From d133b441488d30b0ee1848238a1f6e8da643e19c Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Tue, 27 Apr 2021 18:59:14 -0500 Subject: [PATCH] scsi: 3w-9xxx: Reduce scope of structure packing Currently, all command packet structs used by this driver are packed. However, only one (TW_SG_Entry) actually needs to be packed, because it uses 64-bit addresses at 32-bit alignment. To improve the quality of generated code, stop packing all of the other command packet structs. This requires adjusting the type of one misaligned "reserved" member. After this change, pahole reports that only one type had its layout change: the tw_compat_info member of TW_Device_Extension is now naturally aligned. Link: https://lore.kernel.org/r/20210427235915.39211-3-samuel@sholland.org Signed-off-by: Samuel Holland Signed-off-by: Martin K. Petersen --- drivers/scsi/3w-9xxx.h | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/3w-9xxx.h b/drivers/scsi/3w-9xxx.h index 23b312a53eaf..66c23877f4c2 100644 --- a/drivers/scsi/3w-9xxx.h +++ b/drivers/scsi/3w-9xxx.h @@ -485,13 +485,17 @@ printk(KERN_WARNING "3w-9xxx: ERROR: (0x%02X:0x%04X): %s.\n",a,b,c); \ #define TW_PADDING_LENGTH (sizeof(dma_addr_t) > 4 ? 8 : 0) #define TW_CPU_TO_SGL(x) (sizeof(dma_addr_t) > 4 ? cpu_to_le64(x) : cpu_to_le32(x)) -#pragma pack(1) +#if IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) +typedef u64 twa_addr_t; +#else +typedef u32 twa_addr_t; +#endif /* Scatter Gather List Entry */ typedef struct TAG_TW_SG_Entry { - dma_addr_t address; + twa_addr_t address; u32 length; -} TW_SG_Entry; +} __packed TW_SG_Entry; /* Command Packet */ typedef struct TW_Command { @@ -510,12 +514,12 @@ typedef struct TW_Command { struct { u32 lba; TW_SG_Entry sgl[TW_ESCALADE_MAX_SGL_LENGTH]; - dma_addr_t padding; + twa_addr_t padding; } io; struct { TW_SG_Entry sgl[TW_ESCALADE_MAX_SGL_LENGTH]; u32 padding; - dma_addr_t padding2; + twa_addr_t padding2; } param; } byte8_offset; } TW_Command; @@ -545,7 +549,7 @@ typedef struct TAG_TW_Command_Apache_Header { unsigned char err_specific_desc[98]; struct { unsigned char size_header; - unsigned short reserved; + unsigned char reserved[2]; unsigned char size_sense; } header_desc; } TW_Command_Apache_Header; @@ -645,8 +649,6 @@ typedef struct TAG_TW_Compatibility_Info unsigned short fw_on_ctlr_build; } TW_Compatibility_Info; -#pragma pack() - typedef struct TAG_TW_Device_Extension { u32 __iomem *base_addr; unsigned long *generic_buffer_virt[TW_Q_LENGTH]; -- 2.11.0