selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/drivers/firmware/imx/sm-lmm.c b/drivers/firmware/imx/sm-lmm.c
new file mode 100644
index 000000000..6807bf563
--- /dev/null
+++ b/drivers/firmware/imx/sm-lmm.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025 NXP
+ */
+
+#include <linux/firmware/imx/sm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+static const struct scmi_imx_lmm_proto_ops *imx_lmm_ops;
+static struct scmi_protocol_handle *ph;
+
+int scmi_imx_lmm_info(u32 lmid, struct scmi_imx_lmm_info *info)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	if (!info)
+		return -EINVAL;
+
+	return imx_lmm_ops->lmm_info(ph, lmid, info);
+};
+EXPORT_SYMBOL(scmi_imx_lmm_info);
+
+int scmi_imx_lmm_reset_vector_set(u32 lmid, u32 cpuid, u32 flags, u64 vector)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	return imx_lmm_ops->lmm_reset_vector_set(ph, lmid, cpuid, flags, vector);
+}
+EXPORT_SYMBOL(scmi_imx_lmm_reset_vector_set);
+
+int scmi_imx_lmm_operation(u32 lmid, enum scmi_imx_lmm_op op, u32 flags)
+{
+	if (!ph)
+		return -EPROBE_DEFER;
+
+	switch (op) {
+	case SCMI_IMX_LMM_BOOT:
+		return imx_lmm_ops->lmm_power_boot(ph, lmid, true);
+	case SCMI_IMX_LMM_POWER_ON:
+		return imx_lmm_ops->lmm_power_boot(ph, lmid, false);
+	case SCMI_IMX_LMM_SHUTDOWN:
+		return imx_lmm_ops->lmm_shutdown(ph, lmid, flags);
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(scmi_imx_lmm_operation);
+
+static int scmi_imx_lmm_probe(struct scmi_device *sdev)
+{
+	const struct scmi_handle *handle = sdev->handle;
+
+	if (!handle)
+		return -ENODEV;
+
+	if (imx_lmm_ops) {
+		dev_err(&sdev->dev, "lmm already initialized\n");
+		return -EEXIST;
+	}
+
+	imx_lmm_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_IMX_LMM, &ph);
+	if (IS_ERR(imx_lmm_ops))
+		return PTR_ERR(imx_lmm_ops);
+
+	return 0;
+}
+
+static const struct scmi_device_id scmi_id_table[] = {
+	{ SCMI_PROTOCOL_IMX_LMM, "imx-lmm" },
+	{ },
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_imx_lmm_driver = {
+	.name = "scmi-imx-lmm",
+	.probe = scmi_imx_lmm_probe,
+	.id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_imx_lmm_driver);
+
+MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
+MODULE_DESCRIPTION("IMX SM LMM driver");
+MODULE_LICENSE("GPL");