Index: sys/sys/_smr.h =================================================================== --- sys/sys/_smr.h +++ sys/sys/_smr.h @@ -35,4 +35,110 @@ typedef int32_t smr_delta_t; typedef struct smr *smr_t; +#define SMR_ENTERED(smr) \ + (curthread->td_critnest != 0 && zpcpu_get((smr))->c_seq != SMR_SEQ_INVALID) + +#define SMR_ASSERT_ENTERED(smr) \ + KASSERT(SMR_ENTERED(smr), ("Not in smr section")) + +#define SMR_ASSERT_NOT_ENTERED(smr) \ + KASSERT(!SMR_ENTERED(smr), ("In smr section.")); + +#define SMR_ASSERT(ex, fn) \ + KASSERT((ex), (fn ": Assertion " #ex " failed at %s:%d", __FILE__, __LINE__)) + +/* Type restricting pointer access to force smr accessors. */ +#define SMR_TYPE_DECLARE(smrtype, type) \ +typedef struct { \ + type __ptr; /* Do not access directly */ \ +} smrtype + +/* + * SMR Accessors are meant to provide safe access to SMR protected + * pointers and prevent misuse and accidental access. + * + * Accessors are grouped by type: + * entered - Use while in a read section (between smr_enter/smr_exit()) + * serialized - Use while holding a lock that serializes writers. Updates + * are synchronized with readers via included barriers. + * unserialized - Use after the memory is out of scope and not visible to + * readers. + * + * All acceses include a parameter for an assert to verify the required + * synchronization. For example, a writer might use: + * + * smr_serialized_store(pointer, value, mtx_owned(&writelock)); + * + * These are only enabled in INVARIANTS kernels. + */ + +/* + * Read from an SMR protected pointer while in a read section. + */ +#define smr_entered_load(p, smr) ({ \ + SMR_ASSERT(SMR_ENTERED((smr)), "smr_entered_load"); \ + (__typeof((p)->__ptr))atomic_load_acq_ptr((uintptr_t *)&(p)->__ptr); \ +}) + +/* + * Read from an SMR protected pointer while serialized by an + * external mechanism. 'ex' should contain an assert that the + * external mechanism is held. i.e. mtx_owned() + */ +#define smr_serialized_load(p, ex) ({ \ + SMR_ASSERT(ex, "smr_serialized_load"); \ + (__typeof((p)->__ptr))atomic_load_ptr(&(p)->__ptr); \ +}) + +/* + * Store 'v' to an SMR protected pointer while serialized by an + * external mechanism. 'ex' should contain an assert that the + * external mechanism is held. i.e. mtx_owned() + * + * Writers that are serialized with mutual exclusion or on a single + * thread should use smr_serialized_store() rather than swap. + */ +#define smr_serialized_store(p, v, ex) do { \ + SMR_ASSERT(ex, "smr_serialized_store"); \ + __typeof((p)->__ptr) _v = (v); \ + atomic_store_rel_ptr((uintptr_t *)&(p)->__ptr, (uintptr_t)_v); \ +} while (0) + +/* + * swap 'v' with an SMR protected pointer and return the old value + * while serialized by an external mechanism. 'ex' should contain + * an assert that the external mechanism is provided. i.e. mtx_owned() + * + * Swap permits multiple writers to update a pointer concurrently. + */ +#define smr_serialized_swap(p, v, ex) ({ \ + SMR_ASSERT(ex, "smr_serialized_swap"); \ + __typeof((p)->__ptr) _v = (v); \ + /* Release barrier guarantees contents are visible to reader */ \ + atomic_thread_fence_rel(); \ + (__typeof((p)->__ptr))atomic_swap_ptr( \ + (uintptr_t *)&(p)->__ptr, (uintptr_t)_v); \ +}) + +/* + * Read from an SMR protected pointer when no serialization is required + * such as in the destructor callback or when the caller guarantees other + * synchronization. + */ +#define smr_unserialized_load(p, ex) ({ \ + SMR_ASSERT(ex, "smr_unserialized_load"); \ + (__typeof((p)->__ptr))atomic_load_ptr(&(p)->__ptr); \ +}) + +/* + * Store to an SMR protected pointer when no serialiation is required + * such as in the destructor callback or when the caller guarantees other + * synchronization. + */ +#define smr_unserialized_store(p, v, ex) do { \ + SMR_ASSERT(ex, "smr_unserialized_store"); \ + __typeof((p)->__ptr) _v = (v); \ + atomic_store_ptr((uintptr_t *)&(p)->__ptr, (uintptr_t)_v); \ +} while (0) + #endif /* __SYS_SMR_H_ */ Index: sys/sys/smr.h =================================================================== --- sys/sys/smr.h +++ sys/sys/smr.h @@ -82,111 +82,9 @@ #define SMR_LAZY 0x0001 /* Higher latency write, fast read. */ #define SMR_DEFERRED 0x0002 /* Aggregate updates to wr_seq. */ -#define SMR_ENTERED(smr) \ - (curthread->td_critnest != 0 && zpcpu_get((smr))->c_seq != SMR_SEQ_INVALID) - -#define SMR_ASSERT_ENTERED(smr) \ - KASSERT(SMR_ENTERED(smr), ("Not in smr section")) - -#define SMR_ASSERT_NOT_ENTERED(smr) \ - KASSERT(!SMR_ENTERED(smr), ("In smr section.")); - -#define SMR_ASSERT(ex, fn) \ - KASSERT((ex), (fn ": Assertion " #ex " failed at %s:%d", __FILE__, __LINE__)) - -/* - * SMR Accessors are meant to provide safe access to SMR protected - * pointers and prevent misuse and accidental access. - * - * Accessors are grouped by type: - * entered - Use while in a read section (between smr_enter/smr_exit()) - * serialized - Use while holding a lock that serializes writers. Updates - * are synchronized with readers via included barriers. - * unserialized - Use after the memory is out of scope and not visible to - * readers. - * - * All acceses include a parameter for an assert to verify the required - * synchronization. For example, a writer might use: - * - * smr_serialized_store(pointer, value, mtx_owned(&writelock)); - * - * These are only enabled in INVARIANTS kernels. - */ - -/* Type restricting pointer access to force smr accessors. */ -#define SMR_TYPE_DECLARE(smrtype, type) \ -typedef struct { \ - type __ptr; /* Do not access directly */ \ -} smrtype - -/* - * Read from an SMR protected pointer while in a read section. - */ -#define smr_entered_load(p, smr) ({ \ - SMR_ASSERT(SMR_ENTERED((smr)), "smr_entered_load"); \ - (__typeof((p)->__ptr))atomic_load_acq_ptr((uintptr_t *)&(p)->__ptr); \ -}) - -/* - * Read from an SMR protected pointer while serialized by an - * external mechanism. 'ex' should contain an assert that the - * external mechanism is held. i.e. mtx_owned() - */ -#define smr_serialized_load(p, ex) ({ \ - SMR_ASSERT(ex, "smr_serialized_load"); \ - (__typeof((p)->__ptr))atomic_load_ptr(&(p)->__ptr); \ -}) - -/* - * Store 'v' to an SMR protected pointer while serialized by an - * external mechanism. 'ex' should contain an assert that the - * external mechanism is held. i.e. mtx_owned() - * - * Writers that are serialized with mutual exclusion or on a single - * thread should use smr_serialized_store() rather than swap. - */ -#define smr_serialized_store(p, v, ex) do { \ - SMR_ASSERT(ex, "smr_serialized_store"); \ - __typeof((p)->__ptr) _v = (v); \ - atomic_store_rel_ptr((uintptr_t *)&(p)->__ptr, (uintptr_t)_v); \ -} while (0) - -/* - * swap 'v' with an SMR protected pointer and return the old value - * while serialized by an external mechanism. 'ex' should contain - * an assert that the external mechanism is provided. i.e. mtx_owned() - * - * Swap permits multiple writers to update a pointer concurrently. - */ -#define smr_serialized_swap(p, v, ex) ({ \ - SMR_ASSERT(ex, "smr_serialized_swap"); \ - __typeof((p)->__ptr) _v = (v); \ - /* Release barrier guarantees contents are visible to reader */ \ - atomic_thread_fence_rel(); \ - (__typeof((p)->__ptr))atomic_swap_ptr( \ - (uintptr_t *)&(p)->__ptr, (uintptr_t)_v); \ -}) - -/* - * Read from an SMR protected pointer when no serialization is required - * such as in the destructor callback or when the caller guarantees other - * synchronization. - */ -#define smr_unserialized_load(p, ex) ({ \ - SMR_ASSERT(ex, "smr_unserialized_load"); \ - (__typeof((p)->__ptr))atomic_load_ptr(&(p)->__ptr); \ -}) - /* - * Store to an SMR protected pointer when no serialiation is required - * such as in the destructor callback or when the caller guarantees other - * synchronization. + * This API provides accessors for safe use. See sys/_smr.h. */ -#define smr_unserialized_store(p, v, ex) do { \ - SMR_ASSERT(ex, "smr_unserialized_store"); \ - __typeof((p)->__ptr) _v = (v); \ - atomic_store_ptr((uintptr_t *)&(p)->__ptr, (uintptr_t)_v); \ -} while (0) /* * Return the current write sequence number. This is not the same as the