[PATCH v4 03/12] PCI: pci-bridge-emul: Add support for PCI Bridge Subsystem Vendor ID capability

Pali Rohár
2022-02-22T15:54:44Z

This is read-only capability in PCI config space. Put it between base PCI
capability and base PCI Express capability.

Driver just have to specify subsystem_vendor_id and subsystem_id fields in
emulated bridge structure and pci-bridge-emul takes care of correctly
compose PCI Bridge Subsystem Vendor ID capability.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
drivers/pci/pci-bridge-emul.c | 69 +++++++++++++++++++++++++----------
drivers/pci/pci-bridge-emul.h | 2 +
2 files changed, 51 insertions(+), 20 deletions(-)

diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c
index c4b9837006ff..a5b662cc89d0 100644
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -21,8 +21,11 @@
#include "pci-bridge-emul.h"

#define PCI_BRIDGE_CONF_END PCI_STD_HEADER_SIZEOF
+#define PCI_CAP_SSID_SIZEOF (PCI_SSVID_DEVICE_ID + 2)
+#define PCI_CAP_SSID_START PCI_BRIDGE_CONF_END
+#define PCI_CAP_SSID_END (PCI_CAP_SSID_START + PCI_CAP_SSID_SIZEOF)
#define PCI_CAP_PCIE_SIZEOF (PCI_EXP_SLTSTA2 + 2)
-#define PCI_CAP_PCIE_START PCI_BRIDGE_CONF_END
+#define PCI_CAP_PCIE_START PCI_CAP_SSID_END
#define PCI_CAP_PCIE_END (PCI_CAP_PCIE_START + PCI_CAP_PCIE_SIZEOF)

/**
@@ -315,6 +318,25 @@ struct pci_bridge_reg_behavior pcie_cap_regs_behavior[PCI_CAP_PCIE_SIZEOF / 4] =
},
};

+static pci_bridge_emul_read_status_t
+pci_bridge_emul_read_ssid(struct pci_bridge_emul *bridge, int reg, u32 *value)
+{
+ switch (reg) {
+ case PCI_CAP_LIST_ID:
+ *value = PCI_CAP_ID_SSVID |
+ (bridge->has_pcie ? (PCI_CAP_PCIE_START << 8) : 0);
+ return PCI_BRIDGE_EMUL_HANDLED;
+
+ case PCI_SSVID_VENDOR_ID:
+ *value = bridge->subsystem_vendor_id |
+ (bridge->subsystem_id << 16);
+ return PCI_BRIDGE_EMUL_HANDLED;
+
+ default:
+ return PCI_BRIDGE_EMUL_NOT_HANDLED;
+ }
+}
+
/*
* Initialize a pci_bridge_emul structure to represent a fake PCI
* bridge configuration space. The caller needs to have initialized
@@ -341,9 +363,17 @@ int pci_bridge_emul_init(struct pci_bridge_emul *bridge,
if (!bridge->pci_regs_behavior)
return -ENOMEM;

- if (bridge->has_pcie) {
+ if (bridge->subsystem_vendor_id)
+ bridge->conf.capabilities_pointer = PCI_CAP_SSID_START;
+ else if (bridge->has_pcie)
bridge->conf.capabilities_pointer = PCI_CAP_PCIE_START;
+ else
+ bridge->conf.capabilities_pointer = 0;
+
+ if (bridge->conf.capabilities_pointer)
bridge->conf.status |= cpu_to_le16(PCI_STATUS_CAP_LIST);
+
+ if (bridge->has_pcie) {
bridge->pcie_conf.cap_id = PCI_CAP_ID_EXP;
bridge->pcie_conf.cap |= cpu_to_le16(PCI_EXP_TYPE_ROOT_PORT << 4);
bridge->pcie_cap_regs_behavior =
@@ -427,26 +457,28 @@ int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where,
read_op = bridge->ops->read_base;
cfgspace = (__le32 *) &bridge->conf;
behavior = bridge->pci_regs_behavior;
- } else if (!bridge->has_pcie) {
- /* PCIe space is not implemented, and no PCI capabilities */
- *value = 0;
- return PCIBIOS_SUCCESSFUL;
- } else if (reg < PCI_CAP_PCIE_END) {
+ } else if (reg >= PCI_CAP_SSID_START && reg < PCI_CAP_SSID_END && bridge->subsystem_vendor_id) {
+ /* Emulated PCI Bridge Subsystem Vendor ID capability */
+ reg -= PCI_CAP_SSID_START;
+ read_op = pci_bridge_emul_read_ssid;
+ cfgspace = NULL;
+ behavior = NULL;
+ } else if (reg >= PCI_CAP_PCIE_START && reg < PCI_CAP_PCIE_END && bridge->has_pcie) {
/* Our emulated PCIe capability */
reg -= PCI_CAP_PCIE_START;
read_op = bridge->ops->read_pcie;
cfgspace = (__le32 *) &bridge->pcie_conf;
behavior = bridge->pcie_cap_regs_behavior;
- } else if (reg < PCI_CFG_SPACE_SIZE) {
- /* Rest of PCI space not implemented */
- *value = 0;
- return PCIBIOS_SUCCESSFUL;
- } else {
+ } else if (reg >= PCI_CFG_SPACE_SIZE && bridge->has_pcie) {
/* PCIe extended capability space */
reg -= PCI_CFG_SPACE_SIZE;
read_op = bridge->ops->read_ext;
cfgspace = NULL;
behavior = NULL;
+ } else {
+ /* Not implemented */
+ *value = 0;
+ return PCIBIOS_SUCCESSFUL;
}

if (read_op)
@@ -504,24 +536,21 @@ int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where,
write_op = bridge->ops->write_base;
cfgspace = (__le32 *) &bridge->conf;
behavior = bridge->pci_regs_behavior;
- } else if (!bridge->has_pcie) {
- /* PCIe space is not implemented, and no PCI capabilities */
- return PCIBIOS_SUCCESSFUL;
- } else if (reg < PCI_CAP_PCIE_END) {
+ } else if (reg >= PCI_CAP_PCIE_START && reg < PCI_CAP_PCIE_END && bridge->has_pcie) {
/* Our emulated PCIe capability */
reg -= PCI_CAP_PCIE_START;
write_op = bridge->ops->write_pcie;
cfgspace = (__le32 *) &bridge->pcie_conf;
behavior = bridge->pcie_cap_regs_behavior;
- } else if (reg < PCI_CFG_SPACE_SIZE) {
- /* Rest of PCI space not implemented */
- return PCIBIOS_SUCCESSFUL;
- } else {
+ } else if (reg >= PCI_CFG_SPACE_SIZE && bridge->has_pcie) {
/* PCIe extended capability space */
reg -= PCI_CFG_SPACE_SIZE;
write_op = bridge->ops->write_ext;
cfgspace = NULL;
behavior = NULL;
+ } else {
+ /* Not implemented */
+ return PCIBIOS_SUCCESSFUL;
}

shift = (where & 0x3) * 8;
diff --git a/drivers/pci/pci-bridge-emul.h b/drivers/pci/pci-bridge-emul.h
index 6b5f75b2ad02..71392b67471d 100644
--- a/drivers/pci/pci-bridge-emul.h
+++ b/drivers/pci/pci-bridge-emul.h
@@ -132,6 +132,8 @@ struct pci_bridge_emul {
struct pci_bridge_reg_behavior *pcie_cap_regs_behavior;
void *data;
bool has_pcie;
+ u16 subsystem_vendor_id;
+ u16 subsystem_id;
};

enum {