Commit b9aa0805 authored by Alex Elder's avatar Alex Elder Committed by David S. Miller
Browse files

net: ipa: implement MAX_READS_BEATS QSB data 



Starting with IPA v4.0, a limit is placed on the number of bytes
outstanding in a transaction, to reduce latency.  The limit is
imposed only if this value is non-zero.

We don't use a non-zero value for SC7180, but newer versions of IPA
do.  Prepare for that by allowing a programmed value to be specified
in the platform configuration data.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8a81efac

drivers/net/ipa/ipa_data-sc7180.c

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ static const struct ipa_qsb_data ipa_qsb_data[] = { 
	[IPA_QSB_MASTER_DDR] = {

		.max_writes	= 8,

		.max_reads	= 12,

		/* no outstanding read byte (beat) limit */

	},

};

drivers/net/ipa/ipa_data.h

+2 −0
Original line number Diff line number Diff line
@@ -59,10 +59,12 @@ enum ipa_qsb_master_id { 
 * struct ipa_qsb_data - Qualcomm System Bus configuration data

 * @max_writes:	Maximum outstanding write requests for this master

 * @max_reads:	Maximum outstanding read requests for this master

 * @max_reads_beats: Max outstanding read bytes in 8-byte "beats" (if non-zero)

 */

struct ipa_qsb_data {

	u8 max_writes;

	u8 max_reads;

	u8 max_reads_beats;		/* Not present for IPA v3.5.1 */

};



/**

drivers/net/ipa/ipa_main.c

+8 −2
Original line number Diff line number Diff line
@@ -274,10 +274,16 @@ ipa_hardware_config_qsb(struct ipa *ipa, const struct ipa_data *data) 


	/* Max outstanding read accesses for QSB masters */

	val = u32_encode_bits(data0->max_reads, GEN_QMB_0_MAX_READS_FMASK);

	/* GEN_QMB_0_MAX_READS_BEATS is 0 (IPA v4.0 and above) */

	if (data->qsb_count > 1)

	if (ipa->version >= IPA_VERSION_4_0)

		val |= u32_encode_bits(data0->max_reads_beats,

				       GEN_QMB_0_MAX_READS_BEATS_FMASK);

	if (data->qsb_count > 1) {

		val |= u32_encode_bits(data1->max_reads,

				       GEN_QMB_1_MAX_READS_FMASK);

		if (ipa->version >= IPA_VERSION_4_0)

			val |= u32_encode_bits(data1->max_reads_beats,

					       GEN_QMB_1_MAX_READS_BEATS_FMASK);

	}

	iowrite32(val, ipa->reg_virt + IPA_REG_QSB_MAX_READS_OFFSET);

}