[PATCH 0/5] IB/hfi1: For 4.8 rc 5

[PATCH 0/5] IB/hfi1: For 4.8 rc 5

[Dennis Dalessandro]

Hi Doug,

Here are five patches which fix bugs that we think would be appropraite for
the next RC. This should apply cleanly on top of your GitHub 4.8 rc tree. 

Patches can also be seen in my repo and have passed 0day builds at:
https://github.com/ddalessa/kernel/tree/for-4.8

---

Dean Luick (1):
      IB/hfi1: Add QSFP sanity pre-check

Dennis Dalessandro (1):
      IB/hfi1: Fix AHG KDETH Intr shift

Harish Chegondi (1):
      IB/hfi1: Make n_krcvqs be an unsigned long integer

Mike Marciniszyn (1):
      IB/hfi1: Rework debugfs to use SRCU

Sebastian Sanchez (1):
      IB/hfi1: Fix SGE length for misaligned PIO copy


 drivers/infiniband/hw/hfi1/chip.c      |   92 ++++++++++++++++++++--
 drivers/infiniband/hw/hfi1/chip.h      |    1 
 drivers/infiniband/hw/hfi1/debugfs.c   |  132 +++++++++++++-------------------
 drivers/infiniband/hw/hfi1/hfi.h       |    4 +
 drivers/infiniband/hw/hfi1/init.c      |    3 -
 drivers/infiniband/hw/hfi1/pio_copy.c  |   12 +++
 drivers/infiniband/hw/hfi1/user_sdma.c |    5 +
 7 files changed, 155 insertions(+), 94 deletions(-)

--
-Denny
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[PATCH 1/5] IB/hfi1: Fix SGE length for misaligned PIO copy

[Dennis Dalessandro]

From: Sebastian Sanchez <sebastian.sanchez-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

When trying to align the source pointer and there's a byte carry
in an SGE copy, bytes are borrowed from the next quad-word X to
complete the required quad-word copy. Then, the SGE length is
reduced by the number of borrowed bytes. After this, if the
remaining number of bytes from quad-word X (extra bytes) is
greater than the new SGE length, the number of extra bytes needs
to be updated to the new SGE length. Otherwise, when the
SGE length gets updated again after the extra bytes are read to
create the new byte carry, it goes negative, which then becomes
a very large number as the SGE length is an unsigned integer.
This causes SGE buffer to be over-read.

Reviewed-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/pio_copy.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/pio_copy.c b/drivers/infiniband/hw/hfi1/pio_copy.c
index 8c25e1b..3a1ef30 100644
--- a/drivers/infiniband/hw/hfi1/pio_copy.c
+++ b/drivers/infiniband/hw/hfi1/pio_copy.c
@@ -771,6 +771,9 @@ void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes)
 			read_extra_bytes(pbuf, from, to_fill);
 			from += to_fill;
 			nbytes -= to_fill;
+			/* may not be enough valid bytes left to align */
+			if (extra > nbytes)
+				extra = nbytes;
 
 			/* ...now write carry */
 			dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
@@ -798,6 +801,15 @@ void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes)
 			read_low_bytes(pbuf, from, extra);
 			from += extra;
 			nbytes -= extra;
+			/*
+			 * If no bytes are left, return early - we are done.
+			 * NOTE: This short-circuit is *required* because
+			 * "extra" may have been reduced in size and "from"
+			 * is not aligned, as required when leaving this
+			 * if block.
+			 */
+			if (nbytes == 0)
+				return;
 		}
 
 		/* at this point, from is QW aligned */

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[PATCH 2/5] IB/hfi1: Fix AHG KDETH Intr shift

[Dennis Dalessandro]

In the set_txreq_header_ahg(), The KDETH Intr bit is obtained from the
header in the user sdma request using a KDETH_GET shift and mask macro.
This value is then futher right shifted by 16 causing us to lose the
value i.e it is shifted to zero, leading to the following
smatch warning:
drivers/infiniband/hw/hfi1/user_sdma.c:1482 set_txreq_header_ahg()
warn: mask and shift to zero

The Intr bit should be left shifted into its correct position in the
KDETH header before the AHG update.

