drivers/staging/fsl-mc/bus/irq-gic-v3-its-fsl-mc-msi.c

   1 /*
   2  * Freescale Management Complex (MC) bus driver MSI support
   3  *
   4  * Copyright (C) 2015-2016 Freescale Semiconductor, Inc.
   5  * Author: German Rivera <German.Rivera@freescale.com>
   6  *
   7  * This file is licensed under the terms of the GNU General Public
   8  * License version 2. This program is licensed "as is" without any
   9  * warranty of any kind, whether express or implied.
  10  */
  11
  12 #include <linux/of_device.h>
  13 #include <linux/of_address.h>
  14 #include <linux/irqchip/arm-gic-v3.h>
  15 #include <linux/irq.h>
  16 #include <linux/msi.h>
  17 #include <linux/of.h>
  18 #include <linux/of_irq.h>
  19 #include "fsl-mc-private.h"
  20
  21 static struct irq_chip its_msi_irq_chip = {
  22         .name = "ITS-fMSI",
  23         .irq_mask = irq_chip_mask_parent,
  24         .irq_unmask = irq_chip_unmask_parent,
  25         .irq_eoi = irq_chip_eoi_parent,
  26         .irq_set_affinity = msi_domain_set_affinity
  27 };
  28
  29 static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
  30                                   struct device *dev,
  31                                   int nvec, msi_alloc_info_t *info)
  32 {
  33         struct fsl_mc_device *mc_bus_dev;
  34         struct msi_domain_info *msi_info;
  35
  36         if (WARN_ON(!dev_is_fsl_mc(dev)))
  37                 return -EINVAL;
  38
  39         mc_bus_dev = to_fsl_mc_device(dev);
  40         if (WARN_ON(!(mc_bus_dev->flags & FSL_MC_IS_DPRC)))
  41                 return -EINVAL;
  42
  43         /*
  44          * Set the device Id to be passed to the GIC-ITS:
  45          *
  46          * NOTE: This device id corresponds to the IOMMU stream ID
  47          * associated with the DPRC object (ICID).
  48          */
  49         info->scratchpad[0].ul = mc_bus_dev->icid;
  50         msi_info = msi_get_domain_info(msi_domain->parent);
  51         return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
  52 }
  53
  54 static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {
  55         .msi_prepare = its_fsl_mc_msi_prepare,
  56 };
  57
  58 static struct msi_domain_info its_fsl_mc_msi_domain_info = {
  59         .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
  60         .ops    = &its_fsl_mc_msi_ops,
  61         .chip   = &its_msi_irq_chip,
  62 };
  63
  64 static const struct of_device_id its_device_id[] = {
  65         {       .compatible     = "arm,gic-v3-its",     },
  66         {},
  67 };
  68
  69 int __init its_fsl_mc_msi_init(void)
  70 {
  71         struct device_node *np;
  72         struct irq_domain *parent;
  73         struct irq_domain *mc_msi_domain;
  74
  75         for (np = of_find_matching_node(NULL, its_device_id); np;
  76              np = of_find_matching_node(np, its_device_id)) {
  77                 if (!of_property_read_bool(np, "msi-controller"))
  78                         continue;
  79
  80                 parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
  81                 if (!parent || !msi_get_domain_info(parent)) {
  82                         pr_err("%s: unable to locate ITS domain\n",
  83                                np->full_name);
  84                         continue;
  85                 }
  86
  87                 mc_msi_domain = fsl_mc_msi_create_irq_domain(
  88                                                  of_node_to_fwnode(np),
  89                                                  &its_fsl_mc_msi_domain_info,
  90                                                  parent);
  91                 if (!mc_msi_domain) {
  92                         pr_err("%s: unable to create fsl-mc domain\n",
  93                                np->full_name);
  94                         continue;
  95                 }
  96
  97                 WARN_ON(mc_msi_domain->host_data !=
  98                         &its_fsl_mc_msi_domain_info);
  99
 100                 pr_info("fsl-mc MSI: %s domain created\n", np->full_name);
 101         }
 102
 103         return 0;
 104 }
 105
 106 void its_fsl_mc_msi_cleanup(void)
 107 {
 108         struct device_node *np;
 109
 110         for (np = of_find_matching_node(NULL, its_device_id); np;
 111              np = of_find_matching_node(np, its_device_id)) {
 112                 struct irq_domain *mc_msi_domain = irq_find_matching_host(
 113                                                         np,
 114                                                         DOMAIN_BUS_FSL_MC_MSI);
 115
 116                 if (!of_property_read_bool(np, "msi-controller"))
 117                         continue;
 118
 119                 if (mc_msi_domain &&
 120                     mc_msi_domain->host_data == &its_fsl_mc_msi_domain_info)
 121                         irq_domain_remove(mc_msi_domain);
 122         }
 123 }