drivers/parisc/gsc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Interrupt management for most GSC and related devices.
   4  *
   5  * (c) Copyright 1999 Alex deVries for The Puffin Group
   6  * (c) Copyright 1999 Grant Grundler for Hewlett-Packard
   7  * (c) Copyright 1999 Matthew Wilcox
   8  * (c) Copyright 2000 Helge Deller
   9  * (c) Copyright 2001 Matthew Wilcox for Hewlett-Packard
  10  */
  11
  12 #include <linux/bitops.h>
  13 #include <linux/errno.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ioport.h>
  17 #include <linux/module.h>
  18 #include <linux/types.h>
  19
  20 #include <asm/hardware.h>
  21 #include <asm/io.h>
  22
  23 #include "gsc.h"
  24
  25 #undef DEBUG
  26
  27 #ifdef DEBUG
  28 #define DEBPRINTK printk
  29 #else
  30 #define DEBPRINTK(x,...)
  31 #endif
  32
  33 int gsc_alloc_irq(struct gsc_irq *i)
  34 {
  35         int irq = txn_alloc_irq(GSC_EIM_WIDTH);
  36         if (irq < 0) {
  37                 printk("cannot get irq\n");
  38                 return irq;
  39         }
  40
  41         i->txn_addr = txn_alloc_addr(irq);
  42         i->txn_data = txn_alloc_data(irq);
  43         i->irq = irq;
  44
  45         return irq;
  46 }
  47
  48 int gsc_claim_irq(struct gsc_irq *i, int irq)
  49 {
  50         int c = irq;
  51
  52         irq += CPU_IRQ_BASE; /* virtualize the IRQ first */
  53
  54         irq = txn_claim_irq(irq);
  55         if (irq < 0) {
  56                 printk("cannot claim irq %d\n", c);
  57                 return irq;
  58         }
  59
  60         i->txn_addr = txn_alloc_addr(irq);
  61         i->txn_data = txn_alloc_data(irq);
  62         i->irq = irq;
  63
  64         return irq;
  65 }
  66
  67 EXPORT_SYMBOL(gsc_alloc_irq);
  68 EXPORT_SYMBOL(gsc_claim_irq);
  69
  70 /* Common interrupt demultiplexer used by Asp, Lasi & Wax.  */
  71 irqreturn_t gsc_asic_intr(int gsc_asic_irq, void *dev)
  72 {
  73         unsigned long irr;
  74         struct gsc_asic *gsc_asic = dev;
  75
  76         irr = gsc_readl(gsc_asic->hpa + OFFSET_IRR);
  77         if (irr == 0)
  78                 return IRQ_NONE;
  79
  80         DEBPRINTK("%s intr, mask=0x%x\n", gsc_asic->name, irr);
  81
  82         do {
  83                 int local_irq = __ffs(irr);
  84                 unsigned int irq = gsc_asic->global_irq[local_irq];
  85                 generic_handle_irq(irq);
  86                 irr &= ~(1 << local_irq);
  87         } while (irr);
  88
  89         return IRQ_HANDLED;
  90 }
  91
  92 int gsc_find_local_irq(unsigned int irq, int *global_irqs, int limit)
  93 {
  94         int local_irq;
  95
  96         for (local_irq = 0; local_irq < limit; local_irq++) {
  97                 if (global_irqs[local_irq] == irq)
  98                         return local_irq;
  99         }
 100
 101         return NO_IRQ;
 102 }
 103
 104 static void gsc_asic_mask_irq(struct irq_data *d)
 105 {
 106         struct gsc_asic *irq_dev = irq_data_get_irq_chip_data(d);
 107         int local_irq = gsc_find_local_irq(d->irq, irq_dev->global_irq, 32);
 108         u32 imr;
 109
 110         DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, d->irq,
 111                         irq_dev->name, imr);
 112
 113         /* Disable the IRQ line by clearing the bit in the IMR */
 114         imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
 115         imr &= ~(1 << local_irq);
 116         gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
 117 }
 118
 119 static void gsc_asic_unmask_irq(struct irq_data *d)
 120 {
 121         struct gsc_asic *irq_dev = irq_data_get_irq_chip_data(d);
 122         int local_irq = gsc_find_local_irq(d->irq, irq_dev->global_irq, 32);
 123         u32 imr;
 124
 125         DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, d->irq,
 126                         irq_dev->name, imr);
 127
 128         /* Enable the IRQ line by setting the bit in the IMR */
 129         imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
 130         imr |= 1 << local_irq;
 131         gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
 132         /*
 133          * FIXME: read IPR to make sure the IRQ isn't already pending.
 134          *   If so, we need to read IRR and manually call do_irq().