Reported-by: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Reviewed-by: Mitko Haralanov <mitko.haralanov-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Harish Chegondi <harish.chegondi-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Jubin John <jubin.john-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/user_sdma.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c
index 0ecf279..1694037 100644
--- a/drivers/infiniband/hw/hfi1/user_sdma.c
+++ b/drivers/infiniband/hw/hfi1/user_sdma.c
@@ -114,6 +114,8 @@ MODULE_PARM_DESC(sdma_comp_size, "Size of User SDMA completion ring. Default: 12
 #define KDETH_HCRC_LOWER_SHIFT    24
 #define KDETH_HCRC_LOWER_MASK     0xff
 
+#define AHG_KDETH_INTR_SHIFT 12
+
 #define PBC2LRH(x) ((((x) & 0xfff) << 2) - 4)
 #define LRH2PBC(x) ((((x) >> 2) + 1) & 0xfff)
 
@@ -1480,7 +1482,8 @@ static int set_txreq_header_ahg(struct user_sdma_request *req,
 		/* Clear KDETH.SH on last packet */
 		if (unlikely(tx->flags & TXREQ_FLAGS_REQ_LAST_PKT)) {
 			val |= cpu_to_le16(KDETH_GET(hdr->kdeth.ver_tid_offset,
-								INTR) >> 16);
+						     INTR) <<
+					   AHG_KDETH_INTR_SHIFT);
 			val &= cpu_to_le16(~(1U << 13));
 			AHG_HEADER_SET(req->ahg, diff, 7, 16, 14, val);
 		} else {

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[PATCH 3/5] IB/hfi1: Add QSFP sanity pre-check

[Dennis Dalessandro]

From: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Sometimes a QSFP device does not respond in the expected time
after a power-on.  Add a read pre-check/retry when starting
the link on driver load.

Reviewed-by: Easwar Hariharan <easwar.hariharan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/chip.c |   86 ++++++++++++++++++++++++++++++++++---
 drivers/infiniband/hw/hfi1/chip.h |    1 
 drivers/infiniband/hw/hfi1/hfi.h  |    2 +
 drivers/infiniband/hw/hfi1/init.c |    1 
 4 files changed, 82 insertions(+), 8 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index b32638d..ec3635a 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -9490,6 +9490,78 @@ static void init_lcb(struct hfi1_devdata *dd)
 	write_csr(dd, DC_LCB_CFG_TX_FIFOS_RESET, 0x00);
 }
 
+/*
+ * Perform a test read on the QSFP.  Return 0 on success, -ERRNO
+ * on error.
+ */
+static int test_qsfp_read(struct hfi1_pportdata *ppd)
+{
+	int ret;
+	u8 status;
+
+	/* report success if not a QSFP */
+	if (ppd->port_type != PORT_TYPE_QSFP)
+		return 0;
+
+	/* read byte 2, the status byte */
+	ret = one_qsfp_read(ppd, ppd->dd->hfi1_id, 2, &status, 1);
+	if (ret < 0)
+		return ret;
+	if (ret != 1)
+		return -EIO;
+
+	return 0; /* success */
+}
+
+/*
+ * Values for QSFP retry.
+ *
+ * Give up after 10s (20 x 500ms).  The overall timeout was empirically
+ * arrived at from experience on a large cluster.
+ */
+#define MAX_QSFP_RETRIES 20
+#define QSFP_RETRY_WAIT 500 /* msec */
+
+/*
+ * Try a QSFP read.  If it fails, schedule a retry for later.
+ * Called on first link activation after driver load.
+ */
+static void try_start_link(struct hfi1_pportdata *ppd)
+{
+	if (test_qsfp_read(ppd)) {
+		/* read failed */
+		if (ppd->qsfp_retry_count >= MAX_QSFP_RETRIES) {
+			dd_dev_err(ppd->dd, "QSFP not responding, giving up\n");
+			return;
+		}
+		dd_dev_info(ppd->dd,
+			    "QSFP not responding, waiting and retrying %d\n",
+			    (int)ppd->qsfp_retry_count);
+		ppd->qsfp_retry_count++;
+		queue_delayed_work(ppd->hfi1_wq, &ppd->start_link_work,
+				   msecs_to_jiffies(QSFP_RETRY_WAIT));
+		return;
+	}
+	ppd->qsfp_retry_count = 0;
+
+	/*
+	 * Tune the SerDes to a ballpark setting for optimal signal and bit
+	 * error rate.  Needs to be done before starting the link.
+	 */
+	tune_serdes(ppd);
+	start_link(ppd);
+}
+
+/*
+ * Workqueue function to start the link after a delay.
+ */
+void handle_start_link(struct work_struct *work)
+{
+	struct hfi1_pportdata *ppd = container_of(work, struct hfi1_pportdata,
+						  start_link_work.work);
+	try_start_link(ppd);
+}
+
 int bringup_serdes(struct hfi1_pportdata *ppd)
 {
 	struct hfi1_devdata *dd = ppd->dd;
@@ -9525,14 +9597,8 @@ int bringup_serdes(struct hfi1_pportdata *ppd)
 		set_qsfp_int_n(ppd, 1);
 	}
 
