Re: [PATCH 13/15] octeontx2-af: Add support for CGX link management
flat view
From: Arnd Bergmann <arnd@arndb.de>
Date: 2018-09-28 14:42:24
On Fri, Sep 28, 2018 at 8:09 AM [off-list ref] wrote:
quoted hunk ↗ jump to hunk
+/* scratchx(0) CSR used for ATF->non-secure SW communication. + * This acts as the status register + * Provides details on command ack/status, link status, error details + */ +struct cgx_evt_sts { + uint64_t ack:1; + uint64_t evt_type:1; /* cgx_evt_type */ + uint64_t stat:1; /* cgx_stat */ + uint64_t id:6; /* cgx_evt_id/cgx_cmd_id */ + uint64_t reserved:55; +}; + +/* Response to command IDs with command status as CGX_STAT_FAIL + * + * Not applicable for commands : + * CGX_CMD_LINK_BRING_UP/DOWN/CGX_EVT_LINK_CHANGE + * check struct cgx_lnk_sts comments + */ +struct cgx_err_sts_s { + uint64_t reserved1:9; + uint64_t type:10; /* cgx_error_type */ + uint64_t reserved2:35; +}; + +/* Response to cmd ID as CGX_CMD_GET_FW_VER with cmd status as + * CGX_STAT_SUCCESS + */ +struct cgx_ver_s { + uint64_t reserved1:9; + uint64_t major_ver:4; + uint64_t minor_ver:4; + uint64_t reserved2:47; +};
From what I can tell, you pass these structures to the device, so they
are a binary interface. I don't think you can rely on bitfields to work
correctly here, they are generally not portable and I wouldn't rely
on them doing the right thing if you build a big-endian kernel.
It's better to use bitmasks on a u64 value instead to make it obviously
portable.
Arnd