[PATCH net-next 0/6] net: ipa: start adding IPA v4.5 support

[PATCH net-next 0/6] net: ipa: start adding IPA v4.5 support

[Alex Elder]

This series starts updating the IPA code to support IPA hardware
version 4.5.

The first patch fixes a problem found while preparing these updates.
Testing shows the code works with or without the change, and with
the fix the code matches "downstream" Qualcomm code.

The second patch updates the definitions for IPA register offsets
and field masks to reflect the changes that come with IPA v4.5.  A
few register updates have been deferred until later, because making
use of them involves some nontrivial code updates.

One type of change that IPA v4.5 brings is expanding the range of
certain configuration values.  High-order bits are added in a few
cases, and the third patch implements the code changes necessary to
use those newly available bits.

The fourth patch implements several fairly minor changes to the code
required for IPA v4.5 support.

The last two patches implement changes to the GSI registers used for
IPA.  Almost none of the registers change, but the range of memory
in which most of the GSI registers is located is shifted by a fixed
amount.  The fifth patch updates the GSI register definitions, and
the last patch implements the memory shift for IPA v4.5.

					-Alex

Alex Elder (6):
  net: ipa: reverse logic on escape buffer use
  net: ipa: update IPA registers for IPA v4.5
  net: ipa: add new most-significant bits to registers
  net: ipa: add support to code for IPA v4.5
  net: ipa: update gsi registers for IPA v4.5
  net: ipa: adjust GSI register addresses

 drivers/net/ipa/gsi.c          | 35 ++++++++++++---
 drivers/net/ipa/gsi_reg.h      | 24 ++++++++++
 drivers/net/ipa/ipa_endpoint.c | 49 ++++++++++++++------
 drivers/net/ipa/ipa_main.c     | 76 +++++++++++++++++++++----------
 drivers/net/ipa/ipa_reg.h      | 81 ++++++++++++++++++++++++++++++++--
 drivers/net/ipa/ipa_version.h  |  1 +
 6 files changed, 220 insertions(+), 46 deletions(-)

-- 
2.20.1

[PATCH net-next 1/6] net: ipa: reverse logic on escape buffer use

[Alex Elder]

Starting with IPA v4.2 there is a GSI channel option to use an
"escape buffer" instead of prefetch buffers.  This should be used
for all channels *except* the AP command TX channel.  The logic
that implements this has it backwards; fix this bug.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/gsi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index eb4c5d408a835..2cf10c9f0143d 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -781,8 +781,10 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell)
 	if (gsi->version == IPA_VERSION_3_5_1 && doorbell)
 		val |= USE_DB_ENG_FMASK;
 
-	/* Starting with IPA v4.0 the command channel uses the escape buffer */
-	if (gsi->version != IPA_VERSION_3_5_1 && channel->command)
+	/* v4.0 introduces an escape buffer for prefetch.  We use it
+	 * on all but the AP command channel.
+	 */
+	if (gsi->version != IPA_VERSION_3_5_1 && !channel->command)
 		val |= USE_ESCAPE_BUF_ONLY_FMASK;
 
 	iowrite32(val, gsi->virt + GSI_CH_C_QOS_OFFSET(channel_id));
-- 
2.20.1

[PATCH net-next 2/6] net: ipa: update IPA registers for IPA v4.5

[Alex Elder]

Update "ipa_reg.h" so that register definitions support IPA hardware
version 4.5, in addition to versions 3.5.1 through v4.2.  Most of
the register definitions are the same, but in some cases fields are
added, changed, or eliminated.

Updates for a few IPA v4.5 registers are more complex, and adding
those definition will be deferred to separate patches.  This patch
only updates the register offset and field definitions, and adds
informational comments.

The only code change avoids accessing the backward compatibility
register for IPA version 4.5 in ipa_hardware_config().  Other IPA
v4.5-specific code changes will come later.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_main.c    | 15 +++++++++------
 drivers/net/ipa/ipa_reg.h     | 36 +++++++++++++++++++++++++++++++++--
 drivers/net/ipa/ipa_version.h |  1 +
 3 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index e9bd0d72f2db1..7cd7f6cc05b3c 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -310,14 +310,17 @@ static void ipa_hardware_dcd_deconfig(struct ipa *ipa)
  */
 static void ipa_hardware_config(struct ipa *ipa)
 {
+	enum ipa_version version = ipa->version;
 	u32 granularity;
 	u32 val;
 
-	/* Fill in backward-compatibility register, based on version */
-	val = ipa_reg_bcr_val(ipa->version);
-	iowrite32(val, ipa->reg_virt + IPA_REG_BCR_OFFSET);
+	/* IPA v4.5 has no backward compatibility register */
+	if (version < IPA_VERSION_4_5) {
+		val = ipa_reg_bcr_val(version);
+		iowrite32(val, ipa->reg_virt + IPA_REG_BCR_OFFSET);
+	}
 
-	if (ipa->version != IPA_VERSION_3_5_1) {
+	if (version != IPA_VERSION_3_5_1) {
 		/* Enable open global clocks (hardware workaround) */
 		val = GLOBAL_FMASK;
 		val |= GLOBAL_2X_CLK_FMASK;
@@ -340,8 +343,8 @@ static void ipa_hardware_config(struct ipa *ipa)
 	iowrite32(val, ipa->reg_virt + IPA_REG_COUNTER_CFG_OFFSET);
 
