* [PATCH 01/10] powerpc/vas: init missing fields from [rt]xattr
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 02/10] powerpc/vas: Validate window credits Sukadev Bhattiprolu
` (8 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Initialize a few missing window context fields from the window attributes
specified by the caller. These fields are currently set to their default
values by the caller (NX-842), but would be good to apply them anyway.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 5aae845..cec7ab7 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -679,10 +679,13 @@ static void init_winctx_for_rxwin(struct vas_window *rxwin,
winctx->nx_win = rxattr->nx_win;
winctx->fault_win = rxattr->fault_win;
+ winctx->user_win = rxattr->user_win;
+ winctx->rej_no_credit = rxattr->rej_no_credit;
winctx->rx_word_mode = rxattr->rx_win_ord_mode;
winctx->tx_word_mode = rxattr->tx_win_ord_mode;
winctx->rx_wcred_mode = rxattr->rx_wcred_mode;
winctx->tx_wcred_mode = rxattr->tx_wcred_mode;
+ winctx->notify_early = rxattr->notify_early;
if (winctx->nx_win) {
winctx->data_stamp = true;
@@ -889,11 +892,14 @@ static void init_winctx_for_txwin(struct vas_window *txwin,
winctx->user_win = txattr->user_win;
winctx->nx_win = txwin->rxwin->nx_win;
winctx->pin_win = txattr->pin_win;
+ winctx->rej_no_credit = txattr->rej_no_credit;
+ winctx->rsvd_txbuf_enable = txattr->rsvd_txbuf_enable;
winctx->rx_wcred_mode = txattr->rx_wcred_mode;
winctx->tx_wcred_mode = txattr->tx_wcred_mode;
winctx->rx_word_mode = txattr->rx_win_ord_mode;
winctx->tx_word_mode = txattr->tx_win_ord_mode;
+ winctx->rsvd_txbuf_count = txattr->rsvd_txbuf_count;
if (winctx->nx_win) {
winctx->data_stamp = true;
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 02/10] powerpc/vas: Validate window credits
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 01/10] powerpc/vas: init missing fields from [rt]xattr Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 03/10] powerpc/vas: Cleanup some debug code Sukadev Bhattiprolu
` (7 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
NX-842, the only user of VAS, sets the window credits to default values
but VAS should check the credits against the possible max values.
The VAS_WCREDS_MIN is not needed and can be dropped.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 6 ++++++
arch/powerpc/platforms/powernv/vas.h | 4 ++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index cec7ab7..a2fe120 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -738,6 +738,9 @@ static bool rx_win_args_valid(enum vas_cop_type cop,
if (attr->rx_fifo_size > VAS_RX_FIFO_SIZE_MAX)
return false;
+ if (attr->wcreds_max > VAS_RX_WCREDS_MAX)
+ return false;
+
if (attr->nx_win) {
/* cannot be fault or user window if it is nx */
if (attr->fault_win || attr->user_win)
@@ -927,6 +930,9 @@ static bool tx_win_args_valid(enum vas_cop_type cop,
if (cop > VAS_COP_TYPE_MAX)
return false;
+ if (attr->wcreds_max > VAS_TX_WCREDS_MAX)
+ return false;
+
if (attr->user_win &&
(cop != VAS_COP_TYPE_FTW || attr->rsvd_txbuf_count))
return false;
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index 38dee5d..fea0de4 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -106,8 +106,8 @@
*
* TODO: Needs tuning for per-process credits
*/
-#define VAS_WCREDS_MIN 16
-#define VAS_WCREDS_MAX ((64 << 10) - 1)
+#define VAS_RX_WCREDS_MAX ((64 << 10) - 1)
+#define VAS_TX_WCREDS_MAX ((4 << 10) - 1)
#define VAS_WCREDS_DEFAULT (1 << 10)
/*
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 03/10] powerpc/vas: Cleanup some debug code
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 01/10] powerpc/vas: init missing fields from [rt]xattr Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 02/10] powerpc/vas: Validate window credits Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 04/10] powerpc/vas: Drop poll_window_cast_out() Sukadev Bhattiprolu