 135          */
 136 }
 137
 138 #ifdef CONFIG_SMP
 139 static int gsc_set_affinity_irq(struct irq_data *d, const struct cpumask *dest,
 140                                 bool force)
 141 {
 142         struct gsc_asic *gsc_dev = irq_data_get_irq_chip_data(d);
 143         struct cpumask tmask;
 144         int cpu_irq;
 145
 146         if (!cpumask_and(&tmask, dest, cpu_online_mask))
 147                 return -EINVAL;
 148
 149         cpu_irq = cpu_check_affinity(d, &tmask);
 150         if (cpu_irq < 0)
 151                 return cpu_irq;
 152
 153         gsc_dev->gsc_irq.txn_addr = txn_affinity_addr(d->irq, cpu_irq);
 154         gsc_dev->eim = ((u32) gsc_dev->gsc_irq.txn_addr) | gsc_dev->gsc_irq.txn_data;
 155
 156         /* switch IRQ's for devices below LASI/WAX to other CPU */
 157         gsc_writel(gsc_dev->eim, gsc_dev->hpa + OFFSET_IAR);
 158
 159         irq_data_update_effective_affinity(d, &tmask);
 160
 161         return IRQ_SET_MASK_OK;
 162 }
 163 #endif
 164
 165
 166 static struct irq_chip gsc_asic_interrupt_type = {
 167         .name           =       "GSC-ASIC",
 168         .irq_unmask     =       gsc_asic_unmask_irq,
 169         .irq_mask       =       gsc_asic_mask_irq,
 170 #ifdef CONFIG_SMP
 171         .irq_set_affinity =     gsc_set_affinity_irq,
 172 #endif
 173 };
 174
 175 int gsc_assign_irq(struct irq_chip *type, void *data)
 176 {
 177         static int irq = GSC_IRQ_BASE;
 178
 179         if (irq > GSC_IRQ_MAX)
 180                 return NO_IRQ;
 181
 182         irq_set_chip_and_handler(irq, type, handle_simple_irq);
 183         irq_set_chip_data(irq, data);
 184
 185         return irq++;
 186 }
 187
 188 void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp)
 189 {
 190         int irq = asic->global_irq[local_irq];
 191
 192         if (irq <= 0) {
 193                 irq = gsc_assign_irq(&gsc_asic_interrupt_type, asic);
 194                 if (irq == NO_IRQ)
 195                         return;
 196
 197                 asic->global_irq[local_irq] = irq;
 198         }
 199         *irqp = irq;
 200 }
 201
 202 struct gsc_fixup_struct {
 203         void (*choose_irq)(struct parisc_device *, void *);
 204         void *ctrl;
 205 };
 206
 207 static int gsc_fixup_irqs_callback(struct device *dev, void *data)
 208 {
 209         struct parisc_device *padev = to_parisc_device(dev);
 210         struct gsc_fixup_struct *gf = data;
 211
 212         /* work-around for 715/64 and others which have parent
 213            at path [5] and children at path [5/0/x] */
 214         if (padev->id.hw_type == HPHW_FAULTY)
 215                 gsc_fixup_irqs(padev, gf->ctrl, gf->choose_irq);
 216         gf->choose_irq(padev, gf->ctrl);
 217
 218         return 0;
 219 }
 220
 221 void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
 222                         void (*choose_irq)(struct parisc_device *, void *))
 223 {
 224         struct gsc_fixup_struct data = {
 225                 .choose_irq     = choose_irq,
 226                 .ctrl           = ctrl,
 227         };
 228
 229         device_for_each_child(&parent->dev, &data, gsc_fixup_irqs_callback);
 230 }
 231
 232 int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic)
 233 {
 234         struct resource *res;
 235         int i;
 236
 237         gsc_asic->gsc = parent;
 238
 239         /* Initialise local irq -> global irq mapping */
 240         for (i = 0; i < 32; i++) {
 241                 gsc_asic->global_irq[i] = NO_IRQ;
 242         }
 243
 244         /* allocate resource region */
 245         res = request_mem_region(gsc_asic->hpa, 0x100000, gsc_asic->name);
 246         if (res) {
 247                 res->flags = IORESOURCE_MEM;    /* do not mark it busy ! */
 248         }
 249
 250 #if 0
 251         printk(KERN_WARNING "%s IRQ %d EIM 0x%x", gsc_asic->name,
 252                         parent->irq, gsc_asic->eim);
 253         if (gsc_readl(gsc_asic->hpa + OFFSET_IMR))
 254                 printk("  IMR is non-zero! (0x%x)",
 255                                 gsc_readl(gsc_asic->hpa + OFFSET_IMR));
 256         printk("\n");
 257 #endif
 258
 259         return 0;
 260 }