/*
* IOMMU API for GART in Tegra20
*
* Copyright (c) 2010-2012, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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 St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define pr_fmt(fmt) "%s(): " fmt, __func__
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/iommu.h>
#include <linux/of.h>
#include <asm/cacheflush.h>
/* bitmap of the page sizes currently supported */
#define GART_IOMMU_PGSIZES (SZ_4K)
#define GART_REG_BASE 0x24
#define GART_CONFIG (0x24 - GART_REG_BASE)
#define GART_ENTRY_ADDR (0x28 - GART_REG_BASE)
#define GART_ENTRY_DATA (0x2c - GART_REG_BASE)
#define GART_ENTRY_PHYS_ADDR_VALID (1 << 31)
#define GART_PAGE_SHIFT 12
#define GART_PAGE_SIZE (1 << GART_PAGE_SHIFT)
#define GART_PAGE_MASK \
(~(GART_PAGE_SIZE - 1) & ~GART_ENTRY_PHYS_ADDR_VALID)
struct gart_client {
struct device *dev;
struct list_head list;
};
struct gart_device {
void __iomem *regs;
u32 *savedata;
u32 page_count; /* total remappable size */
dma_addr_t iovmm_base; /* offset to vmm_area */
spinlock_t pte_lock; /* for pagetable */
struct list_head client;
spinlock_t client_lock; /* for client list */
struct device *dev;
};
static struct gart_device *gart_handle; /* unique for a system */
#define GART_PTE(_pfn) \
(GART_ENTRY_PHYS_ADDR_VALID | ((_pfn) << PAGE_SHIFT))
/*
* Any interaction between any block on PPSB and a block on APB or AHB
* must have these read-back to ensure the APB/AHB bus transaction is
* complete before initiating activity on the PPSB block.
*/
#define FLUSH_GART_REGS(gart) ((void)readl((gart)->regs + GART_CONFIG))
#define for_each_gart_pte(gart, iova) \
for (iova = gart->iovmm_base; \
iova < gart->iovmm_base + GART_PAGE_SIZE * gart->page_count; \
iova += GART_PAGE_SIZE)
static inline void gart_set_pte(struct gart_device *gart,
unsigned long offs, u32 pte)
{
writel(offs, gart->regs + GART_ENTRY_ADDR);
writel(pte, gart->regs + GART_ENTRY_DATA);
dev_dbg(gart->dev, "%s %08lx:%08x\n",
pte ? "map" : "unmap", offs, pte & GART_PAGE_MASK);
}
static inline unsigned long gart_read_pte(struct gart_device *gart,
unsigned long offs)
{
unsigned long pte;
writel(offs, gart->regs + GART_ENTRY_ADDR);
pte = readl(gart->regs + GART_ENTRY_DATA);
return pte;
}
static void do_gart_setup(struct gart_device *gart, const u32 *data)
{
unsigned long iova;
for_each_gart_pte(gart, iova)
gart_set_pte(gart, iova, data ? *(data++) : 0);
writel(1, gart->regs + GART_CONFIG);
FLUSH_GART_REGS(gart);
}
#ifdef DEBUG
static void gart_dump_table(struct gart_device *gart)
{
unsigned long iova;
unsigned long flags;
spin_lock_irqsave(&gart->pte_lock, flags);
for_each_gart_pte(gart, iova) {
unsigned long pte;
pte = gart_read_pte(gart, iova);
dev_dbg(gart->dev, "%s %08lx:%08lx\n",
(GART_ENTRY_PHYS_ADDR_VALID & pte) ? "v" : " ",
iova, pte & GART_PAGE_MASK);
}
spin_unlock_irqrestore(&gart->pte_lock, flags);
}
#else
static inline void gart_dump_table(struct gart_device *gart)
{
}
#endif
static inline bool gart_iova_range_valid(struct gart_device *gart,
unsigned long iova, size_t bytes)
{
unsigned long iova_start, iova_end, gart_start, gart_end;
iova_start = iova;
iova_end = iova_start + bytes - 1;
gart_start = gart->iovmm_base;
gart_end = gart_start + gart->page_count * GART_PAGE_SIZE - 1;
if (iova_start < gart_start)
return false;
if (iova_end > gart_end)
return false;
return true;
}
static int gart_iommu_attach_dev(struct iommu_domain *domain,
struct device *dev)
{
