arch/ppc64/kernel/ItLpQueue.c - arm/linux-arm64-legacy - Git at Google

 /*
  * ItLpQueue.c
  * Copyright (C) 2001 Mike Corrigan  IBM Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */

 #include <linux/stddef.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/bootmem.h>
 #include <linux/seq_file.h>
 #include <linux/proc_fs.h>
 #include <asm/system.h>
 #include <asm/paca.h>
 #include <asm/iSeries/ItLpQueue.h>
 #include <asm/iSeries/HvLpEvent.h>
 #include <asm/iSeries/HvCallEvent.h>

 /*
  * The LpQueue is used to pass event data from the hypervisor to
  * the partition.  This is where I/O interrupt events are communicated.
  *
  * It is written to by the hypervisor so cannot end up in the BSS.
  */
 struct hvlpevent_queue hvlpevent_queue __attribute__((__section__(".data")));

 DEFINE_PER_CPU(unsigned long[HvLpEvent_Type_NumTypes], hvlpevent_counts);

 static char *event_types[HvLpEvent_Type_NumTypes] = {
 	"Hypervisor\t\t",
 	"Machine Facilities\t",
 	"Session Manager\t",
 	"SPD I/O\t\t",
 	"Virtual Bus\t\t",
 	"PCI I/O\t\t",
 	"RIO I/O\t\t",
 	"Virtual Lan\t\t",
 	"Virtual I/O\t\t"
 };

 static __inline__ int set_inUse(void)
 {
 	int t;
 	u32 * inUseP = &hvlpevent_queue.xInUseWord;

 	__asm__ __volatile__("\n\
 1:	lwarx	%0,0,%2		\n\
 	cmpwi	0,%0,0		\n\
 	li	%0,0		\n\
 	bne-	2f		\n\
 	addi	%0,%0,1		\n\
 	stwcx.	%0,0,%2		\n\
 	bne-	1b		\n\
 2:	eieio"
 	: "=&r" (t), "=m" (hvlpevent_queue.xInUseWord)
 	: "r" (inUseP), "m" (hvlpevent_queue.xInUseWord)
 	: "cc");

 	return t;
 }

 static __inline__ void clear_inUse(void)
 {
 	hvlpevent_queue.xInUseWord = 0;
 }

 /* Array of LpEvent handler functions */
 extern LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
 unsigned long ItLpQueueInProcess = 0;

 static struct HvLpEvent * get_next_hvlpevent(void)
 {
 	struct HvLpEvent * nextLpEvent =
 		(struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
 	if ( nextLpEvent->xFlags.xValid ) {
 		/* rmb() needed only for weakly consistent machines (regatta) */
 		rmb();
 		/* Set pointer to next potential event */
 		hvlpevent_queue.xSlicCurEventPtr += ((nextLpEvent->xSizeMinus1 +
 				      LpEventAlign ) /
 				      LpEventAlign ) *
 				      LpEventAlign;
 		/* Wrap to beginning if no room at end */
 		if (hvlpevent_queue.xSlicCurEventPtr > hvlpevent_queue.xSlicLastValidEventPtr)
 			hvlpevent_queue.xSlicCurEventPtr = hvlpevent_queue.xSlicEventStackPtr;
 	}
 	else
 		nextLpEvent = NULL;

 	return nextLpEvent;
 }

 static unsigned long spread_lpevents = NR_CPUS;

 int hvlpevent_is_pending(void)
 {
 	struct HvLpEvent *next_event;

 	if (smp_processor_id() >= spread_lpevents)
 		return 0;

 	next_event = (struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
 	return next_event->xFlags.xValid | hvlpevent_queue.xPlicOverflowIntPending;
 }

 static void hvlpevent_clear_valid( struct HvLpEvent * event )
 {
 	/* Clear the valid bit of the event
 	 * Also clear bits within this event that might
 	 * look like valid bits (on 64-byte boundaries)
    	 */
 	unsigned extra = (( event->xSizeMinus1 + LpEventAlign ) /
 						 LpEventAlign ) - 1;
 	switch ( extra ) {
 	  case 3:
 	   ((struct HvLpEvent*)((char*)event+3*LpEventAlign))->xFlags.xValid=0;
 	  case 2:
 	   ((struct HvLpEvent*)((char*)event+2*LpEventAlign))->xFlags.xValid=0;
 	  case 1:
 	   ((struct HvLpEvent*)((char*)event+1*LpEventAlign))->xFlags.xValid=0;
 	  case 0:
 	   ;
 	}
 	mb();
 	event->xFlags.xValid = 0;
 }

 void process_hvlpevents(struct pt_regs *regs)
 {
 	struct HvLpEvent * nextLpEvent;

