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Arnd Bergmann authored
clang points out that the lpfc_name structure has an 8-byte alignment requirement on most architectures, but is embedded in a number of other structures that are forced to be only 1-byte aligned: drivers/scsi/lpfc/lpfc_hw.h:1516:30: error: field pe within 'struct lpfc_fdmi_reg_port_list' is less aligned than 'struct lpfc_fdmi_port_entry' and is usually due to 'struct lpfc_fdmi_reg_port_list' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] struct lpfc_fdmi_port_entry pe; drivers/scsi/lpfc/lpfc_hw.h:850:19: error: field portName within 'struct _ADISC' is less aligned than 'struct lpfc_name' and is usually due to 'struct _ADISC' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] drivers/scsi/lpfc/lpfc_hw.h:851:19: error: field nodeName within 'struct _ADISC' is less aligned than 'struct lpfc_name' and is usually due to 'struct _ADISC' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] drivers/scsi/lpfc/lpfc_hw.h:922:19: error: field portName within 'struct _RNID' is less aligned than 'struct lpfc_name' and is usually due to 'struct _RNID' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] drivers/scsi/lpfc/lpfc_hw.h:923:19: error: field nodeName within 'struct _RNID' is less aligned than 'struct lpfc_name' and is usually due to 'struct _RNID' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] From the git history, I can see that all the __packed annotations were done specifically to avoid introducing implicit padding around the lpfc_name instances, though this was probably the wrong approach. To improve this, only annotate the one uint64_t field inside of lpfc_name as packed, with an explicit 4-byte alignment, as is the default already on the 32-bit x86 ABI but not on most others. With this, the other __packed annotations can be removed again, as this avoids the incorrect padding. Two other structures change their layout as a result of this change: - struct _LOGO never gained a __packed annotation even though it has the same alignment problem as the others but is not used anywhere in the driver today. - struct serv_param similarly has this issue, and it is used, my guess is that this is only an internal structure rather than part of a binary interface, so the padding has no negative effect here. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20230616090705.2623408-1-arnd@kernel.orgReviewed-by: Justin Tee <justin.tee@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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