-	/*
-	 * Tune the SerDes to a ballpark setting for
-	 * optimal signal and bit error rate
-	 * Needs to be done before starting the link
-	 */
-	tune_serdes(ppd);
-
-	return start_link(ppd);
+	try_start_link(ppd);
+	return 0;
 }
 
 void hfi1_quiet_serdes(struct hfi1_pportdata *ppd)
@@ -9549,6 +9615,10 @@ void hfi1_quiet_serdes(struct hfi1_pportdata *ppd)
 	ppd->driver_link_ready = 0;
 	ppd->link_enabled = 0;
 
+	ppd->qsfp_retry_count = MAX_QSFP_RETRIES; /* prevent more retries */
+	flush_delayed_work(&ppd->start_link_work);
+	cancel_delayed_work_sync(&ppd->start_link_work);
+
 	ppd->offline_disabled_reason =
 			HFI1_ODR_MASK(OPA_LINKDOWN_REASON_SMA_DISABLED);
 	set_link_down_reason(ppd, OPA_LINKDOWN_REASON_SMA_DISABLED, 0,
diff --git a/drivers/infiniband/hw/hfi1/chip.h b/drivers/infiniband/hw/hfi1/chip.h
index ed11107..e295737 100644
--- a/drivers/infiniband/hw/hfi1/chip.h
+++ b/drivers/infiniband/hw/hfi1/chip.h
@@ -706,6 +706,7 @@ void handle_link_up(struct work_struct *work);
 void handle_link_down(struct work_struct *work);
 void handle_link_downgrade(struct work_struct *work);
 void handle_link_bounce(struct work_struct *work);
+void handle_start_link(struct work_struct *work);
 void handle_sma_message(struct work_struct *work);
 void reset_qsfp(struct hfi1_pportdata *ppd);
 void qsfp_event(struct work_struct *work);
diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index a021e66..28b9128 100644
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -605,6 +605,7 @@ struct hfi1_pportdata {
 	struct work_struct freeze_work;
 	struct work_struct link_downgrade_work;
 	struct work_struct link_bounce_work;
+	struct delayed_work start_link_work;
 	/* host link state variables */
 	struct mutex hls_lock;
 	u32 host_link_state;
@@ -659,6 +660,7 @@ struct hfi1_pportdata {
 	u8 linkinit_reason;
 	u8 local_tx_rate;	/* rate given to 8051 firmware */
 	u8 last_pstate;		/* info only */
+	u8 qsfp_retry_count;
 
 	/* placeholders for IB MAD packet settings */
 	u8 overrun_threshold;
diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index b793545..000dc07 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -500,6 +500,7 @@ void hfi1_init_pportdata(struct pci_dev *pdev, struct hfi1_pportdata *ppd,
 	INIT_WORK(&ppd->link_downgrade_work, handle_link_downgrade);
 	INIT_WORK(&ppd->sma_message_work, handle_sma_message);
 	INIT_WORK(&ppd->link_bounce_work, handle_link_bounce);
+	INIT_DELAYED_WORK(&ppd->start_link_work, handle_start_link);
 	INIT_WORK(&ppd->linkstate_active_work, receive_interrupt_work);
 	INIT_WORK(&ppd->qsfp_info.qsfp_work, qsfp_event);
 

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[PATCH 4/5] IB/hfi1: Make n_krcvqs be an unsigned long integer

[Dennis Dalessandro]

From: Harish Chegondi <harish.chegondi-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

The global variable n_krcvqs stores the sum of the number of kernel
receive queues of VLs 0-7 which the user can pass to the driver through
the module parameter array krcvqs which is of type unsigned integer. If
the user passes large value(s) into krcvqs parameter array, it can cause
an arithmetic overflow while calculating n_krcvqs which is also of type
unsigned int. The overflow results in an incorrect value of n_krcvqs
which can lead to kernel crash while loading the driver.