` (6 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Cleanuup vas.h and the debug code around ifdef vas_debug.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 8 +++--
arch/powerpc/platforms/powernv/vas.h | 56 +++++++----------------------
2 files changed, 18 insertions(+), 46 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index a2fe120..67ffc5d 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -726,7 +726,10 @@ static void init_winctx_for_rxwin(struct vas_window *rxwin,
static bool rx_win_args_valid(enum vas_cop_type cop,
struct vas_rx_win_attr *attr)
{
- dump_rx_win_attr(attr);
+ pr_debug("Rxattr: fault %d, notify %d, intr %d, early %d, fifo %d\n",
+ attr->fault_win, attr->notify_disable,
+ attr->intr_disable, attr->notify_early,
+ attr->rx_fifo_size);
if (cop >= VAS_COP_TYPE_MAX)
return false;
@@ -1050,7 +1053,8 @@ int vas_paste_crb(struct vas_window *txwin, int offset, bool re)
else
rc = -EINVAL;
- print_fifo_msg_count(txwin);
+ pr_debug("Txwin #%d: Msg count %llu\n", txwin->winid,
+ read_hvwc_reg(txwin, VREG(LRFIFO_PUSH)));
return rc;
}
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index fea0de4..15d2dfa 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -259,6 +259,16 @@
#define VAS_NX_UTIL_ADDER PPC_BITMASK(32, 63)
/*
+ * VREG(x):
+ * Expand a register's short name (eg: LPID) into two parameters:
+ * - the register's short name in string form ("LPID"), and
+ * - the name of the macro (eg: VAS_LPID_OFFSET), defining the
+ * register's offset in the window context
+ */
+#define VREG_SFX(n, s) __stringify(n), VAS_##n##s
+#define VREG(r) VREG_SFX(r, _OFFSET)
+
+/*
* Local Notify Scope Control Register. (Receive windows only).
*/
enum vas_notify_scope {
@@ -385,43 +395,15 @@ struct vas_winctx {
extern struct vas_instance *find_vas_instance(int vasid);
-/*
- * VREG(x):
- * Expand a register's short name (eg: LPID) into two parameters:
- * - the register's short name in string form ("LPID"), and
- * - the name of the macro (eg: VAS_LPID_OFFSET), defining the
- * register's offset in the window context
- */
-#define VREG_SFX(n, s) __stringify(n), VAS_##n##s
-#define VREG(r) VREG_SFX(r, _OFFSET)
-
-#ifdef vas_debug
-static inline void dump_rx_win_attr(struct vas_rx_win_attr *attr)
-{
- pr_err("fault %d, notify %d, intr %d early %d\n",
- attr->fault_win, attr->notify_disable,
- attr->intr_disable, attr->notify_early);
-
- pr_err("rx_fifo_size %d, max value %d\n",
- attr->rx_fifo_size, VAS_RX_FIFO_SIZE_MAX);
-}
-
static inline void vas_log_write(struct vas_window *win, char *name,
void *regptr, u64 val)
{
- if (val)
- pr_err("%swin #%d: %s reg %p, val 0x%016llx\n",
+ if (!val)
+ pr_debug("%swin #%d: %s reg %p, val 0x%016llx\n",
win->tx_win ? "Tx" : "Rx", win->winid, name,
regptr, val);
}
-#else /* vas_debug */
-
-#define vas_log_write(win, name, reg, val)
-#define dump_rx_win_attr(attr)
-
-#endif /* vas_debug */
-
static inline void write_uwc_reg(struct vas_window *win, char *name,
s32 reg, u64 val)
{
@@ -450,18 +432,4 @@ static inline u64 read_hvwc_reg(struct vas_window *win,
return in_be64(win->hvwc_map+reg);
}
-#ifdef vas_debug
-
-static void print_fifo_msg_count(struct vas_window *txwin)
-{
- uint64_t read_hvwc_reg(struct vas_window *w, char *n, uint64_t o);
- pr_devel("Winid %d, Msg count %llu\n", txwin->winid,
- (uint64_t)read_hvwc_reg(txwin, VREG(LRFIFO_PUSH)));
-}
-#else /* vas_debug */
-
-#define print_fifo_msg_count(window)
-
-#endif /* vas_debug */
-
#endif /* _VAS_H */
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 04/10] powerpc/vas: Drop poll_window_cast_out().