struct gart_device *gart;
struct gart_client *client, *c;
int err = 0;
gart = gart_handle;
if (!gart)
return -EINVAL;
domain->priv = gart;
client = devm_kzalloc(gart->dev, sizeof(*c), GFP_KERNEL);
if (!client)
return -ENOMEM;
client->dev = dev;
spin_lock(&gart->client_lock);
list_for_each_entry(c, &gart->client, list) {
if (c->dev == dev) {
dev_err(gart->dev,
"%s is already attached\n", dev_name(dev));
err = -EINVAL;
goto fail;
}
}
list_add(&client->list, &gart->client);
spin_unlock(&gart->client_lock);
dev_dbg(gart->dev, "Attached %s\n", dev_name(dev));
return 0;
fail:
devm_kfree(gart->dev, client);
spin_unlock(&gart->client_lock);
return err;
}
static void gart_iommu_detach_dev(struct iommu_domain *domain,
struct device *dev)
{
struct gart_device *gart = domain->priv;
struct gart_client *c;
spin_lock(&gart->client_lock);
list_for_each_entry(c, &gart->client, list) {
if (c->dev == dev) {
list_del(&c->list);
devm_kfree(gart->dev, c);
dev_dbg(gart->dev, "Detached %s\n", dev_name(dev));
goto out;
}
}
dev_err(gart->dev, "Couldn't find\n");
out:
spin_unlock(&gart->client_lock);
}
static int gart_iommu_domain_init(struct iommu_domain *domain)
{
return 0;
}
static void gart_iommu_domain_destroy(struct iommu_domain *domain)
{
struct gart_device *gart = domain->priv;
if (!gart)
return;
spin_lock(&gart->client_lock);
if (!list_empty(&gart->client)) {
struct gart_client *c;
list_for_each_entry(c, &gart->client, list)
gart_iommu_detach_dev(domain, c->dev);
}
spin_unlock(&gart->client_lock);
domain->priv = NULL;
}
static int gart_iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t pa, size_t bytes, int prot)
{
struct gart_device *gart = domain->priv;
unsigned long flags;
unsigned long pfn;
if (!gart_iova_range_valid(gart, iova, bytes))
return -EINVAL;
spin_lock_irqsave(&gart->pte_lock, flags);
pfn = __phys_to_pfn(pa);
if (!pfn_valid(pfn)) {
dev_err(gart->dev, "Invalid page: %08x\n", pa);
spin_unlock_irqrestore(&gart->pte_lock, flags);
return -EINVAL;
}
gart_set_pte(gart, iova, GART_PTE(pfn));
FLUSH_GART_REGS(gart);
spin_unlock_irqrestore(&gart->pte_lock, flags);
return 0;
}
static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
size_t bytes)
{
struct gart_device *gart = domain->priv;
unsigned long flags;
if (!gart_iova_range_valid(gart, iova, bytes))
return 0;
spin_lock_irqsave(&gart->pte_lock, flags);
gart_set_pte(gart, iova, 0);
FLUSH_GART_REGS(gart);
spin_unlock_irqrestore(&gart->pte_lock, flags);
return 0;
}
static phys_addr_t gart_iommu_iova_to_phys(struct iommu_domain *domain,
unsigned long iova)
{
struct gart_device *gart = domain->priv;
unsigned long pte;
phys_addr_t pa;
unsigned long flags;
if (!gart_iova_range_valid(gart, iova, 0))
return -EINVAL;
spin_lock_irqsave(&gart->pte_lock, flags);
pte = gart_read_pte(gart, iova);
spin_unlock_irqrestore(&gart->pte_lock, flags);
pa = (pte & GART_PAGE_MASK);
if (!pfn_valid(__phys_to_pfn(pa))) {
dev_err(gart->dev, "No entry for %08lx:%08x\n", iova, pa);
gart_dump_table(gart);
return -EINVAL;
}
return pa;
}
static int gart_iommu_domain_has_cap(struct iommu_domain *domain,
unsigned long cap)
{
return 0;
}
static struct iommu_ops gart_iommu_ops = {
.domain_init = gart_iommu_domain_init,
.domain_destroy = gart_iommu_domain_destroy,
.attach_dev = gart_iommu_attach_dev,
.detach_dev = gart_iommu_detach_dev,
.map = gart_iommu_map,
.unmap = gart_iommu_unmap,
.iova_to_phys = gart_iommu_iova_to_phys,
.domain_has_cap = gart_iommu_domain_has_cap,
