@@ -26,6 +26,7 @@
#define FLAG_CFG0 BIT(0)
#define FLAG_CFG1 BIT(1)
#define FLAG_DEV_FIX BIT(2)
+#define FLAG_DEV_HIDDEN BIT(3)
struct loongson_pci_data {
u32 flags;
@@ -134,10 +135,17 @@ static void __iomem *cfg0_map(struct loongson_pci *priv, int bus,
return priv->cfg0_base + addroff;
}
+static bool pdev_may_exist(struct pci_bus *bus, unsigned int device, unsigned int function)
+{
+ return !(pci_is_root_bus(bus) && (device >= 9 && device <= 20) && (function > 0));
+}
+
static void __iomem *pci_loongson_map_bus(struct pci_bus *bus, unsigned int devfn,
int where)
{
unsigned char busnum = bus->number;
+ unsigned int device = PCI_SLOT(devfn);
+ unsigned int function = PCI_FUNC(devfn);
struct loongson_pci *priv = pci_bus_to_loongson_pci(bus);
if (pci_is_root_bus(bus))
@@ -147,9 +158,16 @@ static void __iomem *pci_loongson_map_bus(struct pci_bus *bus, unsigned int devf
* Do not read more than one device on the bus other than
* the host bus.
*/
- if (priv->data->flags & FLAG_DEV_FIX &&
- !pci_is_root_bus(bus) && PCI_SLOT(devfn) > 0)
- return NULL;
+ if ((priv->data->flags & FLAG_DEV_FIX) && bus->self) {
+ if (!pci_is_root_bus(bus) && (device > 0))
+ return NULL;
+ }
+
+ /* Don't access non-existant devices */
+ if (priv->data->flags & FLAG_DEV_HIDDEN) {
+ if (!pdev_may_exist(bus, device, function))
+ return NULL;
+ }
/* CFG0 can only access standard space */
if (where < PCI_CFG_SPACE_SIZE && priv->cfg0_base)
@@ -197,12 +215,12 @@ static struct pci_ops loongson_pci_ops32 = {
};
static const struct loongson_pci_data ls2k_pci_data = {
- .flags = FLAG_CFG1 | FLAG_DEV_FIX,
+ .flags = FLAG_CFG1 | FLAG_DEV_FIX | FLAG_DEV_HIDDEN,
.ops = &loongson_pci_ops,
};
static const struct loongson_pci_data ls7a_pci_data = {
- .flags = FLAG_CFG1 | FLAG_DEV_FIX,
+ .flags = FLAG_CFG1 | FLAG_DEV_FIX | FLAG_DEV_HIDDEN,
.ops = &loongson_pci_ops,
};
@@ -297,7 +315,7 @@ static int loongson_pci_ecam_init(struct pci_config_window *cfg)
return -ENOMEM;
cfg->priv = priv;
- data->flags = FLAG_CFG1;
+ data->flags = FLAG_CFG1 | FLAG_DEV_HIDDEN;
priv->data = data;
priv->cfg1_base = cfg->win - (cfg->busr.start << 16);
On LS2K/LS7A, some non-existant devices don't return 0xffffffff when scanning (they are hidden devices for debug in fact, access the config space may cause machine hang). This is a hardware flaw but we can only avoid it by software now. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> --- drivers/pci/controller/pci-loongson.c | 30 +++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-)