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/*
* 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;
struct iommu_device iommu; /* IOMMU Core handle */
};
struct gart_domain {
struct iommu_domain domain; /* generic domain handle */
struct gart_device *gart; /* link to gart device */
};
static struct gart_device *gart_handle; /* unique for a system */
#define GART_PTE(_pfn) \
(GART_ENTRY_PHYS_ADDR_VALID | ((_pfn) << PAGE_SHIFT))
static struct gart_domain *to_gart_domain(struct iommu_domain *dom)
{
return container_of(dom, struct gart_domain, domain);
}
/*
* 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_domain *gart_domain = to_gart_domain(domain);
struct gart_device *gart = gart_domain->gart;
struct gart_client *client, *c;
int err = 0;
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_domain *gart_domain = to_gart_domain(domain);
struct gart_device *gart = gart_domain->gart;
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 struct iommu_domain *gart_iommu_domain_alloc(unsigned type)
{
struct gart_domain *gart_domain;
struct gart_device *gart;
if (type != IOMMU_DOMAIN_UNMANAGED)
return NULL;
gart = gart_handle;
if (!gart)
return NULL;
gart_domain = kzalloc(sizeof(*gart_domain), GFP_KERNEL);
if (!gart_domain)
return NULL;
gart_domain->gart = gart;
gart_domain->domain.geometry.aperture_start = gart->iovmm_base;
gart_domain->domain.geometry.aperture_end = gart->iovmm_base +
gart->page_count * GART_PAGE_SIZE - 1;
gart_domain->domain.geometry.force_aperture = true;
return &gart_domain->domain;
}
static void gart_iommu_domain_free(struct iommu_domain *domain)
{
struct gart_domain *gart_domain = to_gart_domain(domain);
struct gart_device *gart = gart_domain->gart;
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