1 files changed, 40 insertions, 115 deletions

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 74c9be13f043..ad348c61d5e7 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -23,7 +23,6 @@
 
 #include <linux/io.h>
 #include <linux/iommu.h>
-#include <linux/list.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
@@ -46,30 +45,20 @@
 #define GART_PAGE_MASK                                          \
         (~(GART_PAGE_SIZE - 1) & ~GART_ENTRY_PHYS_ADDR_VALID)
 
-struct gart_client {
-        struct device           *dev;
-        struct list_head        list;
-};
-
 struct gart_device {
         void __iomem            *regs;
         u32                     *savedata;
         u32                     page_count;     /* total remappable size */
         dma_addr_t              iovmm_base;     /* offset to vmm_area */
         spinlock_t              pte_lock;       /* for pagetable */
-        struct list_head        client;
-        spinlock_t              client_lock;    /* for client list */
+        spinlock_t              dom_lock;       /* for active domain */
+        unsigned int            active_devices; /* number of active devices */
         struct iommu_domain     *active_domain; /* current active domain */
         struct device           *dev;
 
         struct iommu_device     iommu;          /* IOMMU Core handle */
 };
 
-struct gart_domain {
-        struct iommu_domain domain;             /* generic domain handle */
-        struct gart_device *gart;               /* link to gart device   */
-};
-
 static struct gart_device *gart_handle; /* unique for a system */
 
 static bool gart_debug;
@@ -77,11 +66,6 @@ static bool gart_debug;
 #define GART_PTE(_pfn)                                          \
         (GART_ENTRY_PHYS_ADDR_VALID | ((_pfn) << PAGE_SHIFT))
 
-static struct gart_domain *to_gart_domain(struct iommu_domain *dom)
-{
-        return container_of(dom, struct gart_domain, domain);
-}
-
 /*
  * 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
@@ -170,125 +154,70 @@ static inline bool gart_iova_range_valid(struct gart_device *gart,
 static int gart_iommu_attach_dev(struct iommu_domain *domain,
                                  struct device *dev)
 {
-        struct gart_domain *gart_domain = to_gart_domain(domain);
         struct gart_device *gart = gart_handle;
-        struct gart_client *client, *c;
-        int err = 0;
-
-        client = kzalloc(sizeof(*c), GFP_KERNEL);
-        if (!client)
-                return -ENOMEM;
-        client->dev = dev;
-
-        spin_lock(&gart->client_lock);
-        list_for_each_entry(c, &gart->client, list) {
-                if (c->dev == dev) {
-                        dev_err(gart->dev,
-                                "%s is already attached\n", dev_name(dev));
-                        err = -EINVAL;
-                        goto fail;
-                }
-        }
-        if (gart->active_domain && gart->active_domain != domain) {
-                dev_err(gart->dev, "Only one domain can be active at a time\n");
-                err = -EINVAL;
-                goto fail;
-        }
-        gart->active_domain = domain;
-        gart_domain->gart = gart;
-        list_add(&client->list, &gart->client);
-        spin_unlock(&gart->client_lock);
-        dev_dbg(gart->dev, "Attached %s\n", dev_name(dev));
-        return 0;
+        int ret = 0;
 
-fail:
-        kfree(client);
-        spin_unlock(&gart->client_lock);
-        return err;
-}
+        spin_lock(&gart->dom_lock);
 
-static void __gart_iommu_detach_dev(struct iommu_domain *domain,
-                                    struct device *dev)
-{
-        struct gart_domain *gart_domain = to_gart_domain(domain);
-        struct gart_device *gart = gart_domain->gart;
-        struct gart_client *c;
-
-        list_for_each_entry(c, &gart->client, list) {
-                if (c->dev == dev) {
-                        list_del(&c->list);
-                        kfree(c);
-                        if (list_empty(&gart->client)) {
-                                gart->active_domain = NULL;
-                                gart_domain->gart = NULL;
-                        }
-                        dev_dbg(gart->dev, "Detached %s\n", dev_name(dev));
-                        return;
-                }
+        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++;
         }
 
-        dev_err(gart->dev, "Couldn't find %s to detach\n", dev_name(dev));
+        spin_unlock(&gart->dom_lock);
+
+        return ret;
 }
 
 static void gart_iommu_detach_dev(struct iommu_domain *domain,
                                   struct device *dev)
 {
-        struct gart_domain *gart_domain = to_gart_domain(domain);
-        struct gart_device *gart = gart_domain->gart;
+        struct gart_device *gart = gart_handle;
+
+        spin_lock(&gart->dom_lock);
 
-        spin_lock(&gart->client_lock);
-        __gart_iommu_detach_dev(domain, dev);
-        spin_unlock(&gart->client_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 gart_domain *gart_domain;
-        struct gart_device *gart;
+        struct gart_device *gart = gart_handle;
+        struct iommu_domain *domain;
 
         if (type != IOMMU_DOMAIN_UNMANAGED)
                 return NULL;
 
-        gart = gart_handle;
-        if (!gart)
-                return NULL;
-
-        gart_domain = kzalloc(sizeof(*gart_domain), GFP_KERNEL);
-        if (!gart_domain)
-                return NULL;
-
-        gart_domain->domain.geometry.aperture_start = gart->iovmm_base;
-        gart_domain->domain.geometry.aperture_end = gart->iovmm_base +
+        domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+        if (domain) {
+                domain->geometry.aperture_start = gart->iovmm_base;
+                domain->geometry.aperture_end = gart->iovmm_base +
                                         gart->page_count * GART_PAGE_SIZE - 1;
-        gart_domain->domain.geometry.force_aperture = true;
+                domain->geometry.force_aperture = true;
+        }
 
-        return &gart_domain->domain;
+        return domain;
 }
 
 static void gart_iommu_domain_free(struct iommu_domain *domain)
 {
-        struct gart_domain *gart_domain = to_gart_domain(domain);
-        struct gart_device *gart = gart_domain->gart;
-
-        if (gart) {
-                spin_lock(&gart->client_lock);
-                if (!list_empty(&gart->client)) {
-                        struct gart_client *c, *tmp;
-
-                        list_for_each_entry_safe(c, tmp, &gart->client, list)
-                                __gart_iommu_detach_dev(domain, c->dev);
-                }
-                spin_unlock(&gart->client_lock);
-        }
-
-        kfree(gart_domain);
+        WARN_ON(gart_handle->active_domain == domain);
+        kfree(domain);
 }
 
 static int gart_iommu_map(struct iommu_domain *domain, unsigned long iova,
                           phys_addr_t pa, size_t bytes, int prot)
 {
-        struct gart_domain *gart_domain = to_gart_domain(domain);
-        struct gart_device *gart = gart_domain->gart;
+        struct gart_device *gart = gart_handle;
         unsigned long flags;
         unsigned long pfn;
         unsigned long pte;
@@ -319,8 +248,7 @@ static int gart_iommu_map(struct iommu_domain *domain, unsigned long iova,
 static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
                                size_t bytes)
 {
-        struct gart_domain *gart_domain = to_gart_domain(domain);
-        struct gart_device *gart = gart_domain->gart;
+        struct gart_device *gart = gart_handle;
         unsigned long flags;
 
         if (!gart_iova_range_valid(gart, iova, bytes))
@@ -335,8 +263,7 @@ static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
 static phys_addr_t gart_iommu_iova_to_phys(struct iommu_domain *domain,
                                            dma_addr_t iova)
 {
-        struct gart_domain *gart_domain = to_gart_domain(domain);
-        struct gart_device *gart = gart_domain->gart;
+        struct gart_device *gart = gart_handle;
         unsigned long pte;
         phys_addr_t pa;
         unsigned long flags;
@@ -395,8 +322,7 @@ static int gart_iommu_of_xlate(struct device *dev,
 
 static void gart_iommu_sync(struct iommu_domain *domain)
 {
-        struct gart_domain *gart_domain = to_gart_domain(domain);
-        struct gart_device *gart = gart_domain->gart;
+        struct gart_device *gart = gart_handle;
 
         FLUSH_GART_REGS(gart);
 }
@@ -483,8 +409,7 @@ struct gart_device *tegra_gart_probe(struct device *dev, struct tegra_mc *mc)
         gart->dev = dev;
         gart_regs = mc->regs + GART_REG_BASE;
         spin_lock_init(&gart->pte_lock);
-        spin_lock_init(&gart->client_lock);
-        INIT_LIST_HEAD(&gart->client);
+        spin_lock_init(&gart->dom_lock);
         gart->regs = gart_regs;
         gart->iovmm_base = (dma_addr_t)res_remap->start;
         gart->page_count = (resource_size(res_remap) >> GART_PAGE_SHIFT);