[PATCH 04/23] IB/hfi1: Export 8051 memory and LCB registers via debugfs

Dennis Dalessandro
2016-12-08T03:32:34Z

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

Both the 8051 memory and LCB register access require multiple
steps and coordination with the driver. This cannot be safely
done with resource0 alone.

The 8051 memory is exported read-only. LCB is exported read/write.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro-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/debugfs.c | 110 ++++++++++++++++++++++++++++++++++
1 files changed, 110 insertions(+), 0 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/debugfs.c b/drivers/infiniband/hw/hfi1/debugfs.c
index 632ba21..8725f4c 100644
--- a/drivers/infiniband/hw/hfi1/debugfs.c
+++ b/drivers/infiniband/hw/hfi1/debugfs.c
@@ -541,6 +541,114 @@ static ssize_t asic_flags_write(struct file *file, const char __user *buf,
return ret;
}

+/* read the dc8051 memory */
+static ssize_t dc8051_memory_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct hfi1_pportdata *ppd = private2ppd(file);
+ ssize_t rval;
+ void *tmp;
+ loff_t start, end;
+
+ /* the checks below expect the position to be positive */
+ if (*ppos < 0)
+ return -EINVAL;
+
+ tmp = kzalloc(DC8051_DATA_MEM_SIZE, GFP_KERNEL);
+ if (!tmp)
+ return -ENOMEM;
+
+ /*
+ * Fill in the requested portion of the temporary buffer from the
+ * 8051 memory. The 8051 memory read is done in terms of 8 bytes.
+ * Adjust start and end to fit. Skip reading anything if out of
+ * range.
+ */
+ start = *ppos & ~0x7; /* round down */
+ if (start < DC8051_DATA_MEM_SIZE) {
+ end = (*ppos + count + 7) & ~0x7; /* round up */
+ if (end > DC8051_DATA_MEM_SIZE)
+ end = DC8051_DATA_MEM_SIZE;
+ rval = read_8051_data(ppd->dd, start, end - start,
+ (u64 *)(tmp + start));
+ if (rval)
+ goto done;
+ }
+
+ rval = simple_read_from_buffer(buf, count, ppos, tmp,
+ DC8051_DATA_MEM_SIZE);
+done:
+ kfree(tmp);
+ return rval;
+}
+
+static ssize_t debugfs_lcb_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct hfi1_pportdata *ppd = private2ppd(file);
+ struct hfi1_devdata *dd = ppd->dd;
+ unsigned long total, csr_off;
+ u64 data;
+
+ if (*ppos < 0)
+ return -EINVAL;
+ /* only read 8 byte quantities */
+ if ((count % 8) != 0)
+ return -EINVAL;
+ /* offset must be 8-byte aligned */
+ if ((*ppos % 8) != 0)
+ return -EINVAL;
+ /* do nothing if out of range or zero count */
+ if (*ppos >= (LCB_END - LCB_START) || !count)
+ return 0;
+ /* reduce count if needed */
+ if (*ppos + count > LCB_END - LCB_START)
+ count = (LCB_END - LCB_START) - *ppos;
+
+ csr_off = LCB_START + *ppos;
+ for (total = 0; total < count; total += 8, csr_off += 8) {
+ if (read_lcb_csr(dd, csr_off, (u64 *)&data))
+ break; /* failed */
+ if (put_user(data, (unsigned long __user *)(buf + total)))
+ break;
+ }
+ *ppos += total;
+ return total;
+}
+
+static ssize_t debugfs_lcb_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct hfi1_pportdata *ppd = private2ppd(file);
+ struct hfi1_devdata *dd = ppd->dd;
+ unsigned long total, csr_off, data;
+
+ if (*ppos < 0)
+ return -EINVAL;
+ /* only write 8 byte quantities */
+ if ((count % 8) != 0)
+ return -EINVAL;
+ /* offset must be 8-byte aligned */
+ if ((*ppos % 8) != 0)
+ return -EINVAL;
+ /* do nothing if out of range or zero count */
+ if (*ppos >= (LCB_END - LCB_START) || !count)
+ return 0;
+ /* reduce count if needed */
+ if (*ppos + count > LCB_END - LCB_START)
+ count = (LCB_END - LCB_START) - *ppos;
+
+ csr_off = LCB_START + *ppos;
+ for (total = 0; total < count; total += 8, csr_off += 8) {
+ if (get_user(data, (unsigned long __user *)(buf + total)))
+ break;
+ if (write_lcb_csr(dd, csr_off, data))
+ break; /* failed */
+ }
+ *ppos += total;
+ return total;
+}
+
/*
* read the per-port QSFP data for ppd
*/
@@ -931,6 +1039,8 @@ static int qsfp2_debugfs_release(struct inode *in, struct file *fp)
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),
+ DEBUGFS_OPS("dc8051_memory", dc8051_memory_read, NULL),
+ DEBUGFS_OPS("lcb", debugfs_lcb_read, debugfs_lcb_write),
};

static void *_sdma_cpu_list_seq_start(struct seq_file *s, loff_t *pos)