x86, SGI UV: TLB shootdown using broadcast assist unit

###

# 64 bit specific files

ifeq ($(CONFIG_X86_64),y)

        obj-y				+= genapic_64.o genapic_flat_64.o genx2apic_uv_x.o

        obj-y				+= genapic_64.o genapic_flat_64.o genx2apic_uv_x.o tlb_uv.o

        obj-$(CONFIG_X86_PM_TIMER)	+= pmtimer_64.o

        obj-$(CONFIG_AUDIT)		+= audit_64.o

	apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt

END(apic_timer_interrupt)

ENTRY(uv_bau_message_intr1)

	apicinterrupt 220,uv_bau_message_interrupt

END(uv_bau_message_intr1)

ENTRY(error_interrupt)

	apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt

END(error_interrupt)

#include <asm/proto.h>

#include <asm/apicdef.h>

#include <asm/idle.h>

#include <asm/uv/uv_hub.h>

#include <asm/uv/uv_bau.h>

#include <mach_ipi.h>

/*

	union smp_flush_state *f;

	cpumask_t cpumask = *cpumaskp;

	if (is_uv_system() && uv_flush_tlb_others(&cpumask, mm, va))

			return;

	/* Caller has disabled preemption */

	sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS;

	f = &per_cpu(flush_state, sender);

/*

 *	SGI UltraViolet TLB flush routines.

 *

 *	(c) 2008 Cliff Wickman <cpw@sgi.com>, SGI.

 *

 *	This code is released under the GNU General Public License version 2 or

 *	later.

 */

#include <linux/mc146818rtc.h>

#include <linux/proc_fs.h>

#include <linux/kernel.h>

#include <asm/mach-bigsmp/mach_apic.h>

#include <asm/mmu_context.h>

#include <asm/idle.h>

#include <asm/genapic.h>

#include <asm/uv/uv_hub.h>

#include <asm/uv/uv_mmrs.h>

#include <asm/uv/uv_bau.h>

struct bau_control **uv_bau_table_bases;

static int uv_bau_retry_limit;

static int uv_nshift;		/* position of pnode (which is nasid>>1) */

static unsigned long uv_mmask;

char *status_table[] = {

	"IDLE",

	"ACTIVE",

	"DESTINATION TIMEOUT",

	"SOURCE TIMEOUT"

};

DEFINE_PER_CPU(struct ptc_stats, ptcstats);

DEFINE_PER_CPU(struct bau_control, bau_control);

/*

 * Free a software acknowledge hardware resource by clearing its Pending

 * bit. This will return a reply to the sender.

 * If the message has timed out, a reply has already been sent by the

 * hardware but the resource has not been released. In that case our

 * clear of the Timeout bit (as well) will free the resource. No reply will

 * be sent (the hardware will only do one reply per message).

 */

static void

uv_reply_to_message(int resource,

		    struct bau_payload_queue_entry *msg,

		    struct bau_msg_status *msp)

{

	int fw;

	fw = (1 << (resource + UV_SW_ACK_NPENDING)) | (1 << resource);

	msg->replied_to = 1;

	msg->sw_ack_vector = 0;

	if (msp)

		msp->seen_by.bits = 0;

	uv_write_local_mmr(UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE_ALIAS, fw);

	return;

}

/*

 * Do all the things a cpu should do for a TLB shootdown message.

 * Other cpu's may come here at the same time for this message.

 */

static void

uv_bau_process_message(struct bau_payload_queue_entry *msg,

		       int msg_slot, int sw_ack_slot)

{

	int cpu;

	unsigned long this_cpu_mask;

	struct bau_msg_status *msp;

	msp = __get_cpu_var(bau_control).msg_statuses + msg_slot;

	cpu = uv_blade_processor_id();

	msg->number_of_cpus =

	    uv_blade_nr_online_cpus(uv_node_to_blade_id(numa_node_id()));

	this_cpu_mask = (unsigned long)1 << cpu;

	if (msp->seen_by.bits & this_cpu_mask)

		return;

	atomic_or_long(&msp->seen_by.bits, this_cpu_mask);

	if (msg->replied_to == 1)

		return;

	if (msg->address == TLB_FLUSH_ALL) {

		local_flush_tlb();

