Merge branch 'ipa-abstract-status'

Alex Elder says:

====================
net: ipa: abstract status parsing

Under some circumstances, IPA generates a "packet status" structure
that describes information about a packet. This is used, for
example, when offload hardware detects an error in a packet, or
otherwise discovers a packet needs special handling. In this case,
the status is delivered (along with the packet it describes) to a
"default" endpoint so that it can be handled by the AP.

Until now, the structure of this status information hasn't changed.
However, to support more than 32 endpoints, this structure required
some changes, such that some fields are rearranged in ways that are
tricky to represent using C code.

This series updates code related to the IPA status structure. The
first patch uses a local variable to avoid recomputing a packet
length more than once. The second stops using sizeof() to determine
the size of an IPA packet status structure. Patches 3-5 extend the
definitions for values held in packet status fields. Patch 6 does a
little general cleanup to make patch 7 simpler. Patch 7 stops using
a C structure to represent packet status; instead, a new function
fetches values "by name" from a buffer containing such a structure.
The last patch updates this function so it also supports IPA v5.0+.
====================

Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ipa/ipa_endpoint.c

···
 
 #define IPA_ENDPOINT_RESET_AGGR_RETRY_MAX	3
 
-/** enum ipa_status_opcode - status element opcode hardware values */
-enum ipa_status_opcode {
-	IPA_STATUS_OPCODE_PACKET		= 0x01,
-	IPA_STATUS_OPCODE_DROPPED_PACKET	= 0x04,
-	IPA_STATUS_OPCODE_SUSPENDED_PACKET	= 0x08,
-	IPA_STATUS_OPCODE_PACKET_2ND_PASS	= 0x40,
+/** enum ipa_status_opcode - IPA status opcode field hardware values */
+enum ipa_status_opcode {				/* *Not* a bitmask */
+	IPA_STATUS_OPCODE_PACKET		= 1,
+	IPA_STATUS_OPCODE_NEW_RULE_PACKET	= 2,
+	IPA_STATUS_OPCODE_DROPPED_PACKET	= 4,
+	IPA_STATUS_OPCODE_SUSPENDED_PACKET	= 8,
+	IPA_STATUS_OPCODE_LOG			= 16,
+	IPA_STATUS_OPCODE_DCMP			= 32,
+	IPA_STATUS_OPCODE_PACKET_2ND_PASS	= 64,
 };
 
-/** enum ipa_status_exception - status element exception type */
-enum ipa_status_exception {
+/** enum ipa_status_exception - IPA status exception field hardware values */
+enum ipa_status_exception {				/* *Not* a bitmask */
 	/* 0 means no exception */
-	IPA_STATUS_EXCEPTION_DEAGGR		= 0x01,
+	IPA_STATUS_EXCEPTION_DEAGGR		= 1,
+	IPA_STATUS_EXCEPTION_IPTYPE		= 4,
+	IPA_STATUS_EXCEPTION_PACKET_LENGTH	= 8,
+	IPA_STATUS_EXCEPTION_FRAG_RULE_MISS	= 16,
+	IPA_STATUS_EXCEPTION_SW_FILTER		= 32,
+	IPA_STATUS_EXCEPTION_NAT		= 64,		/* IPv4 */
+	IPA_STATUS_EXCEPTION_IPV6_CONN_TRACK	= 64,		/* IPv6 */
+	IPA_STATUS_EXCEPTION_UC			= 128,
+	IPA_STATUS_EXCEPTION_INVALID_ENDPOINT	= 129,
+	IPA_STATUS_EXCEPTION_HEADER_INSERT	= 136,
+	IPA_STATUS_EXCEPTION_CHEKCSUM		= 229,
 };
 
