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/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
  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 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 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 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 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 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 0;
  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 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         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
 149 static 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
 156 static 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. */
 164 unsigned 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
 185 static int ehv_pic_host_match(struct irq_host *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
 191 static int ehv_pic_host_map(struct irq_host *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
 220 static int ehv_pic_host_xlate(struct irq_host *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
 251 static struct irq_host_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
 257 void __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_alloc_host(np, IRQ_HOST_MAP_LINEAR,
 279                 NR_EHV_PIC_INTS, &ehv_pic_host_ops, 0);
 280
 281         if (!ehv_pic->irqhost) {
 282                 of_node_put(np);
 283                 kfree(ehv_pic);
 284                 return;
 285         }
 286
 287         np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
 288         if (np2) {
 289                 mpic_percpu_base_vaddr = of_iomap(np2, 0);
 290                 if (!mpic_percpu_base_vaddr)
 291                         pr_err("ehv_pic_init: of_iomap failed\n");
 292
 293                 of_node_put(np2);
 294         }
 295
 296         ehv_pic->irqhost->host_data = ehv_pic;
 297         ehv_pic->hc_irq = ehv_pic_irq_chip;
 298         ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
 299         ehv_pic->coreint_flag = coreint_flag;
 300
 301         global_ehv_pic = ehv_pic;
 302         irq_set_default_host(global_ehv_pic->irqhost);
 303 }