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Commit 98271d41 authored by Sukadev Bhattiprolu's avatar Sukadev Bhattiprolu Committed by Michael Ellerman
Browse files

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: default avatarSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 62c4eda4

arch/powerpc/include/asm/vas.h

+7 −0
Original line number Diff line number Diff line
@@ -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 */

arch/powerpc/platforms/powernv/vas-window.c

+96 −5
Original line number Diff line number Diff line
@@ -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 @@ static struct vas_window *vas_window_alloc(struct vas_instance *vinst) 
	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);