arch/x86/platform/uv/uv_irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * SGI UV IRQ functions
   7  *
   8  * Copyright (C) 2008 Silicon Graphics, Inc. All rights reserved.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/rbtree.h>
  13 #include <linux/slab.h>
  14 #include <linux/irq.h>
  15
  16 #include <asm/apic.h>
  17 #include <asm/uv/uv_irq.h>
  18 #include <asm/uv/uv_hub.h>
  19
  20 /* MMR offset and pnode of hub sourcing interrupts for a given irq */
  21 struct uv_irq_2_mmr_pnode{
  22         struct rb_node          list;
  23         unsigned long           offset;
  24         int                     pnode;
  25         int                     irq;
  26 };
  27
  28 static spinlock_t               uv_irq_lock;
  29 static struct rb_root           uv_irq_root;
  30
  31 static int uv_set_irq_affinity(struct irq_data *, const struct cpumask *, bool);
  32
  33 static void uv_noop(struct irq_data *data) { }
  34
  35 static void uv_ack_apic(struct irq_data *data)
  36 {
  37         ack_APIC_irq();
  38 }
  39
  40 static struct irq_chip uv_irq_chip = {
  41         .name                   = "UV-CORE",
  42         .irq_mask               = uv_noop,
  43         .irq_unmask             = uv_noop,
  44         .irq_eoi                = uv_ack_apic,
  45         .irq_set_affinity       = uv_set_irq_affinity,
  46 };
  47
  48 /*
  49  * Add offset and pnode information of the hub sourcing interrupts to the
  50  * rb tree for a specific irq.
  51  */
  52 static int uv_set_irq_2_mmr_info(int irq, unsigned long offset, unsigned blade)
  53 {
  54         struct rb_node **link = &uv_irq_root.rb_node;
  55         struct rb_node *parent = NULL;
  56         struct uv_irq_2_mmr_pnode *n;
  57         struct uv_irq_2_mmr_pnode *e;
  58         unsigned long irqflags;
  59
  60         n = kmalloc_node(sizeof(struct uv_irq_2_mmr_pnode), GFP_KERNEL,
  61                                 uv_blade_to_memory_nid(blade));
  62         if (!n)
  63                 return -ENOMEM;
  64
  65         n->irq = irq;
  66         n->offset = offset;
  67         n->pnode = uv_blade_to_pnode(blade);
  68         spin_lock_irqsave(&uv_irq_lock, irqflags);
  69         /* Find the right place in the rbtree: */
  70         while (*link) {
  71                 parent = *link;
  72                 e = rb_entry(parent, struct uv_irq_2_mmr_pnode, list);
  73
  74                 if (unlikely(irq == e->irq)) {
  75                         /* irq entry exists */
  76                         e->pnode = uv_blade_to_pnode(blade);
  77                         e->offset = offset;
  78                         spin_unlock_irqrestore(&uv_irq_lock, irqflags);
  79                         kfree(n);
  80                         return 0;
  81                 }
  82
  83                 if (irq < e->irq)
  84                         link = &(*link)->rb_left;
  85                 else
  86                         link = &(*link)->rb_right;
  87         }
  88
  89         /* Insert the node into the rbtree. */
  90         rb_link_node(&n->list, parent, link);
  91         rb_insert_color(&n->list, &uv_irq_root);
  92
  93         spin_unlock_irqrestore(&uv_irq_lock, irqflags);
  94         return 0;
  95 }
  96
  97 /* Retrieve offset and pnode information from the rb tree for a specific irq */
  98 int uv_irq_2_mmr_info(int irq, unsigned long *offset, int *pnode)
  99 {
 100         struct uv_irq_2_mmr_pnode *e;
 101         struct rb_node *n;
 102         unsigned long irqflags;
 103
 104         spin_lock_irqsave(&uv_irq_lock, irqflags);
 105         n = uv_irq_root.rb_node;
 106         while (n) {
 107                 e = rb_entry(n, struct uv_irq_2_mmr_pnode, list);
 108
 109                 if (e->irq == irq) {
 110                         *offset = e->offset;
 111                         *pnode = e->pnode;
 112                         spin_unlock_irqrestore(&uv_irq_lock, irqflags);
 113                         return 0;
 114                 }
 115
 116                 if (irq < e->irq)
 117                         n = n->rb_left;
 118                 else
 119                         n = n->rb_right;
 120         }
 121         spin_unlock_irqrestore(&uv_irq_lock, irqflags);
 122         return -1;
 123 }
 124
 125 /*
 126  * Re-target the irq to the specified CPU and enable the specified MMR located
 127  * on the specified blade to allow the sending of MSIs to the specified CPU.
