riscv_pmp.c: Revert LOG2_CEIL back to run-time log2ceil function
The macro LOG2_CEIL is intended to be used in the pre-processor phase. If
used run-time it will generate a massive amount of extra code (~3.5K) which
is a problem, as the PMP configuration is quite often executed from a first
stage bootloader with a limited amount of code memory.
Code size differences pre- and post:
Memory region Used Size Region Size %age Used
envm: 112064 B 112384 B 99.72%
Memory region Used Size Region Size %age Used
envm: 108952 B 112384 B 96.95%
diff --git a/arch/risc-v/src/common/riscv_pmp.c b/arch/risc-v/src/common/riscv_pmp.c
index 2f63c25..3a9daa2 100644
--- a/arch/risc-v/src/common/riscv_pmp.c
+++ b/arch/risc-v/src/common/riscv_pmp.c
@@ -32,7 +32,6 @@
#include <nuttx/compiler.h>
#include <nuttx/arch.h>
#include <nuttx/irq.h>
-#include <nuttx/lib/math32.h>
#include "riscv_internal.h"
@@ -90,6 +89,32 @@
****************************************************************************/
/****************************************************************************
+ * Name: log2ceil
+ *
+ * Description:
+ * Calculate the up-rounded power-of-two for input.
+ *
+ * Input Parameters:
+ * x - Argument to calculate the power-of-two from.
+ *
+ * Returned Value:
+ * Power-of-two for argument, rounded up.
+ *
+ ****************************************************************************/
+
+static uintptr_t log2ceil(uintptr_t x)
+{
+ uintptr_t pot = 0;
+
+ for (x = x - 1; x; x >>= 1)
+ {
+ pot++;
+ }
+
+ return pot;
+}
+
+/****************************************************************************
* Name: pmp_check_region_attrs
*
* Description:
@@ -143,7 +168,7 @@
/* Get the power-of-two for size, rounded up */
- if ((base & ((UINT64_C(1) << LOG2_CEIL(size)) - 1)) != 0)
+ if ((base & ((UINT64_C(1) << log2ceil(size)) - 1)) != 0)
{
/* The start address is not properly aligned with size */