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
` (2 preceding siblings ...)
2017-09-17 4:05 ` [PATCH 03/10] powerpc/vas: Cleanup some debug code Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 05/10] powerpc/vas: Use helper to unpin/close window Sukadev Bhattiprolu
` (5 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Polling for window cast out is listed in the spec, but turns out that
it is not strictly necessary and slows down window close. Making it a
stub for now.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 34 ++++++++++++++---------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 67ffc5d..8ab8a82 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1079,25 +1079,25 @@ static void poll_window_busy_state(struct vas_window *window)
}
}
+/*
+ * Have the hardware cast a window out of cache and wait for it to
+ * be completed.
+ *
+ * NOTE: It can take a relatively long time to cast the window context
+ * out of the cache. It is not strictly necessary to cast out if:
+ *
+ * - we clear the "Pin Window" bit (so hardware is free to evict)
+ *
+ * - we re-initialize the window context when it is reassigned.
+ *
+ * We do the former in vas_win_close() and latter in vas_win_open().
+ * So, ignoring the cast-out for now. We can add it as needed. If
+ * casting out becomes necessary we should consider offloading the
+ * job to a worker thread, so the window close can proceed quickly.
+ */
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;
- }
+ /* stub for now */
}
/*
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 05/10] powerpc/vas: Use helper to unpin/close window
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
` (3 preceding siblings ...)
2017-09-17 4:05 ` [PATCH 04/10] powerpc/vas: Drop poll_window_cast_out() Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 06/10] powerpc/vas: Reduce polling interval for busy state Sukadev Bhattiprolu
` (4 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Use a helper to have the hardware unpin and mark a window closed.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 8ab8a82..95622a9 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1101,6 +1101,20 @@ static void poll_window_castout(struct vas_window *window)
}
/*
+ * Unpin and close a window so no new requests are accepted and the
+ * hardware can evict this window from cache if necessary.
+ */
+static void unpin_close_window(struct vas_window *window)
+{
+ u64 val;
+
+ 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);
+}
+
+/*
* Close a window.
*
* See Section 1.12.1 of VAS workbook v1.05 for details on closing window:
@@ -1114,8 +1128,6 @@ static void poll_window_castout(struct vas_window *window)
*/
int vas_win_close(struct vas_window *window)
{
- u64 val;
-
if (!window)
return 0;
@@ -1131,11 +1143,7 @@ int vas_win_close(struct vas_window *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);
+ unpin_close_window(window);
poll_window_castout(window);
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 06/10] powerpc/vas: Reduce polling interval for busy state
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
` (4 preceding siblings ...)
2017-09-17 4:05 ` [PATCH 05/10] powerpc/vas: Use helper to unpin/close window Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 07/10] powerpc/vas: Save configured window credits Sukadev Bhattiprolu
` (3 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
A VAS window is normally in "busy" state for only a short duration.
Reduce the time we wait for the window to go to "not-busy" state to
speed-up vas_win_close() a bit.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 95622a9..1422cdd 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1060,21 +1060,23 @@ int vas_paste_crb(struct vas_window *txwin, int offset, bool re)
}
EXPORT_SYMBOL_GPL(vas_paste_crb);
+/*
+ * 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.
+ */
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);
+ schedule_timeout(msecs_to_jiffies(5));
goto retry;
}
}
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 07/10] powerpc/vas: Save configured window credits
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
` (5 preceding siblings ...)
