[PATCH V5 04/15] pci, acpi, ecam: Add flag to indicate whether ECAM region was hot added or not.

[Tomasz Nowicki]

There are two ways we can get ECAM (aka MCFG) regions using ACPI,
first from MCFG static table and second from _CBA method. We cannot remove
static regions, however regions coming from _CBA should be removed while
removing bridge device.

In the light of above we need flag to mark hot added ECAM entries
and user to call pci_mmconfig_insert while adding regions from _CBA method.
Similarly pci_mmconfig_delete while removing hot added regions.

Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
Tested-by: Jeremy Linton <jeremy.linton@xxxxxxx>
Tested-by: Duc Dang <dhdang@xxxxxxx>
Tested-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Tested-by: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
Tested-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
---
 drivers/acpi/pci_mcfg.c  | 4 +++-
 include/linux/pci-acpi.h | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index 0467b00..3282f2a 100644
--- a/drivers/acpi/pci_mcfg.c
+++ b/drivers/acpi/pci_mcfg.c
@@ -74,6 +74,7 @@ static struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
 	new->segment = segment;
 	new->start_bus = start;
 	new->end_bus = end;
+	new->hot_added = false;
 
 	res = &new->res;
 	res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
@@ -205,6 +206,7 @@ int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
 	}
 	rc = pci_mmconfig_map_resource(dev, cfg);
 	if (!rc) {
+		cfg->hot_added = true;
 		list_add_sorted(cfg);
 		dev_info(dev, "MMCONFIG at %pR (base %#lx)\n",
 				 &cfg->res, (unsigned long)addr);
@@ -228,7 +230,7 @@ int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
 	mutex_lock(&pci_mmcfg_lock);
 	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
 		if (cfg->segment == seg && cfg->start_bus == start &&
-		    cfg->end_bus == end) {
+		    cfg->end_bus == end && cfg->hot_added) {
 			list_del_rcu(&cfg->list);
 			synchronize_rcu();
 			pci_mmconfig_unmap_resource(cfg);
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index e9450ef..94d8f38 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -119,6 +119,7 @@ struct pci_mmcfg_region {
 	u8 start_bus;
 	u8 end_bus;
 	char name[PCI_MMCFG_RESOURCE_NAME_LEN];
+	bool hot_added;
 };
 
 extern int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
-- 
1.9.1