[PATCH kernel v4 13/19] powerpc/powernv/npu: Move single TVE handling to NPU PE

[Alexey Kardashevskiy]

Normal PCI PEs have 2 TVEs, one per a DMA window; however NPU PE has only
one which points to one of two tables of the corresponding PCI PE.

So whenever a new DMA window is programmed to PEs, the NPU PE needs to
release old table in order to use the new one.

Commit d41ce7b1bcc3e ("powerpc/powernv/npu: Do not try invalidating 32bit
table when 64bit table is enabled") did just that but in pci-ioda.c
while it actually belongs to npu-dma.c.

This moves the single TVE handling to npu-dma.c. This does not implement
restoring though as it is highly unlikely that we can set the table to
PCI PE and cannot to NPU PE and if that fails, we could only set 32bit
table to NPU PE and this configuration is not really supported or wanted.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
 arch/powerpc/platforms/powernv/npu-dma.c  |  8 +++++++
 arch/powerpc/platforms/powernv/pci-ioda.c | 27 +++--------------------
 2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
index ef1457f..26063fb 100644
--- a/arch/powerpc/platforms/powernv/npu-dma.c
+++ b/arch/powerpc/platforms/powernv/npu-dma.c
@@ -130,6 +130,11 @@ long pnv_npu_set_window(struct pnv_ioda_pe *npe, int num,
 		tbl->it_level_size : tbl->it_size;
 	const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
 	const __u64 win_size = tbl->it_size << tbl->it_page_shift;
+	int num2 = (num == 0) ? 1 : 0;
+
+	/* NPU has just one TVE so if there is another table, remove it first */
+	if (npe->table_group.tables[num2])
+		pnv_npu_unset_window(npe, num2);
 
 	pe_info(npe, "Setting up window %llx..%llx pg=%lx\n",
 			start_addr, start_addr + win_size - 1,
@@ -160,6 +165,9 @@ long pnv_npu_unset_window(struct pnv_ioda_pe *npe, int num)
 	struct pnv_phb *phb = npe->phb;
 	int64_t rc;
 
+	if (!npe->table_group.tables[num])
+		return 0;
+
 	pe_info(npe, "Removing DMA window\n");
 
 	rc = opal_pci_map_pe_dma_window(phb->opal_id, npe->pe_number,
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 6193f1d..07f0751 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2669,23 +2669,14 @@ static struct pnv_ioda_pe *gpe_table_group_to_npe(
 static long pnv_pci_ioda2_npu_set_window(struct iommu_table_group *table_group,
 		int num, struct iommu_table *tbl)
 {
-	struct pnv_ioda_pe *npe = gpe_table_group_to_npe(table_group);
-	int num2 = (num == 0) ? 1 : 0;
 	long ret = pnv_pci_ioda2_set_window(table_group, num, tbl);
 
 	if (ret)
 		return ret;
 
-	if (table_group->tables[num2])
-		pnv_npu_unset_window(npe, num2);
-
-	ret = pnv_npu_set_window(npe, num, tbl);
-	if (ret) {
+	ret = pnv_npu_set_window(gpe_table_group_to_npe(table_group), num, tbl);
+	if (ret)
 		pnv_pci_ioda2_unset_window(table_group, num);
-		if (table_group->tables[num2])
-			pnv_npu_set_window(npe, num2,
-					table_group->tables[num2]);
-	}
 
 	return ret;
 }
@@ -2694,24 +2685,12 @@ static long pnv_pci_ioda2_npu_unset_window(
 		struct iommu_table_group *table_group,
 		int num)
 {
-	struct pnv_ioda_pe *npe = gpe_table_group_to_npe(table_group);
-	int num2 = (num == 0) ? 1 : 0;
 	long ret = pnv_pci_ioda2_unset_window(table_group, num);
 
 	if (ret)
 		return ret;
 
-	if (!npe->table_group.tables[num])
-		return 0;
-
-	ret = pnv_npu_unset_window(npe, num);
-	if (ret)
-		return ret;
-
-	if (table_group->tables[num2])
-		ret = pnv_npu_set_window(npe, num2, table_group->tables[num2]);
-
-	return ret;
+	return pnv_npu_unset_window(gpe_table_group_to_npe(table_group), num);
 }
 
 static void pnv_ioda2_npu_take_ownership(struct iommu_table_group *table_group)
-- 
2.17.1