cxgb4/cxgb4vf: Add code to calculate T5 BAR2 Offsets for SGE Queue Registers

Add new Common Code facilities for calculating T5 BAR2 Offsets for SGE Queue
Registers. This new code can handle situations where

    Queues Per Page * SGE BAR2 Queue Register Area Size > Page Size

Based on original work by Casey Leedom <leedom@chelsio.com>

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -222,6 +222,12 @@ struct tp_err_stats {
 	u32 ofldCongDefer;
 };
 
+struct sge_params {
+	u32 hps;			/* host page size for our PF/VF */
+	u32 eq_qpp;			/* egress queues/page for our PF/VF */
+	u32 iq_qpp;			/* egress queues/page for our PF/VF */
+};
+
 struct tp_params {
 	unsigned int ntxchan;        /* # of Tx channels */
 	unsigned int tre;            /* log2 of core clocks per TP tick */
@@ -285,6 +291,7 @@ enum chip_type {
 };
 
 struct adapter_params {
+	struct sge_params sge;
 	struct tp_params  tp;
 	struct vpd_params vpd;
 	struct pci_params pci;
@@ -995,6 +1002,15 @@ int t4_prep_fw(struct adapter *adap, struct fw_info *fw_info,
 	       const u8 *fw_data, unsigned int fw_size,
 	       struct fw_hdr *card_fw, enum dev_state state, int *reset);
 int t4_prep_adapter(struct adapter *adapter);
+
+enum t4_bar2_qtype { T4_BAR2_QTYPE_EGRESS, T4_BAR2_QTYPE_INGRESS };
+int t4_bar2_sge_qregs(struct adapter *adapter,
+		      unsigned int qid,
+		      enum t4_bar2_qtype qtype,
+		      u64 *pbar2_qoffset,
+		      unsigned int *pbar2_qid);
+
+int t4_init_sge_params(struct adapter *adapter);
 int t4_init_tp_params(struct adapter *adap);
 int t4_filter_field_shift(const struct adapter *adap, int filter_sel);
 int t4_port_init(struct adapter *adap, int mbox, int pf, int vf);

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -4002,6 +4002,126 @@ int t4_prep_adapter(struct adapter *adapter)
 	return 0;
 }
 