		__get_cpu_var(ptcstats).alltlb++;

	} else {

		__flush_tlb_one(msg->address);

		__get_cpu_var(ptcstats).onetlb++;

	}

	__get_cpu_var(ptcstats).requestee++;

	atomic_inc_short(&msg->acknowledge_count);

	if (msg->number_of_cpus == msg->acknowledge_count)

		uv_reply_to_message(sw_ack_slot, msg, msp);

	return;

}

/*

 * Examine the payload queue on all the distribution nodes to see

 * which messages have not been seen, and which cpu(s) have not seen them.

 *

 * Returns the number of cpu's that have not responded.

 */

static int

uv_examine_destinations(struct bau_target_nodemask *distribution)

{

	int sender;

	int i;

	int j;

	int k;

	int count = 0;

	struct bau_control *bau_tablesp;

	struct bau_payload_queue_entry *msg;

	struct bau_msg_status *msp;

	sender = smp_processor_id();

	for (i = 0; i < (sizeof(struct bau_target_nodemask) * BITSPERBYTE);

	     i++) {

		if (bau_node_isset(i, distribution)) {

			bau_tablesp = uv_bau_table_bases[i];

			for (msg = bau_tablesp->va_queue_first, j = 0;

			     j < DESTINATION_PAYLOAD_QUEUE_SIZE; msg++, j++) {

				if ((msg->sending_cpu == sender) &&

				    (!msg->replied_to)) {

					msp = bau_tablesp->msg_statuses + j;

					printk(KERN_DEBUG

				"blade %d: address:%#lx %d of %d, not cpu(s): ",

					       i, msg->address,

					       msg->acknowledge_count,

					       msg->number_of_cpus);

					for (k = 0; k < msg->number_of_cpus;

					     k++) {

						if (!((long)1 << k & msp->

						      seen_by.bits)) {

							count++;

							printk("%d ", k);

						}

					}

					printk("\n");

				}

			}

		}

	}

	return count;

}

/**

 * uv_flush_tlb_others - globally purge translation cache of a virtual

 * address or all TLB's

 * @cpumaskp: mask of all cpu's in which the address is to be removed

 * @mm: mm_struct containing virtual address range

 * @va: virtual address to be removed (or TLB_FLUSH_ALL for all TLB's on cpu)

 *

 * This is the entry point for initiating any UV global TLB shootdown.

 *

 * Purges the translation caches of all specified processors of the given

 * virtual address, or purges all TLB's on specified processors.

 *

 * The caller has derived the cpumaskp from the mm_struct and has subtracted

 * the local cpu from the mask.  This function is called only if there

 * are bits set in the mask. (e.g. flush_tlb_page())

 *

 * The cpumaskp is converted into a nodemask of the nodes containing

 * the cpus.

 */

int

uv_flush_tlb_others(cpumask_t *cpumaskp, struct mm_struct *mm, unsigned long va)

{

	int i;

	int blade;

	int cpu;

	int bit;

	int right_shift;

	int this_blade;

	int exams = 0;

	int tries = 0;

	long source_timeouts = 0;

	long destination_timeouts = 0;

	unsigned long index;

	unsigned long mmr_offset;

	unsigned long descriptor_status;

	struct bau_activation_descriptor *bau_desc;

	ktime_t time1, time2;

	cpu = uv_blade_processor_id();

	this_blade = uv_numa_blade_id();

	bau_desc = __get_cpu_var(bau_control).descriptor_base;

	bau_desc += (UV_ITEMS_PER_DESCRIPTOR * cpu);

	bau_nodes_clear(&bau_desc->distribution, UV_DISTRIBUTION_SIZE);

	i = 0;

	for_each_cpu_mask(bit, *cpumaskp) {

		blade = uv_cpu_to_blade_id(bit);

		if (blade > (UV_DISTRIBUTION_SIZE - 1))

