On Sat, Nov 11 2023 at 20:16, Jacob Pan wrote: > +/* Posted-Interrupt Descriptor */ > +struct pi_desc { > + u32 pir[8]; /* Posted interrupt requested */ > + union { > + struct { > + /* bit 256 - Outstanding Notification */ > + u16 on : 1, > + /* bit 257 - Suppress Notification */ > + sn : 1, > + /* bit 271:258 - Reserved */ > + rsvd_1 : 14; > + /* bit 279:272 - Notification Vector */ > + u8 nv; > + /* bit 287:280 - Reserved */ > + u8 rsvd_2; > + /* bit 319:288 - Notification Destination */ > + u32 ndst; This mixture of bitfields and types is weird and really not intuitive: /* Posted-Interrupt Descriptor */ struct pi_desc { /* Posted interrupt requested */ u32 pir[8]; union { struct { /* bit 256 - Outstanding Notification */ u64 on : 1, /* bit 257 - Suppress Notification */ sn : 1, /* bit 271:258 - Reserved */ : 14, /* bit 279:272 - Notification Vector */ nv : 8, /* bit 287:280 - Reserved */ : 8, /* bit 319:288 - Notification Destination */ ndst : 32; }; u64 control; }; u32 rsvd[6]; } __aligned(64); Hmm? > +static inline bool pi_test_and_set_on(struct pi_desc *pi_desc) > +{ > + return test_and_set_bit(POSTED_INTR_ON, > + (unsigned long *)&pi_desc->control); Please get rid of those line breaks. Thanks, tglx