[PATCH iwl-next v3 02/13] ice: Add function to get RX queue context

[Yahui Cao <yahui.cao@intel.com>]

Export RX queue context get function which is consumed by linux live
migration driver to save and load device state.

Signed-off-by: Yahui Cao <yahui.cao@intel.com>
Signed-off-by: Lingyu Liu <lingyu.liu@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_common.c | 268 ++++++++++++++++++++
 drivers/net/ethernet/intel/ice/ice_common.h |   5 +
 2 files changed, 273 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_common.c b/drivers/net/ethernet/intel/ice/ice_common.c
index 6f12ea050d35..5892d5a22323 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.c
+++ b/drivers/net/ethernet/intel/ice/ice_common.c
@@ -1217,6 +1217,34 @@ ice_copy_rxq_ctx_to_hw(struct ice_hw *hw, u8 *ice_rxq_ctx, u32 rxq_index)
 	return 0;
 }
 
+/**
+ * ice_copy_rxq_ctx_from_hw - Copy rxq context register from HW
+ * @hw: pointer to the hardware structure
+ * @ice_rxq_ctx: pointer to the rxq context
+ * @rxq_index: the index of the Rx queue
+ *
+ * Copy rxq context from HW register space to dense structure
+ */
+static int
+ice_copy_rxq_ctx_from_hw(struct ice_hw *hw, u8 *ice_rxq_ctx, u32 rxq_index)
+{
+	u8 i;
+
+	if (!ice_rxq_ctx || rxq_index > QRX_CTRL_MAX_INDEX)
+		return -EINVAL;
+
+	/* Copy each dword separately from HW */
+	for (i = 0; i < ICE_RXQ_CTX_SIZE_DWORDS; i++) {
+		u32 *ctx = (u32 *)(ice_rxq_ctx + (i * sizeof(u32)));
+
+		*ctx = rd32(hw, QRX_CONTEXT(i, rxq_index));
+
+		ice_debug(hw, ICE_DBG_QCTX, "qrxdata[%d]: %08X\n", i, *ctx);
+	}
+
+	return 0;
+}
+
 /* LAN Rx Queue Context */
 static const struct ice_ctx_ele ice_rlan_ctx_info[] = {
 	/* Field		Width	LSB */
@@ -1268,6 +1296,32 @@ ice_write_rxq_ctx(struct ice_hw *hw, struct ice_rlan_ctx *rlan_ctx,
 	return ice_copy_rxq_ctx_to_hw(hw, ctx_buf, rxq_index);
 }
 
+/**
+ * ice_read_rxq_ctx - Read rxq context from HW
+ * @hw: pointer to the hardware structure
+ * @rlan_ctx: pointer to the rxq context
+ * @rxq_index: the index of the Rx queue
+ *
+ * Read rxq context from HW register space and then converts it from dense
+ * structure to sparse
+ */
+int
+ice_read_rxq_ctx(struct ice_hw *hw, struct ice_rlan_ctx *rlan_ctx,
+		 u32 rxq_index)
+{
+	u8 ctx_buf[ICE_RXQ_CTX_SZ] = { 0 };
+	int status;
+
+	if (!rlan_ctx)
+		return -EINVAL;
+
+	status = ice_copy_rxq_ctx_from_hw(hw, ctx_buf, rxq_index);
+	if (status)
+		return status;
+
+	return ice_get_ctx(ctx_buf, (u8 *)rlan_ctx, ice_rlan_ctx_info);
+}
+
 /* LAN Tx Queue Context */
 const struct ice_ctx_ele ice_tlan_ctx_info[] = {
 				    /* Field			Width	LSB */
@@ -4443,6 +4497,220 @@ ice_set_ctx(struct ice_hw *hw, u8 *src_ctx, u8 *dest_ctx,
 	return 0;
 }
 
