msm_iommu_dev.c

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/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/iommu.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/slab.h>

#include <mach/iommu_hw-8xxx.h>
#include <mach/iommu.h>
#include <mach/clk.h>

struct iommu_ctx_iter_data {
    /* input */
    const char *name;

    /* output */
    struct device *dev;
};

static struct platform_device *msm_iommu_root_dev;

static int each_iommu_ctx(struct device *dev, void *data)
{
    struct iommu_ctx_iter_data *res = data;
    struct msm_iommu_ctx_dev *c = dev->platform_data;

    if (!res || !c || !c->name || !res->name)
        return -EINVAL;

    if (!strcmp(res->name, c->name)) {
        res->dev = dev;
        return 1;
    }
    return 0;
}

static int each_iommu(struct device *dev, void *data)
{
    return device_for_each_child(dev, data, each_iommu_ctx);
}

struct device *msm_iommu_get_ctx(const char *ctx_name)
{
    struct iommu_ctx_iter_data r;
    int found;

    if (!msm_iommu_root_dev) {
        pr_err("No root IOMMU device.\n");
        goto fail;
    }

    r.name = ctx_name;
    found = device_for_each_child(&msm_iommu_root_dev->dev, &r, each_iommu);

    if (!found) {
        pr_err("Could not find context <%s>\n", ctx_name);
        goto fail;
    }

    return r.dev;
fail:
    return NULL;
}
EXPORT_SYMBOL(msm_iommu_get_ctx);

static void msm_iommu_reset(void __iomem *base, int ncb)
{
    int ctx;

    SET_RPUE(base, 0);
    SET_RPUEIE(base, 0);
    SET_ESRRESTORE(base, 0);
    SET_TBE(base, 0);
    SET_CR(base, 0);
    SET_SPDMBE(base, 0);
    SET_TESTBUSCR(base, 0);
    SET_TLBRSW(base, 0);
    SET_GLOBAL_TLBIALL(base, 0);
    SET_RPU_ACR(base, 0);
    SET_TLBLKCRWE(base, 1);

    for (ctx = 0; ctx < ncb; ctx++) {
        SET_BPRCOSH(base, ctx, 0);
        SET_BPRCISH(base, ctx, 0);
        SET_BPRCNSH(base, ctx, 0);
        SET_BPSHCFG(base, ctx, 0);
        SET_BPMTCFG(base, ctx, 0);
        SET_ACTLR(base, ctx, 0);
        SET_SCTLR(base, ctx, 0);
        SET_FSRRESTORE(base, ctx, 0);
        SET_TTBR0(base, ctx, 0);
        SET_TTBR1(base, ctx, 0);
        SET_TTBCR(base, ctx, 0);
        SET_BFBCR(base, ctx, 0);
        SET_PAR(base, ctx, 0);
        SET_FAR(base, ctx, 0);
        SET_CTX_TLBIALL(base, ctx, 0);
        SET_TLBFLPTER(base, ctx, 0);
        SET_TLBSLPTER(base, ctx, 0);
        SET_TLBLKCR(base, ctx, 0);
        SET_PRRR(base, ctx, 0);
        SET_NMRR(base, ctx, 0);
        SET_CONTEXTIDR(base, ctx, 0);
    }
}

static int msm_iommu_probe(struct platform_device *pdev)
{
    struct resource *r, *r2;
    struct clk *iommu_clk;
    struct clk *iommu_pclk;
    struct msm_iommu_drvdata *drvdata;
    struct msm_iommu_dev *iommu_dev = pdev->dev.platform_data;
    void __iomem *regs_base;
    resource_size_t len;
    int ret, irq, par;

    if (pdev->id == -1) {
        msm_iommu_root_dev = pdev;
        return 0;
    }

    drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);