 128  */
 129 static int
 130 arch_enable_uv_irq(char *irq_name, unsigned int irq, int cpu, int mmr_blade,
 131                        unsigned long mmr_offset, int limit)
 132 {
 133         const struct cpumask *eligible_cpu = cpumask_of(cpu);
 134         struct irq_cfg *cfg = irq_get_chip_data(irq);
 135         unsigned long mmr_value;
 136         struct uv_IO_APIC_route_entry *entry;
 137         int mmr_pnode, err;
 138
 139         BUILD_BUG_ON(sizeof(struct uv_IO_APIC_route_entry) !=
 140                         sizeof(unsigned long));
 141
 142         err = assign_irq_vector(irq, cfg, eligible_cpu);
 143         if (err != 0)
 144                 return err;
 145
 146         if (limit == UV_AFFINITY_CPU)
 147                 irq_set_status_flags(irq, IRQ_NO_BALANCING);
 148         else
 149                 irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
 150
 151         irq_set_chip_and_handler_name(irq, &uv_irq_chip, handle_percpu_irq,
 152                                       irq_name);
 153
 154         mmr_value = 0;
 155         entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
 156         entry->vector           = cfg->vector;
 157         entry->delivery_mode    = apic->irq_delivery_mode;
 158         entry->dest_mode        = apic->irq_dest_mode;
 159         entry->polarity         = 0;
 160         entry->trigger          = 0;
 161         entry->mask             = 0;
 162         entry->dest             = apic->cpu_mask_to_apicid(eligible_cpu);
 163
 164         mmr_pnode = uv_blade_to_pnode(mmr_blade);
 165         uv_write_global_mmr64(mmr_pnode, mmr_offset, mmr_value);
 166
 167         if (cfg->move_in_progress)
 168                 send_cleanup_vector(cfg);
 169
 170         return irq;
 171 }
 172
 173 /*
 174  * Disable the specified MMR located on the specified blade so that MSIs are
 175  * longer allowed to be sent.
 176  */
 177 static void arch_disable_uv_irq(int mmr_pnode, unsigned long mmr_offset)
 178 {
 179         unsigned long mmr_value;
 180         struct uv_IO_APIC_route_entry *entry;
 181
 182         BUILD_BUG_ON(sizeof(struct uv_IO_APIC_route_entry) !=
 183                         sizeof(unsigned long));
 184
 185         mmr_value = 0;
 186         entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
 187         entry->mask = 1;
 188
 189         uv_write_global_mmr64(mmr_pnode, mmr_offset, mmr_value);
 190 }
 191
 192 static int
 193 uv_set_irq_affinity(struct irq_data *data, const struct cpumask *mask,
 194                     bool force)
 195 {
 196         struct irq_cfg *cfg = data->chip_data;
 197         unsigned int dest;
 198         unsigned long mmr_value, mmr_offset;
 199         struct uv_IO_APIC_route_entry *entry;
 200         int mmr_pnode;
 201
 202         if (__ioapic_set_affinity(data, mask, &dest))
 203                 return -1;
 204
 205         mmr_value = 0;
 206         entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
 207
 208         entry->vector           = cfg->vector;
 209         entry->delivery_mode    = apic->irq_delivery_mode;
 210         entry->dest_mode        = apic->irq_dest_mode;
 211         entry->polarity         = 0;
 212         entry->trigger          = 0;
 213         entry->mask             = 0;
 214         entry->dest             = dest;
 215
 216         /* Get previously stored MMR and pnode of hub sourcing interrupts */
 217         if (uv_irq_2_mmr_info(data->irq, &mmr_offset, &mmr_pnode))
 218                 return -1;
 219
 220         uv_write_global_mmr64(mmr_pnode, mmr_offset, mmr_value);
 221
 222         if (cfg->move_in_progress)
 223                 send_cleanup_vector(cfg);
 224
 225         return 0;
 226 }
 227
 228 /*
 229  * Set up a mapping of an available irq and vector, and enable the specified
 230  * MMR that defines the MSI that is to be sent to the specified CPU when an
 231  * interrupt is raised.
 232  */
 233 int uv_setup_irq(char *irq_name, int cpu, int mmr_blade,
 234                  unsigned long mmr_offset, int limit)
 235 {
 236         int irq, ret;
 237
 238         irq = create_irq_nr(NR_IRQS_LEGACY, uv_blade_to_memory_nid(mmr_blade));
 239
 240         if (irq <= 0)
 241                 return -EBUSY;
 242
 243         ret = arch_enable_uv_irq(irq_name, irq, cpu, mmr_blade, mmr_offset,
 244                 limit);
 245         if (ret == irq)
 246                 uv_set_irq_2_mmr_info(irq, mmr_offset, mmr_blade);
 247         else
 248                 destroy_irq(irq);
 249
 250         return ret;
 251 }
 252 EXPORT_SYMBOL_GPL(uv_setup_irq);
 253
 254 /*
 255  * Tear down a mapping of an irq and vector, and disable the specified MMR that
 256  * defined the MSI that was to be sent to the specified CPU when an interrupt
 257  * was raised.
 258  *
 259  * Set mmr_blade and mmr_offset to what was passed in on uv_setup_irq().
 260  */
 261 void uv_teardown_irq(unsigned int irq)
 262 {
 263         struct uv_irq_2_mmr_pnode *e;
 264         struct rb_node *n;
 265         unsigned long irqflags;
 266
 267         spin_lock_irqsave(&uv_irq_lock, irqflags);
 268         n = uv_irq_root.rb_node;
 269         while (n) {
 270                 e = rb_entry(n, struct uv_irq_2_mmr_pnode, list);
 271                 if (e->irq == irq) {
 272                         arch_disable_uv_irq(e->pnode, e->offset);
 273                         rb_erase(n, &uv_irq_root);
 274                         kfree(e);
 275                         break;
 276                 }
 277                 if (irq < e->irq)
 278                         n = n->rb_left;
 279                 else
 280                         n = n->rb_right;
 281         }
 282         spin_unlock_irqrestore(&uv_irq_lock, irqflags);
 283         destroy_irq(irq);
 284 }
 285 EXPORT_SYMBOL_GPL(uv_teardown_irq);