blob: 6d40bc1b38bf0ccc2f90a441d04729d492c4d3a5 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* IOMMU API for Graphics Address Relocation Table on Tegra20
*
* Copyright (c) 2010-2012, NVIDIA CORPORATION. All rights reserved.
*
* Author: Hiroshi DOYU <hdoyu@nvidia.com>
*/
#define dev_fmt(fmt) "gart: " fmt
#include <linux/io.h>
#include <linux/iommu.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <soc/tegra/mc.h>
#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 BIT(31)
#define GART_PAGE_SHIFT 12
#define GART_PAGE_SIZE (1 << GART_PAGE_SHIFT)
#define GART_PAGE_MASK GENMASK(30, GART_PAGE_SHIFT)
/* bitmap of the page sizes currently supported */
#define GART_IOMMU_PGSIZES (GART_PAGE_SIZE)
struct gart_device {
void __iomem *regs;
u32 *savedata;
unsigned long iovmm_base; /* offset to vmm_area start */
unsigned long iovmm_end; /* offset to vmm_area end */
spinlock_t pte_lock; /* for pagetable */
spinlock_t dom_lock; /* for active domain */
unsigned int active_devices; /* number of active devices */
struct iommu_domain *active_domain; /* current active domain */
struct iommu_device iommu; /* IOMMU Core handle */
struct device *dev;
};
static struct gart_device *gart_handle; /* unique for a system */
static bool gart_debug;
/*
* 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) readl_relaxed((gart)->regs + GART_CONFIG)
#define for_each_gart_pte(gart, iova) \
for (iova = gart->iovmm_base; \
iova < gart->iovmm_end; \
iova += GART_PAGE_SIZE)
static inline void gart_set_pte(struct gart_device *gart,
unsigned long iova, unsigned long pte)
{
writel_relaxed(iova, gart->regs + GART_ENTRY_ADDR);
writel_relaxed(pte, gart->regs + GART_ENTRY_DATA);
}
static inline unsigned long gart_read_pte(struct gart_device *gart,
unsigned long iova)
{
unsigned long pte;
writel_relaxed(iova, gart->regs + GART_ENTRY_ADDR);
pte = readl_relaxed(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_relaxed(1, gart->regs + GART_CONFIG);
FLUSH_GART_REGS(gart);
}
static inline bool gart_iova_range_invalid(struct gart_device *gart,
unsigned long iova, size_t bytes)
{
return unlikely(iova < gart->iovmm_base || bytes != GART_PAGE_SIZE ||
iova + bytes > gart->iovmm_end);
}
static inline bool gart_pte_valid(struct gart_device *gart, unsigned long iova)
{
return !!(gart_read_pte(gart, iova) & GART_ENTRY_PHYS_ADDR_VALID);
}
static int gart_iommu_attach_dev(struct iommu_domain *domain,
struct device *dev)
{
struct gart_device *gart = gart_handle;
int ret = 0;
spin_lock(&gart->dom_lock);
if (gart->active_domain && gart->active_domain != domain) {
ret = -EBUSY;
} else if (dev->archdata.iommu != domain) {
dev->archdata.iommu = domain;
gart->active_domain = domain;
gart->active_devices++;
}
spin_unlock(&gart->dom_lock);
return ret;
}
static void gart_iommu_detach_dev(struct iommu_domain *domain,
struct device *dev)
{
struct gart_device *gart = gart_handle;
spin_lock(&gart->dom_lock);
if (dev->archdata.iommu == domain) {
dev->archdata.iommu = NULL;
if (--gart->active_devices == 0)
gart->active_domain = NULL;
}
spin_unlock(&gart->dom_lock);
}
static struct iommu_domain *gart_iommu_domain_alloc(unsigned type)
{
struct iommu_domain *domain;
if (type != IOMMU_DOMAIN_UNMANAGED)
return NULL;
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (domain) {
domain->geometry.aperture_start = gart_handle->iovmm_base;
domain->geometry.aperture_end = gart_handle->iovmm_end - 1;
domain->geometry.force_aperture = true;
}
return domain;
}
static void gart_iommu_domain_free(struct iommu_domain *domain)
{
WARN_ON(gart_handle->active_domain == domain);
kfree(domain);
}
static inline int __gart_iommu_map(struct gart_device *gart, unsigned long iova,
unsigned long pa)
{
if (unlikely(gart_debug && gart_pte_valid(gart, iova))) {
dev_err(gart->dev, "Page entry is in-use\n");
return -EINVAL;
}
gart_set_pte(gart, iova, GART_ENTRY_PHYS_ADDR_VALID | pa);
return 0;
}
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 = gart_handle;
int ret;
if (gart_iova_range_invalid(gart, iova, bytes))
return -EINVAL;
spin_lock(&gart->pte_lock);
ret = __gart_iommu_map(gart, iova, (unsigned long)pa);