-/* Status element provided by hardware */
-struct ipa_status {
-	u8 opcode;		/* enum ipa_status_opcode */
-	u8 exception;		/* enum ipa_status_exception */
-	__le16 mask;
-	__le16 pkt_len;
-	u8 endp_src_idx;
-	u8 endp_dst_idx;
-	__le32 metadata;
-	__le32 flags1;
-	__le64 flags2;
-	__le32 flags3;
-	__le32 flags4;
+/** enum ipa_status_mask - IPA status mask field bitmask hardware values */
+enum ipa_status_mask {
+	IPA_STATUS_MASK_FRAG_PROCESS		= BIT(0),
+	IPA_STATUS_MASK_FILT_PROCESS		= BIT(1),
+	IPA_STATUS_MASK_NAT_PROCESS		= BIT(2),
+	IPA_STATUS_MASK_ROUTE_PROCESS		= BIT(3),
+	IPA_STATUS_MASK_TAG_VALID		= BIT(4),
+	IPA_STATUS_MASK_FRAGMENT		= BIT(5),
+	IPA_STATUS_MASK_FIRST_FRAGMENT		= BIT(6),
+	IPA_STATUS_MASK_V4			= BIT(7),
+	IPA_STATUS_MASK_CKSUM_PROCESS		= BIT(8),
+	IPA_STATUS_MASK_AGGR_PROCESS		= BIT(9),
+	IPA_STATUS_MASK_DEST_EOT		= BIT(10),
+	IPA_STATUS_MASK_DEAGGR_PROCESS		= BIT(11),
+	IPA_STATUS_MASK_DEAGG_FIRST		= BIT(12),
+	IPA_STATUS_MASK_SRC_EOT			= BIT(13),
+	IPA_STATUS_MASK_PREV_EOT		= BIT(14),
+	IPA_STATUS_MASK_BYTE_LIMIT		= BIT(15),
 };
 
