From 98271d4198699947d66d6f8a02c09bd27cb90022 Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Mon, 28 Aug 2017 23:23:38 -0700 Subject: [PATCH] powerpc/powernv/vas: Define vas_win_close() interface Define the vas_win_close() interface which should be used to close a send or receive windows. While the hardware configurations required to open send and receive windows differ, the configuration to close a window is the same for both. So we use a single interface to close the window. Signed-off-by: Sukadev Bhattiprolu Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/vas.h | 7 ++ arch/powerpc/platforms/powernv/vas-window.c | 101 +++++++++++++++++++- 2 files changed, 103 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h index 18c59c3ade3d..96bc24d61625 100644 --- a/arch/powerpc/include/asm/vas.h +++ b/arch/powerpc/include/asm/vas.h @@ -95,4 +95,11 @@ void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop) struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop, struct vas_rx_win_attr *attr); +/* + * Close the send or receive window identified by @win. For receive windows + * return -EAGAIN if there are active send windows attached to this receive + * window. + */ +int vas_win_close(struct vas_window *win); + #endif /* __ASM_POWERPC_VAS_H */ diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c index 783c8c6585d4..39aa0e4d8b09 100644 --- a/arch/powerpc/platforms/powernv/vas-window.c +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -130,7 +130,7 @@ static void unmap_region(void *addr, u64 start, int len) /* * Unmap the paste address region for a window. */ -void unmap_paste_region(struct vas_window *window) +static void unmap_paste_region(struct vas_window *window) { int len; u64 busaddr_start; @@ -522,7 +522,7 @@ static int vas_assign_window_id(struct ida *ida) return winid; } -void vas_window_free(struct vas_window *window) +static void vas_window_free(struct vas_window *window) { int winid = window->winid; struct vas_instance *vinst = window->vinst; @@ -560,6 +560,14 @@ out_free: return ERR_PTR(-ENOMEM); } +static void put_rx_win(struct vas_window *rxwin) +{ + /* Better not be a send window! */ + WARN_ON_ONCE(rxwin->tx_win); + + atomic_dec(&rxwin->num_txwins); +} + /* * Get the VAS receive window associated with NX engine identified * by @cop and if applicable, @pswid. @@ -627,7 +635,7 @@ static void set_vinst_win(struct vas_instance *vinst, * Clear this window from the table(s) of windows for this VAS instance. * See also function header of set_vinst_win(). */ -void clear_vinst_win(struct vas_window *window) +static void clear_vinst_win(struct vas_window *window) { int id = window->winid; struct vas_instance *vinst = window->vinst; @@ -839,8 +847,91 @@ struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop, } EXPORT_SYMBOL_GPL(vas_rx_win_open); -/* stub for now */ +static void poll_window_busy_state(struct vas_window *window) +{ + int busy; + u64 val; + +retry: + /* + * Poll Window Busy flag + */ + val = read_hvwc_reg(window, VREG(WIN_STATUS)); + busy = GET_FIELD(VAS_WIN_BUSY, val); + if (busy) { + val = 0; + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ); + goto retry; + } +} + +static void poll_window_castout(struct vas_window *window) +{ + int cached; + u64 val; + + /* Cast window context out of the cache */ +retry: + val = read_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL)); + cached = GET_FIELD(VAS_WIN_CACHE_STATUS, val); + if (cached) { + val = 0ULL; + val = SET_FIELD(VAS_CASTOUT_REQ, val, 1); + val = SET_FIELD(VAS_PUSH_TO_MEM, val, 0); + write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), val); + + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ); + goto retry; + } +} + +/* + * Close a window. + * + * See Section 1.12.1 of VAS workbook v1.05 for details on closing window: + * - Disable new paste operations (unmap paste address) + * - Poll for the "Window Busy" bit to be cleared + * - Clear the Open/Enable bit for the Window. + * - Poll for return of window Credits (implies FIFO empty for Rx win?) + * - Unpin and cast window context out of cache + * + * Besides the hardware, kernel has some bookkeeping of course. + */ int vas_win_close(struct vas_window *window) { - return -1; + u64 val; + + if (!window) + return 0; + + if (!window->tx_win && atomic_read(&window->num_txwins) != 0) { + pr_devel("Attempting to close an active Rx window!\n"); + WARN_ON_ONCE(1); + return -EBUSY; + } + + unmap_paste_region(window); + + clear_vinst_win(window); + + poll_window_busy_state(window); + + /* Unpin window from cache and close it */ + val = read_hvwc_reg(window, VREG(WINCTL)); + val = SET_FIELD(VAS_WINCTL_PIN, val, 0); + val = SET_FIELD(VAS_WINCTL_OPEN, val, 0); + write_hvwc_reg(window, VREG(WINCTL), val); + + poll_window_castout(window); + + /* if send window, drop reference to matching receive window */ + if (window->tx_win) + put_rx_win(window->rxwin); + + vas_window_free(window); + + return 0; } +EXPORT_SYMBOL_GPL(vas_win_close); -- 2.20.1