mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 18:11:56 +00:00
23a5fba4d9
Some PCI host controllers do not expose a configuration space for the root port PCI bridge. Due to this, the Marvell Armada 370/38x/XP PCI controller driver (pci-mvebu) emulates a root port PCI bridge configuration space, and uses that to (among other things) dynamically create the memory windows that correspond to the PCI MEM and I/O regions. Since we now need to add a very similar logic for the Marvell Armada 37xx PCI controller driver (pci-aardvark), instead of duplicating the code, we create in this commit a common logic called pci-bridge-emul. The idea of this logic is to emulate a root port PCI bridge configuration space by providing configuration space read/write operations, and faking behind the scenes the configuration space of a PCI bridge. A PCI host controller driver simply has to call pci_bridge_emul_conf_read() and pci_bridge_emul_conf_write() to read/write the configuration space of the bridge. By default, the PCI bridge configuration space is simply emulated by a chunk of memory, but the PCI host controller can override the behavior of the read and write operations on a per-register basis to do additional actions if needed. We take care of complying with the behavior of the PCI configuration space registers in terms of bits that are read-write, read-only, reserved and write-1-to-clear. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
125 lines
2.9 KiB
C
125 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __PCI_BRIDGE_EMUL_H__
|
|
#define __PCI_BRIDGE_EMUL_H__
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
/* PCI configuration space of a PCI-to-PCI bridge. */
|
|
struct pci_bridge_emul_conf {
|
|
u16 vendor;
|
|
u16 device;
|
|
u16 command;
|
|
u16 status;
|
|
u32 class_revision;
|
|
u8 cache_line_size;
|
|
u8 latency_timer;
|
|
u8 header_type;
|
|
u8 bist;
|
|
u32 bar[2];
|
|
u8 primary_bus;
|
|
u8 secondary_bus;
|
|
u8 subordinate_bus;
|
|
u8 secondary_latency_timer;
|
|
u8 iobase;
|
|
u8 iolimit;
|
|
u16 secondary_status;
|
|
u16 membase;
|
|
u16 memlimit;
|
|
u16 pref_mem_base;
|
|
u16 pref_mem_limit;
|
|
u32 prefbaseupper;
|
|
u32 preflimitupper;
|
|
u16 iobaseupper;
|
|
u16 iolimitupper;
|
|
u8 capabilities_pointer;
|
|
u8 reserve[3];
|
|
u32 romaddr;
|
|
u8 intline;
|
|
u8 intpin;
|
|
u16 bridgectrl;
|
|
};
|
|
|
|
/* PCI configuration space of the PCIe capabilities */
|
|
struct pci_bridge_emul_pcie_conf {
|
|
u8 cap_id;
|
|
u8 next;
|
|
u16 cap;
|
|
u32 devcap;
|
|
u16 devctl;
|
|
u16 devsta;
|
|
u32 lnkcap;
|
|
u16 lnkctl;
|
|
u16 lnksta;
|
|
u32 slotcap;
|
|
u16 slotctl;
|
|
u16 slotsta;
|
|
u16 rootctl;
|
|
u16 rsvd;
|
|
u32 rootsta;
|
|
u32 devcap2;
|
|
u16 devctl2;
|
|
u16 devsta2;
|
|
u32 lnkcap2;
|
|
u16 lnkctl2;
|
|
u16 lnksta2;
|
|
u32 slotcap2;
|
|
u16 slotctl2;
|
|
u16 slotsta2;
|
|
};
|
|
|
|
struct pci_bridge_emul;
|
|
|
|
typedef enum { PCI_BRIDGE_EMUL_HANDLED,
|
|
PCI_BRIDGE_EMUL_NOT_HANDLED } pci_bridge_emul_read_status_t;
|
|
|
|
struct pci_bridge_emul_ops {
|
|
/*
|
|
* Called when reading from the regular PCI bridge
|
|
* configuration space. Return PCI_BRIDGE_EMUL_HANDLED when the
|
|
* operation has handled the read operation and filled in the
|
|
* *value, or PCI_BRIDGE_EMUL_NOT_HANDLED when the read should
|
|
* be emulated by the common code by reading from the
|
|
* in-memory copy of the configuration space.
|
|
*/
|
|
pci_bridge_emul_read_status_t (*read_base)(struct pci_bridge_emul *bridge,
|
|
int reg, u32 *value);
|
|
|
|
/*
|
|
* Same as ->read_base(), except it is for reading from the
|
|
* PCIe capability configuration space.
|
|
*/
|
|
pci_bridge_emul_read_status_t (*read_pcie)(struct pci_bridge_emul *bridge,
|
|
int reg, u32 *value);
|
|
/*
|
|
* Called when writing to the regular PCI bridge configuration
|
|
* space. old is the current value, new is the new value being
|
|
* written, and mask indicates which parts of the value are
|
|
* being changed.
|
|
*/
|
|
void (*write_base)(struct pci_bridge_emul *bridge, int reg,
|
|
u32 old, u32 new, u32 mask);
|
|
|
|
/*
|
|
* Same as ->write_base(), except it is for writing from the
|
|
* PCIe capability configuration space.
|
|
*/
|
|
void (*write_pcie)(struct pci_bridge_emul *bridge, int reg,
|
|
u32 old, u32 new, u32 mask);
|
|
};
|
|
|
|
struct pci_bridge_emul {
|
|
struct pci_bridge_emul_conf conf;
|
|
struct pci_bridge_emul_pcie_conf pcie_conf;
|
|
struct pci_bridge_emul_ops *ops;
|
|
void *data;
|
|
bool has_pcie;
|
|
};
|
|
|
|
void pci_bridge_emul_init(struct pci_bridge_emul *bridge);
|
|
int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where,
|
|
int size, u32 *value);
|
|
int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where,
|
|
int size, u32 value);
|
|
|
|
#endif /* __PCI_BRIDGE_EMUL_H__ */
|