[dpdk-dev] [PATCH 29/36] common/sfc_efx/base: provide helper to check Rx prefix

[Andrew Rybchenko <arybchenko@solarflare.com>]

A new function allows to check if used Rx prefix layout matches
available Rx prefix layout. Length check is out-of-scope of the
function and caller should ensure length is either checked or
different length with everything required in place is handled
properly.

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 drivers/common/sfc_efx/base/efx.h             | 12 ++++++
 drivers/common/sfc_efx/base/efx_rx.c          | 40 +++++++++++++++++++
 .../sfc_efx/rte_common_sfc_efx_version.map    |  1 +
 3 files changed, 53 insertions(+)

diff --git a/drivers/common/sfc_efx/base/efx.h b/drivers/common/sfc_efx/base/efx.h
index 406e96caf8..bd1ac303b1 100644
--- a/drivers/common/sfc_efx/base/efx.h
+++ b/drivers/common/sfc_efx/base/efx.h
@@ -2920,6 +2920,18 @@ typedef struct efx_rx_prefix_layout_s {
 	efx_rx_prefix_field_info_t	erpl_fields[EFX_RX_PREFIX_NFIELDS];
 } efx_rx_prefix_layout_t;
 
+/*
+ * Helper function to find out a bit mask of wanted but not available
+ * Rx prefix fields.
+ *
+ * A field is considered as not available if any parameter mismatch.
+ */
+LIBEFX_API
+extern	__checkReturn	uint32_t
+efx_rx_prefix_layout_check(
+	__in		const efx_rx_prefix_layout_t *available,
+	__in		const efx_rx_prefix_layout_t *wanted);
+
 LIBEFX_API
 extern	__checkReturn	efx_rc_t
 efx_rx_prefix_get_layout(
diff --git a/drivers/common/sfc_efx/base/efx_rx.c b/drivers/common/sfc_efx/base/efx_rx.c
index d6b56fec48..93a73703ed 100644
--- a/drivers/common/sfc_efx/base/efx_rx.c
+++ b/drivers/common/sfc_efx/base/efx_rx.c
@@ -1803,3 +1803,43 @@ siena_rx_fini(
 }
 
 #endif /* EFSYS_OPT_SIENA */
+
+static	__checkReturn	boolean_t
+efx_rx_prefix_layout_fields_match(
+	__in		const efx_rx_prefix_field_info_t *erpfip1,
+	__in		const efx_rx_prefix_field_info_t *erpfip2)
+{
+	if (erpfip1->erpfi_offset_bits != erpfip2->erpfi_offset_bits)
+		return (B_FALSE);
+
+	if (erpfip1->erpfi_width_bits != erpfip2->erpfi_width_bits)
+		return (B_FALSE);
+
+	if (erpfip1->erpfi_big_endian != erpfip2->erpfi_big_endian)
+		return (B_FALSE);
+
+	return (B_TRUE);
+}
+
+	__checkReturn	uint32_t
+efx_rx_prefix_layout_check(
+	__in		const efx_rx_prefix_layout_t *available,
+	__in		const efx_rx_prefix_layout_t *wanted)
+{
+	uint32_t result = 0;
+	unsigned int i;
+
+	EFX_STATIC_ASSERT(EFX_RX_PREFIX_NFIELDS < sizeof (result) * 8);
+	for (i = 0; i < EFX_RX_PREFIX_NFIELDS; ++i) {
+		/* Skip the field if driver does not want to use it */
+		if (wanted->erpl_fields[i].erpfi_width_bits == 0)
+			continue;
+
+		if (efx_rx_prefix_layout_fields_match(
+			    &available->erpl_fields[i],
+			    &wanted->erpl_fields[i]) == B_FALSE)
+			result |= (1U << i);
+	}
+
+	return (result);
+}
diff --git a/drivers/common/sfc_efx/rte_common_sfc_efx_version.map b/drivers/common/sfc_efx/rte_common_sfc_efx_version.map
index fd95fd09e5..f656d5b644 100644
--- a/drivers/common/sfc_efx/rte_common_sfc_efx_version.map
+++ b/drivers/common/sfc_efx/rte_common_sfc_efx_version.map
@@ -141,6 +141,7 @@ INTERNAL {
 	efx_rx_hash_default_support_get;
 	efx_rx_init;
 	efx_rx_prefix_get_layout;
+	efx_rx_prefix_layout_check;
 	efx_rx_qcreate;
 	efx_rx_qcreate_es_super_buffer;
 	efx_rx_qdestroy;
-- 
2.17.1