Commit 6dc26498 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jason Gunthorpe
Browse files

RDMA/srp: Apply the __packed attribute to members instead of structures 

Applying the __packed attribute to an entire data structure results in
suboptimal code on architectures that do not support unaligned accesses.
Hence apply the __packed attribute only to those data members that are
not naturally aligned.

Link: https://lore.kernel.org/r/20210524041211.9480-4-bvanassche@acm.org


Cc: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent c838de1a

include/scsi/srp.h

+9 −17
Original line number Diff line number Diff line
@@ -107,10 +107,10 @@ struct srp_direct_buf { 
 * having the 20-byte structure padded to 24 bytes on 64-bit architectures.

 */

struct srp_indirect_buf {

	struct srp_direct_buf	table_desc;

	struct srp_direct_buf	table_desc __packed __aligned(4);

	__be32			len;

	struct srp_direct_buf	desc_list[];

} __attribute__((packed));

	struct srp_direct_buf	desc_list[] __packed __aligned(4);

};



/* Immediate data buffer descriptor as defined in SRP2. */

struct srp_imm_buf {
@@ -175,13 +175,13 @@ struct srp_login_rsp { 
	u8	opcode;

	u8	reserved1[3];

	__be32	req_lim_delta;

	u64	tag;

	u64	tag __packed __aligned(4);

	__be32	max_it_iu_len;

	__be32	max_ti_iu_len;

	__be16	buf_fmt;

	u8	rsp_flags;

	u8	reserved2[25];

} __attribute__((packed));

};



struct srp_login_rej {

	u8	opcode;
@@ -207,10 +207,6 @@ struct srp_t_logout { 
	u64	tag;

};



/*

 * We need the packed attribute because the SRP spec only aligns the

 * 8-byte LUN field to 4 bytes.

 */

struct srp_tsk_mgmt {

	u8	opcode;

	u8	sol_not;
@@ -225,10 +221,6 @@ struct srp_tsk_mgmt { 
	u8	reserved5[8];

};



/*

 * We need the packed attribute because the SRP spec only aligns the

 * 8-byte LUN field to 4 bytes.

 */

struct srp_cmd {

	u8	opcode;

	u8	sol_not;
@@ -266,7 +258,7 @@ struct srp_rsp { 
	u8	sol_not;

	u8	reserved1[2];

	__be32	req_lim_delta;

	u64	tag;

	u64	tag __packed __aligned(4);

	u8	reserved2[2];

	u8	flags;

	u8	status;
@@ -275,7 +267,7 @@ struct srp_rsp { 
	__be32	sense_data_len;

	__be32	resp_data_len;

	u8	data[];

} __attribute__((packed));

};



struct srp_cred_req {

	u8	opcode;
@@ -301,13 +293,13 @@ struct srp_aer_req { 
	u8	sol_not;

	u8	reserved[2];

	__be32	req_lim_delta;

	u64	tag;

	u64	tag __packed __aligned(4);

	u32	reserved2;

	struct scsi_lun	lun;

	__be32	sense_data_len;

	u32	reserved3;

	u8	sense_data[];

} __attribute__((packed));

};



struct srp_aer_rsp {

	u8	opcode;