On Mon, Sep 11, 2023 at 12:28:33PM +0800, Linyu Yuan wrote:
> Some UDC trace event will save usb gadget information, but it will use
> one int size buffer to save one bit information of usb gadget, so more
> than one int buffer to save several bit fields which is not good.
>
> Add one anonymous union have three u32 members which can be used by trace
> event during fast assign stage to reduce trace buffer usage, and add
> related macro to extract bit fields from u32 members for later trace event
> output state usage.
>
> Also move sg_supported and other bit fields into one anonymous struct
> which inside anonymous union and Change bit fields from unsigned to u32
> type, it will make sure union member have expected u32 size.
>
> Signed-off-by: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
> ---
> include/linux/usb/gadget.h | 63 ++++++++++++++++++++++++++------------
> 1 file changed, 44 insertions(+), 19 deletions(-)
>
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 75bda0783395..cdf62e7f34e7 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -357,6 +357,7 @@ struct usb_gadget_ops {
> * @in_epnum: last used in ep number
> * @mA: last set mA value
> * @otg_caps: OTG capabilities of this gadget.
> + * @dw1: trace event purpose
> * @sg_supported: true if we can handle scatter-gather
> * @is_otg: True if the USB device port uses a Mini-AB jack, so that the
> * gadget driver must provide a USB OTG descriptor.
> @@ -432,25 +433,49 @@ struct usb_gadget {
> unsigned mA;
> struct usb_otg_caps *otg_caps;
>
> - unsigned sg_supported:1;
> - unsigned is_otg:1;
> - unsigned is_a_peripheral:1;
> - unsigned b_hnp_enable:1;
> - unsigned a_hnp_support:1;
> - unsigned a_alt_hnp_support:1;
> - unsigned hnp_polling_support:1;
> - unsigned host_request_flag:1;
> - unsigned quirk_ep_out_aligned_size:1;
> - unsigned quirk_altset_not_supp:1;
> - unsigned quirk_stall_not_supp:1;
> - unsigned quirk_zlp_not_supp:1;
> - unsigned quirk_avoids_skb_reserve:1;
> - unsigned is_selfpowered:1;
> - unsigned deactivated:1;
> - unsigned connected:1;
> - unsigned lpm_capable:1;
> - unsigned wakeup_capable:1;
> - unsigned wakeup_armed:1;
> + union {
> + struct {
> + u32 sg_supported:1;
> + u32 is_otg:1;
> + u32 is_a_peripheral:1;
> + u32 b_hnp_enable:1;
> + u32 a_hnp_support:1;
> + u32 a_alt_hnp_support:1;
> + u32 hnp_polling_support:1;
> + u32 host_request_flag:1;
> + u32 quirk_ep_out_aligned_size:1;
> + u32 quirk_altset_not_supp:1;
> + u32 quirk_stall_not_supp:1;
> + u32 quirk_zlp_not_supp:1;
> + u32 quirk_avoids_skb_reserve:1;
> + u32 is_selfpowered:1;
> + u32 deactivated:1;
> + u32 connected:1;
> + u32 lpm_capable:1;
> + u32 wakeup_capable:1;
> + u32 wakeup_armed:1;
> + } __packed;
> + u32 dw1;
> +#define USB_GADGET_SG_SUPPORTED(n) ((n) & BIT(0))
> +#define USB_GADGET_IS_OTG(n) ((n) & BIT(1))
> +#define USB_GADGET_IS_A_PERIPHERAL(n) ((n) & BIT(2))
> +#define USB_GADGET_B_HNP_ENABLE(n) ((n) & BIT(3))
> +#define USB_GADGET_A_HNP_SUPPORT(n) ((n) & BIT(4))
> +#define USB_GADGET_A_ALT_HNP_SUPPORT(n) ((n) & BIT(5))
> +#define USB_GADGET_HNP_POLLING_SUPPORT(n) ((n) & BIT(6))
> +#define USB_GADGET_HOST_REQUEST_FLAG(n) ((n) & BIT(7))
> +#define USB_GADGET_QUIRK_EP_OUT_ALIGNED_SIZE(n) ((n) & BIT(8))
> +#define USB_GADGET_QUIRK_ALTSET_NOT_SUPP(n) ((n) & BIT(9))
> +#define USB_GADGET_QUIRK_STALL_NOT_SUPP(n) ((n) & BIT(10))
> +#define USB_GADGET_QUIRK_ZLP_NOT_SUPP(n) ((n) & BIT(11))
> +#define USB_GADGET_QUIRK_AVOIDS_SKB_RESERVE(n) ((n) & BIT(12))
> +#define USB_GADGET_IS_SELFPOWERED(n) ((n) & BIT(13))
> +#define USB_GADGET_DEACTIVATED(n) ((n) & BIT(14))
> +#define USB_GADGET_CONNECTED(n) ((n) & BIT(15))
> +#define USB_GADGET_LPM_CAPABLE(n) ((n) & BIT(16))
> +#define USB_GADGET_WAKEUP_CAPABLE(n) ((n) & BIT(17))
> +#define USB_GADGET_WAKEUP_ARMED(n) ((n) & BIT(18))
> + };
Are you sure these #defines will work on all architectures? As far as I
know, the C compiler does not specify that bit fields in packed
structures will be assigned starting from the low-order bit position.
Alan Stern
