kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:

    vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
    can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd

The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.

This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.

Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.

Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 444 insertions, 0 deletions

diff --git a/drivers/crypto/caam/dpseci.c b/drivers/crypto/caam/dpseci.c
new file mode 100644
index 000000000..039df6c57
--- /dev/null
+++ b/drivers/crypto/caam/dpseci.c
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ * Copyright 2013-2016 Freescale Semiconductor Inc.
+ * Copyright 2017-2018 NXP
+ */
+
+#include <linux/fsl/mc.h>
+#include "dpseci.h"
+#include "dpseci_cmd.h"
+
+/**
+ * dpseci_open() - Open a control session for the specified object
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @dpseci_id:	DPSECI unique ID
+ * @token:	Returned token; use in subsequent API calls
+ *
+ * This function can be used to open a control session for an already created
+ * object; an object may have been declared statically in the DPL
+ * or created dynamically.
+ * This function returns a unique authentication token, associated with the
+ * specific object ID and the specific MC portal; this token must be used in all
+ * subsequent commands for this specific object.
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_open(struct fsl_mc_io *mc_io, u32 cmd_flags, int dpseci_id,
+		u16 *token)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_cmd_open *cmd_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_OPEN,
+					  cmd_flags,
+					  0);
+	cmd_params = (struct dpseci_cmd_open *)cmd.params;
+	cmd_params->dpseci_id = cpu_to_le32(dpseci_id);
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	*token = mc_cmd_hdr_read_token(&cmd);
+
+	return 0;
+}
+
+/**
+ * dpseci_close() - Close the control session of the object
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ *
+ * After this function is called, no further operations are allowed on the
+ * object without opening a new control session.
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_close(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token)
+{
+	struct fsl_mc_command cmd = { 0 };
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_CLOSE,
+					  cmd_flags,
+					  token);
+	return mc_send_command(mc_io, &cmd);
+}
+
+/**
+ * dpseci_enable() - Enable the DPSECI, allow sending and receiving frames
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_enable(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token)
+{
+	struct fsl_mc_command cmd = { 0 };
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_ENABLE,
+					  cmd_flags,
+					  token);
+	return mc_send_command(mc_io, &cmd);
+}
+
+/**
+ * dpseci_disable() - Disable the DPSECI, stop sending and receiving frames
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_disable(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token)
+{
+	struct fsl_mc_command cmd = { 0 };
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_DISABLE,
+					  cmd_flags,
+					  token);
+
+	return mc_send_command(mc_io, &cmd);
+}
+
+/**
+ * dpseci_reset() - Reset the DPSECI, returns the object to initial state
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_reset(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token)
+{
+	struct fsl_mc_command cmd = { 0 };
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_RESET,
+					  cmd_flags,
+					  token);
+	return mc_send_command(mc_io, &cmd);
+}
+
+/**
+ * dpseci_is_enabled() - Check if the DPSECI is enabled.
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @en:		Returns '1' if object is enabled; '0' otherwise
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_is_enabled(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token,
+		      int *en)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_rsp_is_enabled *rsp_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_IS_ENABLED,
+					  cmd_flags,
+					  token);
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	rsp_params = (struct dpseci_rsp_is_enabled *)cmd.params;
+	*en = dpseci_get_field(rsp_params->is_enabled, ENABLE);
+
+	return 0;
+}
+
+/**
+ * dpseci_get_attributes() - Retrieve DPSECI attributes
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @attr:	Returned object's attributes