 	/* IPA v4.2 does not support hashed tables, so disable them */
-	if (ipa->version == IPA_VERSION_4_2) {
-		u32 offset = ipa_reg_filt_rout_hash_en_offset(ipa->version);
+	if (version == IPA_VERSION_4_2) {
+		u32 offset = ipa_reg_filt_rout_hash_en_offset(version);
 
 		iowrite32(0, ipa->reg_virt + offset);
 	}
diff --git a/drivers/net/ipa/ipa_reg.h b/drivers/net/ipa/ipa_reg.h
index d02e7ecc6fc01..f6ac9884fd326 100644
--- a/drivers/net/ipa/ipa_reg.h
+++ b/drivers/net/ipa/ipa_reg.h
@@ -65,12 +65,13 @@ struct ipa;
  * of valid bits for the register.
  */
 
-/* The next field is not supported for IPA v4.1 */
 #define IPA_REG_COMP_CFG_OFFSET				0x0000003c
+/* The next field is not supported for IPA v4.1 */
 #define ENABLE_FMASK				GENMASK(0, 0)
 #define GSI_SNOC_BYPASS_DIS_FMASK		GENMASK(1, 1)
 #define GEN_QMB_0_SNOC_BYPASS_DIS_FMASK		GENMASK(2, 2)
 #define GEN_QMB_1_SNOC_BYPASS_DIS_FMASK		GENMASK(3, 3)
+/* The next field is not present for IPA v4.5 */
 #define IPA_DCMP_FAST_CLK_EN_FMASK		GENMASK(4, 4)
 /* The remaining fields are not present for IPA v3.5.1 */
 #define IPA_QMB_SELECT_CONS_EN_FMASK		GENMASK(5, 5)
@@ -86,6 +87,8 @@ struct ipa;
 #define GSI_MULTI_AXI_MASTERS_DIS_FMASK		GENMASK(15, 15)
 #define IPA_QMB_SELECT_GLOBAL_EN_FMASK		GENMASK(16, 16)
 #define IPA_ATOMIC_FETCHER_ARB_LOCK_DIS_FMASK	GENMASK(20, 17)
+/* The next field is present for IPA v4.5 */
+#define IPA_FULL_FLUSH_WAIT_RSC_CLOSE_EN_FMASK	GENMASK(21, 21)
 
 #define IPA_REG_CLKON_CFG_OFFSET			0x00000044
 #define RX_FMASK				GENMASK(0, 0)
@@ -105,6 +108,7 @@ struct ipa;
 #define ACK_MNGR_FMASK				GENMASK(14, 14)
 #define D_DCPH_FMASK				GENMASK(15, 15)
 #define H_DCPH_FMASK				GENMASK(16, 16)
+/* The next field is not present for IPA v4.5 */
 #define DCMP_FMASK				GENMASK(17, 17)
 #define NTF_TX_CMDQS_FMASK			GENMASK(18, 18)
 #define TX_0_FMASK				GENMASK(19, 19)
@@ -119,6 +123,8 @@ struct ipa;
 #define GSI_IF_FMASK				GENMASK(27, 27)
 #define GLOBAL_FMASK				GENMASK(28, 28)
 #define GLOBAL_2X_CLK_FMASK			GENMASK(29, 29)
+/* The next field is present for IPA v4.5 */
+#define DPL_FIFO_FMASK				GENMASK(30, 30)
 
 #define IPA_REG_ROUTE_OFFSET				0x00000048
 #define ROUTE_DIS_FMASK				GENMASK(0, 0)
@@ -174,6 +180,7 @@ static inline u32 ipa_reg_state_aggr_active_offset(enum ipa_version version)
 	return 0x000000b4;
 }
 
+/* The next register is not present for IPA v4.5 */
 #define IPA_REG_BCR_OFFSET				0x000001d0
 /* The next two fields are not present for IPA v4.2 */
 #define BCR_CMDQ_L_LACK_ONE_ENTRY_FMASK		GENMASK(0, 0)
@@ -205,6 +212,8 @@ static inline u32 ipa_reg_bcr_val(enum ipa_version version)
 			BCR_HOLB_DROP_L2_IRQ_FMASK |
 			BCR_DUAL_TX_FMASK;
 
+	/* assert(version != IPA_VERSION_4_5); */
+
 	return 0x00000000;
 }
 
@@ -241,6 +250,8 @@ static inline u32 ipa_aggr_granularity_val(u32 usec)
 #define DMAW_MAX_BEATS_256_DIS_FMASK		GENMASK(11, 11)
 #define PA_MASK_EN_FMASK			GENMASK(12, 12)
 #define PREFETCH_ALMOST_EMPTY_SIZE_TX1_FMASK	GENMASK(16, 13)
+/* The next field is present for IPA v4.5 */
+#define DUAL_TX_ENABLE_FMASK			GENMASK(17, 17)
 /* The next two fields are present for IPA v4.2 only */
 #define SSPND_PA_NO_START_STATE_FMASK		GENMASK(18, 18)
 #define SSPND_PA_NO_BQ_STATE_FMASK		GENMASK(19, 19)
@@ -253,7 +264,7 @@ static inline u32 ipa_aggr_granularity_val(u32 usec)
 
