Re: [PATCH 4/4 v4] iommu/fsl: Freescale PAMU driver and IOMMU APIimplementation.
From: Scott Wood
Date: Mon Nov 05 2012 - 18:11:57 EST
On 11/05/2012 05:04:13 PM, Timur Tabi wrote:
Varun Sethi wrote:
> + /* PAACE Offset 0x00 */
> + u32 wbah; /* only valid for
Primary PAACE */
> + u32 addr_bitfields; /* See P/S PAACE_AF_* */
> +
> + /* PAACE Offset 0x08 */
> + /* Interpretation of first 32 bits dependent on DD above */
> + union {
> + struct {
> + /* Destination ID, see PAACE_DID_* defines */
> + u8 did;
> + /* Partition ID */
> + u8 pid;
> + /* Snoop ID */
> + u8 snpid;
> + /* coherency_required : 1 reserved : 7 */
Please use this format, which is easier to read:
/* 1 == coherency required, 7 == reserved */
Every time I look at this comment, I think you are using bitfields.
It is meant as a pseudo-bitfield. "7 == reserved" doesn't make much
sense -- that would leave a lot of other values neither defined nor
explicitly reserved.
That said, the "See PAACE_DA_*" comment should be sufficient and avoids
making people have to care about what bitfield ordering the comment
writer was assuming.
-Scott
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