Fix by changing the data type of n_krcvqs to unsigned long. This patch
also changes the data type of other variables that get their values from
n_krcvqs.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Harish Chegondi <harish.chegondi-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/chip.c |    6 +++---
 drivers/infiniband/hw/hfi1/hfi.h  |    2 +-
 drivers/infiniband/hw/hfi1/init.c |    2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index ec3635a..cc38004 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -12935,7 +12935,7 @@ fail:
  */
 static int set_up_context_variables(struct hfi1_devdata *dd)
 {
-	int num_kernel_contexts;
+	unsigned long num_kernel_contexts;
 	int total_contexts;
 	int ret;
 	unsigned ngroups;
@@ -12964,9 +12964,9 @@ static int set_up_context_variables(struct hfi1_devdata *dd)
 	 */
 	if (num_kernel_contexts > (dd->chip_send_contexts - num_vls - 1)) {
 		dd_dev_err(dd,
-			   "Reducing # kernel rcv contexts to: %d, from %d\n",
+			   "Reducing # kernel rcv contexts to: %d, from %lu\n",
 			   (int)(dd->chip_send_contexts - num_vls - 1),
-			   (int)num_kernel_contexts);
+			   num_kernel_contexts);
 		num_kernel_contexts = dd->chip_send_contexts - num_vls - 1;
 	}
 	/*
diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index 28b9128..325ec21 100644
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -1806,7 +1806,7 @@ extern unsigned int hfi1_max_mtu;
 extern unsigned int hfi1_cu;
 extern unsigned int user_credit_return_threshold;
 extern int num_user_contexts;
-extern unsigned n_krcvqs;
+extern unsigned long n_krcvqs;
 extern uint krcvqs[];
 extern int krcvqsset;
 extern uint kdeth_qp;
diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index 000dc07..384b43d 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -94,7 +94,7 @@ module_param_array(krcvqs, uint, &krcvqsset, S_IRUGO);
 MODULE_PARM_DESC(krcvqs, "Array of the number of non-control kernel receive queues by VL");
 
 /* computed based on above array */
-unsigned n_krcvqs;
+unsigned long n_krcvqs;
 
 static unsigned hfi1_rcvarr_split = 25;
 module_param_named(rcvarr_split, hfi1_rcvarr_split, uint, S_IRUGO);

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[PATCH 5/5] IB/hfi1: Rework debugfs to use SRCU

[Dennis Dalessandro]

From: Mike Marciniszyn <mike.marciniszyn-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

The debugfs RCU trips many debug kernel warnings because of potential
sleeps with an RCU read lock held. This includes both user copy calls
and slab allocations throughout the file.

This patch switches the RCU to use SRCU for file remove/access
race protection.

In one case, the SRCU is implicit in the use of the raw debugfs file
object and just works.

In the seq_file case, a wrapper around seq_read() and seq_lseek() is
used to enforce the SRCU using the debugfs supplied functions
debugfs_use_file_start() and debugfs_use_file_stop().

The sychronize_rcu() is deleted since the SRCU prevents the remove
access race.

The RCU locking is kept for qp_stats since the QP hash list is
protected using the non-sleepable RCU.

Reviewed-by: Sebastian Sanchez <sebastian.sanchez-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/debugfs.c |  132 +++++++++++++---------------------
 1 files changed, 52 insertions(+), 80 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/debugfs.c b/drivers/infiniband/hw/hfi1/debugfs.c
index a49cc88..5e9be16 100644
--- a/drivers/infiniband/hw/hfi1/debugfs.c
+++ b/drivers/infiniband/hw/hfi1/debugfs.c
@@ -59,6 +59,40 @@
 
 static struct dentry *hfi1_dbg_root;
 
+/* wrappers to enforce srcu in seq file */
+static ssize_t hfi1_seq_read(
+	struct file *file,
+	char __user *buf,
+	size_t size,
+	loff_t *ppos)
+{
+	struct dentry *d = file->f_path.dentry;
+	int srcu_idx;
+	ssize_t r;
+
+	r = debugfs_use_file_start(d, &srcu_idx);
+	if (likely(!r))
+		r = seq_read(file, buf, size, ppos);
+	debugfs_use_file_finish(srcu_idx);
+	return r;
+}
+
+static loff_t hfi1_seq_lseek(
+	struct file *file,
+	loff_t offset,
+	int whence)
+{
+	struct dentry *d = file->f_path.dentry;
+	int srcu_idx;
+	loff_t r;
+
+	r = debugfs_use_file_start(d, &srcu_idx);
+	if (likely(!r))
+		r = seq_lseek(file, offset, whence);
+	debugfs_use_file_finish(srcu_idx);
+	return r;
+}
+
 #define private2dd(file) (file_inode(file)->i_private)
 #define private2ppd(file) (file_inode(file)->i_private)
 
