net: ipa: add support to code for IPA v4.5

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>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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);

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);

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;
 	}