			BUG();

		if (blade == this_blade)

			continue;

		bau_node_set(blade, &bau_desc->distribution);

		/* leave the bits for the remote cpu's in the mask until

		   success; on failure we fall back to the IPI method */

		i++;

	}

	if (i == 0)

		goto none_to_flush;

	__get_cpu_var(ptcstats).requestor++;

	__get_cpu_var(ptcstats).ntargeted += i;

	bau_desc->payload.address = va;

	bau_desc->payload.sending_cpu = smp_processor_id();

	if (cpu < UV_CPUS_PER_ACT_STATUS) {

		mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_0;

		right_shift = cpu * UV_ACT_STATUS_SIZE;

	} else {

		mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_1;

		right_shift =

		    ((cpu - UV_CPUS_PER_ACT_STATUS) * UV_ACT_STATUS_SIZE);

	}

	time1 = ktime_get();

retry:

	tries++;

	index = ((unsigned long)

		 1 << UVH_LB_BAU_SB_ACTIVATION_CONTROL_PUSH_SHFT) | cpu;

	uv_write_local_mmr(UVH_LB_BAU_SB_ACTIVATION_CONTROL, index);

	while ((descriptor_status = (((unsigned long)

				      uv_read_local_mmr(mmr_offset) >>

				      right_shift) & UV_ACT_STATUS_MASK)) !=

	       DESC_STATUS_IDLE) {

		if (descriptor_status == DESC_STATUS_SOURCE_TIMEOUT) {

			source_timeouts++;

			if (source_timeouts > SOURCE_TIMEOUT_LIMIT)

				source_timeouts = 0;

			__get_cpu_var(ptcstats).s_retry++;

			goto retry;

		}

		/* spin here looking for progress at the destinations */

		if (descriptor_status == DESC_STATUS_DESTINATION_TIMEOUT) {

			destination_timeouts++;

			if (destination_timeouts > DESTINATION_TIMEOUT_LIMIT) {

				/* returns # of cpus not responding */

				if (uv_examine_destinations

				    (&bau_desc->distribution) == 0) {

					__get_cpu_var(ptcstats).d_retry++;

					goto retry;

				}

				exams++;

				if (exams >= uv_bau_retry_limit) {

					printk(KERN_DEBUG

					       "uv_flush_tlb_others");

					printk("giving up on cpu %d\n",

					       smp_processor_id());

					goto unsuccessful;

				}

				/* delays can hang up the simulator

				   udelay(1000);

				 */

				destination_timeouts = 0;

			}

		}

	}

	if (tries > 1)

		__get_cpu_var(ptcstats).retriesok++;

	/* on success, clear the remote cpu's from the mask so we don't

	   use the IPI method of shootdown on them */

	for_each_cpu_mask(bit, *cpumaskp) {

		blade = uv_cpu_to_blade_id(bit);

		if (blade == this_blade)

			continue;

		cpu_clear(bit, *cpumaskp);

	}

unsuccessful:

	time2 = ktime_get();

	__get_cpu_var(ptcstats).sflush_ns += (time2.tv64 - time1.tv64);

none_to_flush:

	if (cpus_empty(*cpumaskp))

		return 1;

	/* Cause the caller to do an IPI-style TLB shootdown on

	   the cpu's still in the mask */

	__get_cpu_var(ptcstats).ptc_i++;

	return 0;

}

/*

 * The BAU message interrupt comes here. (registered by set_intr_gate)

 * See entry_64.S

 *

 * We received a broadcast assist message.

 *

 * Interrupts may have been disabled; this interrupt could represent

 * the receipt of several messages.

 *

 * All cores/threads on this node get this interrupt.

 * The last one to see it does the s/w ack.