-/* Field masks for struct ipa_status structure fields */
-#define IPA_STATUS_MASK_TAG_VALID_FMASK		GENMASK(4, 4)
-#define IPA_STATUS_SRC_IDX_FMASK		GENMASK(4, 0)
-#define IPA_STATUS_DST_IDX_FMASK		GENMASK(4, 0)
-#define IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK	GENMASK(31, 22)
-#define IPA_STATUS_FLAGS2_TAG_FMASK		GENMASK_ULL(63, 16)
+/* Special IPA filter/router rule field value indicating "rule miss" */
+#define IPA_STATUS_RULE_MISS	0x3ff	/* 10-bit filter/router rule fields */
+
+/** The IPA status nat_type field uses enum ipa_nat_type hardware values */
+
+/* enum ipa_status_field_id - IPA packet status structure field identifiers */
+enum ipa_status_field_id {
+	STATUS_OPCODE,			/* enum ipa_status_opcode */
+	STATUS_EXCEPTION,		/* enum ipa_status_exception */
+	STATUS_MASK,			/* enum ipa_status_mask (bitmask) */
+	STATUS_LENGTH,
+	STATUS_SRC_ENDPOINT,
+	STATUS_DST_ENDPOINT,
+	STATUS_METADATA,
+	STATUS_FILTER_LOCAL,		/* Boolean */
+	STATUS_FILTER_HASH,		/* Boolean */
+	STATUS_FILTER_GLOBAL,		/* Boolean */
+	STATUS_FILTER_RETAIN,		/* Boolean */
+	STATUS_FILTER_RULE_INDEX,
+	STATUS_ROUTER_LOCAL,		/* Boolean */
+	STATUS_ROUTER_HASH,		/* Boolean */
+	STATUS_UCP,			/* Boolean */
+	STATUS_ROUTER_TABLE,
+	STATUS_ROUTER_RULE_INDEX,
+	STATUS_NAT_HIT,			/* Boolean */
+	STATUS_NAT_INDEX,
+	STATUS_NAT_TYPE,		/* enum ipa_nat_type */
+	STATUS_TAG_LOW32,		/* Low-order 32 bits of 48-bit tag */
+	STATUS_TAG_HIGH16,		/* High-order 16 bits of 48-bit tag */
+	STATUS_SEQUENCE,
+	STATUS_TIME_OF_DAY,
+	STATUS_HEADER_LOCAL,		/* Boolean */
+	STATUS_HEADER_OFFSET,
+	STATUS_FRAG_HIT,		/* Boolean */
+	STATUS_FRAG_RULE_INDEX,
+};
+
+/* Size in bytes of an IPA packet status structure */
+#define IPA_STATUS_SIZE			sizeof(__le32[4])
+
+/* IPA status structure decoder; looks up field values for a structure */
+static u32 ipa_status_extract(struct ipa *ipa, const void *data,
+			      enum ipa_status_field_id field)
+{
+	enum ipa_version version = ipa->version;
+	const __le32 *word = data;
+
+	switch (field) {
+	case STATUS_OPCODE:
+		return le32_get_bits(word[0], GENMASK(7, 0));
+	case STATUS_EXCEPTION:
+		return le32_get_bits(word[0], GENMASK(15, 8));
+	case STATUS_MASK:
+		return le32_get_bits(word[0], GENMASK(31, 16));
+	case STATUS_LENGTH:
+		return le32_get_bits(word[1], GENMASK(15, 0));
+	case STATUS_SRC_ENDPOINT:
+		if (version < IPA_VERSION_5_0)
+			return le32_get_bits(word[1], GENMASK(20, 16));
+		return le32_get_bits(word[1], GENMASK(23, 16));
+	/* Status word 1, bits 21-23 are reserved (not IPA v5.0+) */
+	/* Status word 1, bits 24-26 are reserved (IPA v5.0+) */
+	case STATUS_DST_ENDPOINT:
+		if (version < IPA_VERSION_5_0)
+			return le32_get_bits(word[1], GENMASK(28, 24));
+		return le32_get_bits(word[7], GENMASK(23, 16));
+	/* Status word 1, bits 29-31 are reserved */
+	case STATUS_METADATA:
+		return le32_to_cpu(word[2]);
+	case STATUS_FILTER_LOCAL:
+		return le32_get_bits(word[3], GENMASK(0, 0));
+	case STATUS_FILTER_HASH:
+		return le32_get_bits(word[3], GENMASK(1, 1));
+	case STATUS_FILTER_GLOBAL:
+		return le32_get_bits(word[3], GENMASK(2, 2));
+	case STATUS_FILTER_RETAIN:
+		return le32_get_bits(word[3], GENMASK(3, 3));
+	case STATUS_FILTER_RULE_INDEX:
+		return le32_get_bits(word[3], GENMASK(13, 4));
+	/* ROUTER_TABLE is in word 3, bits 14-21 (IPA v5.0+) */
+	case STATUS_ROUTER_LOCAL:
+		if (version < IPA_VERSION_5_0)
+			return le32_get_bits(word[3], GENMASK(14, 14));
+		return le32_get_bits(word[1], GENMASK(27, 27));
+	case STATUS_ROUTER_HASH:
+		if (version < IPA_VERSION_5_0)
+			return le32_get_bits(word[3], GENMASK(15, 15));
+		return le32_get_bits(word[1], GENMASK(28, 28));
+	case STATUS_UCP:
+		if (version < IPA_VERSION_5_0)
+			return le32_get_bits(word[3], GENMASK(16, 16));
+		return le32_get_bits(word[7], GENMASK(31, 31));
+	case STATUS_ROUTER_TABLE:
+		if (version < IPA_VERSION_5_0)
+			return le32_get_bits(word[3], GENMASK(21, 17));
+		return le32_get_bits(word[3], GENMASK(21, 14));
+	case STATUS_ROUTER_RULE_INDEX:
+		return le32_get_bits(word[3], GENMASK(31, 22));
+	case STATUS_NAT_HIT:
+		return le32_get_bits(word[4], GENMASK(0, 0));
+	case STATUS_NAT_INDEX:
+		return le32_get_bits(word[4], GENMASK(13, 1));
+	case STATUS_NAT_TYPE:
+		return le32_get_bits(word[4], GENMASK(15, 14));
+	case STATUS_TAG_LOW32:
+		return le32_get_bits(word[4], GENMASK(31, 16)) |
+			(le32_get_bits(word[5], GENMASK(15, 0)) << 16);
+	case STATUS_TAG_HIGH16:
+		return le32_get_bits(word[5], GENMASK(31, 16));
+	case STATUS_SEQUENCE:
+		return le32_get_bits(word[6], GENMASK(7, 0));
+	case STATUS_TIME_OF_DAY:
+		return le32_get_bits(word[6], GENMASK(31, 8));
+	case STATUS_HEADER_LOCAL:
+		return le32_get_bits(word[7], GENMASK(0, 0));
+	case STATUS_HEADER_OFFSET:
+		return le32_get_bits(word[7], GENMASK(10, 1));
+	case STATUS_FRAG_HIT:
+		return le32_get_bits(word[7], GENMASK(11, 11));
+	case STATUS_FRAG_RULE_INDEX:
+		return le32_get_bits(word[7], GENMASK(15, 12));
+	/* Status word 7, bits 16-30 are reserved */
+	/* Status word 7, bit 31 is reserved (not IPA v5.0+) */
+	default:
+		WARN(true, "%s: bad field_id %u\n", __func__, field);
+		return 0;
+	}
+}
 
