Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6

* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
  [S390] guest page hinting light
  [S390] tty3270: fix put_char fail/success conversion.
  [S390] compat ptrace cleanup
  [S390] s390mach compile warning
  [S390] cio: Fix parsing mechanism for blacklisted devices.
  [S390] cio: Remove cio_msg kernel parameter.
  [S390] s390-kvm: leave sie context on work. Removes preemption requirement
  [S390] s390: Optimize user and work TIF check

11 files changed, 157 insertions, 130 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 29a7940f284..1d035082e78 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -430,6 +430,13 @@ config CMM_IUCV
 	  Select this option to enable the special message interface to
 	  the cooperative memory management.
 
+config PAGE_STATES
+	bool "Unused page notification"
+	help
+	  This enables the notification of unused pages to the
+	  hypervisor. The ESSA instruction is used to do the states
+	  changes between a page that has content and the unused state.
+
 config VIRT_TIMER
 	bool "Virtual CPU timer support"
 	help
diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S
index 743d54f0b8d..d003a6e16af 100644
--- a/arch/s390/kernel/compat_wrapper.S
+++ b/arch/s390/kernel/compat_wrapper.S
@@ -121,7 +121,7 @@ sys32_ptrace_wrapper:
 	lgfr	%r3,%r3			# long
 	llgtr	%r4,%r4			# long
 	llgfr	%r5,%r5			# long
-	jg	sys_ptrace		# branch to system call
+	jg	compat_sys_ptrace	# branch to system call
 
 	.globl	sys32_alarm_wrapper
 sys32_alarm_wrapper:
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index bdbb3bcd78a..708cf9cf9a3 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -279,8 +279,6 @@ sysc_do_restart:
 	st	%r2,SP_R2(%r15)   # store return value (change R2 on stack)
 
 sysc_return:
-	tm	SP_PSW+1(%r15),0x01	# returning to user ?
-	bno	BASED(sysc_restore)
 	tm	__TI_flags+3(%r9),_TIF_WORK_SVC
 	bnz	BASED(sysc_work)  # there is work to do (signals etc.)
 sysc_restore:
@@ -312,6 +310,8 @@ sysc_work_loop:
 # One of the work bits is on. Find out which one.
 #
 sysc_work:
+	tm	SP_PSW+1(%r15),0x01	# returning to user ?
+	bno	BASED(sysc_restore)
 	tm	__TI_flags+3(%r9),_TIF_MCCK_PENDING
 	bo	BASED(sysc_mcck_pending)
 	tm	__TI_flags+3(%r9),_TIF_NEED_RESCHED
@@ -602,12 +602,6 @@ io_no_vtime:
 	la	%r2,SP_PTREGS(%r15)	# address of register-save area
 	basr	%r14,%r1		# branch to standard irq handler
 io_return:
-	tm	SP_PSW+1(%r15),0x01	# returning to user ?
-#ifdef CONFIG_PREEMPT
-	bno	BASED(io_preempt)	# no -> check for preemptive scheduling
-#else
-	bno	BASED(io_restore)	# no-> skip resched & signal
-#endif
 	tm	__TI_flags+3(%r9),_TIF_WORK_INT
 	bnz	BASED(io_work)		# there is work to do (signals etc.)
 io_restore:
@@ -629,10 +623,18 @@ io_restore_trace_psw:
 	.long	0, io_restore_trace + 0x80000000
 #endif
 
-#ifdef CONFIG_PREEMPT
-io_preempt:
+#
+# switch to kernel stack, then check the TIF bits
+#
+io_work:
+	tm	SP_PSW+1(%r15),0x01	# returning to user ?
+#ifndef CONFIG_PREEMPT
+	bno	BASED(io_restore)	# no-> skip resched & signal
+#else
+	bnz	BASED(io_work_user)	# no -> check for preemptive scheduling
+	# check for preemptive scheduling
 	icm	%r0,15,__TI_precount(%r9)
-	bnz	BASED(io_restore)
+	bnz	BASED(io_restore)	# preemption disabled
 	l	%r1,SP_R15(%r15)
 	s	%r1,BASED(.Lc_spsize)
 	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
@@ -646,10 +648,7 @@ io_resume_loop:
 	br	%r1			# call schedule
 #endif
 
