drivers/irqchip/irq-partition-percpu.c

   1 /*
   2  * Copyright (C) 2016 ARM Limited, All Rights Reserved.
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/bitops.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/irqchip.h>
  21 #include <linux/irqchip/chained_irq.h>
  22 #include <linux/irqchip/irq-partition-percpu.h>
  23 #include <linux/irqdomain.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/slab.h>
  26
  27 struct partition_desc {
  28         int                             nr_parts;
  29         struct partition_affinity       *parts;
  30         struct irq_domain               *domain;
  31         struct irq_desc                 *chained_desc;
  32         unsigned long                   *bitmap;
  33         struct irq_domain_ops           ops;
  34 };
  35
  36 static bool partition_check_cpu(struct partition_desc *part,
  37                                 unsigned int cpu, unsigned int hwirq)
  38 {
  39         return cpumask_test_cpu(cpu, &part->parts[hwirq].mask);
  40 }
  41
  42 static void partition_irq_mask(struct irq_data *d)
  43 {
  44         struct partition_desc *part = irq_data_get_irq_chip_data(d);
  45         struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
  46         struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
  47
  48         if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
  49             chip->irq_mask)
  50                 chip->irq_mask(data);
  51 }
  52
  53 static void partition_irq_unmask(struct irq_data *d)
  54 {
  55         struct partition_desc *part = irq_data_get_irq_chip_data(d);
  56         struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
  57         struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
  58
  59         if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
  60             chip->irq_unmask)
  61                 chip->irq_unmask(data);
  62 }
  63
  64 static int partition_irq_set_irqchip_state(struct irq_data *d,
  65                                            enum irqchip_irq_state which,
  66                                            bool val)
  67 {
  68         struct partition_desc *part = irq_data_get_irq_chip_data(d);
  69         struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
  70         struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
  71
  72         if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
  73             chip->irq_set_irqchip_state)
  74                 return chip->irq_set_irqchip_state(data, which, val);
  75
  76         return -EINVAL;
  77 }
  78
  79 static int partition_irq_get_irqchip_state(struct irq_data *d,
  80                                            enum irqchip_irq_state which,
  81                                            bool *val)
  82 {
  83         struct partition_desc *part = irq_data_get_irq_chip_data(d);
  84         struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
  85         struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
  86
  87         if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
  88             chip->irq_get_irqchip_state)
  89                 return chip->irq_get_irqchip_state(data, which, val);
  90
  91         return -EINVAL;
  92 }
  93
  94 static int partition_irq_set_type(struct irq_data *d, unsigned int type)
  95 {
  96         struct partition_desc *part = irq_data_get_irq_chip_data(d);
  97         struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
  98         struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
  99
 100         if (chip->irq_set_type)
 101                 return chip->irq_set_type(data, type);
 102
 103         return -EINVAL;
 104 }
 105
 106 static void partition_irq_print_chip(struct irq_data *d, struct seq_file *p)
 107 {
 108         struct partition_desc *part = irq_data_get_irq_chip_data(d);
 109         struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
 110         struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
 111
 112         seq_printf(p, " %5s-%lu", chip->name, data->hwirq);
 113 }
 114
 115 static struct irq_chip partition_irq_chip = {
 116         .irq_mask               = partition_irq_mask,
 117         .irq_unmask             = partition_irq_unmask,
 118         .irq_set_type           = partition_irq_set_type,
 119         .irq_get_irqchip_state  = partition_irq_get_irqchip_state,
 120         .irq_set_irqchip_state  = partition_irq_set_irqchip_state,
 121         .irq_print_chip         = partition_irq_print_chip,
 122 };
 123
 124 static void partition_handle_irq(struct irq_desc *desc)
 125 {
 126         struct partition_desc *part = irq_desc_get_handler_data(desc);
 127         struct irq_chip *chip = irq_desc_get_chip(desc);
 128         int cpu = smp_processor_id();
 129         int hwirq;
 130
 131         chained_irq_enter(chip, desc);
 132
 133         for_each_set_bit(hwirq, part->bitmap, part->nr_parts) {
 134                 if (partition_check_cpu(part, cpu, hwirq))
 135                         break;
 136         }
 137
 138         if (unlikely(hwirq == part->nr_parts)) {
 139                 handle_bad_irq(desc);
 140         } else {
 141                 unsigned int irq;
 142                 irq = irq_find_mapping(part->domain, hwirq);
 143                 generic_handle_irq(irq);
 144         }
 145
 146         chained_irq_exit(chip, desc);
 147 }
 148
 149 static int partition_domain_alloc(struct irq_domain *domain, unsigned int virq,
 150                                   unsigned int nr_irqs, void *arg)
 151 {
 152         int ret;
 153         irq_hw_number_t hwirq;
 154         unsigned int type;
 155         struct irq_fwspec *fwspec = arg;
 156         struct partition_desc *part;
 157
 158         BUG_ON(nr_irqs != 1);
 159         ret = domain->ops->translate(domain, fwspec, &hwirq, &type);
 160         if (ret)
 161                 return ret;
 162
 163         part = domain->host_data;
 164
 165         set_bit(hwirq, part->bitmap);
 166         irq_set_chained_handler_and_data(irq_desc_get_irq(part->chained_desc),
 167                                          partition_handle_irq, part);
 168         irq_set_percpu_devid_partition(virq, &part->parts[hwirq].mask);
 169         irq_domain_set_info(domain, virq, hwirq, &partition_irq_chip, part,
 170                             handle_percpu_devid_irq, NULL, NULL);
 171         irq_set_status_flags(virq, IRQ_NOAUTOEN);
 172
 173         return 0;
 174 }
 175
 176 static void partition_domain_free(struct irq_domain *domain, unsigned int virq,
 177                                   unsigned int nr_irqs)
 178 {
 179         struct irq_data *d;
 180
 181         BUG_ON(nr_irqs != 1);
 182
 183         d = irq_domain_get_irq_data(domain, virq);
 184         irq_set_handler(virq, NULL);
 185         irq_domain_reset_irq_data(d);
 186 }
 187
 188 int partition_translate_id(struct partition_desc *desc, void *partition_id)
 189 {
 190         struct partition_affinity *part = NULL;
 191         int i;
 192
 193         for (i = 0; i < desc->nr_parts; i++) {
 194                 if (desc->parts[i].partition_id == partition_id) {
 195                         part = &desc->parts[i];
 196                         break;
 197                 }
 198         }
 199
 200         if (WARN_ON(!part)) {
 201                 pr_err("Failed to find partition\n");
 202                 return -EINVAL;
 203         }
 204
 205         return i;
 206 }
 207
 208 struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
 209                                              struct partition_affinity *parts,
 210                                              int nr_parts,
 211                                              int chained_irq,
 212                                              const struct irq_domain_ops *ops)
 213 {
 214         struct partition_desc *desc;
 215         struct irq_domain *d;
 216
 217         BUG_ON(!ops->select || !ops->translate);
 218
 219         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 220         if (!desc)
 221                 return NULL;
 222
 223         desc->ops = *ops;
 224         desc->ops.free = partition_domain_free;
 225         desc->ops.alloc = partition_domain_alloc;
 226
 227         d = irq_domain_create_linear(fwnode, nr_parts, &desc->ops, desc);
 228         if (!d)
 229                 goto out;
 230         desc->domain = d;
 231
 232         desc->bitmap = kzalloc(sizeof(long) * BITS_TO_LONGS(nr_parts),
 233                                GFP_KERNEL);
 234         if (WARN_ON(!desc->bitmap))
 235                 goto out;
 236
 237         desc->chained_desc = irq_to_desc(chained_irq);
 238         desc->nr_parts = nr_parts;
 239         desc->parts = parts;
 240
 241         return desc;
 242 out:
 243         if (d)
 244                 irq_domain_remove(d);
 245         kfree(desc);
 246
 247         return NULL;
 248 }
 249
 250 struct irq_domain *partition_get_domain(struct partition_desc *dsc)
 251 {
 252         if (dsc)
 253                 return dsc->domain;
 254
 255         return NULL;
 256 }