[PATCH net-next 3/6] net: ipa: add new most-significant bits to registers

[Alex Elder <elder@linaro.org>]

IPA v4.5 adds a few fields to the endpoint header and extended
header configuration registers that represent new high-order bits
for certain offsets and sizes.  Add code to incorporate these upper
bits into the registers for IPA v4.5.

This includes creating ipa_header_size_encoded(), which handles
encoding the metadata offset field for use in the ENDP_INIT_HDR
register in a way appropriate for the hardware version.  This and
ipa_metadata_offset_encoded() ensure the mask argument passed to
u32_encode_bits() is constant.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_endpoint.c | 39 ++++++++++++++++++++++++++--------
 drivers/net/ipa/ipa_reg.h      | 38 +++++++++++++++++++++++++++++++--
 2 files changed, 66 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index 9707300457517..f28ea062aaf1d 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -485,28 +485,34 @@ static void ipa_endpoint_init_cfg(struct ipa_endpoint *endpoint)
 static void ipa_endpoint_init_hdr(struct ipa_endpoint *endpoint)
 {
 	u32 offset = IPA_REG_ENDP_INIT_HDR_N_OFFSET(endpoint->endpoint_id);
+	struct ipa *ipa = endpoint->ipa;
 	u32 val = 0;
 
 	if (endpoint->data->qmap) {
 		size_t header_size = sizeof(struct rmnet_map_header);
+		enum ipa_version version = ipa->version;
 
 		/* We might supply a checksum header after the QMAP header */
 		if (endpoint->toward_ipa && endpoint->data->checksum)
 			header_size += sizeof(struct rmnet_map_ul_csum_header);
-		val |= u32_encode_bits(header_size, HDR_LEN_FMASK);
+		val |= ipa_header_size_encoded(version, header_size);
 
 		/* Define how to fill fields in a received QMAP header */
 		if (!endpoint->toward_ipa) {
-			u32 off;	/* Field offset within header */
+			u32 offset;	/* Field offset within header */
 
 			/* Where IPA will write the metadata value */
-			off = offsetof(struct rmnet_map_header, mux_id);
-			val |= u32_encode_bits(off, HDR_OFST_METADATA_FMASK);
+			offset = offsetof(struct rmnet_map_header, mux_id);
+			val |= ipa_metadata_offset_encoded(version, offset);
 
 			/* Where IPA will write the length */
-			off = offsetof(struct rmnet_map_header, pkt_len);
+			offset = offsetof(struct rmnet_map_header, pkt_len);
+			/* Upper bits are stored in HDR_EXT with IPA v4.5 */
+			if (version == IPA_VERSION_4_5)
+				offset &= field_mask(HDR_OFST_PKT_SIZE_FMASK);
+
 			val |= HDR_OFST_PKT_SIZE_VALID_FMASK;
-			val |= u32_encode_bits(off, HDR_OFST_PKT_SIZE_FMASK);
+			val |= u32_encode_bits(offset, HDR_OFST_PKT_SIZE_FMASK);
 		}
 		/* For QMAP TX, metadata offset is 0 (modem assumes this) */
 		val |= HDR_OFST_METADATA_VALID_FMASK;
@@ -517,13 +523,14 @@ static void ipa_endpoint_init_hdr(struct ipa_endpoint *endpoint)
 		/* HDR_METADATA_REG_VALID is 0 (TX only) */
 	}
 
-	iowrite32(val, endpoint->ipa->reg_virt + offset);
+	iowrite32(val, ipa->reg_virt + offset);
 }
 
 static void ipa_endpoint_init_hdr_ext(struct ipa_endpoint *endpoint)
 {
 	u32 offset = IPA_REG_ENDP_INIT_HDR_EXT_N_OFFSET(endpoint->endpoint_id);
 	u32 pad_align = endpoint->data->rx.pad_align;
+	struct ipa *ipa = endpoint->ipa;
 	u32 val = 0;
 
 	val |= HDR_ENDIANNESS_FMASK;		/* big endian */
@@ -545,9 +552,23 @@ static void ipa_endpoint_init_hdr_ext(struct ipa_endpoint *endpoint)
 	if (!endpoint->toward_ipa)
 		val |= u32_encode_bits(pad_align, HDR_PAD_TO_ALIGNMENT_FMASK);
 
