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|
// SPDX-License-Identifier: GPL-2.0
/*
* Purpose: PCI Express Port Bus Driver's Core Functions
*
* Copyright (C) 2004 Intel
* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/aer.h>
#include "../pci.h"
#include "portdrv.h"
struct portdrv_service_data {
struct pcie_port_service_driver *drv;
struct device *dev;
u32 service;
};
/**
* release_pcie_device - free PCI Express port service device structure
* @dev: Port service device to release
*
* Invoked automatically when device is being removed in response to
* device_unregister(dev). Release all resources being claimed.
*/
static void release_pcie_device(struct device *dev)
{
kfree(to_pcie_device(dev));
}
/*
* Fill in *pme, *aer, *dpc with the relevant Interrupt Message Numbers if
* services are enabled in "mask". Return the number of MSI/MSI-X vectors
* required to accommodate the largest Message Number.
*/
static int pcie_message_numbers(struct pci_dev *dev, int mask,
u32 *pme, u32 *aer, u32 *dpc)
{
u32 nvec = 0, pos;
u16 reg16;
/*
* The Interrupt Message Number indicates which vector is used, i.e.,
* the MSI-X table entry or the MSI offset between the base Message
* Data and the generated interrupt message. See PCIe r3.1, sec
* 7.8.2, 7.10.10, 7.31.2.
*/
if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16);
*pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
nvec = *pme + 1;
}
#ifdef CONFIG_PCIEAER
if (mask & PCIE_PORT_SERVICE_AER) {
u32 reg32;
pos = dev->aer_cap;
if (pos) {
pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS,
®32);
*aer = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;
nvec = max(nvec, *aer + 1);
}
}
#endif
if (mask & PCIE_PORT_SERVICE_DPC) {
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
if (pos) {
pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP,
®16);
*dpc = reg16 & PCI_EXP_DPC_IRQ;
nvec = max(nvec, *dpc + 1);
}
}
return nvec;
}
/**
* pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode
* for given port
* @dev: PCI Express port to handle
* @irqs: Array of interrupt vectors to populate
* @mask: Bitmask of port capabilities returned by get_port_device_capability()
*
* Return value: 0 on success, error code on failure
*/
static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
{
int nr_entries, nvec, pcie_irq;
u32 pme = 0, aer = 0, dpc = 0;
/* Allocate the maximum possible number of MSI/MSI-X vectors */
nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
PCI_IRQ_MSIX | PCI_IRQ_MSI);
if (nr_entries < 0)
return nr_entries;
/* See how many and which Interrupt Message Numbers we actually use */
nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc);
if (nvec > nr_entries) {
pci_free_irq_vectors(dev);
return -EIO;
}
/*
* If we allocated more than we need, free them and reallocate fewer.
*
* Reallocating may change the specific vectors we get, so
* pci_irq_vector() must be done *after* the reallocation.
*
* If we're using MSI, hardware is *allowed* to change the Interrupt
* Message Numbers when we free and reallocate the vectors, but we
* assume it won't because we allocate enough vectors for the
* biggest Message Number we found.
*/
if (nvec != nr_entries) {
pci_free_irq_vectors(dev);
nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
PCI_IRQ_MSIX | PCI_IRQ_MSI);
if (nr_entries < 0)
return nr_entries;
}
/* PME, hotplug and bandwidth notification share an MSI/MSI-X vector */
if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP |
PCIE_PORT_SERVICE_BWNOTIF)) {
pcie_irq = pci_irq_vector(dev, pme);
irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pcie_irq;
irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pcie_irq;
irqs[PCIE_PORT_SERVICE_BWNOTIF_SHIFT] = pcie_irq;
}
if (mask & PCIE_PORT_SERVICE_AER)
irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, aer);
if (mask & PCIE_PORT_SERVICE_DPC)
irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc);
return 0;
}
/**
* pcie_init_service_irqs - initialize irqs for PCI Express port services
* @dev: PCI Express port to handle
* @irqs: Array of irqs to populate
* @mask: Bitmask of port capabilities returned by get_port_device_capability()
*
* Return value: Interrupt mode associated with the port
*/
static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
{
int ret, i;
for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
irqs[i] = -1;
/*
* If we support PME but can't use MSI/MSI-X for it, we have to
* fall back to INTx or other interrupts, e.g., a system shared
* interrupt.
*/
if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
goto legacy_irq;
/* Try to use MSI-X or MSI if supported */
if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
return 0;
legacy_irq:
/* fall back to legacy IRQ */
ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
if (ret < 0)
return -ENODEV;
for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
irqs[i] = pci_irq_vector(dev, 0);
return 0;
}
/**
* get_port_device_capability - discover capabilities of a PCI Express port
* @dev: PCI Express port to examine
*
* The capabilities are read from the port's PCI Express configuration registers
* as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
* 7.9 - 7.11.
*
* Return value: Bitmask of discovered port capabilities
*/
static int get_port_device_capability(struct pci_dev *dev)
{
struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
int services = 0;
if (dev->is_hotplug_bridge &&
(pcie_ports_native || host->native_pcie_hotplug)) {
services |= PCIE_PORT_SERVICE_HP;
/*
* Disable hot-plug interrupts in case they have been enabled
* by the BIOS and the hot-plug service driver is not loaded.
*/
pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
}
#ifdef CONFIG_PCIEAER
if (dev->aer_cap && pci_aer_available() &&
(pcie_ports_native || host->native_aer)) {
services |= PCIE_PORT_SERVICE_AER;
/*
* Disable AER on this port in case it's been enabled by the
* BIOS (the AER service driver will enable it when necessary).
*/
pci_disable_pcie_error_reporting(dev);
}
#endif
/*
* Root ports are capable of generating PME too. Root Complex
* Event Collectors can also generate PMEs, but we don't handle
* those yet.
*/
if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
(pcie_ports_native || host->native_pme)) {
services |= PCIE_PORT_SERVICE_PME;
/*
* Disable PME interrupt on this port in case it's been enabled
* by the BIOS (the PME service driver will enable it when
* necessary).
*/
pcie_pme_interrupt_enable(dev, false);
}
if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
pci_aer_available() && services & PCIE_PORT_SERVICE_AER)
services |= PCIE_PORT_SERVICE_DPC;
if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM ||
pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
services |= PCIE_PORT_SERVICE_BWNOTIF;
return services;
}
/**
* pcie_device_init - allocate and initialize PCI Express port service device
* @pdev: PCI Express port to associate the service device with
* @service: Type of service to
|