Commit 46290c6b authored by Patrick Rudolph's avatar Patrick Rudolph Committed by Guenter Roeck
Browse files

hwmon: (dimmtemp) Support more than 32 DIMMs 



This patch introduces support for handling more than 32 DIMMs by
utilizing bitmap operations. The changes ensure that the driver can
handle a higher number of DIMMs efficiently.

Signed-off-by: default avatarPatrick Rudolph <patrick.rudolph@9elements.com>
Link: https://lore.kernel.org/r/20230711152144.755177-1-Naresh.Solanki@9elements.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 170fea88

drivers/hwmon/peci/dimmtemp.c

+15 −11
Original line number Diff line number Diff line
@@ -219,19 +219,21 @@ static int check_populated_dimms(struct peci_dimmtemp *priv) 
{

	int chan_rank_max = priv->gen_info->chan_rank_max;

	int dimm_idx_max = priv->gen_info->dimm_idx_max;

	u32 chan_rank_empty = 0;

	u32 dimm_mask = 0;

	int chan_rank, dimm_idx, ret;

	DECLARE_BITMAP(dimm_mask, DIMM_NUMS_MAX);

	DECLARE_BITMAP(chan_rank_empty, CHAN_RANK_MAX);



	int chan_rank, dimm_idx, ret, i;

	u32 pcs;



	BUILD_BUG_ON(BITS_PER_TYPE(chan_rank_empty) < CHAN_RANK_MAX);

	BUILD_BUG_ON(BITS_PER_TYPE(dimm_mask) < DIMM_NUMS_MAX);

	if (chan_rank_max * dimm_idx_max > DIMM_NUMS_MAX) {

		WARN_ONCE(1, "Unsupported number of DIMMs - chan_rank_max: %d, dimm_idx_max: %d",

			  chan_rank_max, dimm_idx_max);

		return -EINVAL;

	}



	bitmap_zero(dimm_mask, DIMM_NUMS_MAX);

	bitmap_zero(chan_rank_empty, CHAN_RANK_MAX);



	for (chan_rank = 0; chan_rank < chan_rank_max; chan_rank++) {

		ret = peci_pcs_read(priv->peci_dev, PECI_PCS_DDR_DIMM_TEMP, chan_rank, &pcs);

		if (ret) {
@@ -242,7 +244,7 @@ static int check_populated_dimms(struct peci_dimmtemp *priv) 
			 * detection to be performed at a later point in time.

			 */

			if (ret == -EINVAL) {

				chan_rank_empty |= BIT(chan_rank);

				bitmap_set(chan_rank_empty, chan_rank, 1);

				continue;

			}
@@ -251,7 +253,7 @@ static int check_populated_dimms(struct peci_dimmtemp *priv) 


		for (dimm_idx = 0; dimm_idx < dimm_idx_max; dimm_idx++)

			if (__dimm_temp(pcs, dimm_idx))

				dimm_mask |= BIT(chan_rank * dimm_idx_max + dimm_idx);

				bitmap_set(dimm_mask, chan_rank * dimm_idx_max + dimm_idx, 1);

	}



	/*
@@ -260,7 +262,7 @@ static int check_populated_dimms(struct peci_dimmtemp *priv) 
	 * host platform boot. Retrying a couple of times lets us make sure

	 * that the state is persistent.

	 */

	if (chan_rank_empty == GENMASK(chan_rank_max - 1, 0)) {

	if (bitmap_full(chan_rank_empty, chan_rank_max)) {

		if (priv->no_dimm_retry_count < NO_DIMM_RETRY_COUNT_MAX) {

			priv->no_dimm_retry_count++;
@@ -274,14 +276,16 @@ static int check_populated_dimms(struct peci_dimmtemp *priv) 
	 * It's possible that memory training is not done yet. In this case we

	 * defer the detection to be performed at a later point in time.

	 */

	if (!dimm_mask) {

	if (bitmap_empty(dimm_mask, DIMM_NUMS_MAX)) {

		priv->no_dimm_retry_count = 0;

		return -EAGAIN;

	}



	dev_dbg(priv->dev, "Scanned populated DIMMs: %#x\n", dimm_mask);

	for_each_set_bit(i, dimm_mask, DIMM_NUMS_MAX) {

		dev_dbg(priv->dev, "Found DIMM%#x\n", i);

	}



	bitmap_from_arr32(priv->dimm_mask, &dimm_mask, DIMM_NUMS_MAX);

	bitmap_copy(priv->dimm_mask, dimm_mask, DIMM_NUMS_MAX);



	return 0;

}