+/**
+ * ice_read_byte - read context byte into struct
+ * @src_ctx:  the context structure to read from
+ * @dest_ctx: the context to be written to
+ * @ce_info:  a description of the struct to be filled
+ */
+static void
+ice_read_byte(u8 *src_ctx, u8 *dest_ctx, const struct ice_ctx_ele *ce_info)
+{
+	u8 dest_byte, mask;
+	u8 *src, *target;
+	u16 shift_width;
+
+	/* prepare the bits and mask */
+	shift_width = ce_info->lsb % 8;
+	mask = (u8)(BIT(ce_info->width) - 1);
+
+	/* shift to correct alignment */
+	mask <<= shift_width;
+
+	/* get the current bits from the src bit string */
+	src = src_ctx + (ce_info->lsb / 8);
+
+	memcpy(&dest_byte, src, sizeof(dest_byte));
+
+	dest_byte &= mask;
+
+	dest_byte >>= shift_width;
+
+	/* get the address from the struct field */
+	target = dest_ctx + ce_info->offset;
+
+	/* put it back in the struct */
+	memcpy(target, &dest_byte, sizeof(dest_byte));
+}
+
+/**
+ * ice_read_word - read context word into struct
+ * @src_ctx:  the context structure to read from
+ * @dest_ctx: the context to be written to
+ * @ce_info:  a description of the struct to be filled
+ */
+static void
+ice_read_word(u8 *src_ctx, u8 *dest_ctx, const struct ice_ctx_ele *ce_info)
+{
+	u16 dest_word, mask;
+	u8 *src, *target;
+	__le16 src_word;
+	u16 shift_width;
+
+	/* prepare the bits and mask */
+	shift_width = ce_info->lsb % 8;
+	mask = BIT(ce_info->width) - 1;
+
+	/* shift to correct alignment */
+	mask <<= shift_width;
+
+	/* get the current bits from the src bit string */
+	src = src_ctx + (ce_info->lsb / 8);
+
+	memcpy(&src_word, src, sizeof(src_word));
+
+	/* the data in the memory is stored as little endian so mask it
+	 * correctly
+	 */
+	src_word &= cpu_to_le16(mask);
+
+	/* get the data back into host order before shifting */
+	dest_word = le16_to_cpu(src_word);
+
+	dest_word >>= shift_width;
+
+	/* get the address from the struct field */
+	target = dest_ctx + ce_info->offset;
+
+	/* put it back in the struct */
+	memcpy(target, &dest_word, sizeof(dest_word));
+}
+
+/**
+ * ice_read_dword - read context dword into struct
+ * @src_ctx:  the context structure to read from
+ * @dest_ctx: the context to be written to
+ * @ce_info:  a description of the struct to be filled
+ */
+static void
+ice_read_dword(u8 *src_ctx, u8 *dest_ctx, const struct ice_ctx_ele *ce_info)
+{
+	u32 dest_dword, mask;
+	__le32 src_dword;
+	u8 *src, *target;
+	u16 shift_width;
+
+	/* prepare the bits and mask */
+	shift_width = ce_info->lsb % 8;
+
+	/* if the field width is exactly 32 on an x86 machine, then the shift
+	 * operation will not work because the SHL instructions count is masked
+	 * to 5 bits so the shift will do nothing
+	 */
+	if (ce_info->width < 32)
+		mask = BIT(ce_info->width) - 1;
+	else
+		mask = (u32)~0;
+
+	/* shift to correct alignment */
+	mask <<= shift_width;
+
+	/* get the current bits from the src bit string */
+	src = src_ctx + (ce_info->lsb / 8);
+
+	memcpy(&src_dword, src, sizeof(src_dword));
+
+	/* the data in the memory is stored as little endian so mask it
+	 * correctly
+	 */
+	src_dword &= cpu_to_le32(mask);
+
+	/* get the data back into host order before shifting */
+	dest_dword = le32_to_cpu(src_dword);
+
+	dest_dword >>= shift_width;
+
+	/* get the address from the struct field */
