EMPTY(%r15)		/* store clock */
-	stckc	0x330(%r1)			/* store clock comparator */
-
-	/* Update cputime accounting before going to sleep */
-	lg	%r0,__LC_LAST_UPDATE_TIMER
-	slg	%r0,0x328(%r1)
-	alg	%r0,__LC_SYSTEM_TIMER
-	stg	%r0,__LC_SYSTEM_TIMER
-	mvc	__LC_LAST_UPDATE_TIMER(8),0x328(%r1)
-	lg	%r0,__LC_LAST_UPDATE_CLOCK
-	slg	%r0,__SF_EMPTY(%r15)
-	alg	%r0,__LC_STEAL_TIMER
-	stg	%r0,__LC_STEAL_TIMER
-	mvc	__LC_LAST_UPDATE_CLOCK(8),__SF_EMPTY(%r15)
-
-	/* Activate DAT */
-	stosm	__SF_EMPTY(%r15),0x04
-
-	/* Set prefix page to zero */
-	xc	__SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
-	spx	__SF_EMPTY(%r15)
-
-	/* Save absolute zero pages */
-	larl	%r2,suspend_zero_pages
-	lg	%r2,0(%r2)
-	lghi	%r4,0
-	lghi	%r3,2*PAGE_SIZE
-	lghi	%r5,2*PAGE_SIZE
-1:	mvcle	%r2,%r4,0
-	jo	1b
-
-	/* Copy lowcore to absolute zero lowcore */
-	lghi	%r2,0
-	lgr	%r4,%r10
-	lghi	%r3,2*PAGE_SIZE
-	lghi	%r5,2*PAGE_SIZE
-1:	mvcle	%r2,%r4,0
-	jo	1b
-
-	/* Save image */
-	brasl	%r14,swsusp_save
-
-	/* Restore prefix register and return */
-	lghi	%r1,0x1000
-	spx	0x318(%r1)
-	lmg	%r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
-	lghi	%r2,0
-	BR_EX	%r14
-ENDPROC(swsusp_arch_suspend)
-
-/*
- * Restore saved memory image to correct place and restore register context.
- * Then we return to the function that called swsusp_arch_suspend().
- * swsusp_arch_resume() runs with disabled interrupts.
- */
-ENTRY(swsusp_arch_resume)
-	stmg	%r6,%r15,__SF_GPRS(%r15)
-	lgr	%r1,%r15
-	aghi	%r15,-STACK_FRAME_OVERHEAD
-	stg	%r1,__SF_BACKCHAIN(%r15)
-
-	/* Make all free pages stable */
-	lghi	%r2,1
-	brasl	%r14,arch_set_page_states
-
-	/* Set prefix page to zero */
-	xc	__SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
-	spx	__SF_EMPTY(%r15)
-
-	/* Deactivate DAT */
-	stnsm	__SF_EMPTY(%r15),0xfb
-
-	/* Restore saved image */
-	larl	%r1,restore_pblist
-	lg	%r1,0(%r1)
-	ltgr	%r1,%r1
-	jz	2f
-0:
-	lg	%r2,8(%r1)
-	lg	%r4,0(%r1)
-	iske	%r0,%r4
-	lghi	%r3,PAGE_SIZE
-	lghi	%r5,PAGE_SIZE
-1:
-	mvcle	%r2,%r4,0
-	jo	1b
-	lg	%r2,8(%r1)
-	sske	%r0,%r2
-	lg	%r1,16(%r1)
-	ltgr	%r1,%r1
-	jnz	0b
-2:
-	ptlb				/* flush tlb */
-
-	/* Reset System */
-	larl	%r1,.Lnew_pgm_check_psw
-	epsw	%r2,%r3
-	stm	%r2,%r3,0(%r1)
-	mvc	__LC_PGM_NEW_PSW(16,%r0),0(%r1)
-	larl	%r1,__swsusp_reset_dma
-	lg	%r1,0(%r1)
-	BASR_EX	%r14,%r1
-	larl	%r1,smp_cpu_mt_shift
-	icm	%r1,15,0(%r1)
-	jz	smt_done
-	llgfr	%r1,%r1
-smt_loop:
-	sigp	%r1,%r0,SIGP_SET_MULTI_THREADING
-	brc	8,smt_done			/* accepted */
-	brc	2,smt_loop			/* busy, try again */
-smt_done:
-	larl	%r1,.Lnew_pgm_check_psw
-	lpswe	0(%r1)
-pgm_check_entry:
-
-	/* Switch to original suspend CPU */