 static inline u32 ipa_reg_idle_indication_cfg_offset(enum ipa_version version)
 {
-	if (version == IPA_VERSION_4_2)
+	if (version >= IPA_VERSION_4_2)
 		return 0x00000240;
 
 	return 0x00000220;
@@ -303,12 +314,14 @@ static inline u32 ipa_resource_group_dst_count(enum ipa_version version)
 					(0x00000400 + 0x0020 * (rt))
 #define IPA_REG_SRC_RSRC_GRP_23_RSRC_TYPE_N_OFFSET(rt) \
 					(0x00000404 + 0x0020 * (rt))
+/* The next register is only present for IPA v4.5 */
 #define IPA_REG_SRC_RSRC_GRP_45_RSRC_TYPE_N_OFFSET(rt) \
 					(0x00000408 + 0x0020 * (rt))
 #define IPA_REG_DST_RSRC_GRP_01_RSRC_TYPE_N_OFFSET(rt) \
 					(0x00000500 + 0x0020 * (rt))
 #define IPA_REG_DST_RSRC_GRP_23_RSRC_TYPE_N_OFFSET(rt) \
 					(0x00000504 + 0x0020 * (rt))
+/* The next register is only present for IPA v4.5 */
 #define IPA_REG_DST_RSRC_GRP_45_RSRC_TYPE_N_OFFSET(rt) \
 					(0x00000508 + 0x0020 * (rt))
 /* The next four fields are used for all resource group registers */
@@ -348,7 +361,11 @@ enum ipa_cs_offload_en {
 #define HDR_OFST_PKT_SIZE_FMASK			GENMASK(25, 20)
 #define HDR_A5_MUX_FMASK			GENMASK(26, 26)
 #define HDR_LEN_INC_DEAGG_HDR_FMASK		GENMASK(27, 27)
+/* The next field is not present for IPA v4.5 */
 #define HDR_METADATA_REG_VALID_FMASK		GENMASK(28, 28)
+/* The next two fields are present for IPA v4.5 */
+#define HDR_LEN_MSB_FMASK			GENMASK(29, 28)
+#define HDR_OFST_METADATA_MSB_FMASK		GENMASK(31, 30)
 
 #define IPA_REG_ENDP_INIT_HDR_EXT_N_OFFSET(ep) \
 					(0x00000814 + 0x0070 * (ep))
@@ -358,6 +375,10 @@ enum ipa_cs_offload_en {
 #define HDR_PAYLOAD_LEN_INC_PADDING_FMASK	GENMASK(3, 3)
 #define HDR_TOTAL_LEN_OR_PAD_OFFSET_FMASK	GENMASK(9, 4)
 #define HDR_PAD_TO_ALIGNMENT_FMASK		GENMASK(13, 10)
+/* The next three fields are present for IPA v4.5 */
+#define HDR_TOTAL_LEN_OR_PAD_OFFSET_MSB_FMASK	GENMASK(17, 16)
+#define HDR_OFST_PKT_SIZE_MSB_FMASK		GENMASK(19, 18)
+#define HDR_ADDITIONAL_CONST_LEN_MSB_FMASK	GENMASK(21, 20)
 
 /* Valid only for RX (IPA producer) endpoints */
 #define IPA_REG_ENDP_INIT_HDR_METADATA_MASK_N_OFFSET(rxep) \
@@ -367,10 +388,13 @@ enum ipa_cs_offload_en {
 #define IPA_REG_ENDP_INIT_MODE_N_OFFSET(txep) \
 					(0x00000820 + 0x0070 * (txep))
 #define MODE_FMASK				GENMASK(2, 0)
+/* The next field is present for IPA v4.5 */
+#define DCPH_ENABLE_FMASK			GENMASK(3, 3)
 #define DEST_PIPE_INDEX_FMASK			GENMASK(8, 4)
 #define BYTE_THRESHOLD_FMASK			GENMASK(27, 12)
 #define PIPE_REPLICATION_EN_FMASK		GENMASK(28, 28)
 #define PAD_EN_FMASK				GENMASK(29, 29)
+/* The next register is not present for IPA v4.5 */
 #define HDR_FTCH_DISABLE_FMASK			GENMASK(30, 30)
 
 /** enum ipa_mode - mode field in ENDP_INIT_MODE_N */
@@ -421,6 +445,9 @@ enum ipa_aggr_type {
 /* The next two fields are present for IPA v4.2 only */
 #define BASE_VALUE_FMASK			GENMASK(4, 0)
 #define SCALE_FMASK				GENMASK(12, 8)
+/* The next two fields are present for IPA v4.5 */
+#define TIME_LIMIT_FMASK			GENMASK(4, 0)
+#define GRAN_SEL_FMASK				GENMASK(8, 8)
 