-#
-# switch to kernel stack, then check the TIF bits
-#
-io_work:
+io_work_user:
 	l	%r1,__LC_KERNEL_STACK
 	s	%r1,BASED(.Lc_spsize)
 	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 5a4a7bcd2bb..fee10177dbf 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -271,8 +271,6 @@ sysc_noemu:
 	stg	%r2,SP_R2(%r15) # store return value (change R2 on stack)
 
 sysc_return:
-	tm	SP_PSW+1(%r15),0x01	# returning to user ?
-	jno	sysc_restore
 	tm	__TI_flags+7(%r9),_TIF_WORK_SVC
 	jnz	sysc_work	# there is work to do (signals etc.)
 sysc_restore:
@@ -304,6 +302,8 @@ sysc_work_loop:
 # One of the work bits is on. Find out which one.
 #
 sysc_work:
+	tm	SP_PSW+1(%r15),0x01	# returning to user ?
+	jno	sysc_restore
 	tm	__TI_flags+7(%r9),_TIF_MCCK_PENDING
 	jo	sysc_mcck_pending
 	tm	__TI_flags+7(%r9),_TIF_NEED_RESCHED
@@ -585,12 +585,6 @@ io_no_vtime:
 	la	%r2,SP_PTREGS(%r15)	# address of register-save area
 	brasl	%r14,do_IRQ		# call standard irq handler
 io_return:
-	tm	SP_PSW+1(%r15),0x01	# returning to user ?
-#ifdef CONFIG_PREEMPT
-	jno	io_preempt		# no -> check for preemptive scheduling
-#else
-	jno	io_restore		# no-> skip resched & signal
-#endif
 	tm	__TI_flags+7(%r9),_TIF_WORK_INT
 	jnz	io_work 		# there is work to do (signals etc.)
 io_restore:
@@ -612,10 +606,41 @@ io_restore_trace_psw:
 	.quad	0, io_restore_trace
 #endif
 
-#ifdef CONFIG_PREEMPT
-io_preempt:
+#
+# There is work todo, we need to check if we return to userspace, then
+# check, if we are in SIE, if yes leave it
+#
+io_work:
+	tm	SP_PSW+1(%r15),0x01	# returning to user ?
+#ifndef CONFIG_PREEMPT
+#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
+	jnz	io_work_user		# yes -> no need to check for SIE
+	la	%r1, BASED(sie_opcode)	# we return to kernel here
+	lg	%r2, SP_PSW+8(%r15)
+	clc	0(2,%r1), 0(%r2)	# is current instruction = SIE?
+	jne	io_restore		# no-> return to kernel
+	lg	%r1, SP_PSW+8(%r15)	# yes-> add 4 bytes to leave SIE
+	aghi	%r1, 4
+	stg	%r1, SP_PSW+8(%r15)
+	j	io_restore		# return to kernel
+#else
+	jno	io_restore		# no-> skip resched & signal
+#endif
+#else
+	jnz	io_work_user		# yes -> do resched & signal
+#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
+	la	%r1, BASED(sie_opcode)
+	lg	%r2, SP_PSW+8(%r15)
+	clc	0(2,%r1), 0(%r2)	# is current instruction = SIE?
+	jne	0f			# no -> leave PSW alone
+	lg	%r1, SP_PSW+8(%r15)	# yes-> add 4 bytes to leave SIE
+	aghi	%r1, 4
+	stg	%r1, SP_PSW+8(%r15)
+0:
+#endif
+	# check for preemptive scheduling
 	icm	%r0,15,__TI_precount(%r9)
-	jnz	io_restore
+	jnz	io_restore		# preemption is disabled
 	# switch to kernel stack
 	lg	%r1,SP_R15(%r15)
 	aghi	%r1,-SP_SIZE
@@ -629,10 +654,7 @@ io_resume_loop:
 	jg	preempt_schedule_irq
 #endif
 
-#
-# switch to kernel stack, then check TIF bits
-#
-io_work:
+io_work_user:
 	lg	%r1,__LC_KERNEL_STACK
 	aghi	%r1,-SP_SIZE
 	mvc	SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
@@ -653,6 +675,11 @@ io_work_loop:
 	j	io_restore
 io_work_done:
 
+#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
+sie_opcode:
+	.long 0xb2140000
+#endif
+
 #
 # _TIF_MCCK_PENDING is set, call handler
 #
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 7f427016374..35827b9bd4d 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -292,8 +292,7 @@ poke_user(struct task_struct *child, addr_t addr, addr_t data)
 	return 0;
 }
 
