diff options
Diffstat (limited to 'kernel/drivers/iommu/shmobile-iommu.c')
| -rw-r--r-- | kernel/drivers/iommu/shmobile-iommu.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/kernel/drivers/iommu/shmobile-iommu.c b/kernel/drivers/iommu/shmobile-iommu.c new file mode 100644 index 000000000..a0287519a --- /dev/null +++ b/kernel/drivers/iommu/shmobile-iommu.c @@ -0,0 +1,402 @@ +/* + * IOMMU for 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/dma-mapping.h> +#include <linux/io.h> +#include <linux/iommu.h> +#include <linux/platform_device.h> +#include <linux/sizes.h> +#include <linux/slab.h> +#include <asm/dma-iommu.h> +#include "shmobile-ipmmu.h" + +#define L1_SIZE CONFIG_SHMOBILE_IOMMU_L1SIZE +#define L1_LEN (L1_SIZE / 4) +#define L1_ALIGN L1_SIZE +#define L2_SIZE SZ_1K +#define L2_LEN (L2_SIZE / 4) +#define L2_ALIGN L2_SIZE + +struct shmobile_iommu_domain_pgtable { + uint32_t *pgtable; + dma_addr_t handle; +}; + +struct shmobile_iommu_archdata { + struct list_head attached_list; + struct dma_iommu_mapping *iommu_mapping; + spinlock_t attach_lock; + struct shmobile_iommu_domain *attached; + int num_attached_devices; + struct shmobile_ipmmu *ipmmu; +}; + +struct shmobile_iommu_domain { + struct shmobile_iommu_domain_pgtable l1, l2[L1_LEN]; + spinlock_t map_lock; + spinlock_t attached_list_lock; + struct list_head attached_list; + struct iommu_domain domain; +}; + +static struct shmobile_iommu_archdata *ipmmu_archdata; +static struct kmem_cache *l1cache, *l2cache; + +static struct shmobile_iommu_domain *to_sh_domain(struct iommu_domain *dom) +{ + return container_of(dom, struct shmobile_iommu_domain, domain); +} + +static int pgtable_alloc(struct shmobile_iommu_domain_pgtable *pgtable, + struct kmem_cache *cache, size_t size) +{ + pgtable->pgtable = kmem_cache_zalloc(cache, GFP_ATOMIC); + if (!pgtable->pgtable) + return -ENOMEM; + pgtable->handle = dma_map_single(NULL, pgtable->pgtable, size, + DMA_TO_DEVICE); + return 0; +} + +static void pgtable_free(struct shmobile_iommu_domain_pgtable *pgtable, + struct kmem_cache *cache, size_t size) +{ + dma_unmap_single(NULL, pgtable->handle, size, DMA_TO_DEVICE); + kmem_cache_free(cache, pgtable->pgtable); +} + +static uint32_t pgtable_read(struct shmobile_iommu_domain_pgtable *pgtable, + unsigned int index) +{ + return pgtable->pgtable[index]; +} + +static void pgtable_write(struct shmobile_iommu_domain_pgtable *pgtable, + unsigned int index, unsigned int count, uint32_t val) +{ + unsigned int i; + + for (i = 0; i < count; i++) + pgtable->pgtable[index + i] = val; + dma_sync_single_for_device(NULL, pgtable->handle + index * sizeof(val), + sizeof(val) * count, DMA_TO_DEVICE); +} + +static struct iommu_domain *shmobile_iommu_domain_alloc(unsigned type) +{ + struct shmobile_iommu_domain *sh_domain; + int i, ret; + + if (type != IOMMU_DOMAIN_UNMANAGED) + return NULL; + + sh_domain = kzalloc(sizeof(*sh_domain), GFP_KERNEL); + if (!sh_domain) + return NULL; + ret = pgtable_alloc(&sh_domain->l1, l1cache, L1_SIZE); + if (ret < 0) { + kfree(sh_domain); + return NULL; + } + for (i = 0; i < L1_LEN; i++) + sh_domain->l2[i].pgtable = NULL; + spin_lock_init(&sh_domain->map_lock); + spin_lock_init(&sh_domain->attached_list_lock); + INIT_LIST_HEAD(&sh_domain->attached_list); + return &sh_domain->domain; +} + +static void shmobile_iommu_domain_free(struct iommu_domain *domain) +{ + struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain); + int i; + + for (i = 0; i < L1_LEN; i++) { + if (sh_domain->l2[i].pgtable) + pgtable_free(&sh_domain->l2[i], l2cache, L2_SIZE); + } + pgtable_free(&sh_domain->l1, l1cache, L1_SIZE); + kfree(sh_domain); +} + +static int shmobile_iommu_attach_device(struct iommu_domain *domain, + struct device *dev) +{ + struct