vtd: prune (and rename) cache flush functions

Rename __iommu_flush_cache to iommu_sync_cache and remove
iommu_flush_cache_page. Also remove the iommu_flush_cache_entry
wrapper and just use iommu_sync_cache instead. Note the _entry suffix
was meaningless as the wrapper was already taking a size parameter in
bytes. While there also constify the addr parameter.

No functional change intended.

This is part of XSA-321.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 62298825b9
master date: 2020-07-07 14:38:13 +0200

xen/drivers/passthrough/vtd/extern.h

@@ -43,8 +43,7 @@ void disable_qinval(struct vtd_iommu *iommu);
 int enable_intremap(struct vtd_iommu *iommu, int eim);
 void disable_intremap(struct vtd_iommu *iommu);
 
-void iommu_flush_cache_entry(void *addr, unsigned int size);
-void iommu_flush_cache_page(void *addr, unsigned long npages);
+void iommu_sync_cache(const void *addr, unsigned int size);
 int iommu_alloc(struct acpi_drhd_unit *drhd);
 void iommu_free(struct acpi_drhd_unit *drhd);
 

xen/drivers/passthrough/vtd/intremap.c

@@ -230,7 +230,7 @@ static void free_remap_entry(struct vtd_iommu *iommu, int index)
                      iremap_entries, iremap_entry);
 
     update_irte(iommu, iremap_entry, &new_ire, false);
-    iommu_flush_cache_entry(iremap_entry, sizeof(*iremap_entry));
+    iommu_sync_cache(iremap_entry, sizeof(*iremap_entry));
     iommu_flush_iec_index(iommu, 0, index);
 
     unmap_vtd_domain_page(iremap_entries);
@@ -406,7 +406,7 @@ static int ioapic_rte_to_remap_entry(struct vtd_iommu *iommu,
     }
 
     update_irte(iommu, iremap_entry, &new_ire, !init);
-    iommu_flush_cache_entry(iremap_entry, sizeof(*iremap_entry));
+    iommu_sync_cache(iremap_entry, sizeof(*iremap_entry));
     iommu_flush_iec_index(iommu, 0, index);
 
     unmap_vtd_domain_page(iremap_entries);
@@ -695,7 +695,7 @@ static int msi_msg_to_remap_entry(
     update_irte(iommu, iremap_entry, &new_ire, msi_desc->irte_initialized);
     msi_desc->irte_initialized = true;
 
-    iommu_flush_cache_entry(iremap_entry, sizeof(*iremap_entry));
+    iommu_sync_cache(iremap_entry, sizeof(*iremap_entry));
     iommu_flush_iec_index(iommu, 0, index);
 
     unmap_vtd_domain_page(iremap_entries);

xen/drivers/passthrough/vtd/iommu.c

@@ -140,7 +140,8 @@ static int context_get_domain_id(struct context_entry *context,
 }
 
 static int iommus_incoherent;
-static void __iommu_flush_cache(void *addr, unsigned int size)
+
+void iommu_sync_cache(const void *addr, unsigned int size)
 {
     int i;
     static unsigned int clflush_size = 0;
@@ -155,16 +156,6 @@ static void __iommu_flush_cache(void *addr, unsigned int size)
         cacheline_flush((char *)addr + i);
 }
 
-void iommu_flush_cache_entry(void *addr, unsigned int size)
-{
-    __iommu_flush_cache(addr, size);
-}
-
-void iommu_flush_cache_page(void *addr, unsigned long npages)
-{
-    __iommu_flush_cache(addr, PAGE_SIZE * npages);
-}
-
 /* Allocate page table, return its machine address */
 uint64_t alloc_pgtable_maddr(unsigned long npages, nodeid_t node)
 {
@@ -183,7 +174,7 @@ uint64_t alloc_pgtable_maddr(unsigned long npages, nodeid_t node)
         vaddr = __map_domain_page(cur_pg);
         memset(vaddr, 0, PAGE_SIZE);
 
-        iommu_flush_cache_page(vaddr, 1);
+        iommu_sync_cache(vaddr, PAGE_SIZE);
         unmap_domain_page(vaddr);
         cur_pg++;
     }
@@ -216,7 +207,7 @@ static u64 bus_to_context_maddr(struct vtd_iommu *iommu, u8 bus)
         }
         set_root_value(*root, maddr);
         set_root_present(*root);
-        iommu_flush_cache_entry(root, sizeof(struct root_entry));
+        iommu_sync_cache(root, sizeof(struct root_entry));
     }
     maddr = (u64) get_context_addr(*root);
     unmap_vtd_domain_page(root_entries);
@@ -263,7 +254,7 @@ static u64 addr_to_dma_page_maddr(struct domain *domain, u64 addr, int alloc)
              */
             dma_set_pte_readable(*pte);
             dma_set_pte_writable(*pte);
-            iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
+            iommu_sync_cache(pte, sizeof(struct dma_pte));
         }
 
         if ( level == 2 )
@@ -640,7 +631,7 @@ static int __must_check dma_pte_clear_one(struct domain *domain, u64 addr,
     *flush_flags |= IOMMU_FLUSHF_modified;
 
     spin_unlock(&hd->arch.mapping_lock);
-    iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
+    iommu_sync_cache(pte, sizeof(struct dma_pte));
 
     unmap_vtd_domain_page(page);
 
@@ -679,7 +670,7 @@ static void iommu_free_page_table(struct page_info *pg)
             iommu_free_pagetable(dma_pte_addr(*pte), next_level);
 
         dma_clear_pte(*pte);
-        iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
+        iommu_sync_cache(pte, sizeof(struct dma_pte));
     }
 
     unmap_vtd_domain_page(pt_vaddr);
@@ -1400,7 +1391,7 @@ int domain_context_mapping_one(
     context_set_address_width(*context, agaw);
     context_set_fault_enable(*context);
     context_set_present(*context);
-    iommu_flush_cache_entry(context, sizeof(struct context_entry));
+    iommu_sync_cache(context, sizeof(struct context_entry));
     spin_unlock(&iommu->lock);
 
     /* Context entry was previously non-present (with domid 0). */
@@ -1564,7 +1555,7 @@ int domain_context_unmap_one(
 
     context_clear_present(*context);
     context_clear_entry(*context);
-    iommu_flush_cache_entry(context, sizeof(struct context_entry));
+    iommu_sync_cache(context, sizeof(struct context_entry));
 
     iommu_domid= domain_iommu_domid(domain, iommu);
     if ( iommu_domid == -1 )
@@ -1791,7 +1782,7 @@ static int __must_check intel_iommu_map_page(struct domain *d, dfn_t dfn,
 
     *pte = new;
 
-    iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
+    iommu_sync_cache(pte, sizeof(struct dma_pte));
     spin_unlock(&hd->arch.mapping_lock);
     unmap_vtd_domain_page(page);
 
@@ -1866,7 +1857,7 @@ int iommu_pte_flush(struct domain *d, uint64_t dfn, uint64_t *pte,
     int iommu_domid;
     int rc = 0;
 
-    iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
+    iommu_sync_cache(pte, sizeof(struct dma_pte));
 
     for_each_drhd_unit ( drhd )
     {
@@ -2724,7 +2715,7 @@ static int __init intel_iommu_quarantine_init(struct domain *d)
             dma_set_pte_addr(*pte, maddr);
             dma_set_pte_readable(*pte);
         }
-        iommu_flush_cache_page(parent, 1);
+        iommu_sync_cache(parent, PAGE_SIZE);
 
         unmap_vtd_domain_page(parent);
         parent = map_vtd_domain_page(maddr);