-static int
-do_ptrace_normal(struct task_struct *child, long request, long addr, long data)
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
 	ptrace_area parea; 
 	int copied, ret;
@@ -529,35 +528,19 @@ poke_user_emu31(struct task_struct *child, addr_t addr, addr_t data)
 	return 0;
 }
 
-static int
-do_ptrace_emu31(struct task_struct *child, long request, long addr, long data)
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+			compat_ulong_t caddr, compat_ulong_t cdata)
 {
-	unsigned int tmp;  /* 4 bytes !! */
+	unsigned long addr = caddr;
+	unsigned long data = cdata;
 	ptrace_area_emu31 parea; 
 	int copied, ret;
 
 	switch (request) {
-	case PTRACE_PEEKTEXT:
-	case PTRACE_PEEKDATA:
-		/* read word at location addr. */
-		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
-		if (copied != sizeof(tmp))
-			return -EIO;
-		return put_user(tmp, (unsigned int __force __user *) data);
-
 	case PTRACE_PEEKUSR:
 		/* read the word at location addr in the USER area. */
 		return peek_user_emu31(child, addr, data);
 
-	case PTRACE_POKETEXT:
-	case PTRACE_POKEDATA:
-		/* write the word at location addr. */
-		tmp = data;
-		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 1);
-		if (copied != sizeof(tmp))
-			return -EIO;
-		return 0;
-
 	case PTRACE_POKEUSR:
 		/* write the word at location addr in the USER area */
 		return poke_user_emu31(child, addr, data);
@@ -587,82 +570,11 @@ do_ptrace_emu31(struct task_struct *child, long request, long addr, long data)
 			copied += sizeof(unsigned int);
 		}
 		return 0;
-	case PTRACE_GETEVENTMSG:
-		return put_user((__u32) child->ptrace_message,
-				(unsigned int __force __user *) data);
-	case PTRACE_GETSIGINFO:
-		if (child->last_siginfo == NULL)
-			return -EINVAL;
-		return copy_siginfo_to_user32((compat_siginfo_t
-					       __force __user *) data,
-					      child->last_siginfo);
-	case PTRACE_SETSIGINFO:
-		if (child->last_siginfo == NULL)
-			return -EINVAL;
-		return copy_siginfo_from_user32(child->last_siginfo,
-						(compat_siginfo_t
-						 __force __user *) data);
 	}
-	return ptrace_request(child, request, addr, data);
+	return compat_ptrace_request(child, request, addr, data);
 }
 #endif
 
-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
-{
-	switch (request) {
-	case PTRACE_SYSCALL:
-		/* continue and stop at next (return from) syscall */
-	case PTRACE_CONT:
-		/* restart after signal. */
-		if (!valid_signal(data))
-			return -EIO;
-		if (request == PTRACE_SYSCALL)
-			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		else
-			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		child->exit_code = data;
-		/* make sure the single step bit is not set. */
-		user_disable_single_step(child);
-		wake_up_process(child);
-		return 0;
-
-	case PTRACE_KILL:
-		/*
-		 * make the child exit.  Best I can do is send it a sigkill. 
-		 * perhaps it should be put in the status that it wants to 
-		 * exit.
-		 */
-		if (child->exit_state == EXIT_ZOMBIE) /* already dead */
-			return 0;
-		child->exit_code = SIGKILL;
-		/* make sure the single step bit is not set. */
-		user_disable_single_step(child);
-		wake_up_process(child);
-		return 0;
-
-	case PTRACE_SINGLESTEP:
-		/* set the trap flag. */
-		if (!valid_signal(data))
-			return -EIO;
-		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		child->exit_code = data;
-		user_enable_single_step(child);
-		/* give it a chance to run. */
-		wake_up_process(child);
-		return 0;
-
-	/* Do requests that differ for 31/64 bit */
-	default:
-#ifdef CONFIG_COMPAT
-		if (test_thread_flag(TIF_31BIT))
-			return do_ptrace_emu31(child, request, addr, data);
-#endif
-		return do_ptrace_normal(child, request, addr, data);
-	}
-	/* Not reached.  */
-	return -EIO;
-}
-
 asmlinkage void
 syscall_trace(struct pt_regs *regs, int entryexit)
 {
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index 1761b74d639..e051cad1f1e 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -22,7 +22,6 @@ config KVM
 	select PREEMPT_NOTIFIERS
 	select ANON_INODES
 	select S390_SWITCH_AMODE
-	select PREEMPT
 	---help---
 	  Support hosting paravirtualized guest machines using the SIE
 	  virtualization capability on the mainframe. This should work
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 349581a2610..47a0b642174 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -105,6 +105,9 @@ static intercept_handler_t instruction_handlers[256] = {
 static int handle_noop(struct kvm_vcpu *vcpu)
 {
 	switch (vcpu->arch.sie_block->icptcode) {
+	case 0x0:
+		vcpu->stat.exit_null++;
+		break;
 	case 0x10:
 		vcpu->stat.exit_external_request++;
 		break;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 98d1e73e01f..0ac36a649eb 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -31,6 +31,7 @@
 
