[PATCH v5 02/42] powerpc/powernv: Enable M64 on P7IOC

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

The patch enables M64 window on P7IOC, which has been enabled on
PHB3. Different from PHB3 where 16 M64 BARs are supported and each
of them can be owned by one particular PE# exclusively or divided
evenly to 256 segments, each P7IOC PHB has 16 M64 BARs and each
of them are divided into 8 segments. So each P7IOC PHB can support
128 M64 segments only. Also, P7IOC has M64DT, which helps mapping
one particular M64 segment# to arbitrary PE#. PHB3 doesn't have
M64DT, indicating that one M64 segment can only be pinned to the
fixed PE#. In order to have similar logic to support M64 for PHB3
and P7IOC, we just provide 128 M64 (16 BARs) segments and fixed
mapping between PE# and M64 segment# on P7IOC. In turn, we just
need different phb->init_m64() hooks for P7IOC and PHB3 to support
M64.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
v5:
  * Pinned OPAL API return value type to "int64_t"
  * Don't initialize M64 callbacks for unknown PHB type
  * Fixed comments as suggested by aik
  * Fixed coding style complained by checkpatch.pl
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 110 ++++++++++++++++++++++++++----
 1 file changed, 98 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 573b07a..245ef81 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -174,6 +174,69 @@ static void pnv_ioda_free_pe(struct pnv_phb *phb, int pe)
 	clear_bit(pe, phb->ioda.pe_alloc);
 }
 
+static int pnv_ioda1_init_m64(struct pnv_phb *phb)
+{
+	struct resource *r;
+	int seg;
+
+	/* There are as many M64 segments as the maximum number
+	 * of PEs, which is 128.
+	 */
+	for (seg = 0; seg < phb->ioda.total_pe; seg += 8) {
+		unsigned long base;
+		int64_t rc;
+
+		base = phb->ioda.m64_base + seg * phb->ioda.m64_segsize;
+		rc = opal_pci_set_phb_mem_window(phb->opal_id,
+						 OPAL_M64_WINDOW_TYPE,
+						 seg / 8,
+						 base,
+						 0, /* unused */
+						 8 * phb->ioda.m64_segsize);
+		if (rc != OPAL_SUCCESS) {
+			pr_warn("  Error %lld setting M64 PHB#%d-BAR#%d\n",
+				rc, phb->hose->global_number, seg / 8);
+			goto fail;
+		}
+
+		rc = opal_pci_phb_mmio_enable(phb->opal_id,
+					      OPAL_M64_WINDOW_TYPE,
+					      seg / 8,
+					      OPAL_ENABLE_M64_SPLIT);
+		if (rc != OPAL_SUCCESS) {
+			pr_warn("  Error %lld enabling M64 PHB#%d-BAR#%d\n",
+				rc, phb->hose->global_number, seg / 8);
+			goto fail;
+		}
+	}
+
+	/* Strip off the segment used by the reserved PE, which
+	 * is expected to be 0 or last supported PE#. The PHB's
+	 * first memory window traces the 32-bits MMIO range
+	 * while the second one traces the 64-bits prefetchable
+	 * MMIO range that the PHB supports.
+	 */
+	r = &phb->hose->mem_resources[1];
+	if (phb->ioda.reserved_pe == 0)
+		r->start += phb->ioda.m64_segsize;
+	else if (phb->ioda.reserved_pe == (phb->ioda.total_pe - 1))
+		r->end -= phb->ioda.m64_segsize;
+	else
+		pr_warn("  Cannot strip M64 segment for reserved PE#%d\n",
+			phb->ioda.reserved_pe);
+
+	return 0;
+
+fail:
+	for ( ; seg >= 0; seg -= 8)
+		opal_pci_phb_mmio_enable(phb->opal_id,
+					 OPAL_M64_WINDOW_TYPE,
+					 seg / 8,
+					 OPAL_DISABLE_M64);
+
+	return -EIO;
+}
+
 /* The default M64 BAR is shared by all PEs */
 static int pnv_ioda2_init_m64(struct pnv_phb *phb)
 {
@@ -231,7 +294,7 @@ fail:
 	return -EIO;
 }
 
-static void pnv_ioda2_reserve_m64_pe(struct pnv_phb *phb)
+static void pnv_ioda_reserve_m64_pe(struct pnv_phb *phb)
 {
 	resource_size_t sgsz = phb->ioda.m64_segsize;
 	struct pci_dev *pdev;
@@ -257,8 +320,8 @@ static void pnv_ioda2_reserve_m64_pe(struct pnv_phb *phb)
 	}
 }
 
-static int pnv_ioda2_pick_m64_pe(struct pnv_phb *phb,
-				 struct pci_bus *bus, int all)
+static int pnv_ioda_pick_m64_pe(struct pnv_phb *phb,
+				struct pci_bus *bus, int all)
 {
 	resource_size_t segsz = phb->ioda.m64_segsize;
 	struct pci_dev *pdev;
@@ -355,6 +418,26 @@ done:
 			pe->master = master_pe;
 			list_add_tail(&pe->list, &master_pe->slaves);
 		}
+
+		/* P7IOC supports M64DT, which helps mapping M64 segment
+		 * to one particular PE#. However, PHB3 has fixed mapping
+		 * between M64 segment and PE#. In order to have same logic
+		 * for P7IOC and PHB3, we enforce fixed mapping between M64
+		 * segment and PE# on P7IOC.
+		 */
+		if (phb->type == PNV_PHB_IODA1) {
+			int64_t rc;
+
+			rc = opal_pci_map_pe_mmio_window(phb->opal_id,
+							 pe->pe_number,
+							 OPAL_M64_WINDOW_TYPE,
+							 pe->pe_number / 8,
+							 pe->pe_number % 8);
+			if (rc != OPAL_SUCCESS)
+				pr_warn("%s: Error %lld mapping M64 for PHB#%d-PE#%d\n",
+					__func__, rc, phb->hose->global_number,
+					pe->pe_number);
+		}
 	}
 
 	kfree(pe_alloc);
@@ -369,12 +452,6 @@ static void __init pnv_ioda_parse_m64_window(struct pnv_phb *phb)
 	const u32 *r;
 	u64 pci_addr;
 
-	/* FIXME: Support M64 for P7IOC */
-	if (phb->type != PNV_PHB_IODA2) {
-		pr_info("  Not support M64 window\n");
-		return;
-	}
-
 	if (!firmware_has_feature(FW_FEATURE_OPALv3)) {
 		pr_info("  Firmware too old to support M64 window\n");
 		return;
@@ -403,9 +480,18 @@ static void __init pnv_ioda_parse_m64_window(struct pnv_phb *phb)
 
 	/* Use last M64 BAR to cover M64 window */
 	phb->ioda.m64_bar_idx = 15;
-	phb->init_m64 = pnv_ioda2_init_m64;
-	phb->reserve_m64_pe = pnv_ioda2_reserve_m64_pe;
-	phb->pick_m64_pe = pnv_ioda2_pick_m64_pe;
+	phb->reserve_m64_pe = pnv_ioda_reserve_m64_pe;
+	phb->pick_m64_pe = pnv_ioda_pick_m64_pe;
+	switch (phb->type) {
+	case PNV_PHB_IODA1:
+		phb->init_m64 = pnv_ioda1_init_m64;
+		break;
+	case PNV_PHB_IODA2:
+		phb->init_m64 = pnv_ioda2_init_m64;
+		break;
+	default:
+		pr_debug(" Cannot support M64 for unknown type of PHB\n");
+	}
 }
 
 static void pnv_ioda_freeze_pe(struct pnv_phb *phb, int pe_no)
-- 
2.1.0