On 11/20/19 2:50 PM, Hansen, Dave wrote:
On 11/20/19 1:23 PM, Dave Jiang wrote:+static inline void __iowrite512(void __iomem *__dst, const void *src) +{ + volatile struct { char _[64]; } *dst = __dst;This _looks_ like gibberish. I know it's not, but it is subtle enough that it really needs specific comments.
I'll add comments explaining.
+static inline void iosubmit_cmds512(void __iomem *dst, const void *src, + size_t count) +{ + const u8 *from = src; + const u8 *end = from + count * 64; + + if (!cpu_has_write512()) + return; + + while (from < end) { + __iowrite512(dst, from); + from += 64; + } +}Won't this silently just drop things if the CPU doesn't have movdir64b support? It seems like this shouldn't be called at all if !cpu_has_write512(), but wouldn't something like this be mroe appropriate? if (!cpu_has_write512()) { WARN_ON_ONCE(1); return; } Is the caller just supposed to infer that "dst" was never overwritten?
Thanks. I'll add the WARN().
