[PATCH 09/17] IB/hfi1: Change QSFP functions to use resource reservation

Dennis Dalessandro
2016-03-05T16:50:06Z

Remove the mutex guarding each operation in favor the ASIC
resource acquire/release. Push the resource acquire/release,
above each operation call to allow exclusive access across
multiple operations.

Reviewed-by: Mitko Haralanov <mitko.haralanov-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Easwar Hariharan <easwar.hariharan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Jubin John <jubin.john-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/infiniband/hw/hfi1/chip.c | 20 +++++-
drivers/infiniband/hw/hfi1/chip.h | 3 +
drivers/infiniband/hw/hfi1/debugfs.c | 22 +++++--
drivers/infiniband/hw/hfi1/hfi.h | 14 ++++
drivers/infiniband/hw/hfi1/init.c | 1
drivers/infiniband/hw/hfi1/platform.c | 26 ++++++--
drivers/infiniband/hw/hfi1/qsfp.c | 108 ++++++++++++++++++++++-----------
drivers/infiniband/hw/hfi1/qsfp.h | 4 +
8 files changed, 142 insertions(+), 56 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index 269c977..d3a9b9f 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -6267,8 +6267,8 @@ void handle_8051_request(struct work_struct *work)
cdr_ctrl_byte &= ~(1 << i);
}
}
- qsfp_write(ppd, ppd->dd->hfi1_id, QSFP_CDR_CTRL_BYTE_OFFS,
- &cdr_ctrl_byte, 1);
+ one_qsfp_write(ppd, dd->hfi1_id, QSFP_CDR_CTRL_BYTE_OFFS,
+ &cdr_ctrl_byte, 1);
hreq_response(dd, HREQ_SUCCESS, data);
refresh_qsfp_cache(ppd, &ppd->qsfp_info);
break;
@@ -9290,8 +9290,8 @@ void qsfp_event(struct work_struct *work)
if (qd->check_interrupt_flags) {
u8 qsfp_interrupt_status[16] = {0,};

- if (qsfp_read(ppd, dd->hfi1_id, 6,
- &qsfp_interrupt_status[0], 16) != 16) {
+ if (one_qsfp_read(ppd, dd->hfi1_id, 6,
+ &qsfp_interrupt_status[0], 16) != 16) {
dd_dev_info(dd,
"%s: Failed to read status of QSFP module\n",
__func__);
@@ -9845,7 +9845,17 @@ static int goto_offline(struct hfi1_pportdata *ppd, u8 rem_reason)
if (ppd->port_type == PORT_TYPE_QSFP &&
ppd->qsfp_info.limiting_active &&
qsfp_mod_present(ppd)) {
- set_qsfp_tx(ppd, 0);
+ int ret;
+
+ ret = acquire_chip_resource(dd, qsfp_resource(dd), QSFP_WAIT);
+ if (ret == 0) {
+ set_qsfp_tx(ppd, 0);
+ release_chip_resource(dd, qsfp_resource(dd));
+ } else {
+ /* not fatal, but should warn */
+ dd_dev_err(dd,
+ "Unable to acquire lock to turn off QSFP TX\n");
+ }
}

/*
diff --git a/drivers/infiniband/hw/hfi1/chip.h b/drivers/infiniband/hw/hfi1/chip.h
index 311e6e8..9313963 100644
--- a/drivers/infiniband/hw/hfi1/chip.h
+++ b/drivers/infiniband/hw/hfi1/chip.h
@@ -672,6 +672,9 @@ void finish_chip_resources(struct hfi1_devdata *dd);
/* ms wait time for access to an SBus resoure */
#define SBUS_TIMEOUT 4000 /* long enough for a FW download and SBR */

+/* ms wait time for a qsfp (i2c) chain to become available */
+#define QSFP_WAIT 20000 /* long enough for FW update to the F4 uc */
+
void fabric_serdes_reset(struct hfi1_devdata *dd);
int read_8051_data(struct hfi1_devdata *dd, u32 addr, u32 len, u64 *result);

diff --git a/drivers/infiniband/hw/hfi1/debugfs.c b/drivers/infiniband/hw/hfi1/debugfs.c
index 99845bc..665666c 100644
--- a/drivers/infiniband/hw/hfi1/debugfs.c
+++ b/drivers/infiniband/hw/hfi1/debugfs.c
@@ -465,16 +465,22 @@ static ssize_t __i2c_debugfs_write(struct file *file, const char __user *buf,
goto _free;
}

