drivers/bus/fsl-mc/fsl-mc-msi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Freescale Management Complex (MC) bus driver MSI support
   4  *
   5  * Copyright (C) 2015-2016 Freescale Semiconductor, Inc.
   6  * Author: German Rivera <German.Rivera@freescale.com>
   7  *
   8  */
   9
  10 #include <linux/of_device.h>
  11 #include <linux/of_address.h>
  12 #include <linux/of_irq.h>
  13 #include <linux/irq.h>
  14 #include <linux/irqdomain.h>
  15 #include <linux/msi.h>
  16 #include <linux/acpi_iort.h>
  17
  18 #include "fsl-mc-private.h"
  19
  20 #ifdef GENERIC_MSI_DOMAIN_OPS
  21 /*
  22  * Generate a unique ID identifying the interrupt (only used within the MSI
  23  * irqdomain.  Combine the icid with the interrupt index.
  24  */
  25 static irq_hw_number_t fsl_mc_domain_calc_hwirq(struct fsl_mc_device *dev,
  26                                                 struct msi_desc *desc)
  27 {
  28         /*
  29          * Make the base hwirq value for ICID*10000 so it is readable
  30          * as a decimal value in /proc/interrupts.
  31          */
  32         return (irq_hw_number_t)(desc->fsl_mc.msi_index + (dev->icid * 10000));
  33 }
  34
  35 static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg,
  36                                 struct msi_desc *desc)
  37 {
  38         arg->desc = desc;
  39         arg->hwirq = fsl_mc_domain_calc_hwirq(to_fsl_mc_device(desc->dev),
  40                                               desc);
  41 }
  42 #else
  43 #define fsl_mc_msi_set_desc NULL
  44 #endif
  45
  46 static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info)
  47 {
  48         struct msi_domain_ops *ops = info->ops;
  49
  50         if (!ops)
  51                 return;
  52
  53         /*
  54          * set_desc should not be set by the caller
  55          */
  56         if (!ops->set_desc)
  57                 ops->set_desc = fsl_mc_msi_set_desc;
  58 }
  59
  60 static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
  61                                    struct fsl_mc_device_irq *mc_dev_irq)
  62 {
  63         int error;
  64         struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev;
  65         struct msi_desc *msi_desc = mc_dev_irq->msi_desc;
  66         struct dprc_irq_cfg irq_cfg;
  67
  68         /*
  69          * msi_desc->msg.address is 0x0 when this function is invoked in
  70          * the free_irq() code path. In this case, for the MC, we don't
  71          * really need to "unprogram" the MSI, so we just return.
  72          */
  73         if (msi_desc->msg.address_lo == 0x0 && msi_desc->msg.address_hi == 0x0)
  74                 return;
  75
  76         if (!owner_mc_dev)
  77                 return;
  78
  79         irq_cfg.paddr = ((u64)msi_desc->msg.address_hi << 32) |
  80                         msi_desc->msg.address_lo;
  81         irq_cfg.val = msi_desc->msg.data;
  82         irq_cfg.irq_num = msi_desc->irq;
  83
  84         if (owner_mc_dev == mc_bus_dev) {
  85                 /*
  86                  * IRQ is for the mc_bus_dev's DPRC itself
  87                  */
  88                 error = dprc_set_irq(mc_bus_dev->mc_io,
  89                                      MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
  90                                      mc_bus_dev->mc_handle,
  91                                      mc_dev_irq->dev_irq_index,
  92                                      &irq_cfg);
  93                 if (error < 0) {
  94                         dev_err(&owner_mc_dev->dev,
  95                                 "dprc_set_irq() failed: %d\n", error);
  96                 }
  97         } else {
  98                 /*
  99                  * IRQ is for for a child device of mc_bus_dev
 100                  */
 101                 error = dprc_set_obj_irq(mc_bus_dev->mc_io,
 102                                          MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
 103                                          mc_bus_dev->mc_handle,
 104                                          owner_mc_dev->obj_desc.type,
 105                                          owner_mc_dev->obj_desc.id,
 106                                          mc_dev_irq->dev_irq_index,
 107                                          &irq_cfg);
 108                 if (error < 0) {
 109                         dev_err(&owner_mc_dev->dev,
 110                                 "dprc_obj_set_irq() failed: %d\n", error);
 111                 }
 112         }
 113 }
 114
 115 /*
 116  * NOTE: This function is invoked with interrupts disabled
 117  */
 118 static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
 119                                  struct msi_msg *msg)
 120 {
 121         struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
 122         struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
 123         struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
 124         struct fsl_mc_device_irq *mc_dev_irq =
 125                 &mc_bus->irq_resources[msi_desc->fsl_mc.msi_index];
 126
 127         msi_desc->msg = *msg;
 128
 129         /*
 130          * Program the MSI (paddr, value) pair in the device:
 131          */
 132         __fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq);
 133 }
 134
 135 static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info)
 136 {
 137         struct irq_chip *chip = info->chip;
 138
 139         if (!chip)
 140                 return;
 141
 142         /*
 143          * irq_write_msi_msg should not be set by the caller
 144          */
 145         if (!chip->irq_write_msi_msg)
 146                 chip->irq_write_msi_msg = fsl_mc_msi_write_msg;
 147 }
 148
 149 /**
 150  * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain
 151  * @np:         Optional device-tree node of the interrupt controller
 152  * @info:       MSI domain info
 153  * @parent:     Parent irq domain
 154  *
 155  * Updates the domain and chip ops and creates a fsl-mc MSI
 156  * interrupt domain.
