iommu/shmobile: Add iommu driver for Renesas IPMMU modules

This is the Renesas IPMMU driver and IOMMU API implementation.

The IPMMU module supports the MMU function and the PMB function.  The
MMU function provides address translation by pagetable compatible with
ARMv6.  The PMB function provides address translation including
tile-linear translation.  This patch implements the MMU function.

The iommu driver does not register a platform driver directly because:
- the register space of the MMU function and the PMB function
  have a common register (used for settings flush), so they should ideally
  have a way to appropriately share this register.
- the MMU function uses the IOMMU API while the PMB function does not.
- the two functions may be used independently.

Signed-off-by: Hideki EIRAKU <hdk@igel.co.jp>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

1 files changed, 136 insertions, 0 deletions

diff --git a/drivers/iommu/shmobile-ipmmu.c b/drivers/iommu/shmobile-ipmmu.c
new file mode 100644
index 0000000..8321f89
--- /dev/null
+++ b/drivers/iommu/shmobile-ipmmu.c
@@ -0,0 +1,136 @@
+/*
+ * IPMMU/IPMMUI
+ * Copyright (C) 2012  Hideki EIRAKU
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/platform_data/sh_ipmmu.h>
+#include "shmobile-ipmmu.h"
+
+#define IMCTR1 0x000
+#define IMCTR2 0x004
+#define IMASID 0x010
+#define IMTTBR 0x014
+#define IMTTBCR 0x018
+
+#define IMCTR1_TLBEN (1 << 0)
+#define IMCTR1_FLUSH (1 << 1)
+
+static void ipmmu_reg_write(struct shmobile_ipmmu *ipmmu, unsigned long reg_off,
+			    unsigned long data)
+{
+	iowrite32(data, ipmmu->ipmmu_base + reg_off);
+}
+
+void ipmmu_tlb_flush(struct shmobile_ipmmu *ipmmu)
+{
+	if (!ipmmu)
+		return;
+
+	mutex_lock(&ipmmu->flush_lock);
+	if (ipmmu->tlb_enabled)
+		ipmmu_reg_write(ipmmu, IMCTR1, IMCTR1_FLUSH | IMCTR1_TLBEN);
+	else
+		ipmmu_reg_write(ipmmu, IMCTR1, IMCTR1_FLUSH);
+	mutex_unlock(&ipmmu->flush_lock);
+}
+
+void ipmmu_tlb_set(struct shmobile_ipmmu *ipmmu, unsigned long phys, int size,
+		   int asid)
+{
+	if (!ipmmu)
+		return;
+
+	mutex_lock(&ipmmu->flush_lock);
+	switch (size) {
+	default:
+		ipmmu->tlb_enabled = 0;
+		break;
+	case 0x2000:
+		ipmmu_reg_write(ipmmu, IMTTBCR, 1);
+		ipmmu->tlb_enabled = 1;
+		break;
+	case 0x1000:
+		ipmmu_reg_write(ipmmu, IMTTBCR, 2);
+		ipmmu->tlb_enabled = 1;
+		break;
+	case 0x800:
+		ipmmu_reg_write(ipmmu, IMTTBCR, 3);
+		ipmmu->tlb_enabled = 1;
+		break;
+	case 0x400:
+		ipmmu_reg_write(ipmmu, IMTTBCR, 4);
+		ipmmu->tlb_enabled = 1;
+		break;
+	case 0x200:
+		ipmmu_reg_write(ipmmu, IMTTBCR, 5);
+		ipmmu->tlb_enabled = 1;
+		break;
+	case 0x100:
+		ipmmu_reg_write(ipmmu, IMTTBCR, 6);
+		ipmmu->tlb_enabled = 1;
+		break;
+	case 0x80:
+		ipmmu_reg_write(ipmmu, IMTTBCR, 7);
+		ipmmu->tlb_enabled = 1;
+		break;
+	}
+	ipmmu_reg_write(ipmmu, IMTTBR, phys);
+	ipmmu_reg_write(ipmmu, IMASID, asid);
+	mutex_unlock(&ipmmu->flush_lock);
+}
+
+static int ipmmu_probe(struct platform_device *pdev)
+{
+	struct shmobile_ipmmu *ipmmu;
+	struct resource *res;
+	struct shmobile_ipmmu_platform_data *pdata = pdev->dev.platform_data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot get platform resources\n");
+		return -ENOENT;
+	}
+	ipmmu = devm_kzalloc(&pdev->dev, sizeof(*ipmmu), GFP_KERNEL);
+	if (!ipmmu) {
+		dev_err(&pdev->dev, "cannot allocate device data\n");
+		return -ENOMEM;
+	}
+	mutex_init(&ipmmu->flush_lock);
+	ipmmu->dev = &pdev->dev;
+	ipmmu->ipmmu_base = devm_ioremap_nocache(&pdev->dev, res->start,
+						resource_size(res));
+	if (!ipmmu->ipmmu_base) {
+		dev_err(&pdev->dev, "ioremap_nocache failed\n");
+		return -ENOMEM;
+	}
+	ipmmu->dev_names = pdata->dev_names;
+	ipmmu->num_dev_names = pdata->num_dev_names;
+	platform_set_drvdata(pdev, ipmmu);
+	ipmmu_reg_write(ipmmu, IMCTR1, 0x0); /* disable TLB */
+	ipmmu_reg_write(ipmmu, IMCTR2, 0x0); /* disable PMB */
+	ipmmu_iommu_init(ipmmu);
+	return 0;
+}
+
+static struct platform_driver ipmmu_driver = {
+	.probe = ipmmu_probe,
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "ipmmu",
+	},
+};
+
+static int __init ipmmu_init(void)
+{
+	return platform_driver_register(&ipmmu_driver);
+}
+subsys_initcall(ipmmu_init);