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Implement resets for PCI buses and PCIe bridges.

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For PCI device (i.e. child of a PCI bus), reset tries FLR if
implemented and worked, and falls to power reset otherwise.

For PCIe bus (child of a PCIe bridge or root port), reset
disables PCIe link and then re-trains it, performing what is known as
link-level reset.

Reviewed by:	imp (previous version), jhb (previous version)
Sponsored by:	Mellanox Technologies
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D19646
This commit is contained in:
Konstantin Belousov 2019-04-05 19:25:26 +00:00
parent c53df6da4e
commit 5db2a4a812
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=345963
4 changed files with 125 additions and 15 deletions
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17
sys/amd64/vmm/io/ppt.c
View File

@ -356,25 +356,12 @@ ppt_is_mmio(struct vm *vm, vm_paddr_t gpa)
static void
ppt_pci_reset(device_t dev)
{
int ps;
if (pcie_flr(dev,
max(pcie_get_max_completion_timeout(dev) / 1000, 10),
true))
max(pcie_get_max_completion_timeout(dev) / 1000, 10), true))
return;
/*
* If FLR fails, attempt a power-management reset by cycling
* the device in/out of D3 state.
* PCI spec says we can only go into D3 state from D0 state.
* Transition from D[12] into D0 before going to D3 state.
*/
ps = pci_get_powerstate(dev);
if (ps != PCI_POWERSTATE_D0 && ps != PCI_POWERSTATE_D3)
pci_set_powerstate(dev, PCI_POWERSTATE_D0);
if (pci_get_powerstate(dev) != PCI_POWERSTATE_D3)
pci_set_powerstate(dev, PCI_POWERSTATE_D3);
pci_set_powerstate(dev, ps);
pci_power_reset(dev);
}
int

90
sys/dev/pci/pci.c
View File

@ -126,6 +126,10 @@ static int pci_remap_intr_method(device_t bus, device_t dev,
u_int irq);
static void pci_hint_device_unit(device_t acdev, device_t child,
const char *name, int *unitp);
static int pci_reset_post(device_t dev, device_t child);
static int pci_reset_prepare(device_t dev, device_t child);
static int pci_reset_child(device_t dev, device_t child,
int flags);
static int pci_get_id_method(device_t dev, device_t child,
enum pci_id_type type, uintptr_t *rid);
@ -150,6 +154,9 @@ static device_method_t pci_methods[] = {
DEVMETHOD(bus_driver_added, pci_driver_added),
DEVMETHOD(bus_setup_intr, pci_setup_intr),
DEVMETHOD(bus_teardown_intr, pci_teardown_intr),
DEVMETHOD(bus_reset_prepare, pci_reset_prepare),
DEVMETHOD(bus_reset_post, pci_reset_post),
DEVMETHOD(bus_reset_child, pci_reset_child),
DEVMETHOD(bus_get_dma_tag, pci_get_dma_tag),
DEVMETHOD(bus_get_resource_list,pci_get_resource_list),
@ -6387,6 +6394,89 @@ pcie_flr(device_t dev, u_int max_delay, bool force)
return (true);
}
int
pci_power_reset(device_t dev)
{
int ps;
ps = pci_get_powerstate(dev);
if (ps != PCI_POWERSTATE_D0 && ps != PCI_POWERSTATE_D3)
pci_set_powerstate(dev, PCI_POWERSTATE_D0);
pci_set_powerstate(dev, PCI_POWERSTATE_D3);
pci_set_powerstate(dev, ps);
return (0);
}
/*
* Try link drop and retrain of the downstream port of upstream
* switch, for PCIe. According to the PCIe 3.0 spec 6.6.1, this must
* cause Conventional Hot reset of the device in the slot.
* Alternative, for PCIe, could be the secondary bus reset initiatied
* on the upstream switch PCIR_BRIDGECTL_1, bit 6.
*/
int
pcie_link_reset(device_t port, int pcie_location)
{
uint16_t v;
v = pci_read_config(port, pcie_location + PCIER_LINK_CTL, 2);
v |= PCIEM_LINK_CTL_LINK_DIS;
pci_write_config(port, pcie_location + PCIER_LINK_CTL, v, 2);
pause_sbt("pcier1", mstosbt(20), 0, 0);
v &= ~PCIEM_LINK_CTL_LINK_DIS;
v |= PCIEM_LINK_CTL_RETRAIN_LINK;
pci_write_config(port, pcie_location + PCIER_LINK_CTL, v, 2);
pause_sbt("pcier2", mstosbt(100), 0, 0); /* 100 ms */
v = pci_read_config(port, pcie_location + PCIER_LINK_STA, 2);
return ((v & PCIEM_LINK_STA_TRAINING) != 0 ? ETIMEDOUT : 0);
}
static int
pci_reset_post(device_t dev, device_t child)
{
if (dev == device_get_parent(child))
pci_restore_state(child);
return (0);
}
static int
pci_reset_prepare(device_t dev, device_t child)
{
if (dev == device_get_parent(child))
pci_save_state(child);
return (0);
}
static int
pci_reset_child(device_t dev, device_t child, int flags)
{
int error;
if (dev == NULL || device_get_parent(child) != dev)
return (0);
if ((flags & DEVF_RESET_DETACH) != 0) {
error = device_get_state(child) == DS_ATTACHED ?
device_detach(child) : 0;
} else {
error = BUS_SUSPEND_CHILD(dev, child);
}
if (error == 0) {
if (!pcie_flr(child, 1000, false)) {
error = BUS_RESET_PREPARE(dev, child);
if (error == 0)
pci_power_reset(child);
BUS_RESET_POST(dev, child);
}
if ((flags & DEVF_RESET_DETACH) != 0)
device_probe_and_attach(child);
else
BUS_RESUME_CHILD(dev, child);
}
return (error);
}
const struct pci_device_table *
pci_match_device(device_t child, const struct pci_device_table *id, size_t nelt)
{

