[PATCH 14/17] IB/hfi1: Add ASIC flag view/clear

Dennis Dalessandro
2016-03-05T16:50:33Z

Different OSes using parts of the same hardware may leave
cross-device flags set. Export a debugfs file to view and
clear these flags if needed.

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/debugfs.c | 125 ++++++++++++++++++++++++++++++++++
1 files changed, 125 insertions(+), 0 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/debugfs.c b/drivers/infiniband/hw/hfi1/debugfs.c
index 6a1bc28..dbab9d9 100644
--- a/drivers/infiniband/hw/hfi1/debugfs.c
+++ b/drivers/infiniband/hw/hfi1/debugfs.c
@@ -404,6 +404,130 @@ static ssize_t portcntrs_debugfs_read(struct file *file, char __user *buf,
return rval;
}

+static void check_dyn_flag(u64 scratch0, char *p, int size, int *used,
+ int this_hfi, int hfi, u32 flag, const char *what)
+{
+ u32 mask;
+
+ mask = flag << (hfi ? CR_DYN_SHIFT : 0);
+ if (scratch0 & mask) {
+ *used += scnprintf(p + *used, size - *used,
+ " 0x%08x - HFI%d %s in use, %s device\n",
+ mask, hfi, what,
+ this_hfi == hfi ? "this" : "other");
+ }
+}
+
+static ssize_t asic_flags_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct hfi1_pportdata *ppd;
+ struct hfi1_devdata *dd;
+ u64 scratch0;
+ char *tmp;
+ int ret = 0;
+ int size;
+ 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();
+ return -ENOMEM;
+ }
+
+ scratch0 = read_csr(dd, ASIC_CFG_SCRATCH);
+ used += scnprintf(tmp + used, size - used,
+ "Resource flags: 0x%016llx\n", scratch0);
+
+ /* check permanent flag */
+ if (scratch0 & CR_THERM_INIT) {
+ used += scnprintf(tmp + used, size - used,
+ " 0x%08x - thermal monitoring initialized\n",
+ (u32)CR_THERM_INIT);
+ }
+
+ /* check each dynamic flag on each HFI */
+ for (i = 0; i < 2; i++) {
+ check_dyn_flag(scratch0, tmp, size, &used, dd->hfi1_id, i,
+ CR_SBUS, "SBus");
+ check_dyn_flag(scratch0, tmp, size, &used, dd->hfi1_id, i,
+ CR_EPROM, "EPROM");
+ check_dyn_flag(scratch0, tmp, size, &used, dd->hfi1_id, i,
+ CR_I2C1, "i2c chain 1");
+ check_dyn_flag(scratch0, tmp, size, &used, dd->hfi1_id, i,
+ CR_I2C2, "i2c chain 2");
+ }
+ 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;
+}
+
+static ssize_t asic_flags_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct hfi1_pportdata *ppd;
+ struct hfi1_devdata *dd;
+ char *buff;
+ int ret;
+ unsigned long long value;
+ 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;
+ }
+
+ ret = copy_from_user(buff, buf, count);
+ if (ret > 0) {
+ ret = -EFAULT;
+ goto do_free;
+ }
+
+ /* zero terminate and read the expected integer */
+ buff[count] = 0;
+ ret = kstrtoull(buff, 0, &value);
+ if (ret)
+ goto do_free;
+ clear = value;
+
+ /* obtain exclusive access */
+ mutex_lock(&dd->asic_data->asic_resource_mutex);
+ acquire_hw_mutex(dd);
+
+ scratch0 = read_csr(dd, ASIC_CFG_SCRATCH);
+ scratch0 &= ~clear;
+ write_csr(dd, ASIC_CFG_SCRATCH, scratch0);
+ /* force write to be visible to other HFI on another OS */
+ (void)read_csr(dd, ASIC_CFG_SCRATCH);
+
+ release_hw_mutex(dd);
+ mutex_unlock(&dd->asic_data->asic_resource_mutex);
+
+ /* return the number of bytes written */
+ ret = count;
+
+ do_free:
+ kfree(buff);
+ do_return:
+ rcu_read_unlock();
+ return ret;
+}
+
/*
* read the per-port QSFP data for ppd
*/
@@ -821,6 +945,7 @@ static const struct counter_info port_cntr_ops[] = {
qsfp1_debugfs_open, qsfp1_debugfs_release),
DEBUGFS_XOPS("qsfp2", qsfp2_debugfs_read, qsfp2_debugfs_write,
qsfp2_debugfs_open, qsfp2_debugfs_release),
+ DEBUGFS_OPS("asic_flags", asic_flags_read, asic_flags_write),
};

void hfi1_dbg_ibdev_init(struct hfi1_ibdev *ibd)