linux/arch/powerpc/platforms/4xx/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/pci.h>
  26#include <linux/msi.h>
  27#include <linux/of_platform.h>
  28#include <linux/interrupt.h>
  29#include <linux/export.h>
  30#include <linux/kernel.h>
  31#include <asm/prom.h>
  32#include <asm/hw_irq.h>
  33#include <asm/ppc-pci.h>
  34#include <asm/dcr.h>
  35#include <asm/dcr-regs.h>
  36#include <asm/msi_bitmap.h>
  37
  38#define PEIH_TERMADH    0x00
  39#define PEIH_TERMADL    0x08
  40#define PEIH_MSIED      0x10
  41#define PEIH_MSIMK      0x18
  42#define PEIH_MSIASS     0x20
  43#define PEIH_FLUSH0     0x30
  44#define PEIH_FLUSH1     0x38
  45#define PEIH_CNTRST     0x48
  46
  47static int msi_irqs;
  48
  49struct ppc4xx_msi {
  50        u32 msi_addr_lo;
  51        u32 msi_addr_hi;
  52        void __iomem *msi_regs;
  53        int *msi_virqs;
  54        struct msi_bitmap bitmap;
  55        struct device_node *msi_dev;
  56};
  57
  58static struct ppc4xx_msi ppc4xx_msi;
  59
  60static int ppc4xx_msi_init_allocator(struct platform_device *dev,
  61                struct ppc4xx_msi *msi_data)
  62{
  63        int err;
  64
  65        err = msi_bitmap_alloc(&msi_data->bitmap, msi_irqs,
  66                              dev->dev.of_node);
  67        if (err)
  68                return err;
  69
  70        err = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
  71        if (err < 0) {
  72                msi_bitmap_free(&msi_data->bitmap);
  73                return err;
  74        }
  75
  76        return 0;
  77}
  78
  79static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  80{
  81        int int_no = -ENOMEM;
  82        unsigned int virq;
  83        struct msi_msg msg;
  84        struct msi_desc *entry;
  85        struct ppc4xx_msi *msi_data = &ppc4xx_msi;
  86
  87        dev_dbg(&dev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
  88                __func__, nvec, type);
  89        if (type == PCI_CAP_ID_MSIX)
  90                pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
  91
  92        msi_data->msi_virqs = kmalloc((msi_irqs) * sizeof(int), GFP_KERNEL);
  93        if (!msi_data->msi_virqs)
  94                return -ENOMEM;
  95
  96        for_each_pci_msi_entry(entry, dev) {
  97                int_no = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
  98                if (int_no >= 0)
  99                        break;
 100                if (int_no < 0) {
 101                        pr_debug("%s: fail allocating msi interrupt\n",
 102                                        __func__);
 103                }
 104                virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
 105                if (!virq) {
 106                        dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
 107                        msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
 108                        return -ENOSPC;
 109                }
 110                dev_dbg(&dev->dev, "%s: virq = %d\n", __func__, virq);
 111
 112                /* Setup msi address space */
 113                msg.address_hi = msi_data->msi_addr_hi;
 114                msg.address_lo = msi_data->msi_addr_lo;
 115
 116                irq_set_msi_desc(virq, entry);
 117                msg.data = int_no;
 118                pci_write_msi_msg(virq, &msg);
 119        }
 120        return 0;
 121}
 122
 123void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
 124{
 125        struct msi_desc *entry;
 126        struct ppc4xx_msi *msi_data = &ppc4xx_msi;
 127        irq_hw_number_t hwirq;
 128
 129        dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
 130
 131        for_each_pci_msi_entry(entry, dev) {
 132                if (!entry->irq)
 133                        continue;
 134                hwirq = virq_to_hw(entry->irq);
 135                irq_set_msi_desc(entry->irq, NULL);
 136                irq_dispose_mapping(entry->irq);
 137                msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 138        }
 139}
 140
 141static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
 142                                 struct resource res, struct ppc4xx_msi *msi)
 143{
 144        const u32 *msi_data;
 145        const u32 *msi_mask;
 146        const u32 *sdr_addr;
 147        dma_addr_t msi_phys;
 148        void *msi_virt;
 149
 150        sdr_addr = of_get_property(dev->dev.of_node, "sdr-base", NULL);
 151        if (!sdr_addr)
 152                return -1;
 153
 154        mtdcri(SDR0, *sdr_addr, upper_32_bits(res.start));      /*HIGH addr */
