/*
* 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;
};
static struct shmobile_iommu_archdata *ipmmu_archdata;
static struct kmem_cache *l1cache, *l2cache;
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 int shmobile_iommu_domain_init(struct iommu_domain *domain)
{
struct shmobile_iommu_domain *sh_domain;
int i, ret;
sh_domain = kmalloc(sizeof(*sh_domain), GFP_KERNEL);
if (!sh_domain)
return -ENOMEM;
ret = pgtable_alloc(&sh_domain->l1, l1cache, L1_SIZE);
if (ret < 0) {
kfree(sh_domain);
return ret;
}
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);
domain->priv = sh_domain;
return 0;
}
static void shmobile_iommu_domain_destroy(struct iommu_domain *domain)
{
struct shmobile_iommu_domain *sh_domain = domain->priv;
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);
domain->priv = NULL;
}
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 = domain->priv;
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 = domain->priv;
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 = domain->priv;
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 = domain->priv;
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 = domain->priv;
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_init = shmobile_iommu_domain_init,
.domain_destroy = shmobile_iommu_domain_destroy,
.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;
}