2017-09-17 4:05 ` [PATCH 06/10] powerpc/vas: Reduce polling interval for busy state Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 08/10] powerpc/vas: poll for return of " Sukadev Bhattiprolu
` (2 subsequent siblings)
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Save the configured max window credits for a window in the vas_window
structure. We will need this when polling for return of window credits.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 6 ++++--
arch/powerpc/platforms/powernv/vas.h | 1 +
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 1422cdd..a59a187 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -674,7 +674,7 @@ static void init_winctx_for_rxwin(struct vas_window *rxwin,
winctx->rx_fifo = rxattr->rx_fifo;
winctx->rx_fifo_size = rxattr->rx_fifo_size;
- winctx->wcreds_max = rxattr->wcreds_max ?: VAS_WCREDS_DEFAULT;
+ winctx->wcreds_max = rxwin->wcreds_max;
winctx->pin_win = rxattr->pin_win;
winctx->nx_win = rxattr->nx_win;
@@ -844,6 +844,7 @@ struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
rxwin->nx_win = rxattr->nx_win;
rxwin->user_win = rxattr->user_win;
rxwin->cop = cop;
+ rxwin->wcreds_max = rxattr->wcreds_max ?: VAS_WCREDS_DEFAULT;
if (rxattr->user_win)
rxwin->pid = task_pid_vnr(current);
@@ -893,7 +894,7 @@ static void init_winctx_for_txwin(struct vas_window *txwin,
*/
memset(winctx, 0, sizeof(struct vas_winctx));
- winctx->wcreds_max = txattr->wcreds_max ?: VAS_WCREDS_DEFAULT;
+ winctx->wcreds_max = txwin->wcreds_max;
winctx->user_win = txattr->user_win;
winctx->nx_win = txwin->rxwin->nx_win;
@@ -978,6 +979,7 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
txwin->nx_win = txwin->rxwin->nx_win;
txwin->pid = attr->pid;
txwin->user_win = attr->user_win;
+ txwin->wcreds_max = attr->wcreds_max ?: VAS_WCREDS_DEFAULT;
init_winctx_for_txwin(txwin, attr, &winctx);
diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
index 15d2dfa..ad906f6 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -332,6 +332,7 @@ struct vas_window {
void *hvwc_map; /* HV window context */
void *uwc_map; /* OS/User window context */
pid_t pid; /* Linux process id of owner */
+ int wcreds_max; /* Window credits */
/* Fields applicable only to send windows */
void *paste_kaddr;
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 08/10] powerpc/vas: poll for return of window credits
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
` (6 preceding siblings ...)
2017-09-17 4:05 ` [PATCH 07/10] powerpc/vas: Save configured window credits Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 09/10] powerpc/vas: Create cpu to vas id mapping Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 10/10] powerpc/vas, nx-842: Define and use chip_to_vas_id() Sukadev Bhattiprolu
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Normally, the NX driver waits for the CRBs to be processed before closing
the window. But it is better to ensure that the credits are returned before
the window gets reassigned later.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 45 +++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index a59a187..8e14ce1 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 */
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 09/10] powerpc/vas: Create cpu to vas id mapping
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
` (7 preceding siblings ...)
2017-09-17 4:05 ` [PATCH 08/10] powerpc/vas: poll for return of " Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
2017-09-17 4:05 ` [PATCH 10/10] powerpc/vas, nx-842: Define and use chip_to_vas_id() Sukadev Bhattiprolu
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Create a cpu to vasid mapping so callers can specify -1 instead of
trying to find a VAS id.
Changelog[v2]
[Michael Ellerman] Use per-cpu variables to simplify code.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/powernv/vas.c b/arch/powerpc/platforms/powernv/vas.c
index 565a487..abb7090 100644
--- a/arch/powerpc/platforms/powernv/vas.c
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -18,15 +18,18 @@
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of.h>
+#include <asm/prom.h>
#include "vas.h"
static DEFINE_MUTEX(vas_mutex);
static LIST_HEAD(vas_instances);
+static DEFINE_PER_CPU(int, cpu_vas_id);
+
static int init_vas_instance(struct platform_device *pdev)
{
- int rc, vasid;
+ int rc, cpu, vasid;
struct resource *res;
struct vas_instance *vinst;
struct device_node *dn = pdev->dev.of_node;
@@ -74,6 +77,11 @@ static int init_vas_instance(struct platform_device *pdev)
"paste_win_id_shift 0x%llx\n", pdev->name, vasid,
vinst->paste_base_addr, vinst->paste_win_id_shift);
+ for_each_possible_cpu(cpu) {
+ if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
+ per_cpu(cpu_vas_id, cpu) = vasid;
+ }
+
mutex_lock(&vas_mutex);
list_add(&vinst->node, &vas_instances);
mutex_unlock(&vas_mutex);
@@ -98,6 +106,10 @@ struct vas_instance *find_vas_instance(int vasid)
struct vas_instance *vinst;
mutex_lock(&vas_mutex);
+
+ if (vasid == -1)
+ vasid = per_cpu(cpu_vas_id, smp_processor_id());
+
list_for_each(ent, &vas_instances) {
vinst = list_entry(ent, struct vas_instance, node);
if (vinst->vas_id == vasid) {
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 10/10] powerpc/vas, nx-842: Define and use chip_to_vas_id()
2017-09-17 4:05 [PATCH 00/10] powerpc/vas: cleanup and optimizations Sukadev Bhattiprolu
` (8 preceding siblings ...)
