Transactional memory is currently only supported on KVM-HV, and
not yet on KVM-PR. So it's better to check the device tree first
and fail gracefully if it is not available.
Reviewed-by: Laurent Vivier <lvivier@xxxxxxxxxx>
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
---
v3:
- Removed unnecessary check for "plen >= 26" in cpu_has_tm()
v2:
- Reworked the check for the "ibm,pa-features" and added a comment
- Use a dedicated variable "has_tm" instead of "i" in main()
powerpc/tm.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)
diff --git a/powerpc/tm.c b/powerpc/tm.c
index 6ce750a..b611061 100644
--- a/powerpc/tm.c
+++ b/powerpc/tm.c
@@ -10,6 +10,41 @@
#include <asm/processor.h>
#include <asm/handlers.h>
#include <asm/smp.h>
+#include <asm/setup.h>
+#include <devicetree.h>
+
+/* Check "ibm,pa-features" property of a CPU node for the TM flag */
+static void cpu_has_tm(int fdtnode, u32 regval __unused, void *ptr)
+{
+ const struct fdt_property *prop;
+ int plen;
+
+ prop = fdt_get_property(dt_fdt(), fdtnode, "ibm,pa-features", &plen);
+ if (!prop) /* No features means TM is also not available */
+ return;
+ /* Sanity check for the property layout (first two bytes are header) */
+ assert(plen >= 8 && prop->data[1] == 0 && prop->data[0] <= plen - 2);
+
+ /*
+ * The "Transactional Memory Category Support" flags are at byte
+ * offset 22 and 23 of the attribute type 0, so when adding the
+ * two bytes for the header, we've got to look at offset 24 for
+ * the TM support bit.
+ */
+ if (prop->data[0] >= 24 && (prop->data[24] & 0x80) != 0)
+ *(int *)ptr += 1;
+}
+
+/* Check whether all CPU nodes have the TM flag */
+static bool all_cpus_have_tm(void)
+{
+ int ret;
+ int available = 0;
+
+ ret = dt_for_each_cpu_node(cpu_has_tm, &available);
+
+ return ret == 0 && available == nr_cpus;
+}
static int h_cede(void)
{
@@ -101,11 +136,17 @@ struct {
int main(int argc, char **argv)
{
- bool all;
+ bool all, has_tm;
int i;
report_prefix_push("tm");
+ has_tm = all_cpus_have_tm();
+ report_xfail("TM available in 'ibm,pa-features' property",
+ !has_tm, has_tm);
+ if (!has_tm)
+ return report_summary();
+
all = argc == 1 || !strcmp(argv[1], "all");
for (i = 0; hctests[i].name != NULL; i++) {
--
1.8.3.1
--
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