linux/arch/powerpc/sysdev/ehv_pic.c
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   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
  23#include <asm/io.h>
  24#include <asm/irq.h>
  25#include <asm/smp.h>
  26#include <asm/machdep.h>
  27#include <asm/ehv_pic.h>
  28#include <asm/fsl_hcalls.h>
  29
  30#include "../../../kernel/irq/settings.h"
  31
  32static struct ehv_pic *global_ehv_pic;
  33static DEFINE_SPINLOCK(ehv_pic_lock);
  34
  35static u32 hwirq_intspec[NR_EHV_PIC_INTS];
  36static 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
  45void 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
  52void 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
  59void 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
  66void ehv_pic_direct_end_irq(struct irq_data *d)
  67{
  68        out_be32(mpic_percpu_base_vaddr + MPIC_EOI / 4, 0);
  69}
  70
  71int 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
  87static 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
 112int ehv_pic_set_irq_type(struct irq_data *d, unsigned int flow_type)
 113{
 114        unsigned int src = virq_to_hw(d->irq);
 115        struct irq_desc *desc = irq_to_desc(d->irq);
 116        unsigned int vecpri, vold, vnew, prio, cpu_dest;
 117        unsigned long flags;
 118
 119        if (flow_type == IRQ_TYPE_NONE)
 120                flow_type = IRQ_TYPE_LEVEL_LOW;
 121
 122        irq_settings_clr_level(desc);
 123        irq_settings_set_trigger_mask(desc, flow_type);
 124        if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
 125                irq_settings_set_level(desc);
 126
 127        vecpri = ehv_pic_type_to_vecpri(flow_type);
 128
 129        spin_lock_irqsave(&ehv_pic_lock, flags);
 130        ev_int_get_config(src, &vold, &prio, &cpu_dest);
 131        vnew = vold & ~(EHV_PIC_INFO(VECPRI_POLARITY_MASK) |
 132                        EHV_PIC_INFO(VECPRI_SENSE_MASK));
 133        vnew |= vecpri;
 134
 135        /*
 136         * TODO : Add specific interface call for platform to set
 137         * individual interrupt priorities.
 138         * platform currently using static/default priority for all ints
 139         */
 140
 141        prio = 8;
 142
 143        ev_int_set_config(src, vecpri, prio, cpu_dest);
 144
 145        spin_unlock_irqrestore(&ehv_pic_lock, flags);
 146        return 0;
 147}
 148
 149static struct irq_chip ehv_pic_irq_chip = {
 150        .irq_mask       = ehv_pic_mask_irq,
 151        .irq_unmask     = ehv_pic_unmask_irq,
 152        .irq_eoi        = ehv_pic_end_irq,
 153        .irq_set_type   = ehv_pic_set_irq_type,
 154};
 155
 156static struct irq_chip ehv_pic_direct_eoi_irq_chip = {
 157        .irq_mask       = ehv_pic_mask_irq,
 158        .irq_unmask     = ehv_pic_unmask_irq,
 159        .irq_eoi        = ehv_pic_direct_end_irq,
 160        .irq_set_type   = ehv_pic_set_irq_type,
 161};
 162
 163/* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
 164unsigned int ehv_pic_get_irq(void)
 165{
 166        int irq;
 167
 168        BUG_ON(global_ehv_pic == NULL);
 169
 170        if (global_ehv_pic->coreint_flag)
 171                irq = mfspr(SPRN_EPR); /* if core int mode */
 172        else
 173                ev_int_iack(0, &irq); /* legacy mode */
 174
 175        if (irq == 0xFFFF)    /* 0xFFFF --> no irq is pending */
 176                return NO_IRQ;
 177
 178        /*
 179         * this will also setup revmap[] in the slow path for the first
 180         * time, next calls will always use fast path by indexing revmap
 181         */
 182        return irq_linear_revmap(global_ehv_pic->irqhost, irq);
 183}
 184
 185static int ehv_pic_host_match(struct irq_domain *h, struct device_node *node)
 186{
 187        /* Exact match, unless ehv_pic node is NULL */
 188        return h->of_node == NULL || h->of_node == node;
 189}
 190
 191static int ehv_pic_host_map(struct irq_domain *h, unsigned int virq,