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	{ "userspace_handled", VCPU_STAT(exit_userspace) },
+	{ "exit_null", VCPU_STAT(exit_null) },
 	{ "exit_validity", VCPU_STAT(exit_validity) },
 	{ "exit_stop_request", VCPU_STAT(exit_stop_request) },
 	{ "exit_external_request", VCPU_STAT(exit_external_request) },
@@ -221,10 +222,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	vcpu->arch.guest_fpregs.fpc &= FPC_VALID_MASK;
 	restore_fp_regs(&vcpu->arch.guest_fpregs);
 	restore_access_regs(vcpu->arch.guest_acrs);
-
-	if (signal_pending(current))
-		atomic_set_mask(CPUSTAT_STOP_INT,
-			&vcpu->arch.sie_block->cpuflags);
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
index fb988a48a75..2a745813454 100644
--- a/arch/s390/mm/Makefile
+++ b/arch/s390/mm/Makefile
@@ -5,3 +5,4 @@
 obj-y	 := init.o fault.o extmem.o mmap.o vmem.o pgtable.o
 obj-$(CONFIG_CMM) += cmm.o
 obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+obj-$(CONFIG_PAGE_STATES) += page-states.o
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index fa31de6ae97..29f3a63806b 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -126,6 +126,9 @@ void __init mem_init(void)
         /* clear the zero-page */
         memset(empty_zero_page, 0, PAGE_SIZE);
 
+	/* Setup guest page hinting */
+	cmma_init();
+
 	/* this will put all low memory onto the freelists */
 	totalram_pages += free_all_bootmem();
 
diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c
new file mode 100644
index 00000000000..fc0ad73ffd9
--- /dev/null
+++ b/arch/s390/mm/page-states.c
@@ -0,0 +1,79 @@
+/*
+ * arch/s390/mm/page-states.c
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * Guest page hinting for unused pages.
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+
+#define ESSA_SET_STABLE		1
+#define ESSA_SET_UNUSED		2
+
+static int cmma_flag;
+
+static int __init cmma(char *str)
+{
+	char *parm;
+	parm = strstrip(str);
+	if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) {
+		cmma_flag = 1;
+		return 1;
+	}
+	cmma_flag = 0;
+	if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0)
+		return 1;
+	return 0;
+}
+
+__setup("cmma=", cmma);
+
+void __init cmma_init(void)
+{
+	register unsigned long tmp asm("0") = 0;
+	register int rc asm("1") = -EOPNOTSUPP;
+
+	if (!cmma_flag)
+		return;
+	asm volatile(
+		"       .insn rrf,0xb9ab0000,%1,%1,0,0\n"
+		"0:     la      %0,0\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "+&d" (rc), "+&d" (tmp));
+	if (rc)
+		cmma_flag = 0;
+}
+
+void arch_free_page(struct page *page, int order)
+{
+	int i, rc;
+
+	if (!cmma_flag)
+		return;
+	for (i = 0; i < (1 << order); i++)
+		asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
+			     : "=&d" (rc)
+			     : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT),
+			       "i" (ESSA_SET_UNUSED));
+}
+
+void arch_alloc_page(struct page *page, int order)
+{
+	int i, rc;
+
+	if (!cmma_flag)
+		return;
+	for (i = 0; i < (1 << order); i++)
+		asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
+			     : "=&d" (rc)
+			     : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT),
+			       "i" (ESSA_SET_STABLE));
+}