31
sys/dev/pci/pci_pci.c
View File

@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/pciio.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
@ -80,6 +81,7 @@ static void pcib_pcie_dll_timeout(void *arg);
#endif
static int pcib_request_feature_default(device_t pcib, device_t dev,
enum pci_feature feature);
static int pcib_reset_child(device_t dev, device_t child, int flags);
static device_method_t pcib_methods[] = {
/* Device interface */
@ -106,6 +108,7 @@ static device_method_t pcib_methods[] = {
DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
DEVMETHOD(bus_setup_intr, bus_generic_setup_intr),
DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
DEVMETHOD(bus_reset_child, pcib_reset_child),
/* pcib interface */
DEVMETHOD(pcib_maxslots, pcib_ari_maxslots),
@ -2909,3 +2912,31 @@ pcib_request_feature_default(device_t pcib, device_t dev,
bus = device_get_parent(pcib);
return (PCIB_REQUEST_FEATURE(device_get_parent(bus), dev, feature));
}
static int
pcib_reset_child(device_t dev, device_t child, int flags)
{
struct pci_devinfo *pdinfo;
int error;
error = 0;
if (dev == NULL || device_get_parent(child) != dev)
goto out;
error = ENXIO;
if (device_get_devclass(child) != devclass_find("pci"))
goto out;
pdinfo = device_get_ivars(dev);
if (pdinfo->cfg.pcie.pcie_location != 0 &&
(pdinfo->cfg.pcie.pcie_type == PCIEM_TYPE_DOWNSTREAM_PORT ||
pdinfo->cfg.pcie.pcie_type == PCIEM_TYPE_ROOT_PORT)) {
error = bus_helper_reset_prepare(child, flags);
if (error == 0) {
error = pcie_link_reset(dev,
pdinfo->cfg.pcie.pcie_location);
/* XXXKIB call _post even if error != 0 ? */
bus_helper_reset_post(child, flags);
}
}
out:
return (error);
}

2
sys/dev/pci/pcivar.h
View File

@ -681,6 +681,7 @@ int pci_get_max_read_req(device_t dev);
void pci_restore_state(device_t dev);
void pci_save_state(device_t dev);
int pci_set_max_read_req(device_t dev, int size);
int pci_power_reset(device_t dev);
uint32_t pcie_read_config(device_t dev, int reg, int width);
void pcie_write_config(device_t dev, int reg, uint32_t value, int width);
uint32_t pcie_adjust_config(device_t dev, int reg, uint32_t mask,
@ -688,6 +689,7 @@ uint32_t pcie_adjust_config(device_t dev, int reg, uint32_t mask,
bool pcie_flr(device_t dev, u_int max_delay, bool force);
int pcie_get_max_completion_timeout(device_t dev);
bool pcie_wait_for_pending_transactions(device_t dev, u_int max_delay);
int pcie_link_reset(device_t port, int pcie_location);
void pci_print_faulted_dev(void);