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_get_attributes(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token,
+			  struct dpseci_attr *attr)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_rsp_get_attributes *rsp_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_GET_ATTR,
+					  cmd_flags,
+					  token);
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	rsp_params = (struct dpseci_rsp_get_attributes *)cmd.params;
+	attr->id = le32_to_cpu(rsp_params->id);
+	attr->num_tx_queues = rsp_params->num_tx_queues;
+	attr->num_rx_queues = rsp_params->num_rx_queues;
+	attr->options = le32_to_cpu(rsp_params->options);
+
+	return 0;
+}
+
+/**
+ * dpseci_set_rx_queue() - Set Rx queue configuration
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @queue:	Select the queue relative to number of priorities configured at
+ *		DPSECI creation; use DPSECI_ALL_QUEUES to configure all
+ *		Rx queues identically.
+ * @cfg:	Rx queue configuration
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_set_rx_queue(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token,
+			u8 queue, const struct dpseci_rx_queue_cfg *cfg)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_cmd_queue *cmd_params;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_SET_RX_QUEUE,
+					  cmd_flags,
+					  token);
+	cmd_params = (struct dpseci_cmd_queue *)cmd.params;
+	cmd_params->dest_id = cpu_to_le32(cfg->dest_cfg.dest_id);
+	cmd_params->priority = cfg->dest_cfg.priority;
+	cmd_params->queue = queue;
+	dpseci_set_field(cmd_params->dest_type, DEST_TYPE,
+			 cfg->dest_cfg.dest_type);
+	cmd_params->user_ctx = cpu_to_le64(cfg->user_ctx);
+	cmd_params->options = cpu_to_le32(cfg->options);
+	dpseci_set_field(cmd_params->order_preservation_en, ORDER_PRESERVATION,
+			 cfg->order_preservation_en);
+
+	return mc_send_command(mc_io, &cmd);
+}
+
+/**
+ * dpseci_get_rx_queue() - Retrieve Rx queue attributes
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @queue:	Select the queue relative to number of priorities configured at
+ *		DPSECI creation
+ * @attr:	Returned Rx queue attributes
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_get_rx_queue(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token,
+			u8 queue, struct dpseci_rx_queue_attr *attr)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_cmd_queue *cmd_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_GET_RX_QUEUE,
+					  cmd_flags,
+					  token);
+	cmd_params = (struct dpseci_cmd_queue *)cmd.params;
+	cmd_params->queue = queue;
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	attr->dest_cfg.dest_id = le32_to_cpu(cmd_params->dest_id);
+	attr->dest_cfg.priority = cmd_params->priority;
+	attr->dest_cfg.dest_type = dpseci_get_field(cmd_params->dest_type,
+						    DEST_TYPE);
+	attr->user_ctx = le64_to_cpu(cmd_params->user_ctx);
+	attr->fqid = le32_to_cpu(cmd_params->fqid);
+	attr->order_preservation_en =
+		dpseci_get_field(cmd_params->order_preservation_en,
+				 ORDER_PRESERVATION);
+
+	return 0;
+}
+
+/**
+ * dpseci_get_tx_queue() - Retrieve Tx queue attributes
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @queue:	Select the queue relative to number of priorities configured at
+ *		DPSECI creation
+ * @attr:	Returned Tx queue attributes
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_get_tx_queue(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token,
+			u8 queue, struct dpseci_tx_queue_attr *attr)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_cmd_queue *cmd_params;
+	struct dpseci_rsp_get_tx_queue *rsp_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_GET_TX_QUEUE,
+					  cmd_flags,
+					  token);
+	cmd_params = (struct dpseci_cmd_queue *)cmd.params;
+	cmd_params->queue = queue;
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	rsp_params = (struct dpseci_rsp_get_tx_queue *)cmd.params;
+	attr->fqid = le32_to_cpu(rsp_params->fqid);
+	attr->priority = rsp_params->priority;
+
+	return 0;
+}
+
+/**
+ * dpseci_get_sec_attr() - Retrieve SEC accelerator attributes
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @attr:	Returned SEC attributes
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_get_sec_attr(struct fsl_mc_io *mc_io, u32 cmd_flags, u16 token,
+			struct dpseci_sec_attr *attr)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_rsp_get_sec_attr *rsp_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_GET_SEC_ATTR,
+					  cmd_flags,
+					  token);
