x86/amd-iommu: Introduce increase_address_space function

This function will be used to increase the address space
size of a protection domain.

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

2 files changed, 31 insertions, 0 deletions

diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index 97f3d09d3be5..1b4b3d6c9f04 100644
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -160,6 +160,10 @@
                                   ((1ULL << PM_LEVEL_SHIFT((x))) - 1): \
                                    (0xffffffffffffffffULL))
 #define PM_LEVEL_INDEX(x, a)    (((a) >> PM_LEVEL_SHIFT((x))) & 0x1ffULL)
+#define PM_LEVEL_ENC(x)         (((x) << 9) & 0xe00ULL)
+#define PM_LEVEL_PDE(x, a)      ((a) | PM_LEVEL_ENC((x)) | \
+                                 IOMMU_PTE_P | IOMMU_PTE_IR | IOMMU_PTE_IW)
+
 
 #define IOMMU_PTE_L2_INDEX(address) (((address) >> 30) & 0x1ffULL)
 #define IOMMU_PTE_L1_INDEX(address) (((address) >> 21) & 0x1ffULL)
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 5eab6a84b9cc..fc97b51f0287 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -1325,6 +1325,33 @@ static void update_domain(struct protection_domain *domain)
 }
 
 /*
+ * This function is used to add another level to an IO page table. Adding
+ * another level increases the size of the address space by 9 bits to a size up
+ * to 64 bits.
+ */
+static bool increase_address_space(struct protection_domain *domain,
+                                   gfp_t gfp)
+{
+        u64 *pte;
+
+        if (domain->mode == PAGE_MODE_6_LEVEL)
+                /* address space already 64 bit large */
+                return false;
+
+        pte = (void *)get_zeroed_page(gfp);
+        if (!pte)
+                return false;
+
+        *pte             = PM_LEVEL_PDE(domain->mode,
+                                        virt_to_phys(domain->pt_root));
+        domain->pt_root  = pte;
+        domain->mode    += 1;
+        domain->updated  = true;
+
+        return true;
+}
+
+/*
  * If the pte_page is not yet allocated this function is called
  */
 static u64* alloc_pte(struct protection_domain *dom,