-	iowrite32(val, endpoint->ipa->reg_virt + offset);
-}
+	/* IPA v4.5 adds some most-significant bits to a few fields,
+	 * two of which are defined in the HDR (not HDR_EXT) register.
+	 */
+	if (ipa->version == IPA_VERSION_4_5) {
+		/* HDR_TOTAL_LEN_OR_PAD_OFFSET is 0, so MSB is 0 */
+		if (endpoint->data->qmap && !endpoint->toward_ipa) {
+			u32 offset;
 
+			offset = offsetof(struct rmnet_map_header, pkt_len);
+			offset >>= hweight32(HDR_OFST_PKT_SIZE_FMASK);
+			val |= u32_encode_bits(offset,
+					       HDR_OFST_PKT_SIZE_MSB_FMASK);
+			/* HDR_ADDITIONAL_CONST_LEN is 0 so MSB is 0 */
+		}
+	}
+	iowrite32(val, ipa->reg_virt + offset);
+}
 
 static void ipa_endpoint_init_hdr_metadata_mask(struct ipa_endpoint *endpoint)
 {
diff --git a/drivers/net/ipa/ipa_reg.h b/drivers/net/ipa/ipa_reg.h
index f6ac9884fd326..7d10fa6dcbec1 100644
--- a/drivers/net/ipa/ipa_reg.h
+++ b/drivers/net/ipa/ipa_reg.h
@@ -367,6 +367,40 @@ enum ipa_cs_offload_en {
 #define HDR_LEN_MSB_FMASK			GENMASK(29, 28)
 #define HDR_OFST_METADATA_MSB_FMASK		GENMASK(31, 30)
 
+/* Encoded value for ENDP_INIT_HDR register HDR_LEN* field(s) */
+static inline u32 ipa_header_size_encoded(enum ipa_version version,
+					  u32 header_size)
+{
+	u32 val;
+
+	val = u32_encode_bits(header_size, HDR_LEN_FMASK);
+	if (version < IPA_VERSION_4_5)
+		return val;
+
+	/* IPA v4.5 adds a few more most-significant bits */
+	header_size >>= hweight32(HDR_LEN_FMASK);
+	val |= u32_encode_bits(header_size, HDR_LEN_MSB_FMASK);
+
+	return val;
+}
+
+/* Encoded value for ENDP_INIT_HDR register OFST_METADATA* field(s) */
+static inline u32 ipa_metadata_offset_encoded(enum ipa_version version,
+					      u32 offset)
+{
+	u32 val;
+
+	val = u32_encode_bits(offset, HDR_OFST_METADATA_FMASK);
+	if (version < IPA_VERSION_4_5)
+		return val;
+
+	/* IPA v4.5 adds a few more most-significant bits */
+	offset >>= hweight32(HDR_OFST_METADATA_FMASK);
+	val |= u32_encode_bits(offset, HDR_OFST_METADATA_MSB_FMASK);
+
+	return val;
+}
+
 #define IPA_REG_ENDP_INIT_HDR_EXT_N_OFFSET(ep) \
 					(0x00000814 + 0x0070 * (ep))
 #define HDR_ENDIANNESS_FMASK			GENMASK(0, 0)
@@ -461,7 +495,7 @@ enum ipa_aggr_type {
 
 #define IPA_REG_ENDP_INIT_RSRC_GRP_N_OFFSET(ep) \
 					(0x00000838 + 0x0070 * (ep))
-/* Encoded value for RSRC_GRP endpoint register RSRC_GRP field */
+/* Encoded value for ENDP_INIT_RSRC_GRP register RSRC_GRP field */
 static inline u32 rsrc_grp_encoded(enum ipa_version version, u32 rsrc_grp)
 {
 	switch (version) {
@@ -492,7 +526,7 @@ static inline u32 rsrc_grp_encoded(enum ipa_version version, u32 rsrc_grp)
  * @IPA_SEQ_INVALID:		invalid sequencer type
  *
  * The values defined here are broken into 4-bit nibbles that are written
- * into fields of the INIT_SEQ_N endpoint registers.
+ * into fields of the ENDP_INIT_SEQ registers.
  */
 enum ipa_seq_type {
 	IPA_SEQ_DMA_ONLY			= 0x0000,
-- 
2.20.1