 /* Valid only for TX (IPA consumer) endpoints */
 #define IPA_REG_ENDP_INIT_DEAGGR_N_OFFSET(txep) \
@@ -440,6 +467,8 @@ static inline u32 rsrc_grp_encoded(enum ipa_version version, u32 rsrc_grp)
 	switch (version) {
 	case IPA_VERSION_4_2:
 		return u32_encode_bits(rsrc_grp, GENMASK(0, 0));
+	case IPA_VERSION_4_5:
+		return u32_encode_bits(rsrc_grp, GENMASK(2, 0));
 	default:
 		return u32_encode_bits(rsrc_grp, GENMASK(1, 0));
 	}
@@ -476,6 +505,7 @@ enum ipa_seq_type {
 					(0x00000840 + 0x0070 * (ep))
 #define STATUS_EN_FMASK				GENMASK(0, 0)
 #define STATUS_ENDP_FMASK			GENMASK(5, 1)
+/* The next field is not present for IPA v4.5 */
 #define STATUS_LOCATION_FMASK			GENMASK(8, 8)
 /* The next field is not present for IPA v3.5.1 */
 #define STATUS_PKT_SUPPRESS_FMASK		GENMASK(9, 9)
@@ -550,6 +580,8 @@ enum ipa_irq_id {
 	IPA_IRQ_GSI_EE				= 0x17,
 	IPA_IRQ_GSI_IPA_IF_TLV_RCVD		= 0x18,
 	IPA_IRQ_GSI_UC				= 0x19,
+	/* The next bit is present for IPA v4.5 */
+	IPA_IRQ_TLV_LEN_MIN_DSM			= 0x1a,
 	IPA_IRQ_COUNT,				/* Last; not an id */
 };
 
diff --git a/drivers/net/ipa/ipa_version.h b/drivers/net/ipa/ipa_version.h
index 85449df0f5124..2944e2a890231 100644
--- a/drivers/net/ipa/ipa_version.h
+++ b/drivers/net/ipa/ipa_version.h
@@ -18,6 +18,7 @@ enum ipa_version {
 	IPA_VERSION_4_0,	/* GSI version 2.0 */
 	IPA_VERSION_4_1,	/* GSI version 2.1 */
 	IPA_VERSION_4_2,	/* GSI version 2.2 */
+	IPA_VERSION_4_5,	/* GSI version 2.5 */
 };
 
 #endif /* _IPA_VERSION_H_ */
-- 
2.20.1

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

[Alex Elder]

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

[PATCH net-next 4/6] net: ipa: add support to code for IPA v4.5

[Alex Elder]

Update the IPA code to make use of the updated IPA v4.5 register
definitions.  Generally what this patch does is, if IPA v4.5
hardware is in use:
  - Ensure new registers or fields in IPA v4.5 are updated where
    required
  - Ensure registers or fields not supported in IPA v4.5 are not
    examined when read, or are set to 0 when written
It does this while preserving the existing functionality for IPA
versions lower than v4.5.

The values to program for QSB_MAX_READS and QSB_MAX_WRITES and the
source and destination resource counts are updated to be correct for
all versions through v4.5 as well.

Note that IPA_RESOURCE_GROUP_SRC_MAX and IPA_RESOURCE_GROUP_DST_MAX
already reflect that 5 is an acceptable number of resources (which
IPA v4.5 implements).

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_endpoint.c | 10 +++---
 drivers/net/ipa/ipa_main.c     | 63 ++++++++++++++++++++++++----------
 drivers/net/ipa/ipa_reg.h      |  7 ++++
 3 files changed, 57 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index f28ea062aaf1d..27f543b6780b1 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -520,7 +520,7 @@ static void ipa_endpoint_init_hdr(struct ipa_endpoint *endpoint)
 		/* HDR_ADDITIONAL_CONST_LEN is 0; (RX only) */
 		/* HDR_A5_MUX is 0 */
 		/* HDR_LEN_INC_DEAGG_HDR is 0 */
-		/* HDR_METADATA_REG_VALID is 0 (TX only) */
+		/* HDR_METADATA_REG_VALID is 0 (TX only, version < v4.5) */
 	}
 
 	iowrite32(val, ipa->reg_virt + offset);
@@ -655,6 +655,7 @@ static void ipa_endpoint_init_aggr(struct ipa_endpoint *endpoint)
 			/* other fields ignored */
 		}
 		/* AGGR_FORCE_CLOSE is 0 */
+		/* AGGR_GRAN_SEL is 0 for IPA v4.5 */
 	} else {
 		val |= u32_encode_bits(IPA_BYPASS_AGGR, AGGR_EN_FMASK);
 		/* other fields ignored */
@@ -865,9 +866,10 @@ static void ipa_endpoint_status(struct ipa_endpoint *endpoint)
 			val |= u32_encode_bits(status_endpoint_id,
 					       STATUS_ENDP_FMASK);
 		}
-		/* STATUS_LOCATION is 0 (status element precedes packet) */
-		/* The next field is present for IPA v4.0 and above */
-		/* STATUS_PKT_SUPPRESS_FMASK is 0 */
+		/* STATUS_LOCATION is 0, meaning status element precedes
+		 * packet (not present for IPA v4.5)
+		 */
+		/* STATUS_PKT_SUPPRESS_FMASK is 0 (not present for v3.5.1) */
 	}
 
 	iowrite32(val, ipa->reg_virt + offset);
diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 7cd7f6cc05b3c..f25bcfe51dd4b 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -230,8 +230,10 @@ static void ipa_hardware_config_comp(struct ipa *ipa)
 		val &= ~IPA_QMB_SELECT_CONS_EN_FMASK;
 		val &= ~IPA_QMB_SELECT_PROD_EN_FMASK;
 		val &= ~IPA_QMB_SELECT_GLOBAL_EN_FMASK;
-	} else  {
+	} else if (ipa->version < IPA_VERSION_4_5) {
 		val |= GSI_MULTI_AXI_MASTERS_DIS_FMASK;
+	} else {
+		/* For IPA v4.5 IPA_FULL_FLUSH_WAIT_RSC_CLOSE_EN is 0 */
 	}
 
 	val |= GSI_MULTI_INORDER_RD_DIS_FMASK;
@@ -243,25 +245,47 @@ static void ipa_hardware_config_comp(struct ipa *ipa)
 /* Configure DDR and PCIe max read/write QSB values */
 static void ipa_hardware_config_qsb(struct ipa *ipa)
 {
+	enum ipa_version version = ipa->version;
+	u32 max0;
+	u32 max1;
 	u32 val;
 