shmobile_iommu_archdata *archdata = dev->archdata.iommu; + struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain); + int ret = -EBUSY; + + if (!archdata) + return -ENODEV; + spin_lock(&sh_domain->attached_list_lock); + spin_lock(&archdata->attach_lock); + if (archdata->attached != sh_domain) { + if (archdata->attached) + goto err; + ipmmu_tlb_set(archdata->ipmmu, sh_domain->l1.handle, L1_SIZE, + 0); + ipmmu_tlb_flush(archdata->ipmmu); + archdata->attached = sh_domain; + archdata->num_attached_devices = 0; + list_add(&archdata->attached_list, &sh_domain->attached_list); + } + archdata->num_attached_devices++; + ret = 0; +err: + spin_unlock(&archdata->attach_lock); + spin_unlock(&sh_domain->attached_list_lock); + return ret; +} + +static void shmobile_iommu_detach_device(struct iommu_domain *domain, + struct device *dev) +{ + struct shmobile_iommu_archdata *archdata = dev->archdata.iommu; + struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain); + + if (!archdata) + return; + spin_lock(&sh_domain->attached_list_lock); + spin_lock(&archdata->attach_lock); + archdata->num_attached_devices--; + if (!archdata->num_attached_devices) { + ipmmu_tlb_set(archdata->ipmmu, 0, 0, 0); + ipmmu_tlb_flush(archdata->ipmmu); + archdata->attached = NULL; + list_del(&archdata->attached_list); + } + spin_unlock(&archdata->attach_lock); + spin_unlock(&sh_domain->attached_list_lock); +} + +static void domain_tlb_flush(struct shmobile_iommu_domain *sh_domain) +{ + struct shmobile_iommu_archdata *archdata; + + spin_lock(&sh_domain->attached_list_lock); + list_for_each_entry(archdata, &sh_domain->attached_list, attached_list) + ipmmu_tlb_flush(archdata->ipmmu); + spin_unlock(&sh_domain->attached_list_lock); +} + +static int l2alloc(struct shmobile_iommu_domain *sh_domain, + unsigned int l1index) +{ + int ret; + + if (!sh_domain->l2[l1index].pgtable) { + ret = pgtable_alloc(&sh_domain->l2[l1index], l2cache, L2_SIZE); + if (ret < 0) + return ret; + } + pgtable_write(&sh_domain->l1, l1index, 1, + sh_domain->l2[l1index].handle | 0x1); + return 0; +} + +static void l2realfree(struct shmobile_iommu_domain_pgtable *l2) +{ + if (l2->pgtable) + pgtable_free(l2, l2cache, L2_SIZE); +} + +static void l2free(struct shmobile_iommu_domain *sh_domain, + unsigned int l1index, + struct shmobile_iommu_domain_pgtable *l2) +{ + pgtable_write(&sh_domain->l1, l1index, 1, 0); + if (sh_domain->l2[l1index].pgtable) { + *l2 = sh_domain->l2[l1index]; + sh_domain->l2[l1index].pgtable = NULL; + } +} + +static int shmobile_iommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot) +{ + struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL }; + struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain); + unsigned int l1index, l2index; + int ret; + + l1index = iova >> 20; + switch (size) { + case SZ_4K: + l2index = (iova >> 12) & 0xff; + spin_lock(&sh_domain->map_lock); + ret = l2alloc(sh_domain, l1index); + if (!ret) + pgtable_write(&sh_domain->l2[l1index], l2index, 1, + paddr | 0xff2); + spin_unlock(&sh_domain->map_lock); + break; + case SZ_64K: + l2index = (iova >> 12) & 0xf0; + spin_lock(&sh_domain->map_lock); + ret = l2alloc(sh_domain, l1index); + if (!ret) + pgtable_write(&sh_domain->l2[l1index], l2index, 0x10, + paddr | 0xff1); + spin_unlock(&sh_domain->map_lock); + break; + case SZ_1M: + spin_lock(&sh_domain->map_lock); + l2free(sh_domain, l1index, &l2); + pgtable_write(&sh_domain->l1, l1index, 1, paddr | 0xc02); + spin_unlock(&sh_domain->map_lock); + ret = 0; + break; + default: + ret = -EINVAL; + } + if (!ret) + domain_tlb_flush(sh_domain); + l2realfree(&l2); + return ret; +} + +static size_t shmobile_iommu_unmap(struct iommu_domain *domain, + unsigned long iova, size_t size) +{ + struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL }; + struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain); + unsigned int l1index, l2index; + uint32_t l2entry = 0; + size_t ret = 0; + + l1index = iova >> 20; + if (!