[Xen-changelog] [xen master] amd-iommu: use correct constants in amd_iommu_get_next_table_from_pte()

[patchbot@xxxxxxx]

commit d74d2f53c1aa78ebe27f088f63a2020807d75164
Author:     Paul Durrant <paul.durrant@xxxxxxxxxx>
AuthorDate: Wed Sep 26 14:44:07 2018 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon Oct 15 14:34:53 2018 +0100

    amd-iommu: use correct constants in amd_iommu_get_next_table_from_pte()
    
    ...and change the name to amd_iommu_get_address_from_pte() since the
    address read is not necessarily the address of a next level page table.
    (If the 'next level' field is not 1 - 6 then the address is a page
    address).
    
    The constants in use prior to this patch relate to device table entries
    rather than page table entries. Although they do have the same value, it
    makes the code confusing to read.
    
    This patch also changes the PDE/PTE pointer argument to void *, and
    removes any u32/uint32_t casts in the call sites. Unnecessary casts
    surrounding call sites are also removed.
    
    No functional change.
    
    NOTE: The patch also adds emacs boilerplate to iommu_map.c
    
    Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
    Reviewd-by: Brian Woods <brian.woods@xxxxxxx>
---
 xen/drivers/passthrough/amd/iommu_map.c       | 40 ++++++++++++++++-----------
 xen/drivers/passthrough/amd/pci_amd_iommu.c   | 10 +++----
 xen/include/asm-x86/hvm/svm/amd-iommu-proto.h |  2 +-
 3 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/xen/drivers/passthrough/amd/iommu_map.c 
b/xen/drivers/passthrough/amd/iommu_map.c
index e7e9016838..d03a6d72b9 100644
--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -285,19 +285,18 @@ void iommu_dte_set_guest_cr3(u32 *dte, u16 dom_id, u64 
gcr3,
     dte[1] = entry;
 }
 
-u64 amd_iommu_get_next_table_from_pte(u32 *entry)
+uint64_t amd_iommu_get_address_from_pte(void *pte)
 {
-    u64 addr_lo, addr_hi, ptr;
+    uint32_t *entry = pte;
+    uint64_t addr_lo, addr_hi, ptr;
 
-    addr_lo = get_field_from_reg_u32(
-        entry[0],
-        IOMMU_DEV_TABLE_PAGE_TABLE_PTR_LOW_MASK,
-        IOMMU_DEV_TABLE_PAGE_TABLE_PTR_LOW_SHIFT);
+    addr_lo = get_field_from_reg_u32(entry[0],
+                                     IOMMU_PTE_ADDR_LOW_MASK,
+                                     IOMMU_PTE_ADDR_LOW_SHIFT);
 
-    addr_hi = get_field_from_reg_u32(
-        entry[1],
-        IOMMU_DEV_TABLE_PAGE_TABLE_PTR_HIGH_MASK,
-        IOMMU_DEV_TABLE_PAGE_TABLE_PTR_HIGH_SHIFT);
+    addr_hi = get_field_from_reg_u32(entry[1],
+                                     IOMMU_PTE_ADDR_HIGH_MASK,
+                                     IOMMU_PTE_ADDR_HIGH_SHIFT);
 
     ptr = (addr_hi << 32) | (addr_lo << PAGE_SHIFT);
     return ptr;
@@ -350,11 +349,11 @@ static int iommu_update_pde_count(struct domain *d, 
unsigned long pt_mfn,
     pde = table + pfn_to_pde_idx(dfn, merge_level);
 
     /* get page table of next level */
-    ntable_maddr = amd_iommu_get_next_table_from_pte((u32*)pde);
+    ntable_maddr = amd_iommu_get_address_from_pte(pde);
     ntable = map_domain_page(_mfn(paddr_to_pfn(ntable_maddr)));
 
     /* get the first mfn of next level */
-    first_mfn = amd_iommu_get_next_table_from_pte((u32*)ntable) >> PAGE_SHIFT;
+    first_mfn = amd_iommu_get_address_from_pte(ntable) >> PAGE_SHIFT;
 
     if ( first_mfn == 0 )
         goto out;
@@ -401,7 +400,7 @@ static int iommu_merge_pages(struct domain *d, unsigned 
long pt_mfn,
     pde = table + pfn_to_pde_idx(dfn, merge_level);
 
