Changeset f2cb80a in mainline for kernel/arch/amd64/include/arch/mm/page.h

Timestamp:

2024-02-23T17:57:23Z (17 months ago)

Author:

GitHub <noreply@…>

Children:

192019f

Parents:

86f862c (diff), 90ba06c (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

git-author:

boba-buba <120932204+boba-buba@…> (2024-02-23 17:57:23)

git-committer:

GitHub <noreply@…> (2024-02-23 17:57:23)

Message:

Merge branch 'HelenOS:master' into topic/packet-capture

File:

• kernel/arch/amd64/include/arch/mm/page.h (modified) (4 diffs)

kernel/arch/amd64/include/arch/mm/page.h

@@ -192 +192 @@
         unsigned int accessed : 1;
         unsigned int dirty : 1;
-        unsigned int unused : 1;
+        unsigned int pat : 1;
         unsigned int global : 1;
         unsigned int soft_valid : 1;  /**< Valid content even if present bit is cleared. */
@@ -211 +211 @@
             p->writeable << PAGE_WRITE_SHIFT |
             (!p->no_execute) << PAGE_EXEC_SHIFT |
-            p->global << PAGE_GLOBAL_SHIFT);
+            p->global << PAGE_GLOBAL_SHIFT |
+            p->page_write_through << PAGE_WRITE_COMBINE_SHIFT);
 }
 
@@ -225 +226 @@
         pte_t *p = &pt[i];
 
-        p->page_cache_disable = !(flags & PAGE_CACHEABLE);
         p->present = !(flags & PAGE_NOT_PRESENT);
         p->uaccessible = (flags & PAGE_USER) != 0;
@@ -232 +232 @@
         p->global = (flags & PAGE_GLOBAL) != 0;
 
+        if (flags & PAGE_WRITE_COMBINE) {
+                /* We have mapped PCD+PWT bits to write-combine mode via PAT MSR. */
+                /* (If PAT is unsupported, it will default to uncached.) */
+                p->page_cache_disable = 1;
+                p->page_write_through = 1;
+        } else {
+                p->page_cache_disable = !(flags & PAGE_CACHEABLE);
+                p->page_write_through = 0;
+        }
+
         /*
          * Ensure that there is at least one bit set even if the present bit is cleared.