linux/arch/powerpc/sysdev/ppc4xx_msi.c
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   1/*
   2 * Adding PCI-E MSI support for PPC4XX SoCs.
   3 *
   4 * Copyright (c) 2010, Applied Micro Circuits Corporation
   5 * Authors:     Tirumala R Marri <tmarri@apm.com>
   6 *              Feng Kan <fkan@apm.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 */
  23
  24#include <linux/irq.h>
  25#include <linux/bootmem.h>
  26#include <linux/pci.h>
  27#include <linux/msi.h>
  28#include <linux/of_platform.h>
  29#include <linux/interrupt.h>
  30#include <linux/export.h>
  31#include <linux/kernel.h>
  32#include <asm/prom.h>
  33#include <asm/hw_irq.h>
  34#include <asm/ppc-pci.h>
  35#include <asm/dcr.h>
  36#include <asm/dcr-regs.h>
  37#include <asm/msi_bitmap.h>
  38
  39#define PEIH_TERMADH    0x00
  40#define PEIH_TERMADL    0x08
  41#define PEIH_MSIED      0x10
  42#define PEIH_MSIMK      0x18
  43#define PEIH_MSIASS     0x20
  44#define PEIH_FLUSH0     0x30
  45#define PEIH_FLUSH1     0x38
  46#define PEIH_CNTRST     0x48
  47
  48static int msi_irqs;
  49
  50struct ppc4xx_msi {
  51        u32 msi_addr_lo;
  52        u32 msi_addr_hi;
  53        void __iomem *msi_regs;
  54        int *msi_virqs;
  55        struct msi_bitmap bitmap;
  56        struct device_node *msi_dev;
  57};
  58
  59static struct ppc4xx_msi ppc4xx_msi;
  60
  61static int ppc4xx_msi_init_allocator(struct platform_device *dev,
  62                struct ppc4xx_msi *msi_data)
  63{
  64        int err;
  65
  66        err = msi_bitmap_alloc(&msi_data->bitmap, msi_irqs,
  67                              dev->dev.of_node);
  68        if (err)
  69                return err;
  70
  71        err = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
  72        if (err < 0) {
  73                msi_bitmap_free(&msi_data->bitmap);
  74                return err;
  75        }
  76
  77        return 0;
  78}
  79
  80static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  81{
  82        int int_no = -ENOMEM;
  83        unsigned int virq;
  84        struct msi_msg msg;
  85        struct msi_desc *entry;
  86        struct ppc4xx_msi *msi_data = &ppc4xx_msi;
  87
  88        msi_data->msi_virqs = kmalloc((msi_irqs) * sizeof(int),
  89                                            GFP_KERNEL);
  90        if (!msi_data->msi_virqs)
  91                return -ENOMEM;
  92
  93        list_for_each_entry(entry, &dev->msi_list, list) {
  94                int_no = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
  95                if (int_no >= 0)
  96                        break;
  97                if (int_no < 0) {
  98                        pr_debug("%s: fail allocating msi interrupt\n",
  99                                        __func__);
 100                }
 101                virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
 102                if (virq == NO_IRQ) {
 103                        dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
 104                        msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
 105                        return -ENOSPC;
 106                }
 107                dev_dbg(&dev->dev, "%s: virq = %d\n", __func__, virq);
 108
 109                /* Setup msi address space */
 110                msg.address_hi = msi_data->msi_addr_hi;
 111                msg.address_lo = msi_data->msi_addr_lo;
 112
 113                irq_set_msi_desc(virq, entry);
 114                msg.data = int_no;
 115                write_msi_msg(virq, &msg);
 116        }
 117        return 0;
 118}
 119
 120void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
 121{
 122        struct msi_desc *entry;
 123        struct ppc4xx_msi *msi_data = &ppc4xx_msi;
 124
 125        dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
 126
 127        list_for_each_entry(entry, &dev->msi_list, list) {
 128                if (entry->irq == NO_IRQ)
 129                        continue;
 130                irq_set_msi_desc(entry->irq, NULL);
 131                msi_bitmap_free_hwirqs(&msi_data->bitmap,
 132                                virq_to_hw(entry->irq), 1);
 133                irq_dispose_mapping(entry->irq);
 134        }
 135}
 136
 137static int ppc4xx_msi_check_device(struct pci_dev *pdev, int nvec, int type)
 138{
 139        dev_dbg(&pdev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
 140                __func__, nvec, type);
 141        if (type == PCI_CAP_ID_MSIX)
 142                pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
 143
 144        return 0;
 145}
 146
 147static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
 148                                 struct resource res, struct ppc4xx_msi *msi)
 149{
 150        const u32 *msi_data;
 151        const u32 *msi_mask;
 152        const u32 *sdr_addr;
 153        dma_addr_t msi_phys;
