LXR linux/arch/powerpc/sysdev/ehv

   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/smp.h>
  18#include <linux/interrupt.h>
  19#include <linux/slab.h>
  20#include <linux/spinlock.h>
  21#include <linux/of.h>
  22#include <linux/of_address.h>
  23
  24#include <asm/io.h>
  25#include <asm/irq.h>
  26#include <asm/smp.h>
  27#include <asm/machdep.h>
  28#include <asm/ehv_pic.h>
  29#include <asm/fsl_hcalls.h>
  30
  31static struct ehv_pic *global_ehv_pic;
  32static DEFINE_SPINLOCK(ehv_pic_lock);
  33
  34static u32 hwirq_intspec[NR_EHV_PIC_INTS];
  35static u32 __iomem *mpic_percpu_base_vaddr;
  36
  37#define IRQ_TYPE_MPIC_DIRECT 4
  38#define MPIC_EOI  0x00B0
  39
  40/*
  41 * Linux descriptor level callbacks
  42 */
  43
  44void ehv_pic_unmask_irq(struct irq_data *d)
  45{
  46        unsigned int src = virq_to_hw(d->irq);
  47
  48        ev_int_set_mask(src, 0);
  49}
  50
  51void ehv_pic_mask_irq(struct irq_data *d)
  52{
  53        unsigned int src = virq_to_hw(d->irq);
  54
  55        ev_int_set_mask(src, 1);
  56}
  57
  58void ehv_pic_end_irq(struct irq_data *d)
  59{
  60        unsigned int src = virq_to_hw(d->irq);
  61
  62        ev_int_eoi(src);
  63}
  64
  65void ehv_pic_direct_end_irq(struct irq_data *d)
  66{
  67        out_be32(mpic_percpu_base_vaddr + MPIC_EOI / 4, 0);
  68}
  69
  70int ehv_pic_set_affinity(struct irq_data *d, const struct cpumask *dest,
  71                         bool force)
  72{
  73        unsigned int src = virq_to_hw(d->irq);
  74        unsigned int config, prio, cpu_dest;
  75        int cpuid = irq_choose_cpu(dest);
  76        unsigned long flags;
  77
  78        spin_lock_irqsave(&ehv_pic_lock, flags);
  79        ev_int_get_config(src, &config, &prio, &cpu_dest);
  80        ev_int_set_config(src, config, prio, cpuid);
  81        spin_unlock_irqrestore(&ehv_pic_lock, flags);
  82
  83        return IRQ_SET_MASK_OK;
  84}
  85
  86static unsigned int ehv_pic_type_to_vecpri(unsigned int type)
  87{
  88        /* Now convert sense value */
  89
  90        switch (type & IRQ_TYPE_SENSE_MASK) {
  91        case IRQ_TYPE_EDGE_RISING:
  92                return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
  93                       EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
  94
  95        case IRQ_TYPE_EDGE_FALLING:
  96        case IRQ_TYPE_EDGE_BOTH:
  97                return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
  98                       EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
  99
 100        case IRQ_TYPE_LEVEL_HIGH:
 101                return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
 102                       EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
 103
 104        case IRQ_TYPE_LEVEL_LOW:
 105        default:
 106                return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
 107                       EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
 108        }
 109}
 110
 111int ehv_pic_set_irq_type(struct irq_data *d, unsigned int flow_type)
 112{
 113        unsigned int src = virq_to_hw(d->irq);
 114        unsigned int vecpri, vold, vnew, prio, cpu_dest;
 115        unsigned long flags;
 116
 117        if (flow_type == IRQ_TYPE_NONE)
 118                flow_type = IRQ_TYPE_LEVEL_LOW;
 119
 120        irqd_set_trigger_type(d, flow_type);
 121
 122        vecpri = ehv_pic_type_to_vecpri(flow_type);
 123
 124        spin_lock_irqsave(&ehv_pic_lock, flags);
 125        ev_int_get_config(src, &vold, &prio, &cpu_dest);
 126        vnew = vold & ~(EHV_PIC_INFO(VECPRI_POLARITY_MASK) |
 127                        EHV_PIC_INFO(VECPRI_SENSE_MASK));
 128        vnew |= vecpri;
 129
 130        /*
 131         * TODO : Add specific interface call for platform to set
 132         * individual interrupt priorities.