 	/* If we have recursed, just return */
 	if ( !set_inUse() )
 		return;

 	if (ItLpQueueInProcess == 0)
 		ItLpQueueInProcess = 1;
 	else
 		BUG();

 	for (;;) {
 		nextLpEvent = get_next_hvlpevent();
 		if ( nextLpEvent ) {
 			/* Call appropriate handler here, passing
 			 * a pointer to the LpEvent.  The handler
 			 * must make a copy of the LpEvent if it
 			 * needs it in a bottom half. (perhaps for
 			 * an ACK)
 			 *
 			 *  Handlers are responsible for ACK processing
 			 *
 			 * The Hypervisor guarantees that LpEvents will
 			 * only be delivered with types that we have
 			 * registered for, so no type check is necessary
 			 * here!
   			 */
 			if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes )
 				__get_cpu_var(hvlpevent_counts)[nextLpEvent->xType]++;
 			if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes &&
 			     lpEventHandler[nextLpEvent->xType] )
 				lpEventHandler[nextLpEvent->xType](nextLpEvent, regs);
 			else
 				printk(KERN_INFO "Unexpected Lp Event type=%d\n", nextLpEvent->xType );

 			hvlpevent_clear_valid( nextLpEvent );
 		} else if ( hvlpevent_queue.xPlicOverflowIntPending )
 			/*
 			 * No more valid events. If overflow events are
 			 * pending process them
 			 */
 			HvCallEvent_getOverflowLpEvents( hvlpevent_queue.xIndex);
 		else
 			break;
 	}

 	ItLpQueueInProcess = 0;
 	mb();
 	clear_inUse();
 }

 static int set_spread_lpevents(char *str)
 {
 	unsigned long val = simple_strtoul(str, NULL, 0);

 	/*
 	 * The parameter is the number of processors to share in processing
 	 * lp events.
 	 */
 	if (( val > 0) && (val <= NR_CPUS)) {
 		spread_lpevents = val;
 		printk("lpevent processing spread over %ld processors\n", val);
 	} else {
 		printk("invalid spread_lpevents %ld\n", val);
 	}

 	return 1;
 }
 __setup("spread_lpevents=", set_spread_lpevents);

 void setup_hvlpevent_queue(void)
 {
 	void *eventStack;

 	/*
 	 * Allocate a page for the Event Stack. The Hypervisor needs the
 	 * absolute real address, so we subtract out the KERNELBASE and add
 	 * in the absolute real address of the kernel load area.
 	 */
 	eventStack = alloc_bootmem_pages(LpEventStackSize);
 	memset(eventStack, 0, LpEventStackSize);

 	/* Invoke the hypervisor to initialize the event stack */
 	HvCallEvent_setLpEventStack(0, eventStack, LpEventStackSize);

 	hvlpevent_queue.xSlicEventStackPtr = (char *)eventStack;
 	hvlpevent_queue.xSlicCurEventPtr = (char *)eventStack;
 	hvlpevent_queue.xSlicLastValidEventPtr = (char *)eventStack +
 					(LpEventStackSize - LpEventMaxSize);
 	hvlpevent_queue.xIndex = 0;
 }

 static int proc_lpevents_show(struct seq_file *m, void *v)
 {
 	int cpu, i;
 	unsigned long sum;
 	static unsigned long cpu_totals[NR_CPUS];

 	/* FIXME: do we care that there's no locking here? */
 	sum = 0;
 	for_each_online_cpu(cpu) {
 		cpu_totals[cpu] = 0;
 		for (i = 0; i < HvLpEvent_Type_NumTypes; i++) {
 			cpu_totals[cpu] += per_cpu(hvlpevent_counts, cpu)[i];
 		}
 		sum += cpu_totals[cpu];
 	}

 	seq_printf(m, "LpEventQueue 0\n");
 	seq_printf(m, "  events processed:\t%lu\n", sum);

 	for (i = 0; i < HvLpEvent_Type_NumTypes; ++i) {
 		sum = 0;
 		for_each_online_cpu(cpu) {
 			sum += per_cpu(hvlpevent_counts, cpu)[i];
 		}

 		seq_printf(m, "    %s %10lu\n", event_types[i], sum);
 	}

 	seq_printf(m, "\n  events processed by processor:\n");

 	for_each_online_cpu(cpu) {
 		seq_printf(m, "    CPU%02d  %10lu\n", cpu, cpu_totals[cpu]);
 	}

 	return 0;
 }

 static int proc_lpevents_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, proc_lpevents_show, NULL);
 }

 static struct file_operations proc_lpevents_operations = {
 	.open		= proc_lpevents_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 static int __init proc_lpevents_init(void)
 {
 	struct proc_dir_entry *e;

 	e = create_proc_entry("iSeries/lpevents", S_IFREG|S_IRUGO, NULL);
 	if (e)
 		e->proc_fops = &proc_lpevents_operations;

 	return 0;
 }
 __initcall(proc_lpevents_init);
	/*
	* ItLpQueue.c
	* Copyright (C) 2001 Mike Corrigan IBM Corporation
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*/