@@ -87,8 +121,8 @@ static int _##name##_open(struct inode *inode, struct file *s) \
 static const struct file_operations _##name##_file_ops = { \
 	.owner   = THIS_MODULE, \
 	.open    = _##name##_open, \
-	.read    = seq_read, \
-	.llseek  = seq_lseek, \
+	.read    = hfi1_seq_read, \
+	.llseek  = hfi1_seq_lseek, \
 	.release = seq_release \
 }
 
@@ -105,11 +139,9 @@ do { \
 	DEBUGFS_FILE_CREATE(#name, parent, data, &_##name##_file_ops, S_IRUGO)
 
 static void *_opcode_stats_seq_start(struct seq_file *s, loff_t *pos)
-__acquires(RCU)
 {
 	struct hfi1_opcode_stats_perctx *opstats;
 
-	rcu_read_lock();
 	if (*pos >= ARRAY_SIZE(opstats->stats))
 		return NULL;
 	return pos;
@@ -126,9 +158,7 @@ static void *_opcode_stats_seq_next(struct seq_file *s, void *v, loff_t *pos)
 }
 
 static void _opcode_stats_seq_stop(struct seq_file *s, void *v)
-__releases(RCU)
 {
-	rcu_read_unlock();
 }
 
 static int _opcode_stats_seq_show(struct seq_file *s, void *v)
@@ -285,12 +315,10 @@ DEBUGFS_SEQ_FILE_OPEN(qp_stats)
 DEBUGFS_FILE_OPS(qp_stats);
 
 static void *_sdes_seq_start(struct seq_file *s, loff_t *pos)
-__acquires(RCU)
 {
 	struct hfi1_ibdev *ibd;
 	struct hfi1_devdata *dd;
 
-	rcu_read_lock();
 	ibd = (struct hfi1_ibdev *)s->private;
 	dd = dd_from_dev(ibd);
 	if (!dd->per_sdma || *pos >= dd->num_sdma)
@@ -310,9 +338,7 @@ static void *_sdes_seq_next(struct seq_file *s, void *v, loff_t *pos)
 }
 
 static void _sdes_seq_stop(struct seq_file *s, void *v)
-__releases(RCU)
 {
-	rcu_read_unlock();
 }
 
 static int _sdes_seq_show(struct seq_file *s, void *v)
@@ -339,11 +365,9 @@ static ssize_t dev_counters_read(struct file *file, char __user *buf,
 	struct hfi1_devdata *dd;
 	ssize_t rval;
 
-	rcu_read_lock();
 	dd = private2dd(file);
 	avail = hfi1_read_cntrs(dd, NULL, &counters);
 	rval =  simple_read_from_buffer(buf, count, ppos, counters, avail);
-	rcu_read_unlock();
 	return rval;
 }
 
@@ -356,11 +380,9 @@ static ssize_t dev_names_read(struct file *file, char __user *buf,
 	struct hfi1_devdata *dd;
 	ssize_t rval;
 
-	rcu_read_lock();
 	dd = private2dd(file);
 	avail = hfi1_read_cntrs(dd, &names, NULL);
 	rval =  simple_read_from_buffer(buf, count, ppos, names, avail);
-	rcu_read_unlock();
 	return rval;
 }
 
@@ -383,11 +405,9 @@ static ssize_t portnames_read(struct file *file, char __user *buf,
 	struct hfi1_devdata *dd;
 	ssize_t rval;
 
-	rcu_read_lock();
 	dd = private2dd(file);
 	avail = hfi1_read_portcntrs(dd->pport, &names, NULL);
 	rval = simple_read_from_buffer(buf, count, ppos, names, avail);
-	rcu_read_unlock();
 	return rval;
 }
 
@@ -400,11 +420,9 @@ static ssize_t portcntrs_debugfs_read(struct file *file, char __user *buf,
 	struct hfi1_pportdata *ppd;
 	ssize_t rval;
 
-	rcu_read_lock();
 	ppd = private2ppd(file);
 	avail = hfi1_read_portcntrs(ppd, NULL, &counters);
 	rval = simple_read_from_buffer(buf, count, ppos, counters, avail);
-	rcu_read_unlock();
 	return rval;
 }
 
@@ -434,16 +452,13 @@ static ssize_t asic_flags_read(struct file *file, char __user *buf,
 	int used;
 	int i;
 