+ ret = acquire_chip_resource(ppd->dd, i2c_target(target), 0);
+ if (ret)
+ goto _free;
+
total_written = i2c_write(ppd, target, i2c_addr, offset, buff, count);
if (total_written < 0) {
ret = total_written;
- goto _free;
+ goto _release;
}

*ppos += total_written;

ret = total_written;

+ _release:
+ release_chip_resource(ppd->dd, i2c_target(target));
_free:
kfree(buff);
_return:
@@ -526,10 +532,14 @@ static ssize_t __i2c_debugfs_read(struct file *file, char __user *buf,
goto _return;
}

+ ret = acquire_chip_resource(ppd->dd, i2c_target(target), 0);
+ if (ret)
+ goto _free;
+
total_read = i2c_read(ppd, target, i2c_addr, offset, buff, count);
if (total_read < 0) {
ret = total_read;
- goto _free;
+ goto _release;
}

*ppos += total_read;
@@ -537,11 +547,13 @@ static ssize_t __i2c_debugfs_read(struct file *file, char __user *buf,
ret = copy_to_user(buf, buff, total_read);
if (ret > 0) {
ret = -EFAULT;
- goto _free;
+ goto _release;
}

ret = total_read;

+ _release:
+ release_chip_resource(ppd->dd, i2c_target(target));
_free:
kfree(buff);
_return:
@@ -592,7 +604,7 @@ static ssize_t __qsfp_debugfs_write(struct file *file, const char __user *buf,
goto _free;
}

- total_written = qsfp_write(ppd, target, *ppos, buff, count);
+ total_written = one_qsfp_write(ppd, target, *ppos, buff, count);
if (total_written < 0) {
ret = total_written;
goto _free;
@@ -646,7 +658,7 @@ static ssize_t __qsfp_debugfs_read(struct file *file, char __user *buf,
goto _return;
}

- total_read = qsfp_read(ppd, target, *ppos, buff, count);
+ total_read = one_qsfp_read(ppd, target, *ppos, buff, count);
if (total_read < 0) {
ret = total_read;
goto _free;
diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index e71a1c2..108015c 100644
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -1048,8 +1048,6 @@ struct hfi1_devdata {

struct platform_config platform_config;
struct platform_config_cache pcfg_cache;
- /* control high-level access to qsfp */
- struct mutex qsfp_i2c_mutex;

struct diag_client *diag_client;
spinlock_t hfi1_diag_trans_lock; /* protect diag observer ops */
@@ -1938,6 +1936,18 @@ static inline void setextled(struct hfi1_devdata *dd, u32 on)
write_csr(dd, DCC_CFG_LED_CNTRL, 0x10);
}

+/* return the i2c resource given the target */
+static inline u32 i2c_target(u32 target)
+{
+ return target ? CR_I2C2 : CR_I2C1;
+}
+
+/* return the i2c chain chip resource that this HFI uses for QSFP */
+static inline u32 qsfp_resource(struct hfi1_devdata *dd)
+{
+ return i2c_target(dd->hfi1_id);
+}
+
int hfi1_tempsense_rd(struct hfi1_devdata *dd, struct hfi1_temp *temp);

