diff options
Diffstat (limited to 'Documentation/core-api')
| -rw-r--r-- | Documentation/core-api/printk-formats.rst | 8 | ||||
| -rw-r--r-- | Documentation/core-api/refcount-vs-atomic.rst | 24 | ||||
| -rw-r--r-- | Documentation/core-api/xarray.rst | 15 |
3 files changed, 38 insertions, 9 deletions
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index a7fae45389467..c37ec7cd9c060 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -13,6 +13,10 @@ Integer types If variable is of Type, use printk format specifier: ------------------------------------------------------------ + char %hhd or %hhx + unsigned char %hhu or %hhx + short int %hd or %hx + unsigned short int %hu or %hx int %d or %x unsigned int %u or %x long %ld or %lx @@ -21,6 +25,10 @@ Integer types unsigned long long %llu or %llx size_t %zu or %zx ssize_t %zd or %zx + s8 %hhd or %hhx + u8 %hhu or %hhx + s16 %hd or %hx + u16 %hu or %hx s32 %d or %x u32 %u or %x s64 %lld or %llx diff --git a/Documentation/core-api/refcount-vs-atomic.rst b/Documentation/core-api/refcount-vs-atomic.rst index 322851bada167..976e85adffe8e 100644 --- a/Documentation/core-api/refcount-vs-atomic.rst +++ b/Documentation/core-api/refcount-vs-atomic.rst @@ -54,6 +54,13 @@ must propagate to all other CPUs before the release operation (A-cumulative property). This is implemented using :c:func:`smp_store_release`. +An ACQUIRE memory ordering guarantees that all post loads and +stores (all po-later instructions) on the same CPU are +completed after the acquire operation. It also guarantees that all +po-later stores on the same CPU must propagate to all other CPUs +after the acquire operation executes. This is implemented using +:c:func:`smp_acquire__after_ctrl_dep`. + A control dependency (on success) for refcounters guarantees that if a reference for an object was successfully obtained (reference counter increment or addition happened, function returned true), @@ -119,13 +126,24 @@ Memory ordering guarantees changes: result of obtaining pointer to the object! -case 5) - decrement-based RMW ops that return a value ------------------------------------------------------ +case 5) - generic dec/sub decrement-based RMW ops that return a value +--------------------------------------------------------------------- Function changes: * :c:func:`atomic_dec_and_test` --> :c:func:`refcount_dec_and_test` * :c:func:`atomic_sub_and_test` --> :c:func:`refcount_sub_and_test` + +Memory ordering guarantees changes: + + * fully ordered --> RELEASE ordering + ACQUIRE ordering on success + + +case 6) other decrement-based RMW ops that return a value +--------------------------------------------------------- + +Function changes: + * no atomic counterpart --> :c:func:`refcount_dec_if_one` * ``atomic_add_unless(&var, -1, 1)`` --> ``refcount_dec_not_one(&var)`` @@ -136,7 +154,7 @@ Memory ordering guarantees changes: .. note:: :c:func:`atomic_add_unless` only provides full order on success. -case 6) - lock-based RMW +case 7) - lock-based RMW ------------------------ Function changes: diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst index 6a6d67acaf690..5d54b27c6ebab 100644 --- a/Documentation/core-api/xarray.rst +++ b/Documentation/core-api/xarray.rst @@ -108,12 +108,13 @@ some, but not all of the other indices changing. Sometimes you need to ensure that a subsequent call to :c:func:`xa_store` will not need to allocate memory. The :c:func:`xa_reserve` function -will store a reserved entry at the indicated index. Users of the normal -API will see this entry as containing ``NULL``. If you do not need to -use the reserved entry, you can call :c:func:`xa_release` to remove the -unused entry. If another user has stored to the entry in the meantime, -:c:func:`xa_release` will do nothing; if instead you want the entry to -become ``NULL``, you should use :c:func:`xa_erase`. +will store a reserved entry at the indicated index. Users of the +normal API will see this entry as containing ``NULL``. If you do +not need to use the reserved entry, you can call :c:func:`xa_release` +to remove the unused entry. If another user has stored to the entry +in the meantime, :c:func:`xa_release` will do nothing; if instead you +want the entry to become ``NULL``, you should use :c:func:`xa_erase`. +Using :c:func:`xa_insert` on a reserved entry will fail. If all entries in the array are ``NULL``, the :c:func:`xa_empty` function will return ``true``. @@ -183,6 +184,8 @@ Takes xa_lock internally: * :c:func:`xa_store_bh` * :c:func:`xa_store_irq` * :c:func:`xa_insert` + * :c:func:`xa_insert_bh` + * :c:func:`xa_insert_irq` * :c:func:`xa_erase` * :c:func:`xa_erase_bh` * :c:func:`xa_erase_irq` |