+++ /dev/null
-// 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 = -EINVAL;
- } else if (dev_iommu_priv_get(dev) != domain) {
- dev_iommu_priv_set(dev, domain);
- gart->active_domain = domain;
- gart->active_devices++;
- }
-
- spin_unlock(&gart->dom_lock);
-
- return ret;
-}
-
-static void gart_iommu_set_platform_dma(struct device *dev)
-{
- struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
- struct gart_device *gart = gart_handle;
-
- spin_lock(&gart->dom_lock);
-
- if (dev_iommu_priv_get(dev) == domain) {
- dev_iommu_priv_set(dev, 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, gfp_t gfp)
-{
- 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 iommu_iotlb_gather *gather)
-{
- 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 struct iommu_device *gart_iommu_probe_device(struct device *dev)
-{
- if (!dev_iommu_fwspec_get(dev))
- return ERR_PTR(-ENODEV);
-
- return &gart_handle->iommu;
-}
-
-static int gart_iommu_of_xlate(struct device *dev,
- struct of_phandle_args *args)
-{
- return 0;
-}
-
-static void gart_iommu_sync_map(struct iommu_domain *domain, unsigned long iova,
- size_t size)
-{
- FLUSH_GART_REGS(gart_handle);
-}
-
-static void gart_iommu_sync(struct iommu_domain *domain,
- struct iommu_iotlb_gather *gather)
-{
- size_t length = gather->end - gather->start + 1;
-
- gart_iommu_sync_map(domain, gather->start, length);
-}
-
-static const struct iommu_ops gart_iommu_ops = {
- .domain_alloc = gart_iommu_domain_alloc,
- .probe_device = gart_iommu_probe_device,
- .device_group = generic_device_group,
- .set_platform_dma_ops = gart_iommu_set_platform_dma,
- .pgsize_bitmap = GART_IOMMU_PGSIZES,
- .of_xlate = gart_iommu_of_xlate,
- .default_domain_ops = &(const struct iommu_domain_ops) {
- .attach_dev = gart_iommu_attach_dev,
- .map = gart_iommu_map,
- .unmap = gart_iommu_unmap,
- .iova_to_phys = gart_iommu_iova_to_phys,
- .iotlb_sync_map = gart_iommu_sync_map,
- .iotlb_sync = gart_iommu_sync,
- .free = gart_iommu_domain_free,
- }
-};
-
-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;
-
- err = iommu_device_register(&gart->iommu, &gart_iommu_ops, dev);
- 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");
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