     /* get first mfn */
-    ntable_mfn = amd_iommu_get_next_table_from_pte((u32*)pde) >> PAGE_SHIFT;
+    ntable_mfn = amd_iommu_get_address_from_pte(pde) >> PAGE_SHIFT;
 
     if ( ntable_mfn == 0 )
     {
@@ -410,7 +409,7 @@ static int iommu_merge_pages(struct domain *d, unsigned 
long pt_mfn,
     }
 
     ntable = map_domain_page(_mfn(ntable_mfn));
-    first_mfn = amd_iommu_get_next_table_from_pte((u32*)ntable) >> PAGE_SHIFT;
+    first_mfn = amd_iommu_get_address_from_pte(ntable) >> PAGE_SHIFT;
 
     if ( first_mfn == 0 )
     {
@@ -468,8 +467,7 @@ static int iommu_pde_from_dfn(struct domain *d, unsigned 
long dfn,
         pde = next_table_vaddr + pfn_to_pde_idx(dfn, level);
 
         /* Here might be a super page frame */
-        next_table_mfn = amd_iommu_get_next_table_from_pte((uint32_t*)pde) 
-                         >> PAGE_SHIFT;
+        next_table_mfn = amd_iommu_get_address_from_pte(pde) >> PAGE_SHIFT;
 
         /* Split super page frame into smaller pieces.*/
         if ( iommu_is_pte_present((u32*)pde) &&
@@ -823,3 +821,13 @@ void amd_iommu_share_p2m(struct domain *d)
                         mfn_x(pgd_mfn));
     }
 }
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c 
b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 77323395f2..257b83e2db 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -391,11 +391,11 @@ static void deallocate_page_table(struct page_info *pg)
     for ( index = 0; index < PTE_PER_TABLE_SIZE; index++ )
     {
         pde = table_vaddr + (index * IOMMU_PAGE_TABLE_ENTRY_SIZE);
-        next_table_maddr = amd_iommu_get_next_table_from_pte(pde);
-        next_level = iommu_next_level((u32*)pde);
+        next_table_maddr = amd_iommu_get_address_from_pte(pde);
+        next_level = iommu_next_level(pde);
 
         if ( (next_table_maddr != 0) && (next_level != 0) &&
-             iommu_is_pte_present((u32*)pde) )
+             iommu_is_pte_present(pde) )
         {
             /* We do not support skip levels yet */
             ASSERT(next_level == level - 1);
@@ -520,8 +520,8 @@ static void amd_dump_p2m_table_level(struct page_info* pg, 
int level,
             process_pending_softirqs();
 
         pde = table_vaddr + (index * IOMMU_PAGE_TABLE_ENTRY_SIZE);
-        next_table_maddr = amd_iommu_get_next_table_from_pte(pde);
-        entry = (u32*)pde;
+        next_table_maddr = amd_iommu_get_address_from_pte(pde);
+        entry = pde;
 
         present = get_field_from_reg_u32(entry[0],
                                          IOMMU_PDE_PRESENT_MASK,
diff --git a/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h 
b/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
index b1cc5fa1f8..81b839a724 100644
--- a/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
+++ b/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
@@ -55,7 +55,7 @@ int amd_iommu_update_ivrs_mapping_acpi(void);
 int __must_check amd_iommu_map_page(struct domain *d, dfn_t dfn,
                                     mfn_t mfn, unsigned int flags);
 int __must_check amd_iommu_unmap_page(struct domain *d, dfn_t dfn);
-u64 amd_iommu_get_next_table_from_pte(u32 *entry);
+uint64_t amd_iommu_get_address_from_pte(void *entry);
 int __must_check amd_iommu_alloc_root(struct domain_iommu *hd);
 int amd_iommu_reserve_domain_unity_map(struct domain *domain,
                                        u64 phys_addr, unsigned long size,
--
generated by git-patchbot for /home/xen/git/xen.git#master

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