Changeset 4b1c7c6f in mainline for kernel/arch/arm32/include/arch/mm/page_armv4.h

Timestamp:

2018-03-16T20:57:16Z (6 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Children:

6be2c13

Parents:

973be387

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2018-03-16 20:51:59)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2018-03-16 20:57:16)

Message:

Clean up PAGE_* flags.

Remove "nop flags", they are confusing for readers and any benefit they would
gain in self-documentation they lose in being used inconsistently.

Remove "PAGE_READ", the only place it's used meaningfully is the incomplete
RISC-V implementation, and most call sites assume read is implied.

File:

• kernel/arch/arm32/include/arch/mm/page_armv4.h (modified) (3 diffs)

kernel/arch/arm32/include/arch/mm/page_armv4.h

@@ -138 +138 @@
         int np = (p->descriptor_type == PTE_DESCRIPTOR_NOT_PRESENT);
 
-        return (np << PAGE_PRESENT_SHIFT) | (1 << PAGE_USER_SHIFT) |
-            (1 << PAGE_READ_SHIFT) | (1 << PAGE_WRITE_SHIFT) |
+        return (np << PAGE_NOT_PRESENT_SHIFT) | (1 << PAGE_USER_SHIFT) |
+            (1 << PAGE_WRITE_SHIFT) |
             (1 << PAGE_EXEC_SHIFT) | (1 << PAGE_CACHEABLE_SHIFT);
 }
@@ -156 +156 @@
         int ap = p->access_permission_0;
 
-        return ((dt == PTE_DESCRIPTOR_NOT_PRESENT) << PAGE_PRESENT_SHIFT) |
-            ((ap == PTE_AP_USER_RO_KERNEL_RW) << PAGE_READ_SHIFT) |
-            ((ap == PTE_AP_USER_RW_KERNEL_RW) << PAGE_READ_SHIFT) |
+        return ((dt == PTE_DESCRIPTOR_NOT_PRESENT) << PAGE_NOT_PRESENT_SHIFT) |
             ((ap == PTE_AP_USER_RW_KERNEL_RW) << PAGE_WRITE_SHIFT) |
             ((ap != PTE_AP_USER_NO_KERNEL_RW) << PAGE_USER_SHIFT) |
-            ((ap == PTE_AP_USER_NO_KERNEL_RW) << PAGE_READ_SHIFT) |
             ((ap == PTE_AP_USER_NO_KERNEL_RW) << PAGE_WRITE_SHIFT) |
             (1 << PAGE_EXEC_SHIFT) |
@@ -220 +217 @@
 
         if (flags & PAGE_USER)  {
-                if (flags & PAGE_READ) {
+                if (flags & PAGE_WRITE) {
+                        p->access_permission_0 = p->access_permission_1 =
+                            p->access_permission_2 = p->access_permission_3 =
+                            PTE_AP_USER_RW_KERNEL_RW;
+                } else {
                         p->access_permission_0 = p->access_permission_1 =
                             p->access_permission_2 = p->access_permission_3 =
                             PTE_AP_USER_RO_KERNEL_RW;
                 }
-                if (flags & PAGE_WRITE) {
-                        p->access_permission_0 = p->access_permission_1 =
-                            p->access_permission_2 = p->access_permission_3 =
-                            PTE_AP_USER_RW_KERNEL_RW;
-                }
         }
 }