Remove PAGE_SIZE call sites.
To enable experiments with non-4KiB page sizes, introduce
an inline page_size() function that will either return the runtime
page size (if PAGE_SIZE is not 4096) or a constant 4096 (elsewhere).
This should ensure that there are no changes to the generated code on
unaffected platforms.
Test: source build/envsetup.sh
lunch aosp_cf_arm64_16k_phone-userdebug
m -j32 installclean
m -j32
Test: launch_cvd \
-kernel_path /path/to/out/android14-5.15/dist/Image \
-initramfs_path /path/to/out/android14-5.15/dist/initramfs.img \
-userdata_format=ext4
Bug: 277272383
Bug: 230790254
Change-Id: Ic0ed98b67f7c6b845804b90a4e16649f2fc94028
diff --git a/libc/platform/bionic/page.h b/libc/platform/bionic/page.h
index d063a98..5f4bb6f 100644
--- a/libc/platform/bionic/page.h
+++ b/libc/platform/bionic/page.h
@@ -16,15 +16,39 @@
#pragma once
-// Get PAGE_SIZE and PAGE_MASK.
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/auxv.h>
+
+// For PAGE_SIZE.
#include <sys/user.h>
+inline size_t page_size() {
+ /*
+ * PAGE_SIZE defines the maximum supported page size. Since 4096 is the
+ * minimum supported page size we can just let it be constant folded if it's
+ * also the maximum.
+ */
+#if PAGE_SIZE == 4096
+ return PAGE_SIZE;
+#else
+ static size_t size = getauxval(AT_PAGESZ);
+ return size;
+#endif
+}
+
// Returns the address of the page containing address 'x'.
-#define PAGE_START(x) ((x) & PAGE_MASK)
+inline uintptr_t page_start(uintptr_t x) {
+ return x & ~(page_size() - 1);
+}
// Returns the offset of address 'x' in its page.
-#define PAGE_OFFSET(x) ((x) & ~PAGE_MASK)
+inline uintptr_t page_offset(uintptr_t x) {
+ return x & (page_size() - 1);
+}
// Returns the address of the next page after address 'x', unless 'x' is
// itself at the start of a page.
-#define PAGE_END(x) PAGE_START((x) + (PAGE_SIZE-1))
+inline uintptr_t page_end(uintptr_t x) {
+ return page_start(x + page_size() - 1);
+}