-	/* QMB_0 represents DDR; QMB_1 represents PCIe (not present in 4.2) */
+	/* QMB_0 represents DDR; QMB_1 represents PCIe */
 	val = u32_encode_bits(8, GEN_QMB_0_MAX_WRITES_FMASK);
-	if (ipa->version == IPA_VERSION_4_2)
-		val |= u32_encode_bits(0, GEN_QMB_1_MAX_WRITES_FMASK);
-	else
-		val |= u32_encode_bits(4, GEN_QMB_1_MAX_WRITES_FMASK);
+	switch (version) {
+	case IPA_VERSION_4_2:
+		max1 = 0;		/* PCIe not present */
+		break;
+	case IPA_VERSION_4_5:
+		max1 = 8;
+		break;
+	default:
+		max1 = 4;
+		break;
+	}
+	val |= u32_encode_bits(max1, GEN_QMB_1_MAX_WRITES_FMASK);
 	iowrite32(val, ipa->reg_virt + IPA_REG_QSB_MAX_WRITES_OFFSET);
 
-	if (ipa->version == IPA_VERSION_3_5_1) {
-		val = u32_encode_bits(8, GEN_QMB_0_MAX_READS_FMASK);
-		val |= u32_encode_bits(12, GEN_QMB_1_MAX_READS_FMASK);
-	} else {
-		val = u32_encode_bits(12, GEN_QMB_0_MAX_READS_FMASK);
-		if (ipa->version == IPA_VERSION_4_2)
-			val |= u32_encode_bits(0, GEN_QMB_1_MAX_READS_FMASK);
-		else
-			val |= u32_encode_bits(12, GEN_QMB_1_MAX_READS_FMASK);
+	max1 = 12;
+	switch (version) {
+	case IPA_VERSION_3_5_1:
+		max0 = 8;
+		break;
+	case IPA_VERSION_4_0:
+	case IPA_VERSION_4_1:
+		max0 = 12;
+		break;
+	case IPA_VERSION_4_2:
+		max0 = 12;
+		max1 = 0;		/* PCIe not present */
+		break;
+	case IPA_VERSION_4_5:
+		max0 = 16;
+		break;
+	}
+	val = u32_encode_bits(max0, GEN_QMB_0_MAX_READS_FMASK);
+	val |= u32_encode_bits(max1, GEN_QMB_1_MAX_READS_FMASK);
+	if (version != IPA_VERSION_3_5_1) {
 		/* GEN_QMB_0_MAX_READS_BEATS is 0 */
 		/* GEN_QMB_1_MAX_READS_BEATS is 0 */
 	}
@@ -294,7 +318,7 @@ static void ipa_idle_indication_cfg(struct ipa *ipa,
  */
 static void ipa_hardware_dcd_config(struct ipa *ipa)
 {
-	/* Recommended values for IPA 3.5 according to IPA HPG */
+	/* Recommended values for IPA 3.5 and later according to IPA HPG */
 	ipa_idle_indication_cfg(ipa, 256, false);
 }
 
@@ -320,13 +344,14 @@ static void ipa_hardware_config(struct ipa *ipa)
 		iowrite32(val, ipa->reg_virt + IPA_REG_BCR_OFFSET);
 	}
 
-	if (version != IPA_VERSION_3_5_1) {
-		/* Enable open global clocks (hardware workaround) */
+	/* Implement some hardware workarounds */
+	if (version != IPA_VERSION_3_5_1 && version < IPA_VERSION_4_5) {
+		/* Enable open global clocks (not needed for IPA v4.5) */
 		val = GLOBAL_FMASK;
 		val |= GLOBAL_2X_CLK_FMASK;
 		iowrite32(val, ipa->reg_virt + IPA_REG_CLKON_CFG_OFFSET);
 
-		/* Disable PA mask to allow HOLB drop (hardware workaround) */
+		/* Disable PA mask to allow HOLB drop */
 		val = ioread32(ipa->reg_virt + IPA_REG_TX_CFG_OFFSET);
 		val &= ~PA_MASK_EN_FMASK;
 		iowrite32(val, ipa->reg_virt + IPA_REG_TX_CFG_OFFSET);
diff --git a/drivers/net/ipa/ipa_reg.h b/drivers/net/ipa/ipa_reg.h
index 7d10fa6dcbec1..3fabafd7e32c6 100644
--- a/drivers/net/ipa/ipa_reg.h
+++ b/drivers/net/ipa/ipa_reg.h
@@ -238,6 +238,7 @@ static inline u32 ipa_aggr_granularity_val(u32 usec)
 	return DIV_ROUND_CLOSEST(usec * TIMER_FREQUENCY, USEC_PER_SEC) - 1;
 }
 