+	target = dest_ctx + ce_info->offset;
+
+	/* put it back in the struct */
+	memcpy(target, &dest_dword, sizeof(dest_dword));
+}
+
+/**
+ * ice_read_qword - read context qword into struct
+ * @src_ctx:  the context structure to read from
+ * @dest_ctx: the context to be written to
+ * @ce_info:  a description of the struct to be filled
+ */
+static void
+ice_read_qword(u8 *src_ctx, u8 *dest_ctx, const struct ice_ctx_ele *ce_info)
+{
+	u64 dest_qword, mask;
+	__le64 src_qword;
+	u8 *src, *target;
+	u16 shift_width;
+
+	/* prepare the bits and mask */
+	shift_width = ce_info->lsb % 8;
+
+	/* if the field width is exactly 64 on an x86 machine, then the shift
+	 * operation will not work because the SHL instructions count is masked
+	 * to 6 bits so the shift will do nothing
+	 */
+	if (ce_info->width < 64)
+		mask = BIT_ULL(ce_info->width) - 1;
+	else
+		mask = (u64)~0;
+
+	/* shift to correct alignment */
+	mask <<= shift_width;
+
+	/* get the current bits from the src bit string */
+	src = src_ctx + (ce_info->lsb / 8);
+
+	memcpy(&src_qword, src, sizeof(src_qword));
+
+	/* the data in the memory is stored as little endian so mask it
+	 * correctly
+	 */
+	src_qword &= cpu_to_le64(mask);
+
+	/* get the data back into host order before shifting */
+	dest_qword = le64_to_cpu(src_qword);
+
+	dest_qword >>= shift_width;
+
+	/* get the address from the struct field */
+	target = dest_ctx + ce_info->offset;
+
+	/* put it back in the struct */
+	memcpy(target, &dest_qword, sizeof(dest_qword));
+}
+
+/**
+ * ice_get_ctx - extract context bits from a packed structure
+ * @src_ctx:  pointer to a generic packed context structure
+ * @dest_ctx: pointer to a generic non-packed context structure
+ * @ce_info:  a description of the structure to be read from
+ */
+int
+ice_get_ctx(u8 *src_ctx, u8 *dest_ctx, const struct ice_ctx_ele *ce_info)
+{
+	int i;
+
+	for (i = 0; ce_info[i].width; i++) {
+		switch (ce_info[i].size_of) {
+		case 1:
+			ice_read_byte(src_ctx, dest_ctx, &ce_info[i]);
+			break;
+		case 2:
+			ice_read_word(src_ctx, dest_ctx, &ce_info[i]);
+			break;
+		case 4:
+			ice_read_dword(src_ctx, dest_ctx, &ce_info[i]);
+			break;
+		case 8:
+			ice_read_qword(src_ctx, dest_ctx, &ce_info[i]);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 /**
  * ice_get_lan_q_ctx - get the LAN queue context for the given VSI and TC
  * @hw: pointer to the HW struct
diff --git a/drivers/net/ethernet/intel/ice/ice_common.h b/drivers/net/ethernet/intel/ice/ice_common.h
index 71381d9835a1..657767c50be6 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.h
+++ b/drivers/net/ethernet/intel/ice/ice_common.h
@@ -55,6 +55,9 @@ void ice_set_safe_mode_caps(struct ice_hw *hw);
 int
 ice_write_rxq_ctx(struct ice_hw *hw, struct ice_rlan_ctx *rlan_ctx,
 		  u32 rxq_index);
+int
+ice_read_rxq_ctx(struct ice_hw *hw, struct ice_rlan_ctx *rlan_ctx,
+		 u32 rxq_index);
 
 int
 ice_aq_get_rss_lut(struct ice_hw *hw, struct ice_aq_get_set_rss_lut_params *get_params);
@@ -74,6 +77,8 @@ extern const struct ice_ctx_ele ice_tlan_ctx_info[];
 int
 ice_set_ctx(struct ice_hw *hw, u8 *src_ctx, u8 *dest_ctx,
 	    const struct ice_ctx_ele *ce_info);
+int
+ice_get_ctx(u8 *src_ctx, u8 *dest_ctx, const struct ice_ctx_ele *ce_info);
 
 extern struct mutex ice_global_cfg_lock_sw;
 
-- 
2.34.1