 /* Compute the aggregation size value to use for a given buffer size */
 static u32 ipa_aggr_size_kb(u32 rx_buffer_size, bool aggr_hard_limit)
···
 		return;
 
 	reg = ipa_reg(ipa, ENDP_INIT_NAT);
-	val = ipa_reg_encode(reg, NAT_EN, IPA_NAT_BYPASS);
+	val = ipa_reg_encode(reg, NAT_EN, IPA_NAT_TYPE_BYPASS);
 
 	iowrite32(val, ipa->reg_virt + ipa_reg_n_offset(reg, endpoint_id));
 }
···
 			val |= ipa_reg_encode(reg, STATUS_ENDP,
 					      status_endpoint_id);
 		}
-		/* STATUS_LOCATION is 0, meaning status element precedes
-		 * packet (not present for IPA v4.5+)
+		/* STATUS_LOCATION is 0, meaning IPA packet status
+		 * precedes the packet (not present for IPA v4.5+)
 		 */
 		/* STATUS_PKT_SUPPRESS_FMASK is 0 (not present for v4.0+) */
 	}
···
 	return skb != NULL;
 }
 
-/* The format of a packet status element is the same for several status
- * types (opcodes).  Other types aren't currently supported.
+ /* The format of an IPA packet status structure is the same for several
+  * status types (opcodes).  Other types aren't currently supported.
  */
 static bool ipa_status_format_packet(enum ipa_status_opcode opcode)
 {
···
 	}
 }
 
-static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
-				     const struct ipa_status *status)
+static bool
+ipa_endpoint_status_skip(struct ipa_endpoint *endpoint, const void *data)
 {
+	struct ipa *ipa = endpoint->ipa;
+	enum ipa_status_opcode opcode;
 	u32 endpoint_id;
 
-	if (!ipa_status_format_packet(status->opcode))
+	opcode = ipa_status_extract(ipa, data, STATUS_OPCODE);
+	if (!ipa_status_format_packet(opcode))
 		return true;
-	if (!status->pkt_len)
-		return true;
-	endpoint_id = u8_get_bits(status->endp_dst_idx,
-				  IPA_STATUS_DST_IDX_FMASK);
+
+	endpoint_id = ipa_status_extract(ipa, data, STATUS_DST_ENDPOINT);
 	if (endpoint_id != endpoint->endpoint_id)
 		return true;
 
 	return false;	/* Don't skip this packet, process it */
 }
 
-static bool ipa_endpoint_status_tag(struct ipa_endpoint *endpoint,
-				    const struct ipa_status *status)
+static bool
+ipa_endpoint_status_tag_valid(struct ipa_endpoint *endpoint, const void *data)
 {
 	struct ipa_endpoint *command_endpoint;
+	enum ipa_status_mask status_mask;
 	struct ipa *ipa = endpoint->ipa;
 	u32 endpoint_id;
 
-	if (!le16_get_bits(status->mask, IPA_STATUS_MASK_TAG_VALID_FMASK))
+	status_mask = ipa_status_extract(ipa, data, STATUS_MASK);
+	if (!status_mask)
 		return false;	/* No valid tag */
 
 	/* The status contains a valid tag.  We know the packet was sent to
···
 	 * If the packet came from the AP->command TX endpoint we know
 	 * this packet was sent as part of the pipeline clear process.
 	 */
-	endpoint_id = u8_get_bits(status->endp_src_idx,
-				  IPA_STATUS_SRC_IDX_FMASK);
+	endpoint_id = ipa_status_extract(ipa, data, STATUS_SRC_ENDPOINT);
 	command_endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
 	if (endpoint_id == command_endpoint->endpoint_id) {
 		complete(&ipa->completion);
···
 }
 
 /* Return whether the status indicates the packet should be dropped */
-static bool ipa_endpoint_status_drop(struct ipa_endpoint *endpoint,
-				     const struct ipa_status *status)
+static bool
+ipa_endpoint_status_drop(struct ipa_endpoint *endpoint, const void *data)
 {
-	u32 val;
+	enum ipa_status_exception exception;
+	struct ipa *ipa = endpoint->ipa;
+	u32 rule;
 
 	/* If the status indicates a tagged transfer, we'll drop the packet */
-	if (ipa_endpoint_status_tag(endpoint, status))
+	if (ipa_endpoint_status_tag_valid(endpoint, data))
 		return true;
 