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	rsp_params = (struct dpseci_rsp_get_sec_attr *)cmd.params;
+	attr->ip_id = le16_to_cpu(rsp_params->ip_id);
+	attr->major_rev = rsp_params->major_rev;
+	attr->minor_rev = rsp_params->minor_rev;
+	attr->era = rsp_params->era;
+	attr->deco_num = rsp_params->deco_num;
+	attr->zuc_auth_acc_num = rsp_params->zuc_auth_acc_num;
+	attr->zuc_enc_acc_num = rsp_params->zuc_enc_acc_num;
+	attr->snow_f8_acc_num = rsp_params->snow_f8_acc_num;
+	attr->snow_f9_acc_num = rsp_params->snow_f9_acc_num;
+	attr->crc_acc_num = rsp_params->crc_acc_num;
+	attr->pk_acc_num = rsp_params->pk_acc_num;
+	attr->kasumi_acc_num = rsp_params->kasumi_acc_num;
+	attr->rng_acc_num = rsp_params->rng_acc_num;
+	attr->md_acc_num = rsp_params->md_acc_num;
+	attr->arc4_acc_num = rsp_params->arc4_acc_num;
+	attr->des_acc_num = rsp_params->des_acc_num;
+	attr->aes_acc_num = rsp_params->aes_acc_num;
+	attr->ccha_acc_num = rsp_params->ccha_acc_num;
+	attr->ptha_acc_num = rsp_params->ptha_acc_num;
+
+	return 0;
+}
+
+/**
+ * dpseci_get_api_version() - Get Data Path SEC Interface API version
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @major_ver:	Major version of data path sec API
+ * @minor_ver:	Minor version of data path sec API
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_get_api_version(struct fsl_mc_io *mc_io, u32 cmd_flags,
+			   u16 *major_ver, u16 *minor_ver)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_rsp_get_api_version *rsp_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(DPSECI_CMDID_GET_API_VERSION,
+					  cmd_flags, 0);
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	rsp_params = (struct dpseci_rsp_get_api_version *)cmd.params;
+	*major_ver = le16_to_cpu(rsp_params->major);
+	*minor_ver = le16_to_cpu(rsp_params->minor);
+
+	return 0;
+}
+
+/**
+ * dpseci_set_congestion_notification() - Set congestion group
+ *	notification configuration
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @cfg:	congestion notification configuration
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_set_congestion_notification(struct fsl_mc_io *mc_io, u32 cmd_flags,
+	u16 token, const struct dpseci_congestion_notification_cfg *cfg)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_cmd_congestion_notification *cmd_params;
+
+	cmd.header = mc_encode_cmd_header(
+			DPSECI_CMDID_SET_CONGESTION_NOTIFICATION,
+			cmd_flags,
+			token);
+	cmd_params = (struct dpseci_cmd_congestion_notification *)cmd.params;
+	cmd_params->dest_id = cpu_to_le32(cfg->dest_cfg.dest_id);
+	cmd_params->notification_mode = cpu_to_le16(cfg->notification_mode);
+	cmd_params->priority = cfg->dest_cfg.priority;
+	dpseci_set_field(cmd_params->options, CGN_DEST_TYPE,
+			 cfg->dest_cfg.dest_type);
+	dpseci_set_field(cmd_params->options, CGN_UNITS, cfg->units);
+	cmd_params->message_iova = cpu_to_le64(cfg->message_iova);
+	cmd_params->message_ctx = cpu_to_le64(cfg->message_ctx);
+	cmd_params->threshold_entry = cpu_to_le32(cfg->threshold_entry);
+	cmd_params->threshold_exit = cpu_to_le32(cfg->threshold_exit);
+
+	return mc_send_command(mc_io, &cmd);
+}
+
+/**
+ * dpseci_get_congestion_notification() - Get congestion group notification
+ *	configuration
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPSECI object
+ * @cfg:	congestion notification configuration
+ *
+ * Return:	'0' on success, error code otherwise
+ */
+int dpseci_get_congestion_notification(struct fsl_mc_io *mc_io, u32 cmd_flags,
+	u16 token, struct dpseci_congestion_notification_cfg *cfg)
+{
+	struct fsl_mc_command cmd = { 0 };
+	struct dpseci_cmd_congestion_notification *rsp_params;
+	int err;
+
+	cmd.header = mc_encode_cmd_header(
+			DPSECI_CMDID_GET_CONGESTION_NOTIFICATION,
+			cmd_flags,
+			token);
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return err;
+
+	rsp_params = (struct dpseci_cmd_congestion_notification *)cmd.params;
+	cfg->dest_cfg.dest_id = le32_to_cpu(rsp_params->dest_id);
+	cfg->notification_mode = le16_to_cpu(rsp_params->notification_mode);
+	cfg->dest_cfg.priority = rsp_params->priority;
+	cfg->dest_cfg.dest_type = dpseci_get_field(rsp_params->options,
+						   CGN_DEST_TYPE);
+	cfg->units = dpseci_get_field(rsp_params->options, CGN_UNITS);
+	cfg->message_iova = le64_to_cpu(rsp_params->message_iova);
+	cfg->message_ctx = le64_to_cpu(rsp_params->message_ctx);
+	cfg->threshold_entry = le32_to_cpu(rsp_params->threshold_entry);
+	cfg->threshold_exit = le32_to_cpu(rsp_params->threshold_exit);
+
+	return 0;
+}