-	rcu_read_lock();
 	ppd = private2ppd(file);
 	dd = ppd->dd;
 	size = PAGE_SIZE;
 	used = 0;
 	tmp = kmalloc(size, GFP_KERNEL);
-	if (!tmp) {
-		rcu_read_unlock();
+	if (!tmp)
 		return -ENOMEM;
-	}
 
 	scratch0 = read_csr(dd, ASIC_CFG_SCRATCH);
 	used += scnprintf(tmp + used, size - used,
@@ -470,7 +485,6 @@ static ssize_t asic_flags_read(struct file *file, char __user *buf,
 	used += scnprintf(tmp + used, size - used, "Write bits to clear\n");
 
 	ret = simple_read_from_buffer(buf, count, ppos, tmp, used);
-	rcu_read_unlock();
 	kfree(tmp);
 	return ret;
 }
@@ -486,15 +500,12 @@ static ssize_t asic_flags_write(struct file *file, const char __user *buf,
 	u64 scratch0;
 	u64 clear;
 
-	rcu_read_lock();
 	ppd = private2ppd(file);
 	dd = ppd->dd;
 
 	buff = kmalloc(count + 1, GFP_KERNEL);
-	if (!buff) {
-		ret = -ENOMEM;
-		goto do_return;
-	}
+	if (!buff)
+		return -ENOMEM;
 
 	ret = copy_from_user(buff, buf, count);
 	if (ret > 0) {
@@ -527,8 +538,6 @@ static ssize_t asic_flags_write(struct file *file, const char __user *buf,
 
  do_free:
 	kfree(buff);
- do_return:
-	rcu_read_unlock();
 	return ret;
 }
 
@@ -542,18 +551,14 @@ static ssize_t qsfp_debugfs_dump(struct file *file, char __user *buf,
 	char *tmp;
 	int ret;
 
-	rcu_read_lock();
 	ppd = private2ppd(file);
 	tmp = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!tmp) {
-		rcu_read_unlock();
+	if (!tmp)
 		return -ENOMEM;
-	}
 
 	ret = qsfp_dump(ppd, tmp, PAGE_SIZE);
 	if (ret > 0)
 		ret = simple_read_from_buffer(buf, count, ppos, tmp, ret);
-	rcu_read_unlock();
 	kfree(tmp);
 	return ret;
 }
@@ -569,7 +574,6 @@ static ssize_t __i2c_debugfs_write(struct file *file, const char __user *buf,
 	int offset;
 	int total_written;
 
-	rcu_read_lock();
 	ppd = private2ppd(file);
 
 	/* byte offset format: [offsetSize][i2cAddr][offsetHigh][offsetLow] */
@@ -577,16 +581,12 @@ static ssize_t __i2c_debugfs_write(struct file *file, const char __user *buf,
 	offset = *ppos & 0xffff;
 
 	/* explicitly reject invalid address 0 to catch cp and cat */
-	if (i2c_addr == 0) {
-		ret = -EINVAL;
-		goto _return;
-	}
+	if (i2c_addr == 0)
+		return -EINVAL;
 
 	buff = kmalloc(count, GFP_KERNEL);
-	if (!buff) {
-		ret = -ENOMEM;
-		goto _return;
-	}
+	if (!buff)
+		return -ENOMEM;
 
 	ret = copy_from_user(buff, buf, count);
 	if (ret > 0) {
@@ -606,8 +606,6 @@ static ssize_t __i2c_debugfs_write(struct file *file, const char __user *buf,
 
  _free:
 	kfree(buff);
- _return:
-	rcu_read_unlock();
 	return ret;
 }
 
@@ -636,7 +634,6 @@ static ssize_t __i2c_debugfs_read(struct file *file, char __user *buf,
 	int offset;
 	int total_read;
 
-	rcu_read_lock();
 	ppd = private2ppd(file);
 
 	/* byte offset format: [offsetSize][i2cAddr][offsetHigh][offsetLow] */
@@ -644,16 +641,12 @@ static ssize_t __i2c_debugfs_read(struct file *file, char __user *buf,
 	offset = *ppos & 0xffff;
 
 	/* explicitly reject invalid address 0 to catch cp and cat */
-	if (i2c_addr == 0) {
-		ret = -EINVAL;
-		goto _return;
-	}
+	if (i2c_addr == 0)
+		return -EINVAL;
 
 	buff = kmalloc(count, GFP_KERNEL);
-	if (!buff) {
-		ret = -ENOMEM;
-		goto _return;
-	}
+	if (!buff)
+		return -ENOMEM;
 
 	total_read = i2c_read(ppd, target, i2c_addr, offset, buff, count);
 	if (total_read < 0) {
@@ -673,8 +666,6 @@ static ssize_t __i2c_debugfs_read(struct file *file, char __user *buf,
 
  _free:
 	kfree(buff);
- _return:
-	rcu_read_unlock();
 	return ret;
 }
 
@@ -701,26 +692,20 @@ static ssize_t __qsfp_debugfs_write(struct file *file, const char __user *buf,
 	int ret;
 	int total_written;
 
-	rcu_read_lock();
-	if (*ppos + count > QSFP_PAGESIZE * 4) { /* base page + page00-page03 */
-		ret = -EINVAL;
-		goto _return;
-	}
+	if (*ppos + count > QSFP_PAGESIZE * 4) /* base page + page00-page03 */
+		return -EINVAL;
 
 	ppd = private2ppd(file);
 
 	buff = kmalloc(count, GFP_KERNEL);
-	if (!buff) {
-		ret = -ENOMEM;
-		goto _return;
-	}
+	if (!buff)
+		return -ENOMEM;
 
 	ret = copy_from_user(buff, buf, count);
 	if (ret > 0) {
 		ret = -EFAULT;
 		goto _free;
 	}
-
 	total_written = qsfp_write(ppd, target, *ppos, buff, count);
 	if (total_written < 0) {
 		ret = total_written;
@@ -733,8 +718,6 @@ static ssize_t __qsfp_debugfs_write(struct file *file, const char __user *buf,
 
  _free:
 	kfree(buff);
- _return:
-	rcu_read_unlock();
 	return ret;
 }
 
@@ -761,7 +744,6 @@ static ssize_t __qsfp_debugfs_read(struct file *file, char __user *buf,
 	int ret;
 	int total_read;
 
-	rcu_read_lock();
 	if (*ppos + count > QSFP_PAGESIZE * 4) { /* base page + page00-page03 */
 		ret = -EINVAL;
 		goto _return;
@@ -794,7 +776,6 @@ static ssize_t __qsfp_debugfs_read(struct file *file, char __user *buf,
  _free:
 	kfree(buff);
  _return:
-	rcu_read_unlock();
 	return ret;
 }
 
@@ -1010,7 +991,6 @@ void hfi1_dbg_ibdev_exit(struct hfi1_ibdev *ibd)
 	debugfs_remove_recursive(ibd->hfi1_ibdev_dbg);
 out:
 	ibd->hfi1_ibdev_dbg = NULL;
-	synchronize_rcu();
 }
 
 /*
@@ -1035,9 +1015,7 @@ static const char * const hfi1_statnames[] = {
 };
 
 static void *_driver_stats_names_seq_start(struct seq_file *s, loff_t *pos)
-__acquires(RCU)
 {
-	rcu_read_lock();
 	if (*pos >= ARRAY_SIZE(hfi1_statnames))
 		return NULL;
 	return pos;
@@ -1055,9 +1033,7 @@ static void *_driver_stats_names_seq_next(
 }
 
 static void _driver_stats_names_seq_stop(struct seq_file *s, void *v)
-__releases(RCU)
 {
-	rcu_read_unlock();
 }
 
 static int _driver_stats_names_seq_show(struct seq_file *s, void *v)
@@ -1073,9 +1049,7 @@ DEBUGFS_SEQ_FILE_OPEN(driver_stats_names)
 DEBUGFS_FILE_OPS(driver_stats_names);
 
 static void *_driver_stats_seq_start(struct seq_file *s, loff_t *pos)
-__acquires(RCU)
 {
-	rcu_read_lock();
 	if (*pos >= ARRAY_SIZE(hfi1_statnames))
 		return NULL;
 	return pos;
@@ -1090,9 +1064,7 @@ static void *_driver_stats_seq_next(struct seq_file *s, void *v, loff_t *pos)
 }
 
 static void _driver_stats_seq_stop(struct seq_file *s, void *v)
-__releases(RCU)
 {
-	rcu_read_unlock();
 }
 
 static u64 hfi1_sps_ints(void)

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Re: [PATCH 2/5] IB/hfi1: Fix AHG KDETH Intr shift

[Dalessandro, Dennis]

This patch should say:

From: Jubin John <jubin.john@intel.com>

Not sure why it got cut off. Let me know if you want a v2 or if you
just want to tack that on yourself.

