arch/powerpc/platforms/4xx/hsta

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This source file includes following definitions.
hsta_setup_msi_irqs
hsta_find_hwirq_offset
hsta_teardown_msi_irqs
hsta_msi_probe
hsta_msi_init
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for
   4  * generation of the interrupt.
   5  *
   6  * Copyright © 2013 Alistair Popple <alistair@popple.id.au> IBM Corporation
   7  */
   8 
   9 #include <linux/kernel.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/msi.h>
  12 #include <linux/of.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/pci.h>
  15 #include <linux/semaphore.h>
  16 #include <asm/msi_bitmap.h>
  17 #include <asm/ppc-pci.h>
  18 
  19 struct ppc4xx_hsta_msi {
  20         struct device *dev;
  21 
  22         /* The ioremapped HSTA MSI IO space */
  23         u32 __iomem *data;
  24 
  25         /* Physical address of HSTA MSI IO space */
  26         u64 address;
  27         struct msi_bitmap bmp;
  28 
  29         /* An array mapping offsets to hardware IRQs */
  30         int *irq_map;
  31 
  32         /* Number of hwirqs supported */
  33         int irq_count;
  34 };
  35 static struct ppc4xx_hsta_msi ppc4xx_hsta_msi;
  36 
  37 static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  38 {
  39         struct msi_msg msg;
  40         struct msi_desc *entry;
  41         int irq, hwirq;
  42         u64 addr;
  43 
  44         /* We don't support MSI-X */
  45         if (type == PCI_CAP_ID_MSIX) {
  46                 pr_debug("%s: MSI-X not supported.\n", __func__);
  47                 return -EINVAL;
  48         }
  49 
  50         for_each_pci_msi_entry(entry, dev) {
  51                 irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1);
  52                 if (irq < 0) {
  53                         pr_debug("%s: Failed to allocate msi interrupt\n",
  54                                  __func__);
  55                         return irq;
  56                 }
  57 
  58                 hwirq = ppc4xx_hsta_msi.irq_map[irq];
  59                 if (!hwirq) {
  60                         pr_err("%s: Failed mapping irq %d\n", __func__, irq);
  61                         return -EINVAL;
  62                 }
  63 
  64                 /*
  65                  * HSTA generates interrupts on writes to 128-bit aligned
  66                  * addresses.
  67                  */
  68                 addr = ppc4xx_hsta_msi.address + irq*0x10;
  69                 msg.address_hi = upper_32_bits(addr);
  70                 msg.address_lo = lower_32_bits(addr);
  71 
  72                 /* Data is not used by the HSTA. */
  73                 msg.data = 0;
  74 
  75                 pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq,
  76                          (((u64) msg.address_hi) << 32) | msg.address_lo);
  77 
  78                 if (irq_set_msi_desc(hwirq, entry)) {
  79                         pr_err(
  80                         "%s: Invalid hwirq %d specified in device tree\n",
  81                         __func__, hwirq);
  82                         msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
  83                         return -EINVAL;
  84                 }
  85                 pci_write_msi_msg(hwirq, &msg);
  86         }
  87 
  88         return 0;
  89 }
  90 
  91 static int hsta_find_hwirq_offset(int hwirq)
  92 {
  93         int irq;
  94 
  95         /* Find the offset given the hwirq */
  96         for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++)
  97                 if (ppc4xx_hsta_msi.irq_map[irq] == hwirq)
  98                         return irq;
  99 
 100         return -EINVAL;
 101 }
 102 
 103 static void hsta_teardown_msi_irqs(struct pci_dev *dev)
 104 {
 105         struct msi_desc *entry;
 106         int irq;
 107 
 108         for_each_pci_msi_entry(entry, dev) {
 109                 if (!entry->irq)
 110                         continue;
 111 
 112                 irq = hsta_find_hwirq_offset(entry->irq);
 113 
 114                 /* entry->irq should always be in irq_map */
 115                 BUG_ON(irq < 0);
 116                 irq_set_msi_desc(entry->irq, NULL);
 117                 msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
 118                 pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__,
 119                          entry->irq, irq);
 120         }
 121 }
 122 
 123 static int hsta_msi_probe(struct platform_device *pdev)
 124 {
 125         struct device *dev = &pdev->dev;
 126         struct resource *mem;
 127         int irq, ret, irq_count;
 128         struct pci_controller *phb;
 129 
 130         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 131         if (!mem) {
 132                 dev_err(dev, "Unable to get mmio space\n");
 133                 return -EINVAL;
 134         }
 135 
 136         irq_count = of_irq_count(dev->of_node);
 137         if (!irq_count) {
 138                 dev_err(dev, "Unable to find IRQ range\n");
 139                 return -EINVAL;
 140         }
 141 
 142         ppc4xx_hsta_msi.dev = dev;
 143         ppc4xx_hsta_msi.address = mem->start;
 144         ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem));
 145         ppc4xx_hsta_msi.irq_count = irq_count;
 146         if (!ppc4xx_hsta_msi.data) {
 147                 dev_err(dev, "Unable to map memory\n");
 148                 return -ENOMEM;
 149         }
 150 
 151         ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node);
 152         if (ret)
 153                 goto out;
 154 
 155         ppc4xx_hsta_msi.irq_map = kmalloc_array(irq_count, sizeof(int),
 156                                                 GFP_KERNEL);
 157         if (!ppc4xx_hsta_msi.irq_map) {
 158                 ret = -ENOMEM;
 159                 goto out1;
 160         }
 161 
 162         /* Setup a mapping from irq offsets to hardware irq numbers */
 163         for (irq = 0; irq < irq_count; irq++) {
 164                 ppc4xx_hsta_msi.irq_map[irq] =
 165                         irq_of_parse_and_map(dev->of_node, irq);
 166                 if (!ppc4xx_hsta_msi.irq_map[irq]) {
 167                         dev_err(dev, "Unable to map IRQ\n");
 168                         ret = -EINVAL;
 169                         goto out2;
 170                 }
 171         }
 172 
 173         list_for_each_entry(phb, &hose_list, list_node) {
 174                 phb->controller_ops.setup_msi_irqs = hsta_setup_msi_irqs;
 175                 phb->controller_ops.teardown_msi_irqs = hsta_teardown_msi_irqs;
 176         }
 177         return 0;
 178 
 179 out2:
 180         kfree(ppc4xx_hsta_msi.irq_map);
 181 
 182 out1:
 183         msi_bitmap_free(&ppc4xx_hsta_msi.bmp);
 184 
 185 out:
 186         iounmap(ppc4xx_hsta_msi.data);
 187         return ret;
 188 }
 189 
 190 static const struct of_device_id hsta_msi_ids[] = {
 191         {
 192                 .compatible = "ibm,hsta-msi",
 193         },
 194         {}
 195 };
 196 
 197 static struct platform_driver hsta_msi_driver = {
 198         .probe = hsta_msi_probe,
 199         .driver = {
 200                 .name = "hsta-msi",
 201                 .of_match_table = hsta_msi_ids,
 202         },
 203 };
 204 
 205 static int hsta_msi_init(void)
 206 {
 207         return platform_driver_register(&hsta_msi_driver);
 208 }
 209 subsys_initcall(hsta_msi_init);
/* [<][>][^][v][top][bottom][index][help] */
root/arch/powerpc/platforms/4xx/hsta_msi.c

DEFINITIONS