	#include <linux/stddef.h>
	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/bootmem.h>
	#include <linux/seq_file.h>
	#include <linux/proc_fs.h>
	#include <asm/system.h>
	#include <asm/paca.h>
	#include <asm/iSeries/ItLpQueue.h>
	#include <asm/iSeries/HvLpEvent.h>
	#include <asm/iSeries/HvCallEvent.h>

	/*
	* The LpQueue is used to pass event data from the hypervisor to
	* the partition. This is where I/O interrupt events are communicated.
	*
	* It is written to by the hypervisor so cannot end up in the BSS.
	*/
	struct hvlpevent_queue hvlpevent_queue __attribute__((__section__(".data")));

	DEFINE_PER_CPU(unsigned long[HvLpEvent_Type_NumTypes], hvlpevent_counts);

	static char *event_types[HvLpEvent_Type_NumTypes] = {
	"Hypervisor\t\t",
	"Machine Facilities\t",
	"Session Manager\t",
	"SPD I/O\t\t",
	"Virtual Bus\t\t",
	"PCI I/O\t\t",
	"RIO I/O\t\t",
	"Virtual Lan\t\t",
	"Virtual I/O\t\t"
	};

	static __inline__ int set_inUse(void)
	{
	int t;
	u32 * inUseP = &hvlpevent_queue.xInUseWord;

	__asm__ __volatile__("\n\
	1: lwarx %0,0,%2 \n\
	cmpwi 0,%0,0 \n\
	li %0,0 \n\
	bne- 2f \n\
	addi %0,%0,1 \n\
	stwcx. %0,0,%2 \n\
	bne- 1b \n\
	2: eieio"
	: "=&r" (t), "=m" (hvlpevent_queue.xInUseWord)
	: "r" (inUseP), "m" (hvlpevent_queue.xInUseWord)
	: "cc");

	return t;
	}

	static __inline__ void clear_inUse(void)
	{
	hvlpevent_queue.xInUseWord = 0;
	}

	/* Array of LpEvent handler functions */
	extern LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
	unsigned long ItLpQueueInProcess = 0;

	static struct HvLpEvent * get_next_hvlpevent(void)
	{
	struct HvLpEvent * nextLpEvent =
	(struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
	if ( nextLpEvent->xFlags.xValid ) {
	/* rmb() needed only for weakly consistent machines (regatta) */
	rmb();
	/* Set pointer to next potential event */
	hvlpevent_queue.xSlicCurEventPtr += ((nextLpEvent->xSizeMinus1 +
	LpEventAlign ) /
	LpEventAlign ) *
	LpEventAlign;
	/* Wrap to beginning if no room at end */
	if (hvlpevent_queue.xSlicCurEventPtr > hvlpevent_queue.xSlicLastValidEventPtr)
	hvlpevent_queue.xSlicCurEventPtr = hvlpevent_queue.xSlicEventStackPtr;
	}
	else
	nextLpEvent = NULL;

	return nextLpEvent;
	}

	static unsigned long spread_lpevents = NR_CPUS;

	int hvlpevent_is_pending(void)
	{
	struct HvLpEvent *next_event;

	if (smp_processor_id() >= spread_lpevents)
	return 0;

	next_event = (struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
	return next_event->xFlags.xValid \| hvlpevent_queue.xPlicOverflowIntPending;
	}

	static void hvlpevent_clear_valid( struct HvLpEvent * event )
	{
	/* Clear the valid bit of the event
	* Also clear bits within this event that might
	* look like valid bits (on 64-byte boundaries)
	*/
	unsigned extra = (( event->xSizeMinus1 + LpEventAlign ) /
	LpEventAlign ) - 1;
	switch ( extra ) {
	case 3:
	((struct HvLpEvent)((char)event+3*LpEventAlign))->xFlags.xValid=0;
	case 2:
	((struct HvLpEvent)((char)event+2*LpEventAlign))->xFlags.xValid=0;
	case 1:
	((struct HvLpEvent)((char)event+1*LpEventAlign))->xFlags.xValid=0;
	case 0:
	;
	}
	mb();
	event->xFlags.xValid = 0;
	}

	void process_hvlpevents(struct pt_regs *regs)
	{
	struct HvLpEvent * nextLpEvent;