 133         * platform currently using static/default priority for all ints
 134         */
 135
 136        prio = 8;
 137
 138        ev_int_set_config(src, vecpri, prio, cpu_dest);
 139
 140        spin_unlock_irqrestore(&ehv_pic_lock, flags);
 141        return IRQ_SET_MASK_OK_NOCOPY;
 142}
 143
 144static struct irq_chip ehv_pic_irq_chip = {
 145        .irq_mask       = ehv_pic_mask_irq,
 146        .irq_unmask     = ehv_pic_unmask_irq,
 147        .irq_eoi        = ehv_pic_end_irq,
 148        .irq_set_type   = ehv_pic_set_irq_type,
 149};
 150
 151static struct irq_chip ehv_pic_direct_eoi_irq_chip = {
 152        .irq_mask       = ehv_pic_mask_irq,
 153        .irq_unmask     = ehv_pic_unmask_irq,
 154        .irq_eoi        = ehv_pic_direct_end_irq,
 155        .irq_set_type   = ehv_pic_set_irq_type,
 156};
 157
 158/* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
 159unsigned int ehv_pic_get_irq(void)
 160{
 161        int irq;
 162
 163        BUG_ON(global_ehv_pic == NULL);
 164
 165        if (global_ehv_pic->coreint_flag)
 166                irq = mfspr(SPRN_EPR); /* if core int mode */
 167        else
 168                ev_int_iack(0, &irq); /* legacy mode */
 169
 170        if (irq == 0xFFFF)    /* 0xFFFF --> no irq is pending */
 171                return NO_IRQ;
 172
 173        /*
 174         * this will also setup revmap[] in the slow path for the first
 175         * time, next calls will always use fast path by indexing revmap
 176         */
 177        return irq_linear_revmap(global_ehv_pic->irqhost, irq);
 178}
 179
 180static int ehv_pic_host_match(struct irq_domain *h, struct device_node *node,
 181                              enum irq_domain_bus_token bus_token)
 182{
 183        /* Exact match, unless ehv_pic node is NULL */
 184        struct device_node *of_node = irq_domain_get_of_node(h);
 185        return of_node == NULL || of_node == node;
 186}
 187
 188static int ehv_pic_host_map(struct irq_domain *h, unsigned int virq,
 189                         irq_hw_number_t hw)
 190{
 191        struct ehv_pic *ehv_pic = h->host_data;
 192        struct irq_chip *chip;
 193
 194        /* Default chip */
 195        chip = &ehv_pic->hc_irq;
 196
 197        if (mpic_percpu_base_vaddr)
 198                if (hwirq_intspec[hw] & IRQ_TYPE_MPIC_DIRECT)
 199                        chip = &ehv_pic_direct_eoi_irq_chip;
 200
 201        irq_set_chip_data(virq, chip);
 202        /*
 203         * using handle_fasteoi_irq as our irq handler, this will
 204         * only call the eoi callback and suitable for the MPIC
 205         * controller which set ISR/IPR automatically and clear the
 206         * highest priority active interrupt in ISR/IPR when we do
 207         * a specific eoi
 208         */
 209        irq_set_chip_and_handler(virq, chip, handle_fasteoi_irq);
 210
 211        /* Set default irq type */
 212        irq_set_irq_type(virq, IRQ_TYPE_NONE);
 213
 214        return 0;
 215}
 216
 217static int ehv_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 218                           const u32 *intspec, unsigned int intsize,
 219                           irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 220
 221{
 222        /*
 223         * interrupt sense values coming from the guest device tree
 224         * interrupt specifiers can have four possible sense and
 225         * level encoding information and they need to
 226         * be translated between firmware type & linux type.
 227         */
 228
 229        static unsigned char map_of_senses_to_linux_irqtype[4] = {
 230                IRQ_TYPE_EDGE_FALLING,
 231                IRQ_TYPE_EDGE_RISING,
 232                IRQ_TYPE_LEVEL_LOW,
 233                IRQ_TYPE_LEVEL_HIGH,
 234        };
 235
 236        *out_hwirq = intspec[0];
 237        if (intsize > 1) {
 238                hwirq_intspec[intspec[0]] = intspec[1];
 239                *out_flags = map_of_senses_to_linux_irqtype[intspec[1] &
 240                                                        ~IRQ_TYPE_MPIC_DIRECT];
 241        } else {
 242                *out_flags = IRQ_TYPE_NONE;
 243        }
 244
 245        return 0;
 246}
 247
 248static const struct irq_domain_ops ehv_pic_host_ops = {
 249        .match = ehv_pic_host_match,
 250        .map = ehv_pic_host_map,
 251        .xlate = ehv_pic_host_xlate,
 252};
 253
 254void __init ehv_pic_init(void)
 255{
 256        struct device_node *np, *np2;
 257        struct ehv_pic *ehv_pic;
 258        int coreint_flag = 1;
 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        if (!of_find_property(np, "has-external-proxy", NULL))
 267                coreint_flag = 0;
 268
 269        ehv_pic = kzalloc(sizeof(struct ehv_pic), GFP_KERNEL);
 270        if (!ehv_pic) {
 271                of_node_put(np);
 272                return;
 273        }
 274
 275        ehv_pic->irqhost = irq_domain_add_linear(np, NR_EHV_PIC_INTS,
 276                                                 &ehv_pic_host_ops, ehv_pic);
 277        if (!ehv_pic->irqhost) {
 278                of_node_put(np);
 279                kfree(ehv_pic);
 280                return;
 281        }
 282
 283        np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
 284        if (np2) {
 285                mpic_percpu_base_vaddr = of_iomap(np2, 0);
 286                if (!mpic_percpu_base_vaddr)
 287                        pr_err("ehv_pic_init: of_iomap failed\n");
 288
 289                of_node_put(np2);
 290        }
 291
 292        ehv_pic->hc_irq = ehv_pic_irq_chip;
 293        ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
 294        ehv_pic->coreint_flag = coreint_flag;
 295
 296        global_ehv_pic = ehv_pic;
 297        irq_set_default_host(global_ehv_pic->irqhost);
 298}
 299