net: ipa: make filter/routing hash enable register variable

For IPA v3.5.1, the IPA filter/routing hash enable register actually
does exist, but it is at offset 0x8c into the IPA register space.
For newer versions of IPA it is at offset 0x148.

Define a new inline function ipa_reg_filt_rout_hash_en_offset() to
return the appropriate value for a given version of IPA hardware.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ipa/ipa_main.c

@@ -339,9 +339,12 @@ static void ipa_hardware_config(struct ipa *ipa)
 	val = u32_encode_bits(granularity, AGGR_GRANULARITY);
 	iowrite32(val, ipa->reg_virt + IPA_REG_COUNTER_CFG_OFFSET);
 
-	/* Disable hashed IPv4 and IPv6 routing and filtering for IPA v4.2 */
-	if (ipa->version == IPA_VERSION_4_2)
-		iowrite32(0, ipa->reg_virt + IPA_REG_FILT_ROUT_HASH_EN_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);
+
+		iowrite32(0, ipa->reg_virt + offset);
+	}
 
 	/* Enable dynamic clock division */
 	ipa_hardware_dcd_config(ipa);

drivers/net/ipa/ipa_reg.h

@@ -151,8 +151,13 @@ static inline u32 ipa_reg_state_aggr_active_offset(enum ipa_version version)
 }
 /* ipa->available defines the valid bits in the STATE_AGGR_ACTIVE register */
 
-/* The next register is present for IPA v4.2 and above */
-#define IPA_REG_FILT_ROUT_HASH_EN_OFFSET		0x00000148
+static inline u32 ipa_reg_filt_rout_hash_en_offset(enum ipa_version version)
+{
+	if (version == IPA_VERSION_3_5_1)
+		return 0x000008c;
+
+	return 0x0000148;
+}
 
 static inline u32 ipa_reg_filt_rout_hash_flush_offset(enum ipa_version version)
 {