diff options
| -rw-r--r-- | arch/powerpc/platforms/powernv/vas-fault.c | 9 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/vas-window.c | 36 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/vas.h | 1 |
3 files changed, 46 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/vas-fault.c b/arch/powerpc/platforms/powernv/vas-fault.c index 354577dcf2dc..b6bec64d793e 100644 --- a/arch/powerpc/platforms/powernv/vas-fault.c +++ b/arch/powerpc/platforms/powernv/vas-fault.c @@ -224,6 +224,10 @@ irqreturn_t vas_fault_thread_fn(int irq, void *data) memcpy(crb, fifo, CRB_SIZE); entry->stamp.nx.pswid = cpu_to_be32(FIFO_INVALID_ENTRY); entry->ccw |= cpu_to_be32(CCW0_INVALID); + /* + * Return credit for the fault window. + */ + vas_return_credit(vinst->fault_win, false); pr_devel("VAS[%d] fault_fifo %p, fifo %p, fault_crbs %d\n", vinst->vas_id, vinst->fault_fifo, fifo, @@ -249,6 +253,11 @@ irqreturn_t vas_fault_thread_fn(int irq, void *data) WARN_ON_ONCE(1); } else { update_csb(window, crb); + /* + * Return credit for send window after processing + * fault CRB. + */ + vas_return_credit(window, true); } } } diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c index f12f7eb1a5a6..3ef71209ff58 100644 --- a/arch/powerpc/platforms/powernv/vas-window.c +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -1317,6 +1317,42 @@ int vas_win_close(struct vas_window *window) } EXPORT_SYMBOL_GPL(vas_win_close); +/* + * Return credit for the given window. + * Send windows and fault window uses credit mechanism as follows: + * + * Send windows: + * - The default number of credits available for each send window is + * 1024. It means 1024 requests can be issued asynchronously at the + * same time. If the credit is not available, that request will be + * returned with RMA_Busy. + * - One credit is taken when NX request is issued. + * - This credit is returned after NX processed that request. + * - If NX encounters translation error, kernel will return the + * credit on the specific send window after processing the fault CRB. + * + * Fault window: + * - The total number credits available is FIFO_SIZE/CRB_SIZE. + * Means 4MB/128 in the current implementation. If credit is not + * available, RMA_Reject is returned. + * - A credit is taken when NX pastes CRB in fault FIFO. + * - The kernel with return credit on fault window after reading entry + * from fault FIFO. + */ +void vas_return_credit(struct vas_window *window, bool tx) +{ + uint64_t val; + + val = 0ULL; + if (tx) { /* send window */ + val = SET_FIELD(VAS_TX_WCRED, val, 1); + write_hvwc_reg(window, VREG(TX_WCRED_ADDER), val); + } else { + val = SET_FIELD(VAS_LRX_WCRED, val, 1); + write_hvwc_reg(window, VREG(LRX_WCRED_ADDER), val); + } +} + struct vas_window *vas_pswid_to_window(struct vas_instance *vinst, uint32_t pswid) { diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h index cd165c8b2b57..60bdda663750 100644 --- a/arch/powerpc/platforms/powernv/vas.h +++ b/arch/powerpc/platforms/powernv/vas.h @@ -436,6 +436,7 @@ extern void vas_window_free_dbgdir(struct vas_window *win); extern int vas_setup_fault_window(struct vas_instance *vinst); extern irqreturn_t vas_fault_thread_fn(int irq, void *data); extern irqreturn_t vas_fault_handler(int irq, void *dev_id); +extern void vas_return_credit(struct vas_window *window, bool tx); extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst, uint32_t pswid); |