 192                         irq_hw_number_t hw)
 193{
 194        struct ehv_pic *ehv_pic = h->host_data;
 195        struct irq_chip *chip;
 196
 197        /* Default chip */
 198        chip = &ehv_pic->hc_irq;
 199
 200        if (mpic_percpu_base_vaddr)
 201                if (hwirq_intspec[hw] & IRQ_TYPE_MPIC_DIRECT)
 202                        chip = &ehv_pic_direct_eoi_irq_chip;
 203
 204        irq_set_chip_data(virq, chip);
 205        /*
 206         * using handle_fasteoi_irq as our irq handler, this will
 207         * only call the eoi callback and suitable for the MPIC
 208         * controller which set ISR/IPR automatically and clear the
 209         * highest priority active interrupt in ISR/IPR when we do
 210         * a specific eoi
 211         */
 212        irq_set_chip_and_handler(virq, chip, handle_fasteoi_irq);
 213
 214        /* Set default irq type */
 215        irq_set_irq_type(virq, IRQ_TYPE_NONE);
 216
 217        return 0;
 218}
 219
 220static int ehv_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 221                           const u32 *intspec, unsigned int intsize,
 222                           irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 223
 224{
 225        /*
 226         * interrupt sense values coming from the guest device tree
 227         * interrupt specifiers can have four possible sense and
 228         * level encoding information and they need to
 229         * be translated between firmware type & linux type.
 230         */
 231
 232        static unsigned char map_of_senses_to_linux_irqtype[4] = {
 233                IRQ_TYPE_EDGE_FALLING,
 234                IRQ_TYPE_EDGE_RISING,
 235                IRQ_TYPE_LEVEL_LOW,
 236                IRQ_TYPE_LEVEL_HIGH,
 237        };
 238
 239        *out_hwirq = intspec[0];
 240        if (intsize > 1) {
 241                hwirq_intspec[intspec[0]] = intspec[1];
 242                *out_flags = map_of_senses_to_linux_irqtype[intspec[1] &
 243                                                        ~IRQ_TYPE_MPIC_DIRECT];
 244        } else {
 245                *out_flags = IRQ_TYPE_NONE;
 246        }
 247
 248        return 0;
 249}
 250
 251static const struct irq_domain_ops ehv_pic_host_ops = {
 252        .match = ehv_pic_host_match,
 253        .map = ehv_pic_host_map,
 254        .xlate = ehv_pic_host_xlate,
 255};
 256
 257void __init ehv_pic_init(void)
 258{
 259        struct device_node *np, *np2;
 260        struct ehv_pic *ehv_pic;
 261        int coreint_flag = 1;
 262
 263        np = of_find_compatible_node(NULL, NULL, "epapr,hv-pic");
 264        if (!np) {
 265                pr_err("ehv_pic_init: could not find epapr,hv-pic node\n");
 266                return;
 267        }
 268
 269        if (!of_find_property(np, "has-external-proxy", NULL))
 270                coreint_flag = 0;
 271
 272        ehv_pic = kzalloc(sizeof(struct ehv_pic), GFP_KERNEL);
 273        if (!ehv_pic) {
 274                of_node_put(np);
 275                return;
 276        }
 277
 278        ehv_pic->irqhost = irq_domain_add_linear(np, NR_EHV_PIC_INTS,
 279                                                 &ehv_pic_host_ops, ehv_pic);
 280        if (!ehv_pic->irqhost) {
 281                of_node_put(np);
 282                kfree(ehv_pic);
 283                return;
 284        }
 285
 286        np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
 287        if (np2) {
 288                mpic_percpu_base_vaddr = of_iomap(np2, 0);
 289                if (!mpic_percpu_base_vaddr)
 290                        pr_err("ehv_pic_init: of_iomap failed\n");
 291
 292                of_node_put(np2);
 293        }
 294
 295        ehv_pic->hc_irq = ehv_pic_irq_chip;
 296        ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
 297        ehv_pic->coreint_flag = coreint_flag;
 298
 299        global_ehv_pic = ehv_pic;
 300        irq_set_default_host(global_ehv_pic->irqhost);
 301}
 302