 * (the resource will not be freed until noninterruptable cpus see this

 *  interrupt; hardware will timeout the s/w ack and reply ERROR)

 */

void

uv_bau_message_interrupt(struct pt_regs *regs)

{

	struct bau_payload_queue_entry *pqp;

	struct bau_payload_queue_entry *msg;

	struct pt_regs *old_regs = set_irq_regs(regs);

	ktime_t time1, time2;

	int msg_slot;

	int sw_ack_slot;

	int fw;

	int count = 0;

	unsigned long local_pnode;

	ack_APIC_irq();

	exit_idle();

	irq_enter();

	time1 = ktime_get();

	local_pnode = uv_blade_to_pnode(uv_numa_blade_id());

	pqp = __get_cpu_var(bau_control).va_queue_first;

	msg = __get_cpu_var(bau_control).bau_msg_head;

	while (msg->sw_ack_vector) {

		count++;

		fw = msg->sw_ack_vector;

		msg_slot = msg - pqp;

		sw_ack_slot = ffs(fw) - 1;

		uv_bau_process_message(msg, msg_slot, sw_ack_slot);

		msg++;

		if (msg > __get_cpu_var(bau_control).va_queue_last)

			msg = __get_cpu_var(bau_control).va_queue_first;

		__get_cpu_var(bau_control).bau_msg_head = msg;

	}

	if (!count)

		__get_cpu_var(ptcstats).nomsg++;

	else if (count > 1)

		__get_cpu_var(ptcstats).multmsg++;

	time2 = ktime_get();

	__get_cpu_var(ptcstats).dflush_ns += (time2.tv64 - time1.tv64);

	irq_exit();

	set_irq_regs(old_regs);

	return;

}

static void

uv_enable_timeouts(void)

{

	int i;

	int blade;

	int last_blade;

	int pnode;

	int cur_cpu = 0;

	unsigned long apicid;

	/* better if we had each_online_blade */

	last_blade = -1;

	for_each_online_node(i) {

		blade = uv_node_to_blade_id(i);

		if (blade == last_blade)

			continue;

		last_blade = blade;

		apicid = per_cpu(x86_cpu_to_apicid, cur_cpu);

		pnode = uv_blade_to_pnode(blade);

		cur_cpu += uv_blade_nr_possible_cpus(i);

	}

	return;

}

static void *

uv_ptc_seq_start(struct seq_file *file, loff_t *offset)

{

	if (*offset < num_possible_cpus())

		return offset;

	return NULL;

}

static void *

uv_ptc_seq_next(struct seq_file *file, void *data, loff_t *offset)

{

	(*offset)++;

	if (*offset < num_possible_cpus())

		return offset;

	return NULL;

}

static void

uv_ptc_seq_stop(struct seq_file *file, void *data)

{

}

/*

 * Display the statistics thru /proc

 * data points to the cpu number

 */

static int

uv_ptc_seq_show(struct seq_file *file, void *data)

{

	struct ptc_stats *stat;

	int cpu;

	cpu = *(loff_t *)data;

	if (!cpu) {

		seq_printf(file,

		"# cpu requestor requestee one all sretry dretry ptc_i ");

		seq_printf(file,

		"sw_ack sflush_us dflush_us sok dnomsg dmult starget\n");

	}

	if (cpu < num_possible_cpus() && cpu_online(cpu)) {

		stat = &per_cpu(ptcstats, cpu);

		seq_printf(file, "cpu %d %ld %ld %ld %ld %ld %ld %ld ",

			   cpu, stat->requestor,

			   stat->requestee, stat->onetlb, stat->alltlb,

			   stat->s_retry, stat->d_retry, stat->ptc_i);

		seq_printf(file, "%lx %ld %ld %ld %ld %ld %ld\n",

			   uv_read_global_mmr64(uv_blade_to_pnode

					(uv_cpu_to_blade_id(cpu)),

					UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE),

			   stat->sflush_ns / 1000, stat->dflush_ns / 1000,

			   stat->retriesok, stat->nomsg,

			   stat->multmsg, stat->ntargeted);

	}

	return 0;

}

/*

 *  0: display meaning of the statistics

 * >0: retry limit

 */

static ssize_t

uv_ptc_proc_write(struct file *file, const char __user *user,

		  size_t count, loff_t *data)

