When doing a build for a system with WAITPKG support and a modern
compiler, we get build errors for the "_umonitor" intrinsic, due to the
casting away of the "volatile" on the parameter.
../lib/eal/x86/rte_power_intrinsics.c: In function 'rte_power_monitor':
../lib/eal/x86/rte_power_intrinsics.c:113:22: error: passing argument 1
of '_umonitor' discards 'volatile' qualifier from pointer target type
[-Werror=discarded-qualifiers]
113 | _umonitor(pmc->addr);
| ~~~^~~~~~
We can avoid this issue by using RTE_PTR_ADD(..., 0) to cast the pointer
through "uintptr_t" and thereby remove the volatile without warning.
We also ensure comments are correct for each leg of the
ifdef..else..endif block.
Fixes: 60943c04f3bc ("eal/x86: use intrinsics for power management")
Cc: roret...@linux.microsoft.com
Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
---
lib/eal/x86/rte_power_intrinsics.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/lib/eal/x86/rte_power_intrinsics.c
b/lib/eal/x86/rte_power_intrinsics.c
index 4066d1392e..4f0404bfb8 100644
--- a/lib/eal/x86/rte_power_intrinsics.c
+++ b/lib/eal/x86/rte_power_intrinsics.c
@@ -103,15 +103,15 @@ rte_power_monitor(const struct rte_power_monitor_cond
*pmc,
rte_spinlock_lock(&s->lock);
s->monitor_addr = pmc->addr;
- /*
- * we're using raw byte codes for now as only the newest compiler
- * versions support this instruction natively.
- */
-
/* set address for UMONITOR */
#if defined(RTE_TOOLCHAIN_MSVC) || defined(__WAITPKG__)
- _umonitor(pmc->addr);
+ /* use RTE_PTR_ADD to cast away "volatile" when using the intrinsic */
+ _umonitor(RTE_PTR_ADD(pmc->addr, 0));
#else
+ /*
+ * we're using raw byte codes for compiler versions which
+ * don't support this instruction natively.
+ */
asm volatile(".byte 0xf3, 0x0f, 0xae, 0xf7;"
:
: "D"(pmc->addr));
--
2.39.2