+/**
+ *	t4_bar2_sge_qregs - return BAR2 SGE Queue register information
+ *	@adapter: the adapter
+ *	@qid: the Queue ID
+ *	@qtype: the Ingress or Egress type for @qid
+ *	@pbar2_qoffset: BAR2 Queue Offset
+ *	@pbar2_qid: BAR2 Queue ID or 0 for Queue ID inferred SGE Queues
+ *
+ *	Returns the BAR2 SGE Queue Registers information associated with the
+ *	indicated Absolute Queue ID.  These are passed back in return value
+ *	pointers.  @qtype should be T4_BAR2_QTYPE_EGRESS for Egress Queue
+ *	and T4_BAR2_QTYPE_INGRESS for Ingress Queues.
+ *
+ *	This may return an error which indicates that BAR2 SGE Queue
+ *	registers aren't available.  If an error is not returned, then the
+ *	following values are returned:
+ *
+ *	  *@pbar2_qoffset: the BAR2 Offset of the @qid Registers
+ *	  *@pbar2_qid: the BAR2 SGE Queue ID or 0 of @qid
+ *
+ *	If the returned BAR2 Queue ID is 0, then BAR2 SGE registers which
+ *	require the "Inferred Queue ID" ability may be used.  E.g. the
+ *	Write Combining Doorbell Buffer. If the BAR2 Queue ID is not 0,
+ *	then these "Inferred Queue ID" register may not be used.
+ */
+int t4_bar2_sge_qregs(struct adapter *adapter,
+		      unsigned int qid,
+		      enum t4_bar2_qtype qtype,
+		      u64 *pbar2_qoffset,
+		      unsigned int *pbar2_qid)
+{
+	unsigned int page_shift, page_size, qpp_shift, qpp_mask;
+	u64 bar2_page_offset, bar2_qoffset;
+	unsigned int bar2_qid, bar2_qid_offset, bar2_qinferred;
+
+	/* T4 doesn't support BAR2 SGE Queue registers.
+	 */
+	if (is_t4(adapter->params.chip))
+		return -EINVAL;
+
+	/* Get our SGE Page Size parameters.
+	 */
+	page_shift = adapter->params.sge.hps + 10;
+	page_size = 1 << page_shift;
+
+	/* Get the right Queues per Page parameters for our Queue.
+	 */
+	qpp_shift = (qtype == T4_BAR2_QTYPE_EGRESS
+		     ? adapter->params.sge.eq_qpp
+		     : adapter->params.sge.iq_qpp);
+	qpp_mask = (1 << qpp_shift) - 1;
+
+	/*  Calculate the basics of the BAR2 SGE Queue register area:
+	 *  o The BAR2 page the Queue registers will be in.
+	 *  o The BAR2 Queue ID.
+	 *  o The BAR2 Queue ID Offset into the BAR2 page.
+	 */
+	bar2_page_offset = ((qid >> qpp_shift) << page_shift);
+	bar2_qid = qid & qpp_mask;
+	bar2_qid_offset = bar2_qid * SGE_UDB_SIZE;
+
+	/* If the BAR2 Queue ID Offset is less than the Page Size, then the
+	 * hardware will infer the Absolute Queue ID simply from the writes to
+	 * the BAR2 Queue ID Offset within the BAR2 Page (and we need to use a
+	 * BAR2 Queue ID of 0 for those writes).  Otherwise, we'll simply
+	 * write to the first BAR2 SGE Queue Area within the BAR2 Page with
+	 * the BAR2 Queue ID and the hardware will infer the Absolute Queue ID
+	 * from the BAR2 Page and BAR2 Queue ID.
+	 *
+	 * One important censequence of this is that some BAR2 SGE registers
+	 * have a "Queue ID" field and we can write the BAR2 SGE Queue ID
+	 * there.  But other registers synthesize the SGE Queue ID purely
+	 * from the writes to the registers -- the Write Combined Doorbell
+	 * Buffer is a good example.  These BAR2 SGE Registers are only
+	 * available for those BAR2 SGE Register areas where the SGE Absolute
+	 * Queue ID can be inferred from simple writes.
+	 */
+	bar2_qoffset = bar2_page_offset;
+	bar2_qinferred = (bar2_qid_offset < page_size);
+	if (bar2_qinferred) {
+		bar2_qoffset += bar2_qid_offset;
+		bar2_qid = 0;
+	}
+
+	*pbar2_qoffset = bar2_qoffset;
+	*pbar2_qid = bar2_qid;
+	return 0;
+}
+
+/**
+ *	t4_init_sge_params - initialize adap->params.sge
+ *	@adapter: the adapter
+ *
+ *	Initialize various fields of the adapter's SGE Parameters structure.
+ */
+int t4_init_sge_params(struct adapter *adapter)
+{
+	struct sge_params *sge_params = &adapter->params.sge;
+	u32 hps, qpp;
+	unsigned int s_hps, s_qpp;
+
+	/* Extract the SGE Page Size for our PF.
+	 */
+	hps = t4_read_reg(adapter, SGE_HOST_PAGE_SIZE);
+	s_hps = (HOSTPAGESIZEPF0_S +
+		 (HOSTPAGESIZEPF1_S - HOSTPAGESIZEPF0_S) * adapter->fn);
+	sge_params->hps = ((hps >> s_hps) & HOSTPAGESIZEPF0_M);
+
+	/* Extract the SGE Egress and Ingess Queues Per Page for our PF.
+	 */
+	s_qpp = (QUEUESPERPAGEPF0_S +
+		(QUEUESPERPAGEPF1_S - QUEUESPERPAGEPF0_S) * adapter->fn);
+	qpp = t4_read_reg(adapter, SGE_EGRESS_QUEUES_PER_PAGE_PF);
+	sge_params->eq_qpp = ((qpp >> s_qpp) & QUEUESPERPAGEPF0_MASK);
+	qpp = t4_read_reg(adapter, SGE_INGRESS_QUEUES_PER_PAGE_PF);
+	sge_params->iq_qpp = ((qpp >> s_qpp) & QUEUESPERPAGEPF0_MASK);
+
+	return 0;
+}
+
 /**
  *      t4_init_tp_params - initialize adap->params.tp
  *      @adap: the adapter

drivers/net/ethernet/chelsio/cxgb4/t4_regs.h

@@ -155,13 +155,13 @@
 #define  HOSTPAGESIZEPF2_SHIFT  8
 #define  HOSTPAGESIZEPF2(x)     ((x) << HOSTPAGESIZEPF2_SHIFT)
 
