From: Alex Elder <elder@linaro.org>
Date: Sat, 20 Mar 2021 15:57:04 +0000 (-0500)
Subject: net: ipa: implement MAX_READS_BEATS QSB data
X-Git-Tag: accepted/tizen/unified/20230118.172025~7335^2~462^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b9aa0805ed31ed95c720f1a0bb606de2988b3ef5;p=platform%2Fkernel%2Flinux-rpi.git

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: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ipa/ipa_data-sc7180.c b/drivers/net/ipa/ipa_data-sc7180.c
index 216f790..8fa10d0 100644
--- a/drivers/net/ipa/ipa_data-sc7180.c
+++ b/drivers/net/ipa/ipa_data-sc7180.c
@@ -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 */
 	},
 };
 
diff --git a/drivers/net/ipa/ipa_data.h b/drivers/net/ipa/ipa_data.h
index d50cd5a..4162c47 100644
--- a/drivers/net/ipa/ipa_data.h
+++ b/drivers/net/ipa/ipa_data.h
@@ -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 */
 };
 
 /**
diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 1ce593b4..64b92df 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -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);
 }