+/* The next register is not present for IPA v4.5 */
 #define IPA_REG_TX_CFG_OFFSET				0x000001fc
 /* The first three fields are present for IPA v3.5.1 only */
 #define TX0_PREFETCH_DISABLE_FMASK		GENMASK(0, 0)
@@ -285,6 +286,9 @@ static inline u32 ipa_resource_group_src_count(enum ipa_version version)
 	case IPA_VERSION_4_2:
 		return 1;
 
+	case IPA_VERSION_4_5:
+		return 5;
+
 	default:
 		return 0;
 	}
@@ -304,6 +308,9 @@ static inline u32 ipa_resource_group_dst_count(enum ipa_version version)
 	case IPA_VERSION_4_2:
 		return 1;
 
+	case IPA_VERSION_4_5:
+		return 5;
+
 	default:
 		return 0;
 	}
-- 
2.20.1

Re: [PATCH net-next 4/6] net: ipa: add support to code for IPA v4.5

[Jon Hunter]

On 25/11/2020 20:45, Alex Elder wrote:
> Update the IPA code to make use of the updated IPA v4.5 register
> definitions.  Generally what this patch does is, if IPA v4.5
> hardware is in use:
>   - Ensure new registers or fields in IPA v4.5 are updated where
>     required
>   - Ensure registers or fields not supported in IPA v4.5 are not
>     examined when read, or are set to 0 when written
> It does this while preserving the existing functionality for IPA
> versions lower than v4.5.
> 
> The values to program for QSB_MAX_READS and QSB_MAX_WRITES and the
> source and destination resource counts are updated to be correct for
> all versions through v4.5 as well.
> 
> Note that IPA_RESOURCE_GROUP_SRC_MAX and IPA_RESOURCE_GROUP_DST_MAX
> already reflect that 5 is an acceptable number of resources (which
> IPA v4.5 implements).
> 
> Signed-off-by: Alex Elder <elder@linaro.org>


This change is generating the following build error on ARM64 ...

In file included from drivers/net/ipa/ipa_main.c:9:0:
In function ‘u32_encode_bits’,
    inlined from ‘ipa_hardware_config_qsb.isra.7’ at drivers/net/ipa/ipa_main.c:286:6,
    inlined from ‘ipa_hardware_config’ at drivers/net/ipa/ipa_main.c:363:2,
    inlined from ‘ipa_config.isra.12’ at drivers/net/ipa/ipa_main.c:555:2,
    inlined from ‘ipa_probe’ at drivers/net/ipa/ipa_main.c:835:6:
./include/linux/bitfield.h:131:3: error: call to ‘__field_overflow’ declared with attribute error: value doesn't fit into mask
   __field_overflow();     \
   ^~~~~~~~~~~~~~~~~~
./include/linux/bitfield.h:151:2: note: in expansion of macro ‘____MAKE_OP’
  ____MAKE_OP(u##size,u##size,,)
  ^~~~~~~~~~~
./include/linux/bitfield.h:154:1: note: in expansion of macro ‘__MAKE_OP’
 __MAKE_OP(32)
 ^~~~~~~~~

Cheers
Jon

-- 
nvpublic

Re: [PATCH net-next 4/6] net: ipa: add support to code for IPA v4.5

[Alex Elder]

On 12/1/20 12:11 PM, Jon Hunter wrote:
> 
> On 25/11/2020 20:45, Alex Elder wrote:
>> Update the IPA code to make use of the updated IPA v4.5 register
>> definitions.  Generally what this patch does is, if IPA v4.5
>> hardware is in use:
>>    - Ensure new registers or fields in IPA v4.5 are updated where
>>      required
>>    - Ensure registers or fields not supported in IPA v4.5 are not
>>      examined when read, or are set to 0 when written
>> It does this while preserving the existing functionality for IPA
>> versions lower than v4.5.
>>
>> The values to program for QSB_MAX_READS and QSB_MAX_WRITES and the
>> source and destination resource counts are updated to be correct for
>> all versions through v4.5 as well.
>>
>> Note that IPA_RESOURCE_GROUP_SRC_MAX and IPA_RESOURCE_GROUP_DST_MAX
>> already reflect that 5 is an acceptable number of resources (which
>> IPA v4.5 implements).
>>
>> Signed-off-by: Alex Elder <elder@linaro.org>
> 
> 
> This change is generating the following build error on ARM64 ...

Sorry about that.  Thank you for reporting this, I will investigate.

					-Alex

> In file included from drivers/net/ipa/ipa_main.c:9:0:
> In function ‘u32_encode_bits’,
>      inlined from ‘ipa_hardware_config_qsb.isra.7’ at drivers/net/ipa/ipa_main.c:286:6,
>      inlined from ‘ipa_hardware_config’ at drivers/net/ipa/ipa_main.c:363:2,
>      inlined from ‘ipa_config.isra.12’ at drivers/net/ipa/ipa_main.c:555:2,
>      inlined from ‘ipa_probe’ at drivers/net/ipa/ipa_main.c:835:6:
> ./include/linux/bitfield.h:131:3: error: call to ‘__field_overflow’ declared with attribute error: value doesn't fit into mask
>     __field_overflow();     \
>     ^~~~~~~~~~~~~~~~~~
> ./include/linux/bitfield.h:151:2: note: in expansion of macro ‘____MAKE_OP’
>    ____MAKE_OP(u##size,u##size,,)
>    ^~~~~~~~~~~
> ./include/linux/bitfield.h:154:1: note: in expansion of macro ‘__MAKE_OP’
>   __MAKE_OP(32)
>   ^~~~~~~~~
> 
> Cheers
> Jon
> 

[PATCH net-next 5/6] net: ipa: update gsi registers for IPA v4.5

[Alex Elder]

Very few GSI register definitions change for IPA v4.5, however
as a group their position in memory shifts a constant amount
(handled by the next commit).