(iova & 0xfffff) && size >= SZ_1M) { + spin_lock(&sh_domain->map_lock); + l2free(sh_domain, l1index, &l2); + spin_unlock(&sh_domain->map_lock); + ret = SZ_1M; + goto done; + } + l2index = (iova >> 12) & 0xff; + spin_lock(&sh_domain->map_lock); + if (sh_domain->l2[l1index].pgtable) + l2entry = pgtable_read(&sh_domain->l2[l1index], l2index); + switch (l2entry & 3) { + case 1: + if (l2index & 0xf) + break; + pgtable_write(&sh_domain->l2[l1index], l2index, 0x10, 0); + ret = SZ_64K; + break; + case 2: + pgtable_write(&sh_domain->l2[l1index], l2index, 1, 0); + ret = SZ_4K; + break; + } + spin_unlock(&sh_domain->map_lock); +done: + if (ret) + domain_tlb_flush(sh_domain); + l2realfree(&l2); + return ret; +} + +static phys_addr_t shmobile_iommu_iova_to_phys(struct iommu_domain *domain, + dma_addr_t iova) +{ + struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain); + uint32_t l1entry = 0, l2entry = 0; + unsigned int l1index, l2index; + + l1index = iova >> 20; + l2index = (iova >> 12) & 0xff; + spin_lock(&sh_domain->map_lock); + if (sh_domain->l2[l1index].pgtable) + l2entry = pgtable_read(&sh_domain->l2[l1index], l2index); + else + l1entry = pgtable_read(&sh_domain->l1, l1index); + spin_unlock(&sh_domain->map_lock); + switch (l2entry & 3) { + case 1: + return (l2entry & ~0xffff) | (iova & 0xffff); + case 2: + return (l2entry & ~0xfff) | (iova & 0xfff); + default: + if ((l1entry & 3) == 2) + return (l1entry & ~0xfffff) | (iova & 0xfffff); + return 0; + } +} + +static int find_dev_name(struct shmobile_ipmmu *ipmmu, const char *dev_name) +{ + unsigned int i, n = ipmmu->num_dev_names; + + for (i = 0; i < n; i++) { + if (strcmp(ipmmu->dev_names[i], dev_name) == 0) + return 1; + } + return 0; +} + +static int shmobile_iommu_add_device(struct device *dev) +{ + struct shmobile_iommu_archdata *archdata = ipmmu_archdata; + struct dma_iommu_mapping *mapping; + + if (!find_dev_name(archdata->ipmmu, dev_name(dev))) + return 0; + mapping = archdata->iommu_mapping; + if (!mapping) { + mapping = arm_iommu_create_mapping(&platform_bus_type, 0, + L1_LEN << 20); + if (IS_ERR(mapping)) + return PTR_ERR(mapping); + archdata->iommu_mapping = mapping; + } + dev->archdata.iommu = archdata; + if (arm_iommu_attach_device(dev, mapping)) + pr_err("arm_iommu_attach_device failed\n"); + return 0; +} + +static const struct iommu_ops shmobile_iommu_ops = { + .domain_alloc = shmobile_iommu_domain_alloc, + .domain_free = shmobile_iommu_domain_free, + .attach_dev = shmobile_iommu_attach_device, + .detach_dev = shmobile_iommu_detach_device, + .map = shmobile_iommu_map, + .unmap = shmobile_iommu_unmap, + .map_sg = default_iommu_map_sg, + .iova_to_phys = shmobile_iommu_iova_to_phys, + .add_device = shmobile_iommu_add_device, + .pgsize_bitmap = SZ_1M | SZ_64K | SZ_4K, +}; + +int ipmmu_iommu_init(struct shmobile_ipmmu *ipmmu) +{ + static struct shmobile_iommu_archdata *archdata; + + l1cache = kmem_cache_create("shmobile-iommu-pgtable1", L1_SIZE, + L1_ALIGN, SLAB_HWCACHE_ALIGN, NULL); + if (!l1cache) + return -ENOMEM; + l2cache = kmem_cache_create("shmobile-iommu-pgtable2", L2_SIZE, + L2_ALIGN, SLAB_HWCACHE_ALIGN, NULL); + if (!l2cache) { + kmem_cache_destroy(l1cache); + return -ENOMEM; + } + archdata = kzalloc(sizeof(*archdata), GFP_KERNEL); + if (!archdata) { + kmem_cache_destroy(l1cache); + kmem_cache_destroy(l2cache); + return -ENOMEM; + } + spin_lock_init(&archdata->attach_lock); + archdata->ipmmu = ipmmu; + ipmmu_archdata = archdata; + bus_set_iommu(&platform_bus_type, &shmobile_iommu_ops); + return 0; +} |