    if (!drvdata) {
        ret = -ENOMEM;
        goto fail;
    }

    if (!iommu_dev) {
        ret = -ENODEV;
        goto fail;
    }

    iommu_pclk = clk_get(NULL, "smmu_pclk");
    if (IS_ERR(iommu_pclk)) {
        ret = -ENODEV;
        goto fail;
    }

    ret = clk_enable(iommu_pclk);
    if (ret)
        goto fail_enable;

    iommu_clk = clk_get(&pdev->dev, "iommu_clk");

    if (!IS_ERR(iommu_clk)) {
        if (clk_get_rate(iommu_clk) == 0)
            clk_set_min_rate(iommu_clk, 1);

        ret = clk_enable(iommu_clk);
        if (ret) {
            clk_put(iommu_clk);
            goto fail_pclk;
        }
    } else
        iommu_clk = NULL;

    r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "physbase");

    if (!r) {
        ret = -ENODEV;
        goto fail_clk;
    }

    len = resource_size(r);

    r2 = request_mem_region(r->start, len, r->name);
    if (!r2) {
        pr_err("Could not request memory region: start=%p, len=%d\n",
                            (void *) r->start, len);
        ret = -EBUSY;
        goto fail_clk;
    }

    regs_base = ioremap(r2->start, len);

    if (!regs_base) {
        pr_err("Could not ioremap: start=%p, len=%d\n",
             (void *) r2->start, len);
        ret = -EBUSY;
        goto fail_mem;
    }

    irq = platform_get_irq_byname(pdev, "secure_irq");
    if (irq < 0) {
        ret = -ENODEV;
        goto fail_io;
    }

    msm_iommu_reset(regs_base, iommu_dev->ncb);

    SET_M(regs_base, 0, 1);
    SET_PAR(regs_base, 0, 0);
    SET_V2PCFG(regs_base, 0, 1);
    SET_V2PPR(regs_base, 0, 0);
    par = GET_PAR(regs_base, 0);
    SET_V2PCFG(regs_base, 0, 0);
    SET_M(regs_base, 0, 0);

    if (!par) {
        pr_err("%s: Invalid PAR value detected\n", iommu_dev->name);
        ret = -ENODEV;
        goto fail_io;
    }

    ret = request_irq(irq, msm_iommu_fault_handler, 0,
            "msm_iommu_secure_irpt_handler", drvdata);
    if (ret) {
        pr_err("Request IRQ %d failed with ret=%d\n", irq, ret);
        goto fail_io;
    }


    drvdata->pclk = iommu_pclk;
    drvdata->clk = iommu_clk;
    drvdata->base = regs_base;
    drvdata->irq = irq;
    drvdata->ncb = iommu_dev->ncb;

    pr_info("device %s mapped at %p, irq %d with %d ctx banks\n",
        iommu_dev->name, regs_base, irq, iommu_dev->ncb);

    platform_set_drvdata(pdev, drvdata);

    if (iommu_clk)
        clk_disable(iommu_clk);

    clk_disable(iommu_pclk);

    return 0;
fail_io:
    iounmap(regs_base);
fail_mem:
    release_mem_region(r->start, len);
fail_clk:
    if (iommu_clk) {
        clk_disable(iommu_clk);
        clk_put(iommu_clk);
    }
fail_pclk:
    clk_disable(iommu_pclk);
fail_enable:
    clk_put(iommu_pclk);
fail:
    kfree(drvdata);
    return ret;
}

static int msm_iommu_remove(struct platform_device *pdev)
{
    struct msm_iommu_drvdata *drv = NULL;

    drv = platform_get_drvdata(pdev);
    if (drv) {
        if (drv->clk)
            clk_put(drv->clk);
        clk_put(drv->pclk);
        memset(drv, 0, sizeof(*drv));
        kfree(drv);
        platform_set_drvdata(pdev, NULL);
    }
    return 0;
}

