On 24/01/2024 15:26, Herve Codina wrote:

Hi Vadim,

On Wed, 24 Jan 2024 10:10:46 +0000
Vadim Fedorenko [off-list ref] wrote:

[...]

quoted

quoted

+static int qmc_hdlc_xlate_slot_map(struct qmc_hdlc *qmc_hdlc,
+				   u32 slot_map, struct qmc_chan_ts_info *ts_info)
+{
+	u64 ts_mask_avail;
+	unsigned int bit;
+	unsigned int i;
+	u64 ts_mask;
+	u64 map;
+
+	/* Tx and Rx masks must be identical */
+	if (ts_info->rx_ts_mask_avail != ts_info->tx_ts_mask_avail) {
+		dev_err(qmc_hdlc->dev, "tx and rx available timeslots mismatch (0x%llx, 0x%llx)\n",
+			ts_info->rx_ts_mask_avail, ts_info->tx_ts_mask_avail);
+		return -EINVAL;
+	}
+
+	ts_mask_avail = ts_info->rx_ts_mask_avail;
+	ts_mask = 0;
+	map = slot_map;
+	bit = 0;
+	for (i = 0; i < 64; i++) {
+		if (ts_mask_avail & BIT_ULL(i)) {
+			if (map & BIT_ULL(bit))
+				ts_mask |= BIT_ULL(i);
+			bit++;
+		}
+	}
+
+	if (hweight64(ts_mask) != hweight64(map)) {
+		dev_err(qmc_hdlc->dev, "Cannot translate timeslots 0x%llx -> (0x%llx,0x%llx)\n",
+			map, ts_mask_avail, ts_mask);
+		return -EINVAL;
+	}
+
+	ts_info->tx_ts_mask = ts_mask;
+	ts_info->rx_ts_mask = ts_mask;
+	return 0;
+}
+
+static int qmc_hdlc_xlate_ts_info(struct qmc_hdlc *qmc_hdlc,
+				  const struct qmc_chan_ts_info *ts_info, u32 *slot_map)
+{
+	u64 ts_mask_avail;
+	unsigned int bit;
+	unsigned int i;
+	u64 ts_mask;
+	u64 map;
+

Starting from here ...

quoted

+	/* Tx and Rx masks must be identical */
+	if (ts_info->rx_ts_mask_avail != ts_info->tx_ts_mask_avail) {
+		dev_err(qmc_hdlc->dev, "tx and rx available timeslots mismatch (0x%llx, 0x%llx)\n",
+			ts_info->rx_ts_mask_avail, ts_info->tx_ts_mask_avail);
+		return -EINVAL;
+	}
+	if (ts_info->rx_ts_mask != ts_info->tx_ts_mask) {
+		dev_err(qmc_hdlc->dev, "tx and rx timeslots mismatch (0x%llx, 0x%llx)\n",
+			ts_info->rx_ts_mask, ts_info->tx_ts_mask);
+		return -EINVAL;
+	}
+
+	ts_mask_avail = ts_info->rx_ts_mask_avail;
+	ts_mask = ts_info->rx_ts_mask;
+	map = 0;
+	bit = 0;
+	for (i = 0; i < 64; i++) {
+		if (ts_mask_avail & BIT_ULL(i)) {
+			if (ts_mask & BIT_ULL(i))
+				map |= BIT_ULL(bit);
+			bit++;
+		}
+	}
+
+	if (hweight64(ts_mask) != hweight64(map)) {
+		dev_err(qmc_hdlc->dev, "Cannot translate timeslots (0x%llx,0x%llx) -> 0x%llx\n",
+			ts_mask_avail, ts_mask, map);
+		return -EINVAL;
+	}
+

till here the block looks like copy of the block from previous function.
It worth to make a separate function for it, I think.

quoted

+	if (map >= BIT_ULL(32)) {
+		dev_err(qmc_hdlc->dev, "Slot map out of 32bit (0x%llx,0x%llx) -> 0x%llx\n",
+			ts_mask_avail, ts_mask, map);
+		return -EINVAL;
+	}
+
+	*slot_map = map;
+	return 0;
+}
+

[...]

I am not so sure. There are slighty differences between the two functions.
The error messages and, in particular, the loop in qmc_hdlc_xlate_slot_map() is:
	--- 8< ---
	ts_mask_avail = ts_info->rx_ts_mask_avail;
	ts_mask = 0;
	map = slot_map;
	bit = 0;
	for (i = 0; i < 64; i++) {
		if (ts_mask_avail & BIT_ULL(i)) {
			if (map & BIT_ULL(bit))
				ts_mask |= BIT_ULL(i);
			bit++;
		}
	}
	--- 8< ---

whereas it is the following in qmc_hdlc_xlate_ts_info():
	--- 8< ---
	ts_mask_avail = ts_info->rx_ts_mask_avail;
	ts_mask = ts_info->rx_ts_mask;
	map = 0;
	bit = 0;
	for (i = 0; i < 64; i++) {
		if (ts_mask_avail & BIT_ULL(i)) {
			if (ts_mask & BIT_ULL(i))
				map |= BIT_ULL(bit);
			bit++;
		}
	}
	--- 8< ---

ts_map and map initializations are not the same, i and bit are not used for
the same purpose and the computed value is not computed based on the same
information.

With that pointed, I am not sure that having some common code for both
function will be relevant. Your opinion ?

I see. I'm just thinking if it's possible to use helpers from bitops.h
and bitmap.h here to avoid open-coding common parts of the code.

Best regards,
Hervé