iommu/amd: Implement functions to manage GCR3 table

This patch adds functions necessary to set and clear the
GCR3 values associated with a particular PASID in an IOMMUv2
domain.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index b086173..65a118c 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1637,8 +1637,45 @@ static void free_pagetable(struct protection_domain *domain)
        domain->pt_root = NULL;
 }
 
+static void free_gcr3_tbl_level1(u64 *tbl)
+{
+       u64 *ptr;
+       int i;
+
+       for (i = 0; i < 512; ++i) {
+               if (!(tbl[i] & GCR3_VALID))
+                       continue;
+
+               ptr = __va(tbl[i] & PAGE_MASK);
+
+               free_page((unsigned long)ptr);
+       }
+}
+
+static void free_gcr3_tbl_level2(u64 *tbl)
+{
+       u64 *ptr;
+       int i;
+
+       for (i = 0; i < 512; ++i) {
+               if (!(tbl[i] & GCR3_VALID))
+                       continue;
+
+               ptr = __va(tbl[i] & PAGE_MASK);
+
+               free_gcr3_tbl_level1(ptr);
+       }
+}
+
 static void free_gcr3_table(struct protection_domain *domain)
 {
+       if (domain->glx == 2)
+               free_gcr3_tbl_level2(domain->gcr3_tbl);
+       else if (domain->glx == 1)
+               free_gcr3_tbl_level1(domain->gcr3_tbl);
+       else if (domain->glx != 0)
+               BUG();
+
        free_page((unsigned long)domain->gcr3_tbl);
 }
 
@@ -3282,3 +3319,96 @@ int amd_iommu_flush_tlb(struct iommu_domain *dom, int pasid)
 }
 EXPORT_SYMBOL(amd_iommu_flush_tlb);
 
+static u64 *__get_gcr3_pte(u64 *root, int level, int pasid, bool alloc)
+{
+       int index;
+       u64 *pte;
+
+       while (true) {
+
+               index = (pasid >> (9 * level)) & 0x1ff;
+               pte   = &root[index];
+
+               if (level == 0)
+                       break;
+
+               if (!(*pte & GCR3_VALID)) {
+                       if (!alloc)
+                               return NULL;
+
+                       root = (void *)get_zeroed_page(GFP_ATOMIC);
+                       if (root == NULL)
+                               return NULL;
+
+                       *pte = __pa(root) | GCR3_VALID;
+               }
+
+               root = __va(*pte & PAGE_MASK);
+
+               level -= 1;
+       }
+
+       return pte;
+}
+
+static int __set_gcr3(struct protection_domain *domain, int pasid,
+                     unsigned long cr3)
+{
+       u64 *pte;
+
+       if (domain->mode != PAGE_MODE_NONE)
+               return -EINVAL;
+
+       pte = __get_gcr3_pte(domain->gcr3_tbl, domain->glx, pasid, true);
+       if (pte == NULL)
+               return -ENOMEM;
+
+       *pte = (cr3 & PAGE_MASK) | GCR3_VALID;
+
+       return __amd_iommu_flush_tlb(domain, pasid);
+}
+
+static int __clear_gcr3(struct protection_domain *domain, int pasid)
+{
+       u64 *pte;
+
+       if (domain->mode != PAGE_MODE_NONE)
+               return -EINVAL;
+
+       pte = __get_gcr3_pte(domain->gcr3_tbl, domain->glx, pasid, false);
+       if (pte == NULL)
+               return 0;
+
+       *pte = 0;
+
+       return __amd_iommu_flush_tlb(domain, pasid);
+}
+
+int amd_iommu_domain_set_gcr3(struct iommu_domain *dom, int pasid,
+                             unsigned long cr3)
+{
+       struct protection_domain *domain = dom->priv;
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&domain->lock, flags);
+       ret = __set_gcr3(domain, pasid, cr3);
+       spin_unlock_irqrestore(&domain->lock, flags);
+
+       return ret;
+}
+EXPORT_SYMBOL(amd_iommu_domain_set_gcr3);
+
+int amd_iommu_domain_clear_gcr3(struct iommu_domain *dom, int pasid)
+{
+       struct protection_domain *domain = dom->priv;
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(&domain->lock, flags);
+       ret = __clear_gcr3(domain, pasid);
+       spin_unlock_irqrestore(&domain->lock, flags);
+
+       return ret;
+}
+EXPORT_SYMBOL(amd_iommu_domain_clear_gcr3);

diff --git a/drivers/iommu/amd_iommu_proto.h b/drivers/iommu/amd_iommu_proto.h
index a92dc61..a951a70 100644 (file)
--- a/drivers/iommu/amd_iommu_proto.h
+++ b/drivers/iommu/amd_iommu_proto.h
@@ -43,6 +43,10 @@ extern int amd_iommu_domain_enable_v2(struct iommu_domain *dom, int pasids);
 extern int amd_iommu_flush_page(struct iommu_domain *dom, int pasid,
                                u64 address);
 extern int amd_iommu_flush_tlb(struct iommu_domain *dom, int pasid);
+extern int amd_iommu_domain_set_gcr3(struct iommu_domain *dom, int pasid,
+                                    unsigned long cr3);
+extern int amd_iommu_domain_clear_gcr3(struct iommu_domain *dom, int pasid);
+
 
 #ifndef CONFIG_AMD_IOMMU_STATS
 

diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index ff1dfe9..060724e 100644 (file)
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -279,6 +279,7 @@
 #define DTE_GCR3_SHIFT_B       16
 #define DTE_GCR3_SHIFT_C       43
 
+#define GCR3_VALID             0x01ULL
 
 #define IOMMU_PAGE_MASK (((1ULL << 52) - 1) & ~0xfffULL)
 #define IOMMU_PTE_PRESENT(pte) ((pte) & IOMMU_PTE_P)