 154        void *msi_virt;
 155
 156        sdr_addr = of_get_property(dev->dev.of_node, "sdr-base", NULL);
 157        if (!sdr_addr)
 158                return -1;
 159
 160        mtdcri(SDR0, *sdr_addr, upper_32_bits(res.start));      /*HIGH addr */
 161        mtdcri(SDR0, *sdr_addr + 1, lower_32_bits(res.start));  /* Low addr */
 162
 163        msi->msi_dev = of_find_node_by_name(NULL, "ppc4xx-msi");
 164        if (!msi->msi_dev)
 165                return -ENODEV;
 166
 167        msi->msi_regs = of_iomap(msi->msi_dev, 0);
 168        if (!msi->msi_regs) {
 169                dev_err(&dev->dev, "of_iomap problem failed\n");
 170                return -ENOMEM;
 171        }
 172        dev_dbg(&dev->dev, "PCIE-MSI: msi register mapped 0x%x 0x%x\n",
 173                (u32) (msi->msi_regs + PEIH_TERMADH), (u32) (msi->msi_regs));
 174
 175        msi_virt = dma_alloc_coherent(&dev->dev, 64, &msi_phys, GFP_KERNEL);
 176        if (!msi_virt)
 177                return -ENOMEM;
 178        msi->msi_addr_hi = upper_32_bits(msi_phys);
 179        msi->msi_addr_lo = lower_32_bits(msi_phys & 0xffffffff);
 180        dev_dbg(&dev->dev, "PCIE-MSI: msi address high 0x%x, low 0x%x\n",
 181                msi->msi_addr_hi, msi->msi_addr_lo);
 182
 183        /* Progam the Interrupt handler Termination addr registers */
 184        out_be32(msi->msi_regs + PEIH_TERMADH, msi->msi_addr_hi);
 185        out_be32(msi->msi_regs + PEIH_TERMADL, msi->msi_addr_lo);
 186
 187        msi_data = of_get_property(dev->dev.of_node, "msi-data", NULL);
 188        if (!msi_data)
 189                return -1;
 190        msi_mask = of_get_property(dev->dev.of_node, "msi-mask", NULL);
 191        if (!msi_mask)
 192                return -1;
 193        /* Program MSI Expected data and Mask bits */
 194        out_be32(msi->msi_regs + PEIH_MSIED, *msi_data);
 195        out_be32(msi->msi_regs + PEIH_MSIMK, *msi_mask);
 196
 197        dma_free_coherent(&dev->dev, 64, msi_virt, msi_phys);
 198
 199        return 0;
 200}
 201
 202static int ppc4xx_of_msi_remove(struct platform_device *dev)
 203{
 204        struct ppc4xx_msi *msi = dev->dev.platform_data;
 205        int i;
 206        int virq;
 207
 208        for (i = 0; i < msi_irqs; i++) {
 209                virq = msi->msi_virqs[i];
 210                if (virq != NO_IRQ)
 211                        irq_dispose_mapping(virq);
 212        }
 213
 214        if (msi->bitmap.bitmap)
 215                msi_bitmap_free(&msi->bitmap);
 216        iounmap(msi->msi_regs);
 217        of_node_put(msi->msi_dev);
 218        kfree(msi);
 219
 220        return 0;
 221}
 222
 223static int ppc4xx_msi_probe(struct platform_device *dev)
 224{
 225        struct ppc4xx_msi *msi;
 226        struct resource res;
 227        int err = 0;
 228
 229        dev_dbg(&dev->dev, "PCIE-MSI: Setting up MSI support...\n");
 230
 231        msi = kzalloc(sizeof(struct ppc4xx_msi), GFP_KERNEL);
 232        if (!msi) {
 233                dev_err(&dev->dev, "No memory for MSI structure\n");
 234                return -ENOMEM;
 235        }
 236        dev->dev.platform_data = msi;
 237
 238        /* Get MSI ranges */
 239        err = of_address_to_resource(dev->dev.of_node, 0, &res);
 240        if (err) {
 241                dev_err(&dev->dev, "%s resource error!\n",
 242                        dev->dev.of_node->full_name);
 243                goto error_out;
 244        }
 245
 246        msi_irqs = of_irq_count(dev->dev.of_node);
 247        if (!msi_irqs)
 248                return -ENODEV;
 249
 250        if (ppc4xx_setup_pcieh_hw(dev, res, msi))
 251                goto error_out;
 252
 253        err = ppc4xx_msi_init_allocator(dev, msi);
 254        if (err) {
 255                dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 256                goto error_out;
 257        }
 258        ppc4xx_msi = *msi;
 259
 260        ppc_md.setup_msi_irqs = ppc4xx_setup_msi_irqs;
 261        ppc_md.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
 262        ppc_md.msi_check_device = ppc4xx_msi_check_device;
 263        return err;
 264
 265error_out:
 266        ppc4xx_of_msi_remove(dev);
 267        return err;
 268}
 269static const struct of_device_id ppc4xx_msi_ids[] = {
 270        {
 271                .compatible = "amcc,ppc4xx-msi",
 272        },
 273        {}
 274};
 275static struct platform_driver ppc4xx_msi_driver = {
 276        .probe = ppc4xx_msi_probe,
 277        .remove = ppc4xx_of_msi_remove,
 278        .driver = {
 279                   .name = "ppc4xx-msi",
 280                   .owner = THIS_MODULE,
 281                   .of_match_table = ppc4xx_msi_ids,
 282                   },
 283
 284};
 285
 286static __init int ppc4xx_msi_init(void)
 287{
 288        return platform_driver_register(&ppc4xx_msi_driver);
 289}
 290
 291subsys_initcall(ppc4xx_msi_init);
 292