[PATCH v2 08/10] VAS: Define vas_win_close() interface
From: Sukadev Bhattiprolu <hidden>
Date: 2017-01-26 01:38:49
Subsystem:
char and misc drivers, linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Arnd Bergmann, Greg Kroah-Hartman, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 <redacted> --- arch/powerpc/include/asm/vas.h | 6 +++++ drivers/misc/vas/vas-window.c | 52 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+)
diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index b6362e9..bda851a 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h@@ -75,6 +75,12 @@ struct vas_rx_win_attr { 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); /* * Get/Set bit fields
diff --git a/drivers/misc/vas/vas-window.c b/drivers/misc/vas/vas-window.c
index a640d59..4b06780 100644
--- a/drivers/misc/vas/vas-window.c
+++ b/drivers/misc/vas/vas-window.c@@ -711,3 +711,55 @@ struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop, vas_release_window_id(&vinst->ida, rxwin->winid); return ERR_PTR(rc); } + +int vas_win_close(struct vas_window *window) +{ + uint64_t val; + int cached; + + if (!window) + return 0; + + if (!window->tx_win && atomic_read(&window->num_txwins) != 0) { + pr_devel("VAS: Attempting to close an active Rx window!\n"); + WARN_ON_ONCE(1); + return -EAGAIN; + } + + /* Unpin window from cache and close it */ + val = 0ULL; + val = SET_FIELD(VAS_WINCTL_PIN, val, 0); + val = SET_FIELD(VAS_WINCTL_OPEN, val, 0); + write_hvwc_reg(window, VREG(WINCTL), val); + + /* + * See Section 1.11.1 for details on closing window, including + * - disable new paste operations + * - block till pending requests are completed + * - If Rx window, ensure FIFO is empty. + */ + + /* Cast window context out of the cache */ +retry: + val = read_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL)); + cached = GET_FIELD(val, VAS_WIN_CACHE_STATUS); + 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); + + schedule_timeout(2000); + goto retry; + } + + /* if send window, drop reference to matching receive window */ + if (window->tx_win) + put_rx_win(window->rxwin); + + vas_release_window_id(&window->vinst->ida, window->winid); + + vas_window_free(window); + + return 0; +}
--
2.7.4