 157  *
 158  * Returns:
 159  * A domain pointer or NULL in case of failure.
 160  */
 161 struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
 162                                                 struct msi_domain_info *info,
 163                                                 struct irq_domain *parent)
 164 {
 165         struct irq_domain *domain;
 166
 167         if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE)))
 168                 info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
 169         if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
 170                 fsl_mc_msi_update_dom_ops(info);
 171         if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
 172                 fsl_mc_msi_update_chip_ops(info);
 173
 174         domain = msi_create_irq_domain(fwnode, info, parent);
 175         if (domain)
 176                 irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI);
 177
 178         return domain;
 179 }
 180
 181 struct irq_domain *fsl_mc_find_msi_domain(struct device *dev)
 182 {
 183         struct device *root_dprc_dev;
 184         struct device *bus_dev;
 185         struct irq_domain *msi_domain;
 186         struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
 187
 188         fsl_mc_get_root_dprc(dev, &root_dprc_dev);
 189         bus_dev = root_dprc_dev->parent;
 190
 191         if (bus_dev->of_node) {
 192                 msi_domain = of_msi_map_get_device_domain(dev,
 193                                                   mc_dev->icid,
 194                                                   DOMAIN_BUS_FSL_MC_MSI);
 195
 196                 /*
 197                  * if the msi-map property is missing assume that all the
 198                  * child containers inherit the domain from the parent
 199                  */
 200                 if (!msi_domain)
 201
 202                         msi_domain = of_msi_get_domain(bus_dev,
 203                                                 bus_dev->of_node,
 204                                                 DOMAIN_BUS_FSL_MC_MSI);
 205         } else {
 206                 msi_domain = iort_get_device_domain(dev, mc_dev->icid,
 207                                                     DOMAIN_BUS_FSL_MC_MSI);
 208         }
 209
 210         return msi_domain;
 211 }
 212
 213 static void fsl_mc_msi_free_descs(struct device *dev)
 214 {
 215         struct msi_desc *desc, *tmp;
 216
 217         list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {
 218                 list_del(&desc->list);
 219                 free_msi_entry(desc);
 220         }
 221 }
 222
 223 static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
 224
 225 {
 226         unsigned int i;
 227         int error;
 228         struct msi_desc *msi_desc;
 229
 230         for (i = 0; i < irq_count; i++) {
 231                 msi_desc = alloc_msi_entry(dev, 1, NULL);
 232                 if (!msi_desc) {
 233                         dev_err(dev, "Failed to allocate msi entry\n");
 234                         error = -ENOMEM;
 235                         goto cleanup_msi_descs;
 236                 }
 237
 238                 msi_desc->fsl_mc.msi_index = i;
 239                 INIT_LIST_HEAD(&msi_desc->list);
 240                 list_add_tail(&msi_desc->list, dev_to_msi_list(dev));
 241         }
 242
 243         return 0;
 244
 245 cleanup_msi_descs:
 246         fsl_mc_msi_free_descs(dev);
 247         return error;
 248 }
 249
 250 int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
 251                                  unsigned int irq_count)
 252 {
 253         struct irq_domain *msi_domain;
 254         int error;
 255
 256         if (!list_empty(dev_to_msi_list(dev)))
 257                 return -EINVAL;
 258
 259         error = fsl_mc_msi_alloc_descs(dev, irq_count);
 260         if (error < 0)
 261                 return error;
 262
 263         msi_domain = dev_get_msi_domain(dev);
 264         if (!msi_domain) {
 265                 error = -EINVAL;
 266                 goto cleanup_msi_descs;
 267         }
 268
 269         /*
 270          * NOTE: Calling this function will trigger the invocation of the
 271          * its_fsl_mc_msi_prepare() callback
 272          */
 273         error = msi_domain_alloc_irqs(msi_domain, dev, irq_count);
 274
 275         if (error) {
 276                 dev_err(dev, "Failed to allocate IRQs\n");
 277                 goto cleanup_msi_descs;
 278         }
 279
 280         return 0;
 281
 282 cleanup_msi_descs:
 283         fsl_mc_msi_free_descs(dev);
 284         return error;
 285 }
 286
 287 void fsl_mc_msi_domain_free_irqs(struct device *dev)
 288 {
 289         struct irq_domain *msi_domain;
 290
 291         msi_domain = dev_get_msi_domain(dev);
 292         if (!msi_domain)
 293                 return;
 294
 295         msi_domain_free_irqs(msi_domain, dev);
 296
 297         if (list_empty(dev_to_msi_list(dev)))
 298                 return;
 299
 300         fsl_mc_msi_free_descs(dev);
 301 }