spin_unlock(&gart->pte_lock);
return ret;
}
static inline int __gart_iommu_unmap(struct gart_device *gart,
unsigned long iova)
{
if (unlikely(gart_debug && !gart_pte_valid(gart, iova))) {
dev_err(gart->dev, "Page entry is invalid\n");
return -EINVAL;
}
gart_set_pte(gart, iova, 0);
return 0;
}
static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
size_t bytes)
{
struct gart_device *gart = gart_handle;
int err;
if (gart_iova_range_invalid(gart, iova, bytes))
return 0;
spin_lock(&gart->pte_lock);
err = __gart_iommu_unmap(gart, iova);
spin_unlock(&gart->pte_lock);
return err ? 0 : bytes;
}
static phys_addr_t gart_iommu_iova_to_phys(struct iommu_domain *domain,
dma_addr_t iova)
{
struct gart_device *gart = gart_handle;
unsigned long pte;
if (gart_iova_range_invalid(gart, iova, GART_PAGE_SIZE))
return -EINVAL;
spin_lock(&gart->pte_lock);
pte = gart_read_pte(gart, iova);
spin_unlock(&gart->pte_lock);
return pte & GART_PAGE_MASK;
}
static bool gart_iommu_capable(enum iommu_cap cap)
{
return false;
}
static int gart_iommu_add_device(struct device *dev)
{
struct iommu_group *group;
if (!dev->iommu_fwspec)
return -ENODEV;
group = iommu_group_get_for_dev(dev);
if (IS_ERR(group))
return PTR_ERR(group);
iommu_group_put(group);
iommu_device_link(&gart_handle->iommu, dev);
return 0;
}
static void gart_iommu_remove_device(struct device *dev)
{
iommu_group_remove_device(dev);
iommu_device_unlink(&gart_handle->iommu, dev);
}
static int gart_iommu_of_xlate(struct device *dev,
struct of_phandle_args *args)
{
return 0;
}
static void gart_iommu_sync(struct iommu_domain *domain)
{
FLUSH_GART_REGS(gart_handle);
}
static const struct iommu_ops gart_iommu_ops = {
.capable = gart_iommu_capable,
.domain_alloc = gart_iommu_domain_alloc,
.domain_free = gart_iommu_domain_free,
.attach_dev = gart_iommu_attach_dev,
.detach_dev = gart_iommu_detach_dev,
.add_device = gart_iommu_add_device,
.remove_device = gart_iommu_remove_device,
.device_group = generic_device_group,
.map = gart_iommu_map,
.unmap = gart_iommu_unmap,
.iova_to_phys = gart_iommu_iova_to_phys,
.pgsize_bitmap = GART_IOMMU_PGSIZES,
.of_xlate = gart_iommu_of_xlate,
.iotlb_sync_map = gart_iommu_sync,
.iotlb_sync = gart_iommu_sync,
};
int tegra_gart_suspend(struct gart_device *gart)
{
u32 *data = gart->savedata;
unsigned long iova;
/*
* All GART users shall be suspended at this point. Disable
* address translation to trap all GART accesses as invalid
* memory accesses.
*/
writel_relaxed(0, gart->regs + GART_CONFIG);
FLUSH_GART_REGS(gart);
for_each_gart_pte(gart, iova)
*(data++) = gart_read_pte(gart, iova);
return 0;
}
int tegra_gart_resume(struct gart_device *gart)
{
do_gart_setup(gart, gart->savedata);
return 0;
}
struct gart_device *tegra_gart_probe(struct device *dev, struct tegra_mc *mc)
{
struct gart_device *gart;
struct resource *res;
int err;
BUILD_BUG_ON(PAGE_SHIFT != GART_PAGE_SHIFT);
/* the GART memory aperture is required */
res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 1);
if (!res) {
dev_err(dev, "Memory aperture resource unavailable\n");
return ERR_PTR(-ENXIO);
}
gart = kzalloc(sizeof(*gart), GFP_KERNEL);
if (!gart)
return ERR_PTR(-ENOMEM);
gart_handle = gart;
gart->dev = dev;
gart->regs = mc->regs + GART_REG_BASE;
gart->iovmm_base = res->start;
gart->iovmm_end = res->end + 1;
spin_lock_init(&gart->pte_lock);
spin_lock_init(&gart->dom_lock);
do_gart_setup(gart, NULL);
err = iommu_device_sysfs_add(&gart->iommu, dev, NULL, "gart");
if (err)
goto free_gart;
iommu_device_set_ops(&gart->iommu, &gart_iommu_ops);
iommu_device_set_fwnode(&gart->iommu, dev->fwnode);
err = iommu_device_register(&gart->iommu);
if (err)
goto remove_sysfs;
gart->savedata = vmalloc(resource_size(res) / GART_PAGE_SIZE *
sizeof(u32));
if (!gart->savedata) {
err = -ENOMEM;
goto unregister_iommu;
}
return gart;
unregister_iommu:
iommu_device_unregister(&gart->iommu);
remove_sysfs:
iommu_device_sysfs_remove(&gart->iommu);
free_gart:
kfree(gart);
return ERR_PTR(err);
}
module_param(gart_debug, bool, 0644);
MODULE_PARM_DESC(gart_debug, "Enable GART debugging");