-	larl	%r1,.Lresume_cpu		/* Resume CPU address: r2 */
-	stap	0(%r1)
-	llgh	%r2,0(%r1)
-	llgh	%r1,__LC_EXT_CPU_ADDR(%r0)	/* Suspend CPU address: r1 */
-	cgr	%r1,%r2
-	je	restore_registers		/* r1 = r2 -> nothing to do */
-	larl	%r4,.Lrestart_suspend_psw	/* Set new restart PSW */
-	mvc	__LC_RST_NEW_PSW(16,%r0),0(%r4)
-3:
-	sigp	%r9,%r1,SIGP_INITIAL_CPU_RESET	/* sigp initial cpu reset */
-	brc	8,4f				/* accepted */
-	brc	2,3b				/* busy, try again */
-
-	/* Suspend CPU not available -> panic */
-	larl	%r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD
-	larl	%r2,.Lpanic_string
-	brasl	%r14,sclp_early_printk_force
-	larl	%r3,.Ldisabled_wait_31
-	lpsw	0(%r3)
-4:
-	/* Switch to suspend CPU */
-	sigp	%r9,%r1,SIGP_RESTART	/* sigp restart to suspend CPU */
-	brc	2,4b			/* busy, try again */
-5:
-	sigp	%r9,%r2,SIGP_STOP	/* sigp stop to current resume CPU */
-	brc	2,5b			/* busy, try again */
-6:	j	6b
-
-restart_suspend:
-	larl	%r1,.Lresume_cpu
-	llgh	%r2,0(%r1)
-7:
-	sigp	%r9,%r2,SIGP_SENSE	/* sigp sense, wait for resume CPU */
-	brc	8,7b			/* accepted, status 0, still running */
-	brc	2,7b			/* busy, try again */
-	tmll	%r9,0x40		/* Test if resume CPU is stopped */
-	jz	7b
-
-restore_registers:
-	/* Restore registers */
-	lghi	%r13,0x1000		/* %r1 = pointer to save area */
-
-	/* Ignore time spent in suspended state. */
-	llgf	%r1,0x318(%r13)
-	stck	__LC_LAST_UPDATE_CLOCK(%r1)
-	spt	0x328(%r13)		/* reprogram timer */
-	//sckc	0x330(%r13)		/* set clock comparator */
-
-	lctlg	%c0,%c15,0x380(%r13)	/* load control registers */
-	lam	%a0,%a15,0x340(%r13)	/* load access registers */
-
-	/* Load old stack */
-	lg	%r15,0x2f8(%r13)
-
-	/* Save prefix register */
-	mvc __SF_EMPTY(4,%r15),0x318(%r13)
-
-	/* Restore absolute zero pages */
-	lghi	%r2,0
-	larl	%r4,suspend_zero_pages
-	lg	%r4,0(%r4)
-	lghi	%r3,2*PAGE_SIZE
-	lghi	%r5,2*PAGE_SIZE
-1:	mvcle	%r2,%r4,0
-	jo	1b
-
-	/* Restore prefix register */
-	spx	__SF_EMPTY(%r15)
-
-	/* Activate DAT */
-	stosm	__SF_EMPTY(%r15),0x04
-
-	/* Make all free pages unstable */
-	lghi	%r2,0
-	brasl	%r14,arch_set_page_states
-
-	/* Call arch specific early resume code */
-	brasl	%r14,s390_early_resume
-
-	/* Return 0 */
-	lmg	%r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
-	lghi	%r2,0
-	BR_EX	%r14
-ENDPROC(swsusp_arch_resume)
-
-	.section .data..nosave,"aw",@progbits
-	.align	8
-.Ldisabled_wait_31:
-	.long  0x000a0000,0x00000000
-.Lpanic_string:
-	.asciz	"Resume not possible because suspend CPU is no longer available\n"
-	.align	8
-.Lrestart_suspend_psw:
-	.quad	0x0000000180000000,restart_suspend
-.Lnew_pgm_check_psw:
-	.quad	0,pgm_check_entry
-.Lresume_cpu:
-	.byte	0,0