diff options
Diffstat (limited to 'drivers/iommu/omap-iovmm.c')
| -rw-r--r-- | drivers/iommu/omap-iovmm.c | 742 |
1 files changed, 742 insertions, 0 deletions
diff --git a/drivers/iommu/omap-iovmm.c b/drivers/iommu/omap-iovmm.c new file mode 100644 index 000000000000..e8fdb8830f69 --- /dev/null +++ b/drivers/iommu/omap-iovmm.c @@ -0,0 +1,742 @@ +/* + * omap iommu: simple virtual address space management + * + * Copyright (C) 2008-2009 Nokia Corporation + * + * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/device.h> +#include <linux/scatterlist.h> +#include <linux/iommu.h> + +#include <asm/cacheflush.h> +#include <asm/mach/map.h> + +#include <plat/iommu.h> +#include <plat/iovmm.h> + +#include <plat/iopgtable.h> + +static struct kmem_cache *iovm_area_cachep; + +/* return the offset of the first scatterlist entry in a sg table */ +static unsigned int sgtable_offset(const struct sg_table *sgt) +{ + if (!sgt || !sgt->nents) + return 0; + + return sgt->sgl->offset; +} + +/* return total bytes of sg buffers */ +static size_t sgtable_len(const struct sg_table *sgt) +{ + unsigned int i, total = 0; + struct scatterlist *sg; + + if (!sgt) + return 0; + + for_each_sg(sgt->sgl, sg, sgt->nents, i) { + size_t bytes; + + bytes = sg->length + sg->offset; + + if (!iopgsz_ok(bytes)) { + pr_err("%s: sg[%d] not iommu pagesize(%u %u)\n", + __func__, i, bytes, sg->offset); + return 0; + } + + if (i && sg->offset) { + pr_err("%s: sg[%d] offset not allowed in internal " + "entries\n", __func__, i); + return 0; + } + + total += bytes; + } + + return total; +} +#define sgtable_ok(x) (!!sgtable_len(x)) + +static unsigned max_alignment(u32 addr) +{ + int i; + unsigned pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, }; + for (i = 0; i < ARRAY_SIZE(pagesize) && addr & (pagesize[i] - 1); i++) + ; + return (i < ARRAY_SIZE(pagesize)) ? pagesize[i] : 0; +} + +/* + * calculate the optimal number sg elements from total bytes based on + * iommu superpages + */ +static unsigned sgtable_nents(size_t bytes, u32 da, u32 pa) +{ + unsigned nr_entries = 0, ent_sz; + + if (!IS_ALIGNED(bytes, PAGE_SIZE)) { + pr_err("%s: wrong size %08x\n", __func__, bytes); + return 0; + } + + while (bytes) { + ent_sz = max_alignment(da | pa); + ent_sz = min_t(unsigned, ent_sz, iopgsz_max(bytes)); + nr_entries++; + da += ent_sz; + pa += ent_sz; + bytes -= ent_sz; + } + + return nr_entries; +} + +/* allocate and initialize sg_table header(a kind of 'superblock') */ +static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags, + u32 da, u32 pa) +{ + unsigned int nr_entries; + int err; + struct sg_table *sgt; + + if (!bytes) + return ERR_PTR(-EINVAL); + + if (!IS_ALIGNED(bytes, PAGE_SIZE)) + return ERR_PTR(-EINVAL); + + if (flags & IOVMF_LINEAR) { + nr_entries = sgtable_nents(bytes, da, pa); + if (!nr_entries) + return ERR_PTR(-EINVAL); + } else + nr_entries = bytes / PAGE_SIZE; + + sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); + if (!sgt) + return ERR_PTR(-ENOMEM); + + err = sg_alloc_table(sgt, nr_entries, GFP_KERNEL); + if (err) { + kfree(sgt); + return ERR_PTR(err); + } + + pr_debug("%s: sgt:%p(%d entries)\n", __func__, sgt, nr_entries); + + return sgt; +} + +/* free sg_table header(a kind of superblock) */ +static void sgtable_free(struct sg_table *sgt) +{ + if (!sgt) + return; + + sg_free_table(sgt); + kfree(sgt); + + pr_debug("%s: sgt:%p\n", __func__, sgt); +} + +/* map 'sglist' to a contiguous mpu virtual area and return 'va' */ +static void *vmap_sg(const struct sg_table *sgt) +{ + u32 va; + size_t total; + unsigned int i; + struct scatterlist *sg; + struct vm_struct *new; + const struct mem_type *mtype; + + mtype = get_mem_type(MT_DEVICE); + if (!mtype) + return ERR_PTR(-EINVAL); + + total = sgtable_len(sgt); + if (!total) + return ERR_PTR(-EINVAL); + + new = __get_vm_area(total, VM_IOREMAP, VMALLOC_START, VMALLOC_END); + if (!new) + return ERR_PTR(-ENOMEM); + va = (u32)new->addr; + + for_each_sg(sgt->sgl, sg, sgt->nents, i) { + size_t bytes; + u32 pa; + int err; + + pa = sg_phys(sg) - sg->offset; + bytes = sg->length + sg->offset; + + BUG_ON(bytes != PAGE_SIZE); + + err = ioremap_page(va, pa, mtype); + if (err) + goto err_out; + + va += bytes; + } + + flush_cache_vmap((unsigned long)new->addr, + (unsigned long)(new->addr + total)); + return new->addr; + +err_out: + WARN_ON(1); /* FIXME: cleanup some mpu mappings */ + vunmap(new->addr); + return ERR_PTR(-EAGAIN); +} + +static inline void vunmap_sg(const void *va) +{ + vunmap(va); +} + +static struct iovm_struct *__find_iovm_area(struct omap_iommu *obj, + const u32 da) +{ + struct iovm_struct *tmp; + + list_for_each_entry(tmp, &obj->mmap, list) { + if ((da >= tmp->da_start) && (da < tmp->da_end)) { + size_t len; + + len = tmp->da_end - tmp->da_start; + + dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", + __func__, tmp->da_start, da, tmp->da_end, len, + tmp->flags); + + return tmp; + } + } + + return NULL; +} + +/** + * omap_find_iovm_area - find iovma which includes @da + * @da: iommu device virtual address + * + * Find the existing iovma starting at @da + */ +struct iovm_struct *omap_find_iovm_area(struct omap_iommu *obj, u32 da) +{ + struct iovm_struct *area; + + mutex_lock(&obj->mmap_lock); + area = __find_iovm_area(obj, da); + mutex_unlock(&obj->mmap_lock); + + return area; +} +EXPORT_SYMBOL_GPL(omap_find_iovm_area); + +/* + * This finds the hole(area) which fits the requested address and len + * in iovmas mmap, and returns the new allocated iovma. + */ +static struct iovm_struct *alloc_iovm_area(struct omap_iommu *obj, u32 da, + size_t bytes, u32 flags) +{ + struct iovm_struct *new, *tmp; + u32 start, prev_end, alignment; + + if (!obj || !bytes) + return ERR_PTR(-EINVAL); + + start = da; + alignment = PAGE_SIZE; + + if (~flags & IOVMF_DA_FIXED) { + /* Don't map address 0 */ + start = obj->da_start ? obj->da_start : alignment; + + if (flags & IOVMF_LINEAR) + alignment = iopgsz_max(bytes); + start = roundup(start, alignment); + } else if (start < obj->da_start || start > obj->da_end || + obj->da_end - start < bytes) { + return ERR_PTR(-EINVAL); + } + + tmp = NULL; + if (list_empty(&obj->mmap)) + goto found; + + prev_end = 0; + list_for_each_entry(tmp, &obj->mmap, list) { + + if (prev_end > start) + break; + + if (tmp->da_start > start && (tmp->da_start - start) >= bytes) + goto found; + + if (tmp->da_end >= start && ~flags & IOVMF_DA_FIXED) + start = roundup(tmp->da_end + 1, alignment); + + prev_end = tmp->da_end; + } + + if ((start >= prev_end) && (obj->da_end - start >= bytes)) + goto found; + + dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n", + __func__, da, bytes, flags); + + return