IBM POWER systems support more than one type of memory management unit
(MMU). The Power ISA 3.0 specification, which applies to P9 and later
CPUs, defined a new Radix MMU which, among other things, allows an
anonymous memory page mapping to be converted into a hugepage mapping
at a specific address. This is a required feature in DPDK so we need
to test the MMU type when POWER systems are used and provide a more
useful error message for the user when running on an unsupported
system.
Bugzilla ID: 1221
Suggested-by: Thomas Monjalon <tho...@monjalon.net>
Signed-off-by: David Christensen <d...@linux.vnet.ibm.com>
---
lib/eal/linux/eal.c | 63 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 5f4b2fb0054a..1c546564fa9c 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -910,6 +910,62 @@ is_iommu_enabled(void)
return n > 2;
}
+/*
+ * IBM POWER systems support more than one type of memory management unit
(MMU).
+ * The Power ISA 3.0 specification, which applies to P9 and later CPUs, defined
+ * a new Radix MMU which, among other things, allows an anonymous memory page
+ * mapping to be converted into a hugepage mapping at a specific address. This
+ * is a required feature in DPDK so we need to test the MMU type when POWER
+ * systems are used.
+ */
+static bool
+is_mmu_supported(void)
+{
+#ifdef RTE_ARCH_PPC_64
+ static const char proc_cpuinfo[] = "/proc/cpuinfo";
+ static const char str_mmu[] = "MMU";
+ static const char str_radix[] = "Radix";
+ char buf[512];
+ char *ret = NULL;
+ FILE *f = fopen(proc_cpuinfo, "r");
+
+ if (f == NULL) {
+ RTE_LOG(ERR, EAL, "Cannot open %s\n", proc_cpuinfo);
+ return false;
+ }
+
+ /*
+ * Example "MMU" in /proc/cpuinfo:
+ * ...
+ * model : 8335-GTW
+ * machine : PowerNV 8335-GTW
+ * firmware : OPAL
+ * MMU : Radix
+ * ... or ...
+ * model : IBM,9009-22A
+ * machine : CHRP IBM,9009-22A
+ * MMU : Hash
+ */
+ while (fgets(buf, sizeof(buf), f) != NULL) {
+ ret = strstr(buf, str_mmu);
+ if (ret == NULL)
+ continue;
+ ret += sizeof(str_mmu) - 1;
+ ret = strchr(ret, ':');
+ if (ret == NULL)
+ continue;
+ ret = strstr(ret, str_radix);
+ break;
+ }
+ fclose(f);
+ if (ret == NULL)
+ rte_eal_init_alert("DPDK on PPC64 requires radix-mmu.");
+ return (ret != NULL);
+#else
+ return true;
+#endif
+}
+
static __rte_noreturn void *
eal_worker_thread_loop(void *arg)
{
@@ -983,6 +1039,13 @@ rte_eal_init(int argc, char **argv)
return -1;
}
+ /* verify if mmu is supported */
+ if (!is_mmu_supported()) {
+ rte_eal_init_alert("unsupported mmu type.");
+ rte_errno = ENOTSUP;
+ return -1;
+ }
+
if (!__atomic_compare_exchange_n(&run_once, &has_run, 1, 0,
__ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
rte_eal_init_alert("already called initialization.");
--
2.39.1
