net: ipa: update table cache flushing

Update the code that causes filter and router table caches to be
flushed so that it supports IPA versions 5.0+.  It adds a comment in
ipa_hardware_config_hashing() that explains that cacheing does not
need to be enabled, just as before, because it's enabled by default.
(For the record, the FILT_ROUT_CACHE_CFG register would have been
used if we wanted to explicitly enable these.)
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ipa/ipa_cmd.c

@@ -295,7 +295,11 @@ static bool ipa_cmd_register_write_valid(struct ipa *ipa)
 	 * offset will fit in a register write IPA immediate command.
 	 */
 	if (ipa_table_hash_support(ipa)) {
+		if (ipa->version < IPA_VERSION_5_0)
 			reg = ipa_reg(ipa, FILT_ROUT_HASH_FLUSH);
+		else
+			reg = ipa_reg(ipa, FILT_ROUT_CACHE_FLUSH);
+
 		offset = ipa_reg_offset(reg);
 		name = "filter/route hash flush";
 		if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))

drivers/net/ipa/ipa_main.c

 // SPDX-License-Identifier: GPL-2.0
 
 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
- * Copyright (C) 2018-2022 Linaro Ltd.
+ * Copyright (C) 2018-2023 Linaro Ltd.
  */
 
 #include <linux/types.h>
@@ -432,6 +432,11 @@ static void ipa_hardware_config_hashing(struct ipa *ipa)
 {
 	const struct ipa_reg *reg;
 
+	/* Other than IPA v4.2, all versions enable "hashing".  Starting
+	 * with IPA v5.0, the filter and router tables are implemented
+	 * differently, but the default configuration enables this feature
+	 * (now referred to as "cacheing"), so there's nothing to do here.
+	 */
 	if (ipa->version != IPA_VERSION_4_2)
 		return;
 

drivers/net/ipa/ipa_table.c

 // SPDX-License-Identifier: GPL-2.0
 
 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
- * Copyright (C) 2018-2022 Linaro Ltd.
+ * Copyright (C) 2018-2023 Linaro Ltd.
  */
 
 #include <linux/types.h>
@@ -359,6 +359,7 @@ int ipa_table_hash_flush(struct ipa *ipa)
 		return -EBUSY;
 	}
 
+	if (ipa->version < IPA_VERSION_5_0) {
 		reg = ipa_reg(ipa, FILT_ROUT_HASH_FLUSH);
 		offset = ipa_reg_offset(reg);
 
@@ -366,6 +367,14 @@ int ipa_table_hash_flush(struct ipa *ipa)
 		val |= ipa_reg_bit(reg, IPV6_FILTER_HASH);
 		val |= ipa_reg_bit(reg, IPV4_ROUTER_HASH);
 		val |= ipa_reg_bit(reg, IPV4_FILTER_HASH);
+	} else {
+		reg = ipa_reg(ipa, FILT_ROUT_CACHE_FLUSH);
+		offset = ipa_reg_offset(reg);
+
+		/* IPA v5.0+ uses a unified cache (both IPv4 and IPv6) */
+		val = ipa_reg_bit(reg, ROUTER_CACHE);
+		val |= ipa_reg_bit(reg, FILTER_CACHE);
+	}
 
 	ipa_cmd_register_write_add(trans, offset, val, val, false);