 	/* Deaggregation exceptions we drop; all other types we consume */
-	if (status->exception)
-		return status->exception == IPA_STATUS_EXCEPTION_DEAGGR;
+	exception = ipa_status_extract(ipa, data, STATUS_EXCEPTION);
+	if (exception)
+		return exception == IPA_STATUS_EXCEPTION_DEAGGR;
 
 	/* Drop the packet if it fails to match a routing rule; otherwise no */
-	val = le32_get_bits(status->flags1, IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
+	rule = ipa_status_extract(ipa, data, STATUS_ROUTER_RULE_INDEX);
 
-	return val == field_max(IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
+	return rule == IPA_STATUS_RULE_MISS;
 }
 
 static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,
···
 	u32 buffer_size = endpoint->config.rx.buffer_size;
 	void *data = page_address(page) + NET_SKB_PAD;
 	u32 unused = buffer_size - total_len;
+	struct ipa *ipa = endpoint->ipa;
 	u32 resid = total_len;
 
 	while (resid) {
-		const struct ipa_status *status = data;
+		u32 length;
 		u32 align;
 		u32 len;
 
-		if (resid < sizeof(*status)) {
+		if (resid < IPA_STATUS_SIZE) {
 			dev_err(&endpoint->ipa->pdev->dev,
 				"short message (%u bytes < %zu byte status)\n",
-				resid, sizeof(*status));
+				resid, IPA_STATUS_SIZE);
 			break;
 		}
 
 		/* Skip over status packets that lack packet data */
-		if (ipa_endpoint_status_skip(endpoint, status)) {
-			data += sizeof(*status);
-			resid -= sizeof(*status);
+		length = ipa_status_extract(ipa, data, STATUS_LENGTH);
+		if (!length || ipa_endpoint_status_skip(endpoint, data)) {
+			data += IPA_STATUS_SIZE;
+			resid -= IPA_STATUS_SIZE;
 			continue;
 		}
 
 		/* Compute the amount of buffer space consumed by the packet,
-		 * including the status element.  If the hardware is configured
-		 * to pad packet data to an aligned boundary, account for that.
+		 * including the status.  If the hardware is configured to
+		 * pad packet data to an aligned boundary, account for that.
 		 * And if checksum offload is enabled a trailer containing
 		 * computed checksum information will be appended.
 		 */
 		align = endpoint->config.rx.pad_align ? : 1;
-		len = le16_to_cpu(status->pkt_len);
-		len = sizeof(*status) + ALIGN(len, align);
+		len = IPA_STATUS_SIZE + ALIGN(length, align);
 		if (endpoint->config.checksum)
 			len += sizeof(struct rmnet_map_dl_csum_trailer);
 
-		if (!ipa_endpoint_status_drop(endpoint, status)) {
+		if (!ipa_endpoint_status_drop(endpoint, data)) {
 			void *data2;
 			u32 extra;
-			u32 len2;
 
 			/* Client receives only packet data (no status) */
-			data2 = data + sizeof(*status);
-			len2 = le16_to_cpu(status->pkt_len);
+			data2 = data + IPA_STATUS_SIZE;
 
 			/* Have the true size reflect the extra unused space in
 			 * the original receive buffer.  Distribute the "cost"
···
 			 * buffer.
 			 */
 			extra = DIV_ROUND_CLOSEST(unused * len, total_len);
-			ipa_endpoint_skb_copy(endpoint, data2, len2, extra);
+			ipa_endpoint_skb_copy(endpoint, data2, length, extra);
 		}
 
 		/* Consume status and the full packet it describes */

drivers/net/ipa/ipa_reg.h

···
 	NAT_EN,
 };
 
-/** enum ipa_nat_en - ENDP_INIT_NAT register NAT_EN field value */
-enum ipa_nat_en {
-	IPA_NAT_BYPASS				= 0x0,
-	IPA_NAT_SRC				= 0x1,
-	IPA_NAT_DST				= 0x2,
+/** enum ipa_nat_type - ENDP_INIT_NAT register NAT_EN field value */
+enum ipa_nat_type {
+	IPA_NAT_TYPE_BYPASS			= 0,
+	IPA_NAT_TYPE_SRC			= 1,
+	IPA_NAT_TYPE_DST			= 2,
 };
 
 /* ENDP_INIT_HDR register */