.pgsize_bitmap = GART_IOMMU_PGSIZES,
};
static int tegra_gart_suspend(struct device *dev)
{
struct gart_device *gart = dev_get_drvdata(dev);
unsigned long iova;
u32 *data = gart->savedata;
unsigned long flags;
spin_lock_irqsave(&gart->pte_lock, flags);
for_each_gart_pte(gart, iova)
*(data++) = gart_read_pte(gart, iova);
spin_unlock_irqrestore(&gart->pte_lock, flags);
return 0;
}
static int tegra_gart_resume(struct device *dev)
{
struct gart_device *gart = dev_get_drvdata(dev);
unsigned long flags;
spin_lock_irqsave(&gart->pte_lock, flags);
do_gart_setup(gart, gart->savedata);
spin_unlock_irqrestore(&gart->pte_lock, flags);
return 0;
}
static int tegra_gart_probe(struct platform_device *pdev)
{
struct gart_device *gart;
struct resource *res, *res_remap;
void __iomem *gart_regs;
int err;
struct device *dev = &pdev->dev;
if (gart_handle)
return -EIO;
BUILD_BUG_ON(PAGE_SHIFT != GART_PAGE_SHIFT);
/* the GART memory aperture is required */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
res_remap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res || !res_remap) {
dev_err(dev, "GART memory aperture expected\n");
return -ENXIO;
}
gart = devm_kzalloc(dev, sizeof(*gart), GFP_KERNEL);
if (!gart) {
dev_err(dev, "failed to allocate gart_device\n");
return -ENOMEM;
}
gart_regs = devm_ioremap(dev, res->start, resource_size(res));
if (!gart_regs) {
dev_err(dev, "failed to remap GART registers\n");
err = -ENXIO;
goto fail;
}
gart->dev = &pdev->dev;
spin_lock_init(&gart->pte_lock);
spin_lock_init(&gart->client_lock);
INIT_LIST_HEAD(&gart->client);
gart->regs = gart_regs;
gart->iovmm_base = (dma_addr_t)res_remap->start;
gart->page_count = (resource_size(res_remap) >> GART_PAGE_SHIFT);
gart->savedata = vmalloc(sizeof(u32) * gart->page_count);
if (!gart->savedata) {
dev_err(dev, "failed to allocate context save area\n");
err = -ENOMEM;
goto fail;
}
platform_set_drvdata(pdev, gart);
do_gart_setup(gart, NULL);
gart_handle = gart;
return 0;
fail:
if (gart_regs)
devm_iounmap(dev, gart_regs);
if (gart && gart->savedata)
vfree(gart->savedata);
devm_kfree(dev, gart);
return err;
}
static int tegra_gart_remove(struct platform_device *pdev)
{
struct gart_device *gart = platform_get_drvdata(pdev);
struct device *dev = gart->dev;
writel(0, gart->regs + GART_CONFIG);
if (gart->savedata)
vfree(gart->savedata);
if (gart->regs)
devm_iounmap(dev, gart->regs);
devm_kfree(dev, gart);
gart_handle = NULL;
return 0;
}
const struct dev_pm_ops tegra_gart_pm_ops = {
.suspend = tegra_gart_suspend,
.resume = tegra_gart_resume,
};
#ifdef CONFIG_OF
static struct of_device_id tegra_gart_of_match[] __devinitdata = {
{ .compatible = "nvidia,tegra20-gart", },
{ },
};
MODULE_DEVICE_TABLE(of, tegra_gart_of_match);
#endif
static struct platform_driver tegra_gart_driver = {
.probe = tegra_gart_probe,
.remove = tegra_gart_remove,
.driver = {
.owner = THIS_MODULE,
.name = "tegra-gart",
.pm = &tegra_gart_pm_ops,
.of_match_table = of_match_ptr(tegra_gart_of_match),
},
};
static int __devinit tegra_gart_init(void)
{
bus_set_iommu(&platform_bus_type, &gart_iommu_ops);
return platform_driver_register(&tegra_gart_driver);
}
static void __exit tegra_gart_exit(void)
{
platform_driver_unregister(&tegra_gart_driver);
}
subsys_initcall(tegra_gart_init);
module_exit(tegra_gart_exit);
MODULE_DESCRIPTION("IOMMU API for GART in Tegra20");
MODULE_AUTHOR("Hiroshi DOYU <hdoyu@nvidia.com>");
MODULE_ALIAS("platform:tegra-gart");
MODULE_LICENSE("GPL v2");