 155        mtdcri(SDR0, *sdr_addr + 1, lower_32_bits(res.start));  /* Low addr */
 156
 157        msi->msi_dev = of_find_node_by_name(NULL, "ppc4xx-msi");
 158        if (!msi->msi_dev)
 159                return -ENODEV;
 160
 161        msi->msi_regs = of_iomap(msi->msi_dev, 0);
 162        if (!msi->msi_regs) {
 163                dev_err(&dev->dev, "of_iomap problem failed\n");
 164                return -ENOMEM;
 165        }
 166        dev_dbg(&dev->dev, "PCIE-MSI: msi register mapped 0x%x 0x%x\n",
 167                (u32) (msi->msi_regs + PEIH_TERMADH), (u32) (msi->msi_regs));
 168
 169        msi_virt = dma_alloc_coherent(&dev->dev, 64, &msi_phys, GFP_KERNEL);
 170        if (!msi_virt)
 171                return -ENOMEM;
 172        msi->msi_addr_hi = upper_32_bits(msi_phys);
 173        msi->msi_addr_lo = lower_32_bits(msi_phys & 0xffffffff);
 174        dev_dbg(&dev->dev, "PCIE-MSI: msi address high 0x%x, low 0x%x\n",
 175                msi->msi_addr_hi, msi->msi_addr_lo);
 176
 177        /* Progam the Interrupt handler Termination addr registers */
 178        out_be32(msi->msi_regs + PEIH_TERMADH, msi->msi_addr_hi);
 179        out_be32(msi->msi_regs + PEIH_TERMADL, msi->msi_addr_lo);
 180
 181        msi_data = of_get_property(dev->dev.of_node, "msi-data", NULL);
 182        if (!msi_data)
 183                return -1;
 184        msi_mask = of_get_property(dev->dev.of_node, "msi-mask", NULL);
 185        if (!msi_mask)
 186                return -1;
 187        /* Program MSI Expected data and Mask bits */
 188        out_be32(msi->msi_regs + PEIH_MSIED, *msi_data);
 189        out_be32(msi->msi_regs + PEIH_MSIMK, *msi_mask);
 190
 191        dma_free_coherent(&dev->dev, 64, msi_virt, msi_phys);
 192
 193        return 0;
 194}
 195
 196static int ppc4xx_of_msi_remove(struct platform_device *dev)
 197{
 198        struct ppc4xx_msi *msi = dev->dev.platform_data;
 199        int i;
 200        int virq;
 201
 202        for (i = 0; i < msi_irqs; i++) {
 203                virq = msi->msi_virqs[i];
 204                if (virq)
 205                        irq_dispose_mapping(virq);
 206        }
 207
 208        if (msi->bitmap.bitmap)
 209                msi_bitmap_free(&msi->bitmap);
 210        iounmap(msi->msi_regs);
 211        of_node_put(msi->msi_dev);
 212        kfree(msi);
 213
 214        return 0;
 215}
 216
 217static int ppc4xx_msi_probe(struct platform_device *dev)
 218{
 219        struct ppc4xx_msi *msi;
 220        struct resource res;
 221        int err = 0;
 222        struct pci_controller *phb;
 223
 224        dev_dbg(&dev->dev, "PCIE-MSI: Setting up MSI support...\n");
 225
 226        msi = kzalloc(sizeof(*msi), GFP_KERNEL);
 227        if (!msi) {
 228                dev_err(&dev->dev, "No memory for MSI structure\n");
 229                return -ENOMEM;
 230        }
 231        dev->dev.platform_data = msi;
 232
 233        /* Get MSI ranges */
 234        err = of_address_to_resource(dev->dev.of_node, 0, &res);
 235        if (err) {
 236                dev_err(&dev->dev, "%pOF resource error!\n", dev->dev.of_node);
 237                goto error_out;
 238        }
 239
 240        msi_irqs = of_irq_count(dev->dev.of_node);
 241        if (!msi_irqs)
 242                return -ENODEV;
 243
 244        err = ppc4xx_setup_pcieh_hw(dev, res, msi);
 245        if (err)
 246                goto error_out;
 247
 248        err = ppc4xx_msi_init_allocator(dev, msi);
 249        if (err) {
 250                dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 251                goto error_out;
 252        }
 253        ppc4xx_msi = *msi;
 254
 255        list_for_each_entry(phb, &hose_list, list_node) {
 256                phb->controller_ops.setup_msi_irqs = ppc4xx_setup_msi_irqs;
 257                phb->controller_ops.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
 258        }
 259        return err;
 260
 261error_out:
 262        ppc4xx_of_msi_remove(dev);
 263        return err;
 264}
 265static const struct of_device_id ppc4xx_msi_ids[] = {
 266        {
 267                .compatible = "amcc,ppc4xx-msi",
 268        },
 269        {}
 270};
 271static struct platform_driver ppc4xx_msi_driver = {
 272        .probe = ppc4xx_msi_probe,
 273        .remove = ppc4xx_of_msi_remove,
 274        .driver = {
 275                   .name = "ppc4xx-msi",
 276                   .of_match_table = ppc4xx_msi_ids,
 277                   },
 278
 279};
 280
 281static __init int ppc4xx_msi_init(void)
 282{
 283        return platform_driver_register(&ppc4xx_msi_driver);
 284}
 285
 286subsys_initcall(ppc4xx_msi_init);
 287