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