ERR_PTR(-EINVAL); + +found: + new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL); + if (!new) + return ERR_PTR(-ENOMEM); + + new->iommu = obj; + new->da_start = start; + new->da_end = start + bytes; + new->flags = flags; + + /* + * keep ascending order of iovmas + */ + if (tmp) + list_add_tail(&new->list, &tmp->list); + else + list_add(&new->list, &obj->mmap); + + dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n", + __func__, new->da_start, start, new->da_end, bytes, flags); + + return new; +} + +static void free_iovm_area(struct omap_iommu *obj, struct iovm_struct *area) +{ + size_t bytes; + + BUG_ON(!obj || !area); + + bytes = area->da_end - area->da_start; + + dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n", + __func__, area->da_start, area->da_end, bytes, area->flags); + + list_del(&area->list); + kmem_cache_free(iovm_area_cachep, area); +} + +/** + * omap_da_to_va - convert (d) to (v) + * @obj: objective iommu + * @da: iommu device virtual address + * @va: mpu virtual address + * + * Returns mpu virtual addr which corresponds to a given device virtual addr + */ +void *omap_da_to_va(struct omap_iommu *obj, u32 da) +{ + void *va = NULL; + struct iovm_struct *area; + + mutex_lock(&obj->mmap_lock); + + area = __find_iovm_area(obj, da); + if (!area) { + dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da); + goto out; + } + va = area->va; +out: + mutex_unlock(&obj->mmap_lock); + + return va; +} +EXPORT_SYMBOL_GPL(omap_da_to_va); + +static void sgtable_fill_vmalloc(struct sg_table *sgt, void *_va) +{ + unsigned int i; + struct scatterlist *sg; + void *va = _va; + void *va_end; + + for_each_sg(sgt->sgl, sg, sgt->nents, i) { + struct page *pg; + const size_t bytes = PAGE_SIZE; + + /* + * iommu 'superpage' isn't supported with 'omap_iommu_vmalloc()' + */ + pg = vmalloc_to_page(va); + BUG_ON(!pg); + sg_set_page(sg, pg, bytes, 0); + + va += bytes; + } + + va_end = _va + PAGE_SIZE * i; +} + +static inline void sgtable_drain_vmalloc(struct sg_table *sgt) +{ + /* + * Actually this is not necessary at all, just exists for + * consistency of the code readability. + */ + BUG_ON(!sgt); +} + +/* create 'da' <-> 'pa' mapping from 'sgt' */ +static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new, + const struct sg_table *sgt, u32 flags) +{ + int err; + unsigned int i, j; + struct scatterlist *sg; + u32 da = new->da_start; + int order; + + if (!domain || !sgt) + return -EINVAL; + + BUG_ON(!sgtable_ok(sgt)); + + for_each_sg(sgt->sgl, sg, sgt->nents, i) { + u32 pa; + size_t bytes; + + pa = sg_phys(sg) - sg->offset; + bytes = sg->length + sg->offset; + + flags &= ~IOVMF_PGSZ_MASK; + + if (bytes_to_iopgsz(bytes) < 0) + goto err_out; + + order = get_order(bytes); + + pr_debug("%s: [%d] %08x %08x(%x)\n", __func__, + i, da, pa, bytes); + + err = iommu_map(domain, da, pa, order, flags); + if (err) + goto err_out; + + da += bytes; + } + return 0; + +err_out: + da = new->da_start; + + for_each_sg(sgt->sgl, sg, i, j) { + size_t bytes; + + bytes = sg->length + sg->offset; + order = get_order(bytes); + + /* ignore failures.. we're already handling one */ + iommu_unmap(domain, da, order); + + da += bytes; + } + return err; +} + +/* release 'da' <-> 'pa' mapping */ +static void unmap_iovm_area(struct iommu_domain *domain, struct omap_iommu *obj, + struct iovm_struct *area) +{ + u32 start; + size_t total = area->da_end - area->da_start; + const struct sg_table *sgt = area->sgt; + struct scatterlist *sg; + int i, err; + + BUG_ON(!sgtable_ok(sgt)); + BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE)); + + start = area->da_start; + for_each_sg(sgt->sgl, sg, sgt->nents, i) { + size_t bytes; + int order; + + bytes = sg->length + sg->offset; + order = get_order(bytes); + + err = iommu_unmap(domain, start, order); + if (err < 0) + break; + + dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n", + __func__, start, bytes, area->flags); + + BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE)); + + total -= bytes; + start += bytes; + } + BUG_ON(total); +} + +/* template function for all unmapping */ +static struct sg_table *unmap_vm_area(struct iommu_domain *domain, + struct omap_iommu *obj, const u32 da, + void (*fn)(const void *), u32 flags) +{ + struct sg_table *sgt = NULL; + struct iovm_struct *area; + + if (!IS_ALIGNED(da, PAGE_SIZE)) { + dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da); + return NULL; + } + + mutex_lock(&obj->mmap_lock); + + area = __find_iovm_area(obj, da); + if (!area) { + dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da); + goto out; + } + + if ((area->flags & flags) != flags) { + dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__, + area->flags); + goto out; + } + sgt = (struct sg_table *)area->sgt; + + unmap_iovm_area(domain, obj, area); + + fn(area->va); + + dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__, + area->da_start, da, area->da_end, + area->da_end - area->da_start, area->flags); + + free_iovm_area(obj, area); +out: + mutex_unlock(&obj->mmap_lock); + + return sgt; +} + +static u32 map_iommu_region(struct iommu_domain *domain, struct omap_iommu *obj, + u32 da, const struct sg_table *sgt, void *va, + size_t bytes, u32 flags) +{ + int err = -ENOMEM; + struct iovm_struct *new; + + mutex_lock(&obj->mmap_lock); + + new = alloc_iovm_area(obj, da, bytes, flags); + if (IS_ERR(new)) { + err = PTR_ERR(new); + goto err_alloc_iovma; + } + new->va = va; + new->sgt = sgt; + + if (map_iovm_area(domain, new, sgt, new->flags)) + goto err_map; + + mutex_unlock(&obj->mmap_lock); + + dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n", + __func__, new->da_start, bytes, new->flags, va); + + return new->da_start; + +err_map: + free_iovm_area(obj, new); +err_alloc_iovma: + mutex_unlock(&obj->mmap_lock); + return err; +} + +static inline u32 +__iommu_vmap(struct iommu_domain *domain, struct omap_iommu *obj, + u32 da, const struct sg_table *sgt, + void *va, size_t bytes, u32 flags) +{ + return map_iommu_region(domain, obj, da, sgt, va, bytes, flags); +} + +/** + * omap_iommu_vmap - (d)-(p)-(v) address mapper + * @obj: objective iommu + * @sgt: address of scatter gather table + * @flags: iovma and page property + * + * Creates 1-n-1 mapping with given @sgt and returns @da. + * All @sgt element must be io page size aligned. + */ +u32 omap_iommu_vmap(struct iommu_domain *domain, struct omap_iommu *obj, u32 da, + const struct sg_table *sgt, u32 flags) +{ + size_t bytes; + void *va = NULL; + + if (!obj || !obj->dev || !sgt) + return -EINVAL; + + bytes = sgtable_len(sgt); + if (!bytes) + return -EINVAL; + bytes = PAGE_ALIGN(bytes); + + if (flags & IOVMF_MMIO) { + va = vmap_sg(sgt); + if (IS_ERR(va)) + return PTR_ERR(va); + } + + flags |= IOVMF_DISCONT; + flags |= IOVMF_MMIO; + + da = __iommu_vmap(domain, obj, da, sgt, va, bytes, flags); + if (IS_ERR_VALUE(da)) + vunmap_sg(va); + + return da + sgtable_offset(sgt); +} +EXPORT_SYMBOL_GPL(omap_iommu_vmap); + +/** + * omap_iommu_vunmap - release virtual mapping obtained by 'omap_iommu_vmap()' + * @obj: objective iommu + * @da: iommu device virtual address + * + * Free the iommu virtually contiguous memory area starting at + * @da, which was returned by 'omap_iommu_vmap()'. + */ +struct sg_table * +omap_iommu_vunmap(struct iommu_domain *domain, struct omap_iommu *obj, u32 da) +{ + struct sg_table *sgt; + /* + * 'sgt' is allocated before 'omap_iommu_vmalloc()' is called. + * Just returns 'sgt' to the caller to free + */ + da &= PAGE_MASK; + sgt = unmap_vm_area(domain, obj, da, vunmap_sg, + IOVMF_DISCONT | IOVMF_MMIO); + if (!sgt) + dev_dbg(obj->dev, "%s: No sgt\n", __func__); + return sgt; +} +EXPORT_SYMBOL_GPL(omap_iommu_vunmap); + +/** + * omap_iommu_vmalloc - (d)-(p)-(v) address allocator and mapper + * @obj: objective iommu + * @da: contiguous iommu virtual memory + * @bytes: allocation size + * @flags: iovma and page property + * + * Allocate @bytes linearly and creates 1-n-1 mapping and returns + * @da again, which might be adjusted if 'IOVMF_DA_FIXED' is not set. + */ +u32 +omap_iommu_vmalloc(struct iommu_domain *domain, struct omap_iommu *obj, u32 da, + size_t bytes, u32 flags) +{ + void *va; + struct sg_table *sgt; + + if (!obj || !obj->dev || !bytes) + return -EINVAL; + + bytes = PAGE_ALIGN(bytes); + + va = vmalloc(bytes); + if (!va) + return -ENOMEM; + + flags |= IOVMF_DISCONT; + flags |= IOVMF_ALLOC; + + sgt = sgtable_alloc(bytes, flags, da, 0); + if (IS_ERR(sgt)) { + da = PTR_ERR(sgt); + goto err_sgt_alloc; + } + sgtable_fill_vmalloc(sgt, va); + + da = __iommu_vmap(domain, obj, da, sgt, va, bytes, flags); + if (IS_ERR_VALUE(da)) + goto err_iommu_vmap; + + return da; + +err_iommu_vmap: + sgtable_drain_vmalloc(sgt); + sgtable_free(sgt); +err_sgt_alloc: + vfree(va); + return da; +} +EXPORT_SYMBOL_GPL(omap_iommu_vmalloc); + +/** + * omap_iommu_vfree - release memory allocated by 'omap_iommu_vmalloc()' + * @obj: objective iommu + * @da: iommu device virtual address + * + * Frees the iommu virtually continuous memory area starting at + * @da, as obtained from 'omap_iommu_vmalloc()'. + */ +void omap_iommu_vfree(struct iommu_domain *domain, struct omap_iommu *obj, + const u32 da) +{ + struct sg_table *sgt; + + sgt = unmap_vm_area(domain, obj, da, vfree, + IOVMF_DISCONT | IOVMF_ALLOC); + if (!sgt) + dev_dbg(obj->dev, "%s: No sgt\n", __func__); + sgtable_free(sgt); +} +EXPORT_SYMBOL_GPL(omap_iommu_vfree); + +static int __init iovmm_init(void) +{ + const unsigned long flags = SLAB_HWCACHE_ALIGN; + struct kmem_cache *p; + + p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0, + flags, NULL); + if (!p) + return -ENOMEM; + iovm_area_cachep = p; + + return 0; +} +module_init(iovmm_init); + +static void __exit iovmm_exit(void) +{ + kmem_cache_destroy(iovm_area_cachep); +} +module_exit(iovmm_exit); + +MODULE_DESCRIPTION("omap iommu: simple virtual address space management"); +MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>"); +MODULE_LICENSE("GPL v2"); |