diff options
| -rw-r--r-- | arch/powerpc/platforms/powernv/vas-window.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c index a59a187c0cd1..23c13a7dcf89 100644 --- a/arch/powerpc/platforms/powernv/vas-window.c +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -1063,6 +1063,49 @@ int vas_paste_crb(struct vas_window *txwin, int offset, bool re) EXPORT_SYMBOL_GPL(vas_paste_crb); /* + * If credit checking is enabled for this window, poll for the return + * of window credits (i.e for NX engines to process any outstanding CRBs). + * Since NX-842 waits for the CRBs to be processed before closing the + * window, we should not have to wait for too long. + * + * TODO: We retry in 10ms intervals now. We could/should probably peek at + * the VAS_LRFIFO_PUSH_OFFSET register to get an estimate of pending + * CRBs on the FIFO and compute the delay dynamically on each retry. + * But that is not really needed until we support NX-GZIP access from + * user space. (NX-842 driver waits for CSB and Fast thread-wakeup + * doesn't use credit checking). + */ +static void poll_window_credits(struct vas_window *window) +{ + u64 val; + int creds, mode; + + val = read_hvwc_reg(window, VREG(WINCTL)); + if (window->tx_win) + mode = GET_FIELD(VAS_WINCTL_TX_WCRED_MODE, val); + else + mode = GET_FIELD(VAS_WINCTL_RX_WCRED_MODE, val); + + if (!mode) + return; +retry: + if (window->tx_win) { + val = read_hvwc_reg(window, VREG(TX_WCRED)); + creds = GET_FIELD(VAS_TX_WCRED, val); + } else { + val = read_hvwc_reg(window, VREG(LRX_WCRED)); + creds = GET_FIELD(VAS_LRX_WCRED, val); + } + + if (creds < window->wcreds_max) { + val = 0; + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(msecs_to_jiffies(10)); + goto retry; + } +} + +/* * Wait for the window to go to "not-busy" state. It should only take a * short time to queue a CRB, so window should not be busy for too long. * Trying 5ms intervals. @@ -1149,6 +1192,8 @@ int vas_win_close(struct vas_window *window) unpin_close_window(window); + poll_window_credits(window); + poll_window_castout(window); /* if send window, drop reference to matching receive window */ |