Add definitions and update comments to the set of GSI registers to
support changes that come with IPA v4.5.

Update the logic in gsi_channel_program() to accommodate the new
(expanded) PREFETCH_MODE field in the CH_C_QOS register.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/gsi.c     | 10 ++++++++--
 drivers/net/ipa/gsi_reg.h | 13 +++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 2cf10c9f0143d..67e9eb8fe3293 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -784,8 +784,14 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell)
 	/* v4.0 introduces an escape buffer for prefetch.  We use it
 	 * on all but the AP command channel.
 	 */
-	if (gsi->version != IPA_VERSION_3_5_1 && !channel->command)
-		val |= USE_ESCAPE_BUF_ONLY_FMASK;
+	if (gsi->version != IPA_VERSION_3_5_1 && !channel->command) {
+		/* If not otherwise set, prefetch buffers are used */
+		if (gsi->version < IPA_VERSION_4_5)
+			val |= USE_ESCAPE_BUF_ONLY_FMASK;
+		else
+			val |= u32_encode_bits(GSI_ESCAPE_BUF_ONLY,
+					       PREFETCH_MODE_FMASK);
+	}
 
 	iowrite32(val, gsi->virt + GSI_CH_C_QOS_OFFSET(channel_id));
 
diff --git a/drivers/net/ipa/gsi_reg.h b/drivers/net/ipa/gsi_reg.h
index c1799d1e8a837..2aea17f8f5c4e 100644
--- a/drivers/net/ipa/gsi_reg.h
+++ b/drivers/net/ipa/gsi_reg.h
@@ -105,6 +105,16 @@ enum gsi_channel_type {
 #define USE_DB_ENG_FMASK		GENMASK(9, 9)
 /* The next field is only present for IPA v4.0, v4.1, and v4.2 */
 #define USE_ESCAPE_BUF_ONLY_FMASK	GENMASK(10, 10)
+/* The next two fields are present for IPA v4.5 and above */
+#define PREFETCH_MODE_FMASK		GENMASK(13, 10)
+#define EMPTY_LVL_THRSHOLD_FMASK	GENMASK(23, 16)
+/** enum gsi_prefetch_mode - PREFETCH_MODE field in CH_C_QOS */
+enum gsi_prefetch_mode {
+	GSI_USE_PREFETCH_BUFS			= 0x0,
+	GSI_ESCAPE_BUF_ONLY			= 0x1,
+	GSI_SMART_PREFETCH			= 0x2,
+	GSI_FREE_PREFETCH			= 0x3,
+};
 
 #define GSI_CH_C_SCRATCH_0_OFFSET(ch) \
 		GSI_EE_N_CH_C_SCRATCH_0_OFFSET((ch), GSI_EE_AP)
@@ -287,6 +297,9 @@ enum gsi_iram_size {
 /* The next two values are available for IPA v4.0 and above */
 	IRAM_SIZE_TWO_N_HALF_KB			= 0x2,
 	IRAM_SIZE_THREE_KB			= 0x3,
+	/* The next two values are available for IPA v4.5 and above */
+	IRAM_SIZE_THREE_N_HALF_KB		= 0x4,
+	IRAM_SIZE_FOUR_KB			= 0x5,
 };
 
 /* IRQ condition for each type is cleared by writing type-specific register */
-- 
2.20.1

[PATCH net-next 6/6] net: ipa: adjust GSI register addresses

[Alex Elder]

The offsets for almost all GSI registers we use have different
offsets starting at IPA version 4.5.  Only two registers remain
in their original location.

In a way though, the new register locations are not *that*
different.  The entire group of affected registers has simply
been shifted down in memory by a fixed amount (0xd000).  So for
example, the channel context 0 register that has a base offset of
0x0001c000 for "older" hardware now has a base offset of 0x0000f000.

This patch aims to add support for IPA v4.5 registers at their new
offets in a way that minimizes the amount of code that needs to
change.  It is not ideal, but it avoids the need to maintain
a nearly complete set of additional register offset definitions.

The approach takes advantage of the fact that when accessing GSI
registers we do not access any of memory at lower end of the "gsi"
memory range (with two exceptions already noted).  In particular,
we do not access anything within the bottom 0xd000 bytes of the
GSI memory range.

For IPA version 4.5, after we map the GSI memory, we adjust the
virtual memory pointer downward by the fixed amount (0xd000).
That way, register accesses using the offsets defined by the
existing GSI_REG_*() macros will resolve to the proper locations
for IPA version 4.5.