#endif /* _HFI1_KERNEL_H */
diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index 260a8e1..f21933c 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -1065,7 +1065,6 @@ struct hfi1_devdata *hfi1_alloc_devdata(struct pci_dev *pdev, size_t extra)
spin_lock_init(&dd->sc_init_lock);
spin_lock_init(&dd->dc8051_lock);
spin_lock_init(&dd->dc8051_memlock);
- mutex_init(&dd->qsfp_i2c_mutex);
seqlock_init(&dd->sc2vl_lock);
spin_lock_init(&dd->sde_map_lock);
spin_lock_init(&dd->pio_map_lock);
diff --git a/drivers/infiniband/hw/hfi1/platform.c b/drivers/infiniband/hw/hfi1/platform.c
index 4777414..0a1d074 100644
--- a/drivers/infiniband/hw/hfi1/platform.c
+++ b/drivers/infiniband/hw/hfi1/platform.c
@@ -601,23 +601,30 @@ static void apply_tunings(
static int tune_active_qsfp(struct hfi1_pportdata *ppd, u32 *ptr_tx_preset,
u32 *ptr_rx_preset, u32 *ptr_total_atten)
{
- int ret = 0;
+ int ret;
u16 lss = ppd->link_speed_supported, lse = ppd->link_speed_enabled;
u8 *cache = ppd->qsfp_info.cache;

+ ret = acquire_chip_resource(ppd->dd, qsfp_resource(ppd->dd), QSFP_WAIT);
+ if (ret) {
+ dd_dev_err(ppd->dd, "%s: hfi%d: cannot lock i2c chain\n",
+ __func__, (int)ppd->dd->hfi1_id);
+ return ret;
+ }
+
ppd->qsfp_info.limiting_active = 1;

ret = set_qsfp_tx(ppd, 0);
if (ret)
- return ret;
+ goto bail_unlock;

ret = qual_power(ppd);
if (ret)
- return ret;
+ goto bail_unlock;

ret = qual_bitrate(ppd);
if (ret)
- return ret;
+ goto bail_unlock;

if (ppd->qsfp_info.reset_needed) {
reset_qsfp(ppd);
@@ -629,7 +636,7 @@ static int tune_active_qsfp(struct hfi1_pportdata *ppd, u32 *ptr_tx_preset,

ret = set_qsfp_high_power(ppd);
if (ret)
- return ret;
+ goto bail_unlock;

if (cache[QSFP_EQ_INFO_OFFS] & 0x4) {
ret = get_platform_config_field(
@@ -639,7 +646,7 @@ static int tune_active_qsfp(struct hfi1_pportdata *ppd, u32 *ptr_tx_preset,
ptr_tx_preset, 4);
if (ret) {
*ptr_tx_preset = OPA_INVALID_INDEX;
- return ret;
+ goto bail_unlock;
}
} else {
ret = get_platform_config_field(
@@ -649,7 +656,7 @@ static int tune_active_qsfp(struct hfi1_pportdata *ppd, u32 *ptr_tx_preset,
ptr_tx_preset, 4);
if (ret) {
*ptr_tx_preset = OPA_INVALID_INDEX;
- return ret;
+ goto bail_unlock;
}
}

@@ -658,7 +665,7 @@ static int tune_active_qsfp(struct hfi1_pportdata *ppd, u32 *ptr_tx_preset,
PORT_TABLE_RX_PRESET_IDX, ptr_rx_preset, 4);
if (ret) {
*ptr_rx_preset = OPA_INVALID_INDEX;
- return ret;
+ goto bail_unlock;
}

if ((lss & OPA_LINK_SPEED_25G) && (lse & OPA_LINK_SPEED_25G))
@@ -677,6 +684,9 @@ static int tune_active_qsfp(struct hfi1_pportdata *ppd, u32 *ptr_tx_preset,
apply_rx_amplitude_settings(ppd, *ptr_rx_preset, *ptr_tx_preset);

ret = set_qsfp_tx(ppd, 1);
+
+bail_unlock:
+ release_chip_resource(ppd->dd, qsfp_resource(ppd->dd));
return ret;
}

diff --git a/drivers/infiniband/hw/hfi1/qsfp.c b/drivers/infiniband/hw/hfi1/qsfp.c
index 7e76b93..9ed1963 100644
--- a/drivers/infiniband/hw/hfi1/qsfp.c
+++ b/drivers/infiniband/hw/hfi1/qsfp.c
@@ -59,7 +59,7 @@
#define I2C_MAX_RETRY 4

/*
- * Unlocked i2c write. Must hold dd->qsfp_i2c_mutex.
+ * Raw i2c write. No set-up or lock checking.
*/
static int __i2c_write(struct hfi1_pportdata *ppd, u32 target, int i2c_addr,
int offset, void *bp, int len)
@@ -88,15 +88,16 @@ static int __i2c_write(struct hfi1_pportdata *ppd, u32 target, int i2c_addr,
return cnt;
}

