IB/hfi1: Add ASIC flag view/clear

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@intel.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/staging/rdma/hfi1/debugfs.c b/drivers/staging/rdma/hfi1/debugfs.c
index 6a1bc28..dbab9d9 100644 (file)
--- a/drivers/staging/rdma/hfi1/debugfs.c
+++ b/drivers/staging/rdma/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)