static int msm_iommu_ctx_probe(struct platform_device *pdev)
{
    struct msm_iommu_ctx_dev *c = pdev->dev.platform_data;
    struct msm_iommu_drvdata *drvdata;
    struct msm_iommu_ctx_drvdata *ctx_drvdata = NULL;
    int i, ret;
    if (!c || !pdev->dev.parent) {
        ret = -EINVAL;
        goto fail;
    }

    drvdata = dev_get_drvdata(pdev->dev.parent);

    if (!drvdata) {
        ret = -ENODEV;
        goto fail;
    }

    ctx_drvdata = kzalloc(sizeof(*ctx_drvdata), GFP_KERNEL);
    if (!ctx_drvdata) {
        ret = -ENOMEM;
        goto fail;
    }
    ctx_drvdata->num = c->num;
    ctx_drvdata->pdev = pdev;

    INIT_LIST_HEAD(&ctx_drvdata->attached_elm);
    platform_set_drvdata(pdev, ctx_drvdata);

    ret = clk_enable(drvdata->pclk);
    if (ret)
        goto fail;

    if (drvdata->clk) {
        ret = clk_enable(drvdata->clk);
        if (ret) {
            clk_disable(drvdata->pclk);
            goto fail;
        }
    }

    /* Program the M2V tables for this context */
    for (i = 0; i < MAX_NUM_MIDS; i++) {
        int mid = c->mids[i];
        if (mid == -1)
            break;

        SET_M2VCBR_N(drvdata->base, mid, 0);
        SET_CBACR_N(drvdata->base, c->num, 0);

        /* Set VMID = 0 */
        SET_VMID(drvdata->base, mid, 0);

        /* Set the context number for that MID to this context */
        SET_CBNDX(drvdata->base, mid, c->num);

        /* Set MID associated with this context bank to 0*/
        SET_CBVMID(drvdata->base, c->num, 0);

        /* Set the ASID for TLB tagging for this context */
        SET_CONTEXTIDR_ASID(drvdata->base, c->num, c->num);

        /* Set security bit override to be Non-secure */
        SET_NSCFG(drvdata->base, mid, 3);
    }

    if (drvdata->clk)
        clk_disable(drvdata->clk);
    clk_disable(drvdata->pclk);

    dev_info(&pdev->dev, "context %s using bank %d\n", c->name, c->num);
    return 0;
fail:
    kfree(ctx_drvdata);
    return ret;
}

static int msm_iommu_ctx_remove(struct platform_device *pdev)
{
    struct msm_iommu_ctx_drvdata *drv = NULL;
    drv = platform_get_drvdata(pdev);
    if (drv) {
        memset(drv, 0, sizeof(struct msm_iommu_ctx_drvdata));
        kfree(drv);
        platform_set_drvdata(pdev, NULL);
    }
    return 0;
}

static struct platform_driver msm_iommu_driver = {
    .driver = {
        .name   = "msm_iommu",
    },
    .probe      = msm_iommu_probe,
    .remove     = msm_iommu_remove,
};

static struct platform_driver msm_iommu_ctx_driver = {
    .driver = {
        .name   = "msm_iommu_ctx",
    },
    .probe      = msm_iommu_ctx_probe,
    .remove     = msm_iommu_ctx_remove,
};

static int __init msm_iommu_driver_init(void)
{
    int ret;
    ret = platform_driver_register(&msm_iommu_driver);
    if (ret != 0) {
        pr_err("Failed to register IOMMU driver\n");
        goto error;
    }

    ret = platform_driver_register(&msm_iommu_ctx_driver);
    if (ret != 0) {
        pr_err("Failed to register IOMMU context driver\n");
        goto error;
    }

error:
    return ret;
}

static void __exit msm_iommu_driver_exit(void)
{
    platform_driver_unregister(&msm_iommu_ctx_driver);
    platform_driver_unregister(&msm_iommu_driver);
}

subsys_initcall(msm_iommu_driver_init);
module_exit(msm_iommu_driver_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Stepan Moskovchenko <[email protected]>");