T77: Implement selective TLB flushing hint for modify_flags.

Signed-off-by: Simon Gerber <simon.gerber@inf.ethz.ch>

diff --git a/include/arch/x86_64/barrelfish/invocations_arch.h b/include/arch/x86_64/barrelfish/invocations_arch.h
index 337def4..6c46d44 100644 (file)
--- a/include/arch/x86_64/barrelfish/invocations_arch.h
+++ b/include/arch/x86_64/barrelfish/invocations_arch.h
@@ -258,15 +258,18 @@ static inline errval_t invoke_frame_identify(struct capref frame,
  *                 from the first page in the mapping identified by `frame`
  * \param pages    Number of pages that should get new set of flags
  * \param flags    New set of flags
+ * \param va_hint  Hint for selective TLB flushing
  *
  * \return Error code
  */
 static inline errval_t invoke_frame_modify_flags(struct capref frame,
                                                  size_t offset,
                                                  size_t pages,
-                                                 size_t flags)
+                                                 size_t flags,
+                                                 genvaddr_t va_hint)
 {
-    return cap_invoke4(frame, FrameCmd_ModifyFlags, offset, pages, flags).error;
+    return cap_invoke5(frame, FrameCmd_ModifyFlags, offset,
+                       pages, flags, va_hint).error;
 }
 
 static inline errval_t invoke_iocap_in(struct capref iocap, enum io_cmd cmd,

diff --git a/kernel/arch/x86_64/page_mappings_arch.c b/kernel/arch/x86_64/page_mappings_arch.c
index ffb305b..01794e7 100644 (file)
--- a/kernel/arch/x86_64/page_mappings_arch.c
+++ b/kernel/arch/x86_64/page_mappings_arch.c
@@ -455,9 +455,11 @@ errval_t page_mappings_unmap(struct capability *pgtable, struct cte *mapping,
  * \arg offset the offset from the first page table entry in entries
  * \arg pages the number of pages to modify
  * \arg mflags the new flags
+ * \arg va_hint a user-supplied virtual address for hinting selective TLB
+ *              flushing
  */
 errval_t page_mappings_modify_flags(struct capability *frame, size_t offset,
-                                    size_t pages, size_t mflags)
+                                    size_t pages, size_t mflags, genvaddr_t va_hint)
 {
     struct cte *mapping = cte_for_cap(frame);
     struct mapping_info *info = &mapping->mapping_info;
@@ -486,6 +488,7 @@ errval_t page_mappings_modify_flags(struct capability *frame, size_t offset,
     lvaddr_t base = local_phys_to_mem(info->pte) +
         offset * sizeof(union x86_64_ptable_entry);
 
+    size_t pagesize = BASE_PAGE_SIZE;
     switch(leaf_pt->cap.type) {
         case ObjType_VNode_x86_64_ptable :
             for (int i = 0; i < pages; i++) {
@@ -500,6 +503,7 @@ errval_t page_mappings_modify_flags(struct capability *frame, size_t offset,
                     (union x86_64_ptable_entry *)base + i;
                 paging_x86_64_modify_flags_large(entry, flags);
             }
+            pagesize = LARGE_PAGE_SIZE;
             break;
         case ObjType_VNode_x86_64_pdpt :
             for (int i = 0; i < pages; i++) {
@@ -507,13 +511,28 @@ errval_t page_mappings_modify_flags(struct capability *frame, size_t offset,
                     (union x86_64_ptable_entry *)base + i;
                 paging_x86_64_modify_flags_huge(entry, flags);
             }
+            pagesize = HUGE_PAGE_SIZE;
             break;
         default:
             return SYS_ERR_WRONG_MAPPING;
     }
 
-    /* do full TLB flush */
-    do_full_tlb_flush();
+    if (va_hint != 0) {
+        if (va_hint > BASE_PAGE_SIZE) {
+            // use as direct hint
+            for (int i = 0; i < pages; i++) {
+                // XXX: check proper instructions for large/huge pages
+                do_one_tlb_flush(va_hint + i * pagesize);
+            }
+        } else if (va_hint == 1) {
+            // XXX: remove this or cleanup interface, -SG, 2015-03-11
+            // do computed selective flush
+            return paging_tlb_flush_range(mapping, offset, pages);
+        }
+    } else {
+        /* do full TLB flush */
+        do_full_tlb_flush();
+    }
     return SYS_ERR_OK;
 }
 

diff --git a/kernel/arch/x86_64/syscall.c b/kernel/arch/x86_64/syscall.c
index de66cc7..f22d939 100644 (file)
--- a/kernel/arch/x86_64/syscall.c
+++ b/kernel/arch/x86_64/syscall.c
@@ -491,8 +491,9 @@ static struct sysret handle_frame_modify_flags(struct capability *to,
                              // page in mapped region
     size_t pages  = args[1]; // #pages to modify
     size_t flags  = args[2]; // new flags
+    genvaddr_t va = args[3]; // virtual addr hint
 
-    errval_t err = page_mappings_modify_flags(to, offset, pages, flags);
+    errval_t err = page_mappings_modify_flags(to, offset, pages, flags, va);
 
     return (struct sysret) {
         .error = err,

diff --git a/kernel/include/capabilities.h b/kernel/include/capabilities.h
index 8c7bce3..6eff5e4 100644 (file)
--- a/kernel/include/capabilities.h
+++ b/kernel/include/capabilities.h
@@ -86,7 +86,8 @@ size_t do_unmap(lvaddr_t pt, cslot_t slot, size_t num_pages);
 errval_t page_mappings_unmap(struct capability *pgtable, struct cte *mapping,
                              size_t entry, size_t num_pages);
 errval_t page_mappings_modify_flags(struct capability *mapping, size_t offset,
-                                    size_t pages, size_t flags);
+                                    size_t pages, size_t mflags,
+                                    genvaddr_t va_hint);
 errval_t paging_modify_flags(struct capability *frame, uintptr_t offset,
                              uintptr_t pages, uintptr_t kpi_paging_flags);
 void paging_dump_tables(struct dcb *dispatcher);

diff --git a/lib/barrelfish/target/x86_64/pmap_target.c b/lib/barrelfish/target/x86_64/pmap_target.c
index 1c09d25..eeed61e 100644 (file)
--- a/lib/barrelfish/target/x86_64/pmap_target.c
+++ b/lib/barrelfish/target/x86_64/pmap_target.c
@@ -847,9 +847,14 @@ static errval_t do_single_modify_flags(struct pmap_x86 *pmap, genvaddr_t vaddr,
         // access permissions.
         size_t off = ptentry - page->entry;
         paging_x86_64_flags_t pmap_flags = vregion_to_pmap_flag(flags);
-        err = invoke_frame_modify_flags(page->u.frame.cap, off, pages, pmap_flags);
-        //printf("invoke_frame_modify_flags returned error: %s (%"PRIuERRV")\n",
-        //                 err_getstring(err), err);
+        // calculate TLB flushing hint
+        genvaddr_t va_hint = 0;
+        if (pages == 1) {
+            // do assisted selective flush for single page
+            va_hint = vaddr & ~X86_64_BASE_PAGE_MASK;
+        }
+        err = invoke_frame_modify_flags(page->u.frame.cap, off, pages,
+                                        pmap_flags, va_hint);
         return err;
     } else {
         // overlaps some region border
@@ -857,7 +862,6 @@ static errval_t do_single_modify_flags(struct pmap_x86 *pmap, genvaddr_t vaddr,
         return LIB_ERR_PMAP_EXISTING_MAPPING;
     }
 
-
     return SYS_ERR_OK;
 }