+/*
+ * Caller must hold the i2c chain resource.
+ */
int i2c_write(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int offset,
void *bp, int len)
{
- struct hfi1_devdata *dd = ppd->dd;
int ret;

- ret = mutex_lock_interruptible(&dd->qsfp_i2c_mutex);
- if (ret)
- return ret;
+ if (!check_chip_resource(ppd->dd, qsfp_resource(ppd->dd), __func__))
+ return -EACCES;

/* make sure the TWSI bus is in a sane state */
ret = hfi1_twsi_reset(ppd->dd, target);
@@ -104,18 +105,14 @@ int i2c_write(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int offset,
hfi1_dev_porterr(ppd->dd, ppd->port,
"I2C chain %d write interface reset failed\n",
target);
- goto done;
+ return ret;
}

- ret = __i2c_write(ppd, target, i2c_addr, offset, bp, len);
-
-done:
- mutex_unlock(&dd->qsfp_i2c_mutex);
- return ret;
+ return __i2c_write(ppd, target, i2c_addr, offset, bp, len);
}

/*
- * Unlocked i2c read. Must hold dd->qsfp_i2c_mutex.
+ * Raw i2c read. No set-up or lock checking.
*/
static int __i2c_read(struct hfi1_pportdata *ppd, u32 target, int i2c_addr,
int offset, void *bp, int len)
@@ -157,15 +154,16 @@ exit:
return ret;
}

+/*
+ * Caller must hold the i2c chain resource.
+ */
int i2c_read(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int offset,
void *bp, int len)
{
- struct hfi1_devdata *dd = ppd->dd;
int ret;

- ret = mutex_lock_interruptible(&dd->qsfp_i2c_mutex);
- if (ret)
- return ret;
+ if (!check_chip_resource(ppd->dd, qsfp_resource(ppd->dd), __func__))
+ return -EACCES;

/* make sure the TWSI bus is in a sane state */
ret = hfi1_twsi_reset(ppd->dd, target);
@@ -173,19 +171,17 @@ int i2c_read(struct hfi1_pportdata *ppd, u32 target, int i2c_addr, int offset,
hfi1_dev_porterr(ppd->dd, ppd->port,
"I2C chain %d read interface reset failed\n",
target);
- goto done;
+ return ret;
}

- ret = __i2c_read(ppd, target, i2c_addr, offset, bp, len);
-
-done:
- mutex_unlock(&dd->qsfp_i2c_mutex);
- return ret;
+ return __i2c_read(ppd, target, i2c_addr, offset, bp, len);
}

/*
* Write page n, offset m of QSFP memory as defined by SFF 8636
* by writing @addr = ((256 * n) + m)
+ *
+ * Caller must hold the i2c chain resource.
*/
int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
int len)
@@ -196,9 +192,8 @@ int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
int ret;
u8 page;

- ret = mutex_lock_interruptible(&ppd->dd->qsfp_i2c_mutex);
- if (ret)
- return ret;
+ if (!check_chip_resource(ppd->dd, qsfp_resource(ppd->dd), __func__))
+ return -EACCES;

/* make sure the TWSI bus is in a sane state */
ret = hfi1_twsi_reset(ppd->dd, target);
@@ -206,7 +201,6 @@ int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
hfi1_dev_porterr(ppd->dd, ppd->port,
"QSFP chain %d write interface reset failed\n",
target);
- mutex_unlock(&ppd->dd->qsfp_i2c_mutex);
return ret;
}

@@ -242,16 +236,36 @@ int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
addr += ret;
}

- mutex_unlock(&ppd->dd->qsfp_i2c_mutex);
-
if (ret < 0)
return ret;
return count;
}

