[RFC PATCH v1 31/57] edac: Remove PAGE_SIZE compile-time constant assumption

Ryan Roberts
2024-10-14T12:07:33Z

To prepare for supporting boot-time page size selection, refactor code
to remove assumptions about PAGE_SIZE being compile-time constant. Code
intended to be equivalent when compile-time page size is active.

Convert PAGES_TO_MiB() and MiB_TO_PAGES() to use the ternary operator so
that they continue to work with boot-time page size; Boot-time page size
can't be used with CPP because it's value is not known at compile time.
For compile-time page size builds, the compiler will dead code strip for
the same result.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---

***NOTE***
Any confused maintainers may want to read the cover note here for context:
https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/

drivers/edac/edac_mc.h | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/edac/edac_mc.h b/drivers/edac/edac_mc.h
index 881b00eadf7a5..22132ee86e953 100644
--- a/drivers/edac/edac_mc.h
+++ b/drivers/edac/edac_mc.h
@@ -37,13 +37,12 @@
#include <linux/workqueue.h>
#include <linux/edac.h>

-#if PAGE_SHIFT < 20
-#define PAGES_TO_MiB(pages) ((pages) >> (20 - PAGE_SHIFT))
-#define MiB_TO_PAGES(mb) ((mb) << (20 - PAGE_SHIFT))
-#else /* PAGE_SHIFT > 20 */
-#define PAGES_TO_MiB(pages) ((pages) << (PAGE_SHIFT - 20))
-#define MiB_TO_PAGES(mb) ((mb) >> (PAGE_SHIFT - 20))
-#endif
+#define PAGES_TO_MiB(pages) (PAGE_SHIFT < 20 ? \
+ ((pages) >> (20 - PAGE_SHIFT)) :\
+ ((pages) << (PAGE_SHIFT - 20)))
+#define MiB_TO_PAGES(mb) (PAGE_SHIFT < 20 ? \
+ ((mb) << (20 - PAGE_SHIFT)) : \
+ ((mb) >> (PAGE_SHIFT - 20)))

#define edac_printk(level, prefix, fmt, arg...) \
printk(level "EDAC " prefix ": " fmt, ##arg)
--
2.43.0