-Denny


On Wed, 2016-08-31 at 07:24 -0700, Dennis Dalessandro wrote:
> In the set_txreq_header_ahg(), The KDETH Intr bit is obtained from
> the
> header in the user sdma request using a KDETH_GET shift and mask
> macro.
> This value is then futher right shifted by 16 causing us to lose the
> value i.e it is shifted to zero, leading to the following
> smatch warning:
> drivers/infiniband/hw/hfi1/user_sdma.c:1482 set_txreq_header_ahg()
> warn: mask and shift to zero
> 
> The Intr bit should be left shifted into its correct position in the
> KDETH header before the AHG update.
> 
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Reviewed-by: Mitko Haralanov <mitko.haralanov@intel.com>
> Reviewed-by: Harish Chegondi <harish.chegondi@intel.com>
> Signed-off-by: Jubin John <jubin.john@intel.com>
> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
> ---
>  drivers/infiniband/hw/hfi1/user_sdma.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c
> b/drivers/infiniband/hw/hfi1/user_sdma.c
> index 0ecf279..1694037 100644
> --- a/drivers/infiniband/hw/hfi1/user_sdma.c
> +++ b/drivers/infiniband/hw/hfi1/user_sdma.c
> @@ -114,6 +114,8 @@ MODULE_PARM_DESC(sdma_comp_size, "Size of User
> SDMA completion ring. Default: 12
>  #define KDETH_HCRC_LOWER_SHIFT    24
>  #define KDETH_HCRC_LOWER_MASK     0xff
>  
> +#define AHG_KDETH_INTR_SHIFT 12
> +
>  #define PBC2LRH(x) ((((x) & 0xfff) << 2) - 4)
>  #define LRH2PBC(x) ((((x) >> 2) + 1) & 0xfff)
>  
> @@ -1480,7 +1482,8 @@ static int set_txreq_header_ahg(struct
> user_sdma_request *req,
>  		/* Clear KDETH.SH on last packet */
>  		if (unlikely(tx->flags & TXREQ_FLAGS_REQ_LAST_PKT))
> {
>  			val |= cpu_to_le16(KDETH_GET(hdr-
> >kdeth.ver_tid_offset,
> -								INTR
> ) >> 16);
> +						     INTR) <<
> +					   AHG_KDETH_INTR_SHIFT);
>  			val &= cpu_to_le16(~(1U << 13));
>  			AHG_HEADER_SET(req->ahg, diff, 7, 16, 14,
> val);
>  		} else {
> 
> --
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Re: [PATCH 0/5] IB/hfi1: For 4.8 rc 5

[Doug Ledford]

[-- Attachment #1.1: Type: text/plain, Size: 1744 bytes --]

On 8/31/2016 10:24 AM, Dennis Dalessandro wrote:
> Hi Doug,
> 
> Here are five patches which fix bugs that we think would be appropraite for
> the next RC. This should apply cleanly on top of your GitHub 4.8 rc tree. 
> 
> Patches can also be seen in my repo and have passed 0day builds at:
> https://github.com/ddalessa/kernel/tree/for-4.8
> 
> ---
> 
> Dean Luick (1):
>       IB/hfi1: Add QSFP sanity pre-check
> 
> Dennis Dalessandro (1):
>       IB/hfi1: Fix AHG KDETH Intr shift
> 
> Harish Chegondi (1):
>       IB/hfi1: Make n_krcvqs be an unsigned long integer
> 
> Mike Marciniszyn (1):
>       IB/hfi1: Rework debugfs to use SRCU
> 
> Sebastian Sanchez (1):
>       IB/hfi1: Fix SGE length for misaligned PIO copy
> 
> 
>  drivers/infiniband/hw/hfi1/chip.c      |   92 ++++++++++++++++++++--
>  drivers/infiniband/hw/hfi1/chip.h      |    1 
>  drivers/infiniband/hw/hfi1/debugfs.c   |  132 +++++++++++++-------------------
>  drivers/infiniband/hw/hfi1/hfi.h       |    4 +
>  drivers/infiniband/hw/hfi1/init.c      |    3 -
>  drivers/infiniband/hw/hfi1/pio_copy.c  |   12 +++
>  drivers/infiniband/hw/hfi1/user_sdma.c |    5 +
>  7 files changed, 155 insertions(+), 94 deletions(-)
> 
> --
> -Denny
> 

I ended up taking all 5 patches, but the line count on these is a little
larger than I like to see in this late of an rc.  I can't complain too
much about the QSFP fix as you wrote exactly what I asked for (although
I would have preferred it either in a merge window or earlier rc), but
the RCU locking changes in a later half rc are something I would like to
avoid in the future.

-- 
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
    GPG Key ID: 0E572FDD


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