/*
+ * Perform a stand-alone single QSFP write. Acquire the resource, do the
+ * read, then release the resource.
+ */
+int one_qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
+ int len)
+{
+ struct hfi1_devdata *dd = ppd->dd;
+ u32 resource = qsfp_resource(dd);
+ int ret;
+
+ ret = acquire_chip_resource(dd, resource, QSFP_WAIT);
+ if (ret)
+ return ret;
+ ret = qsfp_write(ppd, target, addr, bp, len);
+ release_chip_resource(dd, resource);
+
+ return ret;
+}
+
+/*
* Access page n, offset m of QSFP memory as defined by SFF 8636
* by reading @addr = ((256 * n) + m)
+ *
+ * Caller must hold the i2c chain resource.
*/
int qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
int len)
@@ -262,9 +276,8 @@ int qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
int ret;
u8 page;

- ret = mutex_lock_interruptible(&ppd->dd->qsfp_i2c_mutex);
- if (ret)
- return ret;
+ if (!check_chip_resource(ppd->dd, qsfp_resource(ppd->dd), __func__))
+ return -EACCES;

/* make sure the TWSI bus is in a sane state */
ret = hfi1_twsi_reset(ppd->dd, target);
@@ -272,7 +285,6 @@ int qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
hfi1_dev_porterr(ppd->dd, ppd->port,
"QSFP chain %d read interface reset failed\n",
target);
- mutex_unlock(&ppd->dd->qsfp_i2c_mutex);
return ret;
}

@@ -309,14 +321,32 @@ int qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
addr += ret;
}

- mutex_unlock(&ppd->dd->qsfp_i2c_mutex);
-
if (ret < 0)
return ret;
return count;
}

/*
+ * Perform a stand-alone single QSFP read. Acquire the resource, do the
+ * read, then release the resource.
+ */
+int one_qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
+ int len)
+{
+ struct hfi1_devdata *dd = ppd->dd;
+ u32 resource = qsfp_resource(dd);
+ int ret;
+
+ ret = acquire_chip_resource(dd, resource, QSFP_WAIT);
+ if (ret)
+ return ret;
+ ret = qsfp_read(ppd, target, addr, bp, len);
+ release_chip_resource(dd, resource);
+
+ return ret;
+}
+
+/*
* This function caches the QSFP memory range in 128 byte chunks.
* As an example, the next byte after address 255 is byte 128 from
* upper page 01H (if existing) rather than byte 0 from lower page 00H.
@@ -341,9 +371,13 @@ int refresh_qsfp_cache(struct hfi1_pportdata *ppd, struct qsfp_data *cp)

if (!qsfp_mod_present(ppd)) {
ret = -ENODEV;
- goto bail;
+ goto bail_no_release;
}

+ ret = acquire_chip_resource(ppd->dd, qsfp_resource(ppd->dd), QSFP_WAIT);
+ if (ret)
+ goto bail_no_release;
+
ret = qsfp_read(ppd, target, 0, cache, QSFP_PAGESIZE);
if (ret != QSFP_PAGESIZE) {
dd_dev_info(ppd->dd,
@@ -406,6 +440,8 @@ int refresh_qsfp_cache(struct hfi1_pportdata *ppd, struct qsfp_data *cp)
}
}

+ release_chip_resource(ppd->dd, qsfp_resource(ppd->dd));
+
spin_lock_irqsave(&ppd->qsfp_info.qsfp_lock, flags);
ppd->qsfp_info.cache_valid = 1;
ppd->qsfp_info.cache_refresh_required = 0;
@@ -414,6 +450,8 @@ int refresh_qsfp_cache(struct hfi1_pportdata *ppd, struct qsfp_data *cp)
return 0;

bail:
+ release_chip_resource(ppd->dd, qsfp_resource(ppd->dd));
+bail_no_release:
memset(cache, 0, (QSFP_MAX_NUM_PAGES * 128));
return ret;
}
diff --git a/drivers/infiniband/hw/hfi1/qsfp.h b/drivers/infiniband/hw/hfi1/qsfp.h
index 2ad5980..831fe4c 100644
--- a/drivers/infiniband/hw/hfi1/qsfp.h
+++ b/drivers/infiniband/hw/hfi1/qsfp.h
@@ -235,3 +235,7 @@ int qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
int len);
int qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
int len);
+int one_qsfp_write(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
+ int len);
+int one_qsfp_read(struct hfi1_pportdata *ppd, u32 target, int addr, void *bp,
+ int len);