2 files changed, 86 insertions, 27 deletions

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 1e5a10de3471..9ab6ebf46f7a 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -570,14 +570,89 @@ int __init detect_intel_iommu(void)
 }
 
 
+static void unmap_iommu(struct intel_iommu *iommu)
+{
+        iounmap(iommu->reg);
+        release_mem_region(iommu->reg_phys, iommu->reg_size);
+}
+
+/**
+ * map_iommu: map the iommu's registers
+ * @iommu: the iommu to map
+ * @phys_addr: the physical address of the base resgister
+ * 
+ * Memory map the iommu's registers.  Start w/ a single page, and
+ * possibly expand if that turns out to be insufficent.  
+ */
+static int map_iommu(struct intel_iommu *iommu, u64 phys_addr)
+{
+        int map_size, err=0;
+
+        iommu->reg_phys = phys_addr;
+        iommu->reg_size = VTD_PAGE_SIZE;
+
+        if (!request_mem_region(iommu->reg_phys, iommu->reg_size, iommu->name)) {
+                pr_err("IOMMU: can't reserve memory\n");
+                err = -EBUSY;
+                goto out;
+        }
+
+        iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
+        if (!iommu->reg) {
+                pr_err("IOMMU: can't map the region\n");
+                err = -ENOMEM;
+                goto release;
+        }
+
+        iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
+        iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
+
+        if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) {
+                err = -EINVAL;
+                warn_invalid_dmar(phys_addr, " returns all ones");
+                goto unmap;
+        }
+
+        /* the registers might be more than one page */
+        map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
+                         cap_max_fault_reg_offset(iommu->cap));
+        map_size = VTD_PAGE_ALIGN(map_size);
+        if (map_size > iommu->reg_size) {
+                iounmap(iommu->reg);
+                release_mem_region(iommu->reg_phys, iommu->reg_size);
+                iommu->reg_size = map_size;
+                if (!request_mem_region(iommu->reg_phys, iommu->reg_size,
+                                        iommu->name)) {
+                        pr_err("IOMMU: can't reserve memory\n");
+                        err = -EBUSY;
+                        goto out;
+                }
+                iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
+                if (!iommu->reg) {
+                        pr_err("IOMMU: can't map the region\n");
+                        err = -ENOMEM;
+                        goto release;
+                }
+        }
+        err = 0;
+        goto out;
+
+unmap:
+        iounmap(iommu->reg);
+release:
+        release_mem_region(iommu->reg_phys, iommu->reg_size);
+out:
+        return err;
+}
+
 int alloc_iommu(struct dmar_drhd_unit *drhd)
 {
         struct intel_iommu *iommu;
-        int map_size;
         u32 ver;
         static int iommu_allocated = 0;
         int agaw = 0;
         int msagaw = 0;
+        int err;
 
         if (!drhd->reg_base_addr) {
                 warn_invalid_dmar(0, "");
@@ -591,19 +666,13 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
         iommu->seq_id = iommu_allocated++;
         sprintf (iommu->name, "dmar%d", iommu->seq_id);
 
-        iommu->reg = ioremap(drhd->reg_base_addr, VTD_PAGE_SIZE);
-        if (!iommu->reg) {
-                pr_err("IOMMU: can't map the region\n");
+        err = map_iommu(iommu, drhd->reg_base_addr);
+        if (err) {
+                pr_err("IOMMU: failed to map %s\n", iommu->name);
                 goto error;
         }
-        iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
-        iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
-
-        if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) {
-                warn_invalid_dmar(drhd->reg_base_addr, " returns all ones");
-                goto err_unmap;
-        }
 
+        err = -EINVAL;
         agaw = iommu_calculate_agaw(iommu);
         if (agaw < 0) {
                 pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
@@ -621,19 +690,6 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
 
         iommu->node = -1;
 
-        /* the registers might be more than one page */
-        map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
-                cap_max_fault_reg_offset(iommu->cap));
-        map_size = VTD_PAGE_ALIGN(map_size);
-        if (map_size > VTD_PAGE_SIZE) {
-                iounmap(iommu->reg);
-                iommu->reg = ioremap(drhd->reg_base_addr, map_size);
-                if (!iommu->reg) {
-                        pr_err("IOMMU: can't map the region\n");
-                        goto error;
-                }
-        }
-
         ver = readl(iommu->reg + DMAR_VER_REG);
         pr_info("IOMMU %d: reg_base_addr %llx ver %d:%d cap %llx ecap %llx\n",
                 iommu->seq_id,
@@ -648,10 +704,10 @@ int alloc_iommu(struct dmar_drhd_unit *drhd)
         return 0;
 
  err_unmap:
-        iounmap(iommu->reg);
+        unmap_iommu(iommu);
  error:
         kfree(iommu);
-        return -1;
+        return err;
 }
 
 void free_iommu(struct intel_iommu *iommu)
@@ -662,7 +718,8 @@ void free_iommu(struct intel_iommu *iommu)
         free_dmar_iommu(iommu);
 
         if (iommu->reg)
-                iounmap(iommu->reg);
+                unmap_iommu(iommu);
+
         kfree(iommu);
 }
 
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index e6ca56de9936..78e2ada50cd5 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -308,6 +308,8 @@ enum {
 
 struct intel_iommu {
         void __iomem    *reg; /* Pointer to hardware regs, virtual addr */
+        u64             reg_phys; /* physical address of hw register set */
+        u64             reg_size; /* size of hw register set */
         u64             cap;
         u64             ecap;
         u32             gcmd; /* Holds TE, EAFL. Don't need SRTP, SFL, WBF */