ntb: intel: add hw workaround for NTB BAR alignment

Add NTB_HWERR_BAR_ALIGN hw errata flag to work around issue where the
aligment for the XLAT base must be BAR size aligned rather than 4k page
aligned. On ICX platform, the XLAT base can be 4k page size aligned
rather than BAR size aligned unlike the previous gen Intel NTB. However,
a silicon errata prevented this from working as expected and a workaround
is introduced to resolve the issue.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

1 files changed, 65 insertions, 13 deletions

diff --git a/drivers/ntb/hw/intel/ntb_hw_gen4.c b/drivers/ntb/hw/intel/ntb_hw_gen4.c
index aab614099d34..28fa0ab7b0fb 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen4.c
+++ b/drivers/ntb/hw/intel/ntb_hw_gen4.c
@@ -177,6 +177,9 @@ int gen4_init_dev(struct intel_ntb_dev *ndev)
 
 	ndev->reg = &gen4_reg;
 
+	if (pdev_is_ICX(pdev))
+		ndev->hwerr_flags |= NTB_HWERR_BAR_ALIGN;
+
 	ppd1 = ioread32(ndev->self_mmio + GEN4_PPD1_OFFSET);
 	ndev->ntb.topo = gen4_ppd_topo(ndev, ppd1);
 	dev_dbg(&pdev->dev, "ppd %#x topo %s\n", ppd1,
@@ -342,9 +345,14 @@ static int intel_ntb4_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
 	else
 		mw_size = bar_size;
 
-	/* hardware requires that addr is aligned to bar size */
-	if (addr & (bar_size - 1))
-		return -EINVAL;
+	if (ndev->hwerr_flags & NTB_HWERR_BAR_ALIGN) {
+		/* hardware requires that addr is aligned to bar size */
+		if (addr & (bar_size - 1))
+			return -EINVAL;
+	} else {
+		if (addr & (PAGE_SIZE - 1))
+			return -EINVAL;
+	}
 
 	/* make sure the range fits in the usable mw size */
 	if (size > mw_size)
@@ -353,7 +361,6 @@ static int intel_ntb4_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
 	mmio = ndev->self_mmio;
 	xlat_reg = ndev->xlat_reg->bar2_xlat + (idx * 0x10);
 	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10);
-	idx_reg = ndev->xlat_reg->bar2_idx + (idx * 0x2);
 	base = pci_resource_start(ndev->ntb.pdev, bar);
 
 	/* Set the limit if supported, if size is not mw_size */
@@ -387,16 +394,19 @@ static int intel_ntb4_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
 
 	dev_dbg(&ntb->pdev->dev, "BAR %d IMXLMT: %#Lx\n", bar, reg_val);
 
-	iowrite16(base_idx, mmio + idx_reg);
-	reg_val16 = ioread16(mmio + idx_reg);
-	if (reg_val16 != base_idx) {
-		iowrite64(base, mmio + limit_reg);
-		iowrite64(0, mmio + xlat_reg);
-		iowrite16(0, mmio + idx_reg);
-		return -EIO;
+	if (ndev->hwerr_flags & NTB_HWERR_BAR_ALIGN) {
+		idx_reg = ndev->xlat_reg->bar2_idx + (idx * 0x2);
+		iowrite16(base_idx, mmio + idx_reg);
+		reg_val16 = ioread16(mmio + idx_reg);
+		if (reg_val16 != base_idx) {
+			iowrite64(base, mmio + limit_reg);
+			iowrite64(0, mmio + xlat_reg);
+			iowrite16(0, mmio + idx_reg);
+			return -EIO;
+		}
+		dev_dbg(&ntb->pdev->dev, "BAR %d IMBASEIDX: %#x\n", bar, reg_val16);
 	}
 
-	dev_dbg(&ntb->pdev->dev, "BAR %d IMBASEIDX: %#x\n", bar, reg_val16);
 
 	return 0;
 }
@@ -471,9 +481,51 @@ int intel_ntb4_link_disable(struct ntb_dev *ntb)
 	return 0;
 }
 
+static int intel_ntb4_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+				   resource_size_t *addr_align,
+				   resource_size_t *size_align,
+				   resource_size_t *size_max)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	resource_size_t bar_size, mw_size;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
+		idx += 1;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (idx == ndev->b2b_idx)
+		mw_size = bar_size - ndev->b2b_off;
+	else
+		mw_size = bar_size;
+
+	if (addr_align) {
+		if (ndev->hwerr_flags & NTB_HWERR_BAR_ALIGN)
+			*addr_align = pci_resource_len(ndev->ntb.pdev, bar);
+		else
+			*addr_align = PAGE_SIZE;
+	}
+
+	if (size_align)
+		*size_align = 1;
+
+	if (size_max)
+		*size_max = mw_size;
+
+	return 0;
+}
+
 const struct ntb_dev_ops intel_ntb4_ops = {
 	.mw_count		= intel_ntb_mw_count,
-	.mw_get_align		= intel_ntb_mw_get_align,
+	.mw_get_align		= intel_ntb4_mw_get_align,
 	.mw_set_trans		= intel_ntb4_mw_set_trans,
 	.peer_mw_count		= intel_ntb_peer_mw_count,
 	.peer_mw_get_addr	= intel_ntb_peer_mw_get_addr,