-#define  HOSTPAGESIZEPF1_MASK   0x0000000fU
-#define  HOSTPAGESIZEPF1_SHIFT  4
-#define  HOSTPAGESIZEPF1(x)     ((x) << HOSTPAGESIZEPF1_SHIFT)
+#define  HOSTPAGESIZEPF1_M	0x0000000fU
+#define  HOSTPAGESIZEPF1_S	4
+#define  HOSTPAGESIZEPF1(x)     ((x) << HOSTPAGESIZEPF1_S)
 
-#define  HOSTPAGESIZEPF0_MASK   0x0000000fU
-#define  HOSTPAGESIZEPF0_SHIFT  0
-#define  HOSTPAGESIZEPF0(x)     ((x) << HOSTPAGESIZEPF0_SHIFT)
+#define  HOSTPAGESIZEPF0_M	0x0000000fU
+#define  HOSTPAGESIZEPF0_S	0
+#define  HOSTPAGESIZEPF0(x)     ((x) << HOSTPAGESIZEPF0_S)
 
 #define SGE_EGRESS_QUEUES_PER_PAGE_PF 0x1010
 #define SGE_EGRESS_QUEUES_PER_PAGE_VF_A 0x1014

drivers/net/ethernet/chelsio/cxgb4vf/t4vf_common.h

@@ -138,6 +138,7 @@ struct sge_params {
 	u32 sge_host_page_size;		/* PF0-7 page sizes */
 	u32 sge_egress_queues_per_page;	/* PF0-7 egress queues/page */
 	u32 sge_ingress_queues_per_page;/* PF0-7 ingress queues/page */
+	u32 sge_vf_hps;                 /* host page size for our vf */
 	u32 sge_vf_eq_qpp;		/* egress queues/page for our VF */
 	u32 sge_vf_iq_qpp;		/* ingress queues/page for our VF */
 	u32 sge_fl_buffer_size[16];	/* free list buffer sizes */
@@ -282,6 +283,13 @@ int t4vf_port_init(struct adapter *, int);
 int t4vf_fw_reset(struct adapter *);
 int t4vf_set_params(struct adapter *, unsigned int, const u32 *, const u32 *);
 
+enum t4_bar2_qtype { T4_BAR2_QTYPE_EGRESS, T4_BAR2_QTYPE_INGRESS };
+int t4_bar2_sge_qregs(struct adapter *adapter,
+		      unsigned int qid,
+		      enum t4_bar2_qtype qtype,
+		      u64 *pbar2_qoffset,
+		      unsigned int *pbar2_qid);
+
 int t4vf_get_sge_params(struct adapter *);
 int t4vf_get_vpd_params(struct adapter *);
 int t4vf_get_dev_params(struct adapter *);

drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c

@@ -429,6 +429,95 @@ int t4vf_set_params(struct adapter *adapter, unsigned int nparams,
 	return t4vf_wr_mbox(adapter, &cmd, sizeof(cmd), NULL);
 }
 
