[PATCH 05/11] PCI: endpoint: pci-epf-vntb: Allocate packed outbound MW space

A packed MW group can use one outbound iATU region only when its EPC
address range is contiguous.

Allocate one EPC address range for the group and expose each logical MW
as a subrange. Singleton MWs keep separate allocations.

Signed-off-by: Koichiro Den <[email protected]>
---
 drivers/pci/endpoint/functions/pci-epf-vntb.c | 26 +++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 0c72b907c289..aa8d304fe861 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -226,6 +226,15 @@ static int epf_ntb_get_mw_group(struct epf_ntb *ntb, unsigned int mw,
 	return 0;
 }
 
+static u64 epf_ntb_mw_group_size(struct epf_ntb *ntb, unsigned int first,
+				 unsigned int count)
+{
+	unsigned int last = first + count - 1;
+
+	return ntb->mw_layout[last].offset - ntb->mw_layout[first].offset +
+	       ntb->mw_layout[last].size;
+}
+
 /**
  * epf_ntb_configure_mw() - Configure the Outbound Address Space for VHOST
  *   to access the memory window of HOST
@@ -891,6 +900,8 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
 	struct device *dev = &ntb->epf->dev;
 	u64 bar_size[BAR_5 + 1] = {};
 	bool bar_set[BAR_5 + 1] = {};
+	unsigned int count;
+	unsigned int j;
 
 	for (i = 0; i < ntb->num_mws; i++) {
 		size = ntb->mw_layout[i].size;
@@ -900,7 +911,6 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
 	}
 
 	for (i = 0; i < ntb->num_mws; i++) {
-		size = ntb->mw_layout[i].size;
 		barno = ntb->mw_layout[i].barno;
 
 		if (bar_set[barno])
@@ -926,6 +936,9 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
 
 alloc_vpci_mw:
 		/* Allocate EPC outbound memory windows to vpci vntb device */
+		count = ntb->packed_mws ? ntb->packed_mws : 1;
+		size = epf_ntb_mw_group_size(ntb, i, count);
+		/* Only the group head owns the allocation handle. */
 		ntb->vpci_mw_addr[i] = pci_epc_mem_alloc_addr(ntb->epf->epc,
 							      &ntb->vpci_mw_phy[i],
 							      size);
@@ -935,6 +948,13 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
 			i++;
 			goto err_alloc_mem;
 		}
+
+		for (j = 1; j < count; j++)
+			ntb->vpci_mw_phy[i + j] = ntb->vpci_mw_phy[i] +
+				ntb->mw_layout[i + j].offset -
+				ntb->mw_layout[i].offset;
+
+		i += count - 1;
 	}
 
 	return ret;
@@ -953,6 +973,7 @@ static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
 {
 	bool bar_cleared[BAR_5 + 1] = {};
 	enum pci_barno barno;
+	unsigned int count;
 	int i;
 
 	for (i = 0; i < num_mws; i++) {
@@ -968,10 +989,11 @@ static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
 		if (!ntb->vpci_mw_addr[i])
 			continue;
 
+		count = ntb->packed_mws ? ntb->packed_mws : 1;
 		pci_epc_mem_free_addr(ntb->epf->epc,
 				      ntb->vpci_mw_phy[i],
 				      ntb->vpci_mw_addr[i],
-				      ntb->mw_layout[i].size);
+				      epf_ntb_mw_group_size(ntb, i, count));
 		ntb->vpci_mw_addr[i] = NULL;
 	}
 }
-- 
2.51.0