[PATCH net-next 6/8] net: ipa: IPA status preparatory cleanups

Alex Elder
2023-01-25T20:46:29Z

The next patch reworks how the IPA packet status structure is
interpreted. This patch does some preparatory work, to make it
easier to see the effect of that change:
- Change a few functions that access fields in a IPA packet status
structure to store field values in local variables with names
related to the field.
- Pass a void pointer rather than an (equivalent) status pointer
to two functions called by ipa_endpoint_status_parse().
- Use "rule" rather than "val" as the name of a variable that
holds a routing rule ID.
- Consistently use "IPA packet status" rather than "status
element" when referring to this data structure.

Signed-off-by: Alex Elder <elder@linaro.org>
---
drivers/net/ipa/ipa_endpoint.c | 43 ++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
index ee3c29b1efea9..5097eb1bbadb0 100644
--- a/drivers/net/ipa/ipa_endpoint.c
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -1182,8 +1182,8 @@ static void ipa_endpoint_status(struct ipa_endpoint *endpoint)
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+) */
}
@@ -1339,8 +1339,8 @@ static bool ipa_endpoint_skb_build(struct ipa_endpoint *endpoint,
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)
{
@@ -1358,9 +1358,11 @@ 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)
{
+ enum ipa_status_opcode opcode;
u32 endpoint_id;

- if (!ipa_status_format_packet(status->opcode))
+ opcode = status->opcode;
+ if (!ipa_status_format_packet(opcode))
return true;

endpoint_id = u8_get_bits(status->endp_dst_idx,
@@ -1371,14 +1373,16 @@ static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
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 struct ipa_status *status)
{
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))
+ status_mask = le16_get_bits(status->mask, IPA_STATUS_MASK_TAG_VALID);
+ if (!status_mask)
return false; /* No valid tag */

/* The status contains a valid tag. We know the packet was sent to
@@ -1404,20 +1408,23 @@ static bool ipa_endpoint_status_tag(struct ipa_endpoint *endpoint,
static bool ipa_endpoint_status_drop(struct ipa_endpoint *endpoint,
const struct ipa_status *status)
{
- u32 val;
+ enum ipa_status_exception exception;
+ 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, status))
return true;

/* Deaggregation exceptions we drop; all other types we consume */
- if (status->exception)
- return status->exception == IPA_STATUS_EXCEPTION_DEAGGR;
+ exception = 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 = le32_get_bits(status->flags1,
+ IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);

- return val == field_max(IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
+ return rule == field_max(IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
}

static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,
@@ -1443,15 +1450,15 @@ static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,

/* Skip over status packets that lack packet data */
length = le16_to_cpu(status->pkt_len);
- if (!length || ipa_endpoint_status_skip(endpoint, status)) {
+ 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.
*/
@@ -1460,7 +1467,7 @@ static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,
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;

--
2.34.1