2017-09-17 4:05 ` [PATCH 09/10] powerpc/vas: Create cpu to vas id mapping Sukadev Bhattiprolu
@ 2017-09-17 4:05 ` Sukadev Bhattiprolu
9 siblings, 0 replies; 11+ messages in thread
From: Sukadev Bhattiprolu @ 2017-09-17 4:05 UTC (permalink / raw)
To: Michael Ellerman
Cc: Benjamin Herrenschmidt, mikey, hbabu, linuxppc-dev, linux-kernel
Define a helper, chip_to_vas_id() to map a given chip id to corresponding
vas id.
Normally, callers of vas_rx_win_open() and vas_tx_win_open() would need
the VAS window to be on the same chip where the calling thread is executing.
These callers can pass in -1 for the VAS id.
This interface will be useful if a thread running on one chip wants to open
a window on another chip (like the NX-842 driver does during start up).
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/vas.h | 9 +++++++++
arch/powerpc/platforms/powernv/vas.c | 11 +++++++++++
drivers/crypto/nx/nx-842-powernv.c | 18 +++---------------
3 files changed, 23 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index fd5963a..044748f 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -104,6 +104,15 @@ struct vas_tx_win_attr {
};
/*
+ * Helper to map a chip id to VAS id.
+ * For POWER9, this is a 1:1 mapping. In the future this maybe a 1:N
+ * mapping in which case, we will need to update this helper.
+ *
+ * Return the VAS id or -1 if no matching vasid is found.
+ */
+int chip_to_vas_id(int chipid);
+
+/*
* Helper to initialize receive window attributes to defaults for an
* NX window.
*/
diff --git a/arch/powerpc/platforms/powernv/vas.c b/arch/powerpc/platforms/powernv/vas.c
index abb7090..cd9a733 100644
--- a/arch/powerpc/platforms/powernv/vas.c
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -123,6 +123,17 @@ struct vas_instance *find_vas_instance(int vasid)
return NULL;
}
+int chip_to_vas_id(int chipid)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ if (cpu_to_chip_id(cpu) == chipid)
+ return per_cpu(cpu_vas_id, cpu);
+ }
+ return -1;
+}
+
static int vas_probe(struct platform_device *pdev)
{
return init_vas_instance(pdev);
diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
index 874ddf5..eb221ed 100644
--- a/drivers/crypto/nx/nx-842-powernv.c
+++ b/drivers/crypto/nx/nx-842-powernv.c
@@ -847,24 +847,12 @@ static int __init nx842_powernv_probe_vas(struct device_node *pn)
return -EINVAL;
}
- for_each_compatible_node(dn, NULL, "ibm,power9-vas-x") {
- if (of_get_ibm_chip_id(dn) == chip_id)
- break;
- }
-
- if (!dn) {
- pr_err("Missing VAS device node\n");
+ vasid = chip_to_vas_id(chip_id);
+ if (vasid < 0) {
+ pr_err("Unable to map chip_id %d to vasid\n", chip_id);
return -EINVAL;
}
- if (of_property_read_u32(dn, "ibm,vas-id", &vasid)) {
- pr_err("Missing ibm,vas-id device property\n");
- of_node_put(dn);
- return -EINVAL;
- }
-
- of_node_put(dn);
-
for_each_child_of_node(pn, dn) {
if (of_device_is_compatible(dn, "ibm,p9-nx-842")) {
ret = vas_cfg_coproc_info(dn, chip_id, vasid);
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread