arch/powerpc/sysdev/ehv_pic.c

   1 /*
   2  *  Driver for ePAPR Embedded Hypervisor PIC
   3  *
   4  *  Copyright 2008-2011 Freescale Semiconductor, Inc.
   5  *
   6  *  Author: Ashish Kalra <ashish.kalra@freescale.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public License
   9  * version 2.  This program is licensed "as is" without any warranty of any
  10  * kind, whether express or implied.
  11  */
  12
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/irq.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/smp.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/slab.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/of.h>
  23 #include <linux/of_address.h>
  24
  25 #include <asm/io.h>
  26 #include <asm/irq.h>
  27 #include <asm/smp.h>
  28 #include <asm/machdep.h>
  29 #include <asm/ehv_pic.h>
  30 #include <asm/fsl_hcalls.h>
  31
  32 static struct ehv_pic *global_ehv_pic;
  33 static DEFINE_SPINLOCK(ehv_pic_lock);
  34
  35 static u32 hwirq_intspec[NR_EHV_PIC_INTS];
  36 static u32 __iomem *mpic_percpu_base_vaddr;
  37
  38 #define IRQ_TYPE_MPIC_DIRECT 4
  39 #define MPIC_EOI  0x00B0
  40
  41 /*
  42  * Linux descriptor level callbacks
  43  */
  44
  45 static void ehv_pic_unmask_irq(struct irq_data *d)
  46 {
  47         unsigned int src = virq_to_hw(d->irq);
  48
  49         ev_int_set_mask(src, 0);
  50 }
  51
  52 static void ehv_pic_mask_irq(struct irq_data *d)
  53 {
  54         unsigned int src = virq_to_hw(d->irq);
  55
  56         ev_int_set_mask(src, 1);
  57 }
  58
  59 static void ehv_pic_end_irq(struct irq_data *d)
  60 {
  61         unsigned int src = virq_to_hw(d->irq);
  62
  63         ev_int_eoi(src);
  64 }
  65
  66 static void ehv_pic_direct_end_irq(struct irq_data *d)
  67 {
  68         out_be32(mpic_percpu_base_vaddr + MPIC_EOI / 4, 0);
  69 }
  70
  71 static int ehv_pic_set_affinity(struct irq_data *d, const struct cpumask *dest,
  72                          bool force)
  73 {
  74         unsigned int src = virq_to_hw(d->irq);
  75         unsigned int config, prio, cpu_dest;
  76         int cpuid = irq_choose_cpu(dest);
  77         unsigned long flags;
  78
  79         spin_lock_irqsave(&ehv_pic_lock, flags);
  80         ev_int_get_config(src, &config, &prio, &cpu_dest);
  81         ev_int_set_config(src, config, prio, cpuid);
  82         spin_unlock_irqrestore(&ehv_pic_lock, flags);
  83
  84         return IRQ_SET_MASK_OK;
  85 }
  86
  87 static unsigned int ehv_pic_type_to_vecpri(unsigned int type)
  88 {
  89         /* Now convert sense value */
  90
  91         switch (type & IRQ_TYPE_SENSE_MASK) {
  92         case IRQ_TYPE_EDGE_RISING:
  93                 return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
  94                        EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
  95
  96         case IRQ_TYPE_EDGE_FALLING:
  97         case IRQ_TYPE_EDGE_BOTH:
  98                 return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
  99                        EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
 100
 101         case IRQ_TYPE_LEVEL_HIGH:
 102                 return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
 103                        EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
 104
 105         case IRQ_TYPE_LEVEL_LOW:
 106         default:
 107                 return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
 108                        EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
 109         }
 110 }
 111
 112 static int ehv_pic_set_irq_type(struct irq_data *d, unsigned int flow_type)
 113 {
 114         unsigned int src = virq_to_hw(d->irq);
 115         unsigned int vecpri, vold, vnew, prio, cpu_dest;
 116         unsigned long flags;
 117
 118         if (flow_type == IRQ_TYPE_NONE)
 119                 flow_type = IRQ_TYPE_LEVEL_LOW;
 120
 121         irqd_set_trigger_type(d, flow_type);
 122
 123         vecpri = ehv_pic_type_to_vecpri(flow_type);
 124
 125         spin_lock_irqsave(&ehv_pic_lock, flags);
 126         ev_int_get_config(src, &vold, &prio, &cpu_dest);
 127         vnew = vold & ~(EHV_PIC_INFO(VECPRI_POLARITY_MASK) |
 128                         EHV_PIC_INFO(VECPRI_SENSE_MASK));
 129         vnew |= vecpri;
 130
 131         /*
 132          * TODO : Add specific interface call for platform to set
 133          * individual interrupt priorities.
 134          * platform currently using static/default priority for all ints
 135          */
 136
 137         prio = 8;
 138
 139         ev_int_set_config(src, vecpri, prio, cpu_dest);
 140
 141         spin_unlock_irqrestore(&ehv_pic_lock, flags);
 142         return IRQ_SET_MASK_OK_NOCOPY;
 143 }
 144
 145 static struct irq_chip ehv_pic_irq_chip = {
 146         .irq_mask       = ehv_pic_mask_irq,
 147         .irq_unmask     = ehv_pic_unmask_irq,
 148         .irq_eoi        = ehv_pic_end_irq,
 149         .irq_set_type   = ehv_pic_set_irq_type,
 150 };
 151
 152 static struct irq_chip ehv_pic_direct_eoi_irq_chip = {
 153         .irq_mask       = ehv_pic_mask_irq,
 154         .irq_unmask     = ehv_pic_unmask_irq,
 155         .irq_eoi        = ehv_pic_direct_end_irq,
 156         .irq_set_type   = ehv_pic_set_irq_type,
 157 };
 158
 159 /* Return an interrupt vector or 0 if no interrupt is pending. */
 160 unsigned int ehv_pic_get_irq(void)
 161 {
 162         int irq;
 163
 164         BUG_ON(global_ehv_pic == NULL);
 165
 166         if (global_ehv_pic->coreint_flag)
 167                 irq = mfspr(SPRN_EPR); /* if core int mode */
 168         else
 169                 ev_int_iack(0, &irq); /* legacy mode */
 170
 171         if (irq == 0xFFFF)    /* 0xFFFF --> no irq is pending */
 172                 return 0;
 173
 174         /*
 175          * this will also setup revmap[] in the slow path for the first
 176          * time, next calls will always use fast path by indexing revmap
 177          */
 178         return irq_linear_revmap(global_ehv_pic->irqhost, irq);
 179 }
 180
 181 static int ehv_pic_host_match(struct irq_domain *h, struct device_node *node,
 182                               enum irq_domain_bus_token bus_token)
 183 {
 184         /* Exact match, unless ehv_pic node is NULL */
 185         struct device_node *of_node = irq_domain_get_of_node(h);
 186         return of_node == NULL || of_node == node;
 187 }
 188
 189 static int ehv_pic_host_map(struct irq_domain *h, unsigned int virq,
 190                          irq_hw_number_t hw)
 191 {
 192         struct ehv_pic *ehv_pic = h->host_data;
 193         struct irq_chip *chip;
 194
 195         /* Default chip */
 196         chip = &ehv_pic->hc_irq;
 197
 198         if (mpic_percpu_base_vaddr)
 199                 if (hwirq_intspec[hw] & IRQ_TYPE_MPIC_DIRECT)
 200                         chip = &ehv_pic_direct_eoi_irq_chip;
 201
 202         irq_set_chip_data(virq, chip);
 203         /*
 204          * using handle_fasteoi_irq as our irq handler, this will
 205          * only call the eoi callback and suitable for the MPIC
 206          * controller which set ISR/IPR automatically and clear the
 207          * highest priority active interrupt in ISR/IPR when we do
 208          * a specific eoi
 209          */
 210         irq_set_chip_and_handler(virq, chip, handle_fasteoi_irq);
 211
 212         /* Set default irq type */
 213         irq_set_irq_type(virq, IRQ_TYPE_NONE);
 214
 215         return 0;
 216 }
 217
 218 static int ehv_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 219                            const u32 *intspec, unsigned int intsize,
 220                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 221
 222 {
 223         /*
 224          * interrupt sense values coming from the guest device tree
 225          * interrupt specifiers can have four possible sense and
 226          * level encoding information and they need to
 227          * be translated between firmware type & linux type.
 228          */
 229
 230         static unsigned char map_of_senses_to_linux_irqtype[4] = {
 231                 IRQ_TYPE_EDGE_FALLING,
 232                 IRQ_TYPE_EDGE_RISING,
 233                 IRQ_TYPE_LEVEL_LOW,
 234                 IRQ_TYPE_LEVEL_HIGH,
 235         };
 236
 237         *out_hwirq = intspec[0];
 238         if (intsize > 1) {
 239                 hwirq_intspec[intspec[0]] = intspec[1];
 240                 *out_flags = map_of_senses_to_linux_irqtype[intspec[1] &
 241                                                         ~IRQ_TYPE_MPIC_DIRECT];
 242         } else {
 243                 *out_flags = IRQ_TYPE_NONE;
 244         }
 245
 246         return 0;
 247 }
 248
 249 static const struct irq_domain_ops ehv_pic_host_ops = {
 250         .match = ehv_pic_host_match,
 251         .map = ehv_pic_host_map,
 252         .xlate = ehv_pic_host_xlate,
 253 };
 254
 255 void __init ehv_pic_init(void)
 256 {
 257         struct device_node *np, *np2;
 258         struct ehv_pic *ehv_pic;
 259
 260         np = of_find_compatible_node(NULL, NULL, "epapr,hv-pic");
 261         if (!np) {
 262                 pr_err("ehv_pic_init: could not find epapr,hv-pic node\n");
 263                 return;
 264         }
 265
 266         ehv_pic = kzalloc(sizeof(struct ehv_pic), GFP_KERNEL);
 267         if (!ehv_pic) {
 268                 of_node_put(np);
 269                 return;
 270         }
 271
 272         ehv_pic->irqhost = irq_domain_add_linear(np, NR_EHV_PIC_INTS,
 273                                                  &ehv_pic_host_ops, ehv_pic);
 274         if (!ehv_pic->irqhost) {
 275                 of_node_put(np);
 276                 kfree(ehv_pic);
 277                 return;
 278         }
 279
 280         np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
 281         if (np2) {
 282                 mpic_percpu_base_vaddr = of_iomap(np2, 0);
 283                 if (!mpic_percpu_base_vaddr)
 284                         pr_err("ehv_pic_init: of_iomap failed\n");
 285
 286                 of_node_put(np2);
 287         }
 288
 289         ehv_pic->hc_irq = ehv_pic_irq_chip;
 290         ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
 291         ehv_pic->coreint_flag = of_property_read_bool(np, "has-external-proxy");
 292
 293         global_ehv_pic = ehv_pic;
 294         irq_set_default_host(global_ehv_pic->irqhost);
 295 }