The two registers *not* affected by this offset are accessed only
in gsi_irq_setup().  There, for IPA version 4.5, we undo the general
register adjustment by adding the fixed amount back to the virtual
address to access these registers.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/gsi.c     | 21 +++++++++++++++++++--
 drivers/net/ipa/gsi_reg.h | 11 +++++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 67e9eb8fe3293..c4795249719d4 100644
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -195,6 +195,8 @@ static void gsi_irq_type_disable(struct gsi *gsi, enum gsi_irq_type_id type_id)
 /* Turn off all GSI interrupts initially */
 static void gsi_irq_setup(struct gsi *gsi)
 {
+	u32 adjust;
+
 	/* Disable all interrupt types */
 	gsi_irq_type_update(gsi, 0);
 
@@ -203,8 +205,12 @@ static void gsi_irq_setup(struct gsi *gsi)
 	iowrite32(0, gsi->virt + GSI_CNTXT_SRC_EV_CH_IRQ_MSK_OFFSET);
 	iowrite32(0, gsi->virt + GSI_CNTXT_GLOB_IRQ_EN_OFFSET);
 	iowrite32(0, gsi->virt + GSI_CNTXT_SRC_IEOB_IRQ_MSK_OFFSET);
-	iowrite32(0, gsi->virt + GSI_INTER_EE_SRC_CH_IRQ_OFFSET);
-	iowrite32(0, gsi->virt + GSI_INTER_EE_SRC_EV_CH_IRQ_OFFSET);
+
+	/* Reverse the offset adjustment for inter-EE register offsets */
+	adjust = gsi->version < IPA_VERSION_4_5 ? 0 : GSI_EE_REG_ADJUST;
+	iowrite32(0, gsi->virt + adjust + GSI_INTER_EE_SRC_CH_IRQ_OFFSET);
+	iowrite32(0, gsi->virt + adjust + GSI_INTER_EE_SRC_EV_CH_IRQ_OFFSET);
+
 	iowrite32(0, gsi->virt + GSI_CNTXT_GSI_IRQ_EN_OFFSET);
 }
 
@@ -2089,6 +2095,7 @@ int gsi_init(struct gsi *gsi, struct platform_device *pdev,
 	struct device *dev = &pdev->dev;
 	struct resource *res;
 	resource_size_t size;
+	u32 adjust;
 	int ret;
 
 	gsi_validate_build();
@@ -2115,11 +2122,21 @@ int gsi_init(struct gsi *gsi, struct platform_device *pdev,
 		return -EINVAL;
 	}
 
+	/* Make sure we can make our pointer adjustment if necessary */
+	adjust = gsi->version < IPA_VERSION_4_5 ? 0 : GSI_EE_REG_ADJUST;
+	if (res->start < adjust) {
+		dev_err(dev, "DT memory resource \"gsi\" too low (< %u)\n",
+			adjust);
+		return -EINVAL;
+	}
+
 	gsi->virt = ioremap(res->start, size);
 	if (!gsi->virt) {
 		dev_err(dev, "unable to remap \"gsi\" memory\n");
 		return -ENOMEM;
 	}
+	/* Adjust register range pointer downward for newer IPA versions */
+	gsi->virt -= adjust;
 
 	init_completion(&gsi->completion);
 
diff --git a/drivers/net/ipa/gsi_reg.h b/drivers/net/ipa/gsi_reg.h
index 2aea17f8f5c4e..0e138bbd82053 100644
--- a/drivers/net/ipa/gsi_reg.h
+++ b/drivers/net/ipa/gsi_reg.h
@@ -38,6 +38,17 @@
  * (though the actual limit is hardware-dependent).
  */
 
+/* GSI EE registers as a group are shifted downward by a fixed
+ * constant amount for IPA versions 4.5 and beyond.  This applies
+ * to all GSI registers we use *except* the ones that disable
+ * inter-EE interrupts for channels and event channels.
+ *
+ * We handle this by adjusting the pointer to the mapped GSI memory
+ * region downward.  Then in the one place we use them (gsi_irq_setup())
+ * we undo that adjustment for the inter-EE interrupt registers.
+ */
+#define GSI_EE_REG_ADJUST			0x0000d000	/* IPA v4.5+ */
+
 #define GSI_INTER_EE_SRC_CH_IRQ_OFFSET \
 			GSI_INTER_EE_N_SRC_CH_IRQ_OFFSET(GSI_EE_AP)
 #define GSI_INTER_EE_N_SRC_CH_IRQ_OFFSET(ee) \
-- 
2.20.1

Re: [PATCH net-next 0/6] net: ipa: start adding IPA v4.5 support

[Jakub Kicinski]

On Wed, 25 Nov 2020 14:45:16 -0600 Alex Elder wrote:
> This series starts updating the IPA code to support IPA hardware
> version 4.5.
> 
> The first patch fixes a problem found while preparing these updates.
> Testing shows the code works with or without the change, and with
> the fix the code matches "downstream" Qualcomm code.
> 
> The second patch updates the definitions for IPA register offsets
> and field masks to reflect the changes that come with IPA v4.5.  A
> few register updates have been deferred until later, because making
> use of them involves some nontrivial code updates.
> 
> One type of change that IPA v4.5 brings is expanding the range of
> certain configuration values.  High-order bits are added in a few
> cases, and the third patch implements the code changes necessary to
> use those newly available bits.
> 
> The fourth patch implements several fairly minor changes to the code
> required for IPA v4.5 support.
> 
> The last two patches implement changes to the GSI registers used for
> IPA.  Almost none of the registers change, but the range of memory
> in which most of the GSI registers is located is shifted by a fixed
> amount.  The fifth patch updates the GSI register definitions, and
> the last patch implements the memory shift for IPA v4.5.

Applied, thanks!