	/* If we have recursed, just return */
	if ( !set_inUse() )
	return;

	if (ItLpQueueInProcess == 0)
	ItLpQueueInProcess = 1;
	else
	BUG();

	for (;;) {
	nextLpEvent = get_next_hvlpevent();
	if ( nextLpEvent ) {
	/* Call appropriate handler here, passing
	* a pointer to the LpEvent. The handler
	* must make a copy of the LpEvent if it
	* needs it in a bottom half. (perhaps for
	* an ACK)
	*
	* Handlers are responsible for ACK processing
	*
	* The Hypervisor guarantees that LpEvents will
	* only be delivered with types that we have
	* registered for, so no type check is necessary
	* here!
	*/
	if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes )
	__get_cpu_var(hvlpevent_counts)[nextLpEvent->xType]++;
	if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes &&
	lpEventHandler[nextLpEvent->xType] )
	lpEventHandler[nextLpEvent->xType](nextLpEvent, regs);
	else
	printk(KERN_INFO "Unexpected Lp Event type=%d\n", nextLpEvent->xType );

	hvlpevent_clear_valid( nextLpEvent );
	} else if ( hvlpevent_queue.xPlicOverflowIntPending )
	/*
	* No more valid events. If overflow events are
	* pending process them
	*/
	HvCallEvent_getOverflowLpEvents( hvlpevent_queue.xIndex);
	else
	break;
	}

	ItLpQueueInProcess = 0;
	mb();
	clear_inUse();
	}

	static int set_spread_lpevents(char *str)
	{
	unsigned long val = simple_strtoul(str, NULL, 0);

	/*
	* The parameter is the number of processors to share in processing
	* lp events.
	*/
	if (( val > 0) && (val <= NR_CPUS)) {
	spread_lpevents = val;
	printk("lpevent processing spread over %ld processors\n", val);
	} else {
	printk("invalid spread_lpevents %ld\n", val);
	}

	return 1;
	}
	__setup("spread_lpevents=", set_spread_lpevents);

	void setup_hvlpevent_queue(void)
	{
	void *eventStack;

	/*
	* Allocate a page for the Event Stack. The Hypervisor needs the
	* absolute real address, so we subtract out the KERNELBASE and add
	* in the absolute real address of the kernel load area.
	*/
	eventStack = alloc_bootmem_pages(LpEventStackSize);
	memset(eventStack, 0, LpEventStackSize);

	/* Invoke the hypervisor to initialize the event stack */
	HvCallEvent_setLpEventStack(0, eventStack, LpEventStackSize);

	hvlpevent_queue.xSlicEventStackPtr = (char *)eventStack;
	hvlpevent_queue.xSlicCurEventPtr = (char *)eventStack;
	hvlpevent_queue.xSlicLastValidEventPtr = (char *)eventStack +
	(LpEventStackSize - LpEventMaxSize);
	hvlpevent_queue.xIndex = 0;
	}

	static int proc_lpevents_show(struct seq_file m, void v)
	{
	int cpu, i;
	unsigned long sum;
	static unsigned long cpu_totals[NR_CPUS];

	/* FIXME: do we care that there's no locking here? */
	sum = 0;
	for_each_online_cpu(cpu) {
	cpu_totals[cpu] = 0;
	for (i = 0; i < HvLpEvent_Type_NumTypes; i++) {
	cpu_totals[cpu] += per_cpu(hvlpevent_counts, cpu)[i];
	}
	sum += cpu_totals[cpu];
	}

	seq_printf(m, "LpEventQueue 0\n");
	seq_printf(m, " events processed:\t%lu\n", sum);

	for (i = 0; i < HvLpEvent_Type_NumTypes; ++i) {
	sum = 0;
	for_each_online_cpu(cpu) {
	sum += per_cpu(hvlpevent_counts, cpu)[i];
	}

	seq_printf(m, " %s %10lu\n", event_types[i], sum);
	}

	seq_printf(m, "\n events processed by processor:\n");

	for_each_online_cpu(cpu) {
	seq_printf(m, " CPU%02d %10lu\n", cpu, cpu_totals[cpu]);
	}

	return 0;
	}

	static int proc_lpevents_open(struct inode inode, struct file file)
	{
	return single_open(file, proc_lpevents_show, NULL);
	}

	static struct file_operations proc_lpevents_operations = {
	.open = proc_lpevents_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int __init proc_lpevents_init(void)
	{
	struct proc_dir_entry *e;

	e = create_proc_entry("iSeries/lpevents", S_IFREG\|S_IRUGO, NULL);
	if (e)
	e->proc_fops = &proc_lpevents_operations;

	return 0;
	}
	__initcall(proc_lpevents_init);