{

	long newmode;

	char optstr[64];

	if (copy_from_user(optstr, user, count))

		return -EFAULT;

	optstr[count - 1] = '\0';

	if (strict_strtoul(optstr, 10, &newmode) < 0) {

		printk(KERN_DEBUG "%s is invalid\n", optstr);

		return -EINVAL;

	}

	if (newmode == 0) {

		printk(KERN_DEBUG "# cpu:      cpu number\n");

		printk(KERN_DEBUG

		"requestor:  times this cpu was the flush requestor\n");

		printk(KERN_DEBUG

		"requestee:  times this cpu was requested to flush its TLBs\n");

		printk(KERN_DEBUG

		"one:        times requested to flush a single address\n");

		printk(KERN_DEBUG

		"all:        times requested to flush all TLB's\n");

		printk(KERN_DEBUG

		"sretry:     number of retries of source-side timeouts\n");

		printk(KERN_DEBUG

		"dretry:     number of retries of destination-side timeouts\n");

		printk(KERN_DEBUG

		"ptc_i:      times UV fell through to IPI-style flushes\n");

		printk(KERN_DEBUG

		"sw_ack:     image of UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE\n");

		printk(KERN_DEBUG

		"sflush_us:  microseconds spent in uv_flush_tlb_others()\n");

		printk(KERN_DEBUG

		"dflush_us:  microseconds spent in handling flush requests\n");

		printk(KERN_DEBUG "sok:        successes on retry\n");

		printk(KERN_DEBUG "dnomsg:     interrupts with no message\n");

		printk(KERN_DEBUG

		"dmult:      interrupts with multiple messages\n");

		printk(KERN_DEBUG "starget:    nodes targeted\n");

	} else {

		uv_bau_retry_limit = newmode;

		printk(KERN_DEBUG "timeout retry limit:%d\n",

		       uv_bau_retry_limit);

	}

	return count;

}

static const struct seq_operations uv_ptc_seq_ops = {

	.start = uv_ptc_seq_start,

	.next = uv_ptc_seq_next,

	.stop = uv_ptc_seq_stop,

	.show = uv_ptc_seq_show

};

static int

uv_ptc_proc_open(struct inode *inode, struct file *file)

{

	return seq_open(file, &uv_ptc_seq_ops);

}

static const struct file_operations proc_uv_ptc_operations = {

	.open = uv_ptc_proc_open,

	.read = seq_read,

	.write = uv_ptc_proc_write,

	.llseek = seq_lseek,

	.release = seq_release,

};

static struct proc_dir_entry *proc_uv_ptc;

static int __init

uv_ptc_init(void)

{

	static struct proc_dir_entry *sgi_proc_dir;

	sgi_proc_dir = NULL;

	if (!is_uv_system())

		return 0;

	sgi_proc_dir = proc_mkdir("sgi_uv", NULL);

	if (!sgi_proc_dir)

		return -EINVAL;

	proc_uv_ptc = create_proc_entry(UV_PTC_BASENAME, 0444, NULL);

	if (!proc_uv_ptc) {

		printk(KERN_ERR "unable to create %s proc entry\n",

		       UV_PTC_BASENAME);

		return -EINVAL;

	}

	proc_uv_ptc->proc_fops = &proc_uv_ptc_operations;

	return 0;

}

static void __exit

uv_ptc_exit(void)

{

	remove_proc_entry(UV_PTC_BASENAME, NULL);

}

module_init(uv_ptc_init);

module_exit(uv_ptc_exit);

/*

 * Initialization of BAU-related structures

 */

int __init

uv_bau_init(void)

{

	int i;

	int j;

	int blade;

	int nblades;

	int *ip;

	int pnode;

	int last_blade;

	int cur_cpu = 0;

	unsigned long pa;

	unsigned long n;

	unsigned long m;

	unsigned long mmr_image;

	unsigned long apicid;

	char *cp;

	struct bau_control *bau_tablesp;

	struct bau_activation_descriptor *adp, *ad2;

	struct bau_payload_queue_entry *pqp;

	struct bau_msg_status *msp;

	struct bau_control *bcp;

	if (!is_uv_system())

		return 0;

	uv_bau_retry_limit = 1;

	if ((sizeof(struct bau_local_cpumask) * BITSPERBYTE) <

	    MAX_CPUS_PER_NODE) {

		printk(KERN_ERR

			"uv_bau_init: bau_local_cpumask.bits too small\n");