+/**
+ *	t4_bar2_sge_qregs - return BAR2 SGE Queue register information
+ *	@adapter: the adapter
+ *	@qid: the Queue ID
+ *	@qtype: the Ingress or Egress type for @qid
+ *	@pbar2_qoffset: BAR2 Queue Offset
+ *	@pbar2_qid: BAR2 Queue ID or 0 for Queue ID inferred SGE Queues
+ *
+ *	Returns the BAR2 SGE Queue Registers information associated with the
+ *	indicated Absolute Queue ID.  These are passed back in return value
+ *	pointers.  @qtype should be T4_BAR2_QTYPE_EGRESS for Egress Queue
+ *	and T4_BAR2_QTYPE_INGRESS for Ingress Queues.
+ *
+ *	This may return an error which indicates that BAR2 SGE Queue
+ *	registers aren't available.  If an error is not returned, then the
+ *	following values are returned:
+ *
+ *	  *@pbar2_qoffset: the BAR2 Offset of the @qid Registers
+ *	  *@pbar2_qid: the BAR2 SGE Queue ID or 0 of @qid
+ *
+ *	If the returned BAR2 Queue ID is 0, then BAR2 SGE registers which
+ *	require the "Inferred Queue ID" ability may be used.  E.g. the
+ *	Write Combining Doorbell Buffer. If the BAR2 Queue ID is not 0,
+ *	then these "Inferred Queue ID" register may not be used.
+ */
+int t4_bar2_sge_qregs(struct adapter *adapter,
+		      unsigned int qid,
+		      enum t4_bar2_qtype qtype,
+		      u64 *pbar2_qoffset,
+		      unsigned int *pbar2_qid)
+{
+	unsigned int page_shift, page_size, qpp_shift, qpp_mask;
+	u64 bar2_page_offset, bar2_qoffset;
+	unsigned int bar2_qid, bar2_qid_offset, bar2_qinferred;
+
+	/* T4 doesn't support BAR2 SGE Queue registers.
+	 */
+	if (is_t4(adapter->params.chip))
+		return -EINVAL;
+
+	/* Get our SGE Page Size parameters.
+	 */
+	page_shift = adapter->params.sge.sge_vf_hps + 10;
+	page_size = 1 << page_shift;
+
+	/* Get the right Queues per Page parameters for our Queue.
+	 */
+	qpp_shift = (qtype == T4_BAR2_QTYPE_EGRESS
+		     ? adapter->params.sge.sge_vf_eq_qpp
+		     : adapter->params.sge.sge_vf_iq_qpp);
+	qpp_mask = (1 << qpp_shift) - 1;
+
+	/* Calculate the basics of the BAR2 SGE Queue register area:
+	 *  o The BAR2 page the Queue registers will be in.
+	 *  o The BAR2 Queue ID.
+	 *  o The BAR2 Queue ID Offset into the BAR2 page.
+	 */
+	bar2_page_offset = ((qid >> qpp_shift) << page_shift);
+	bar2_qid = qid & qpp_mask;
+	bar2_qid_offset = bar2_qid * SGE_UDB_SIZE;
+
+	/* If the BAR2 Queue ID Offset is less than the Page Size, then the
+	 * hardware will infer the Absolute Queue ID simply from the writes to
+	 * the BAR2 Queue ID Offset within the BAR2 Page (and we need to use a
+	 * BAR2 Queue ID of 0 for those writes).  Otherwise, we'll simply
+	 * write to the first BAR2 SGE Queue Area within the BAR2 Page with
+	 * the BAR2 Queue ID and the hardware will infer the Absolute Queue ID
+	 * from the BAR2 Page and BAR2 Queue ID.
+	 *
+	 * One important censequence of this is that some BAR2 SGE registers
+	 * have a "Queue ID" field and we can write the BAR2 SGE Queue ID
+	 * there.  But other registers synthesize the SGE Queue ID purely
+	 * from the writes to the registers -- the Write Combined Doorbell
+	 * Buffer is a good example.  These BAR2 SGE Registers are only
+	 * available for those BAR2 SGE Register areas where the SGE Absolute
+	 * Queue ID can be inferred from simple writes.
+	 */
+	bar2_qoffset = bar2_page_offset;
+	bar2_qinferred = (bar2_qid_offset < page_size);
+	if (bar2_qinferred) {
+		bar2_qoffset += bar2_qid_offset;
+		bar2_qid = 0;
+	}
+
+	*pbar2_qoffset = bar2_qoffset;
+	*pbar2_qid = bar2_qid;
+	return 0;
+}
+
 /**
  *	t4vf_get_sge_params - retrieve adapter Scatter gather Engine parameters
  *	@adapter: the adapter
@@ -507,7 +596,7 @@ int t4vf_get_sge_params(struct adapter *adapter)
 	 */
 	if (!is_t4(adapter->params.chip)) {
 		u32 whoami;
-		unsigned int pf, s_qpp;
+		unsigned int pf, s_hps, s_qpp;
 
 		params[0] = (FW_PARAMS_MNEM_V(FW_PARAMS_MNEM_REG) |
 			     FW_PARAMS_PARAM_XYZ_V(
@@ -533,6 +622,13 @@ int t4vf_get_sge_params(struct adapter *adapter)
 		whoami = t4_read_reg(adapter,
 				     T4VF_PL_BASE_ADDR + A_PL_VF_WHOAMI);
 		pf = SOURCEPF_GET(whoami);
+
+		s_hps = (HOSTPAGESIZEPF0_S +
+			 (HOSTPAGESIZEPF1_S - HOSTPAGESIZEPF0_S) * pf);
+		sge_params->sge_vf_hps =
+			((sge_params->sge_host_page_size >> s_hps)
+			 & HOSTPAGESIZEPF0_M);
+
 		s_qpp = (QUEUESPERPAGEPF0_S +
 			 (QUEUESPERPAGEPF1_S - QUEUESPERPAGEPF0_S) * pf);
 		sge_params->sge_vf_eq_qpp =