On Tuesday 14 August 2012, Catalin Marinas wrote:
>
> +/*
> + * TCR flags.
> + */
> +#define TCR_TxSZ(x) (((64 - (x)) << 16) | ((64 - (x)) << 0))
> +#define TCR_IRGN_NC ((0 << 8) | (0 << 24))
> +#define TCR_IRGN_WBWA ((1 << 8) | (1 << 24))
> +#define TCR_IRGN_WT ((2 << 8) | (2 << 24))
> +#define TCR_IRGN_WBnWA ((3 << 8) | (3 << 24))
> +#define TCR_IRGN_MASK ((3 << 8) | (3 << 24))
> +#define TCR_ORGN_NC ((0 << 10) | (0 << 26))
> +#define TCR_ORGN_WBWA ((1 << 10) | (1 << 26))
> +#define TCR_ORGN_WT ((2 << 10) | (2 << 26))
> +#define TCR_ORGN_WBnWA ((3 << 10) | (3 << 26))
> +#define TCR_ORGN_MASK ((3 << 10) | (3 << 26))
> +#define TCR_SHARED ((3 << 12) | (3 << 28))
> +#define TCR_TG0_64K (1 << 14)
> +#define TCR_TG1_64K (1 << 30)
> +#define TCR_IPS_40BIT (2 << 32)
> +#define TCR_ASID16 (1 << 36)
> +
As a matter of coding style, I would much prefer tables like this to be
written as
#define TCR_IRGN_MASK 0x0000000003000300
#define TCR_IRGN_WBnWA 0x0000000003000300
#define TCR_IRGN_WT 0x0000000002000200
#define TCR_IRGN_WBWA 0x0000000001000100
#define TCR_IRGN_NC 0x0000000000000000
#define TCR_ORGN_MASK 0x000000000c000c00
#define TCR_ORGN_WBnWA 0x000000000c000c00
#define TCR_ORGN_WT 0x0000000008000800
#define TCR_ORGN_WBWA 0x0000000004000400
#define TCR_ORGN_NC 0x0000000000000000
The advantage of this is that you can visually compare the bitmasks
to a hex dump, and if you are suffering from endian-confused documentation
authors, there is no ambiguity about which end of the word is bit zero.
Arnd
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