		BUG();

	}

	uv_nshift = uv_hub_info->n_val;

	uv_mmask = ((unsigned long)1 << uv_hub_info->n_val) - 1;

	nblades = 0;

	last_blade = -1;

	for_each_online_node(i) {

		blade = uv_node_to_blade_id(i);

		if (blade == last_blade)

			continue;

		last_blade = blade;

		nblades++;

	}

	uv_bau_table_bases = (struct bau_control **)

	    kmalloc(nblades * sizeof(struct bau_control *), GFP_KERNEL);

	if (!uv_bau_table_bases)

		BUG();

	/* better if we had each_online_blade */

	last_blade = -1;

	for_each_online_node(i) {

		blade = uv_node_to_blade_id(i);

		if (blade == last_blade)

			continue;

		last_blade = blade;

		bau_tablesp =

		    kmalloc_node(sizeof(struct bau_control), GFP_KERNEL, i);

		if (!bau_tablesp)

			BUG();

		bau_tablesp->msg_statuses =

		    kmalloc_node(sizeof(struct bau_msg_status) *

				 DESTINATION_PAYLOAD_QUEUE_SIZE, GFP_KERNEL, i);

		if (!bau_tablesp->msg_statuses)

			BUG();

		for (j = 0, msp = bau_tablesp->msg_statuses;

		     j < DESTINATION_PAYLOAD_QUEUE_SIZE; j++, msp++) {

			bau_cpubits_clear(&msp->seen_by, (int)

					  uv_blade_nr_possible_cpus(blade));

		}

		bau_tablesp->watching =

		    kmalloc_node(sizeof(int) * DESTINATION_NUM_RESOURCES,

				 GFP_KERNEL, i);

		if (!bau_tablesp->watching)

			BUG();

		for (j = 0, ip = bau_tablesp->watching;

		     j < DESTINATION_PAYLOAD_QUEUE_SIZE; j++, ip++) {

			*ip = 0;

		}

		uv_bau_table_bases[i] = bau_tablesp;

		pnode = uv_blade_to_pnode(blade);

		if (sizeof(struct bau_activation_descriptor) != 64)

			BUG();

		adp = (struct bau_activation_descriptor *)

		    kmalloc_node(16384, GFP_KERNEL, i);

		if (!adp)

			BUG();

		if ((unsigned long)adp & 0xfff)

			BUG();

		pa = __pa((unsigned long)adp);

		n = pa >> uv_nshift;

		m = pa & uv_mmask;

		mmr_image = uv_read_global_mmr64(pnode,

						 UVH_LB_BAU_SB_DESCRIPTOR_BASE);

		if (mmr_image)

			uv_write_global_mmr64(pnode, (unsigned long)

					      UVH_LB_BAU_SB_DESCRIPTOR_BASE,

					      (n << UV_DESC_BASE_PNODE_SHIFT |

					       m));

		for (j = 0, ad2 = adp; j < UV_ACTIVATION_DESCRIPTOR_SIZE;

		     j++, ad2++) {

			memset(ad2, 0,

			       sizeof(struct bau_activation_descriptor));

			ad2->header.sw_ack_flag = 1;

			ad2->header.base_dest_nodeid =

			    uv_blade_to_pnode(uv_cpu_to_blade_id(0));

			ad2->header.command = UV_NET_ENDPOINT_INTD;

			ad2->header.int_both = 1;

			/* all others need to be set to zero:

			   fairness chaining multilevel count replied_to */

		}

		pqp = (struct bau_payload_queue_entry *)

		    kmalloc_node((DESTINATION_PAYLOAD_QUEUE_SIZE + 1) *