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authorLinus Torvalds <torvalds@linux-foundation.org>2021-11-13 20:18:06 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-13 20:18:06 +0300
commitbe427a88a3dc2de30688b08d078f4f4c1bb035d6 (patch)
tree8c3b1632ec18c5022cde45dc4ed92759779b1e50 /arch
parentb89f311d7e25eb246376ac10de46d6ecc6b6ed5c (diff)
parenta4751f157c194431fae9e9c493f456df8272b871 (diff)
downloadlinux-be427a88a3dc2de30688b08d078f4f4c1bb035d6.tar.xz
Merge tag 's390-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Vasily Gorbik: - Add PCI automatic error recovery. - Fix tape driver timer initialization broken during timers api cleanup. - Fix bogus CPU measurement counters values on CPUs offlining. - Check the validity of subchanel before reading other fields in the schib in cio code. * tag 's390-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/cio: check the subchannel validity for dev_busid s390/cpumf: cpum_cf PMU displays invalid value after hotplug remove s390/tape: fix timer initialization in tape_std_assign() s390/pci: implement minimal PCI error recovery PCI: Export pci_dev_lock() s390/pci: implement reset_slot for hotplug slot s390/pci: refresh function handle in iomap
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/pci.h6
-rw-r--r--arch/s390/kernel/perf_cpum_cf.c4
-rw-r--r--arch/s390/pci/pci.c148
-rw-r--r--arch/s390/pci/pci_event.c230
-rw-r--r--arch/s390/pci/pci_insn.c4
-rw-r--r--arch/s390/pci/pci_irq.c9
6 files changed, 387 insertions, 14 deletions
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 6b3c366af78e..90824be5ce9a 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -210,9 +210,11 @@ int zpci_deconfigure_device(struct zpci_dev *zdev);
void zpci_device_reserved(struct zpci_dev *zdev);
bool zpci_is_device_configured(struct zpci_dev *zdev);
+int zpci_hot_reset_device(struct zpci_dev *zdev);
int zpci_register_ioat(struct zpci_dev *, u8, u64, u64, u64);
int zpci_unregister_ioat(struct zpci_dev *, u8);
void zpci_remove_reserved_devices(void);
+void zpci_update_fh(struct zpci_dev *zdev, u32 fh);
/* CLP */
int clp_setup_writeback_mio(void);
@@ -294,8 +296,10 @@ void zpci_debug_exit(void);
void zpci_debug_init_device(struct zpci_dev *, const char *);
void zpci_debug_exit_device(struct zpci_dev *);
-/* Error reporting */
+/* Error handling */
int zpci_report_error(struct pci_dev *, struct zpci_report_error_header *);
+int zpci_clear_error_state(struct zpci_dev *zdev);
+int zpci_reset_load_store_blocked(struct zpci_dev *zdev);
#ifdef CONFIG_NUMA
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c
index 6f431fa9e4d7..ee8707abdb6a 100644
--- a/arch/s390/kernel/perf_cpum_cf.c
+++ b/arch/s390/kernel/perf_cpum_cf.c
@@ -687,8 +687,10 @@ static void cpumf_pmu_stop(struct perf_event *event, int flags)
false);
if (cfdiag_diffctr(cpuhw, event->hw.config_base))
cfdiag_push_sample(event, cpuhw);
- } else
+ } else if (cpuhw->flags & PMU_F_RESERVED) {
+ /* Only update when PMU not hotplugged off */
hw_perf_event_update(event);
+ }
hwc->state |= PERF_HES_UPTODATE;
}
}
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 872d772b73d2..2f9b78fa82a5 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -481,6 +481,34 @@ static void zpci_free_iomap(struct zpci_dev *zdev, int entry)
spin_unlock(&zpci_iomap_lock);
}
+static void zpci_do_update_iomap_fh(struct zpci_dev *zdev, u32 fh)
+{
+ int bar, idx;
+
+ spin_lock(&zpci_iomap_lock);
+ for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
+ if (!zdev->bars[bar].size)
+ continue;
+ idx = zdev->bars[bar].map_idx;
+ if (!zpci_iomap_start[idx].count)
+ continue;
+ WRITE_ONCE(zpci_iomap_start[idx].fh, zdev->fh);
+ }
+ spin_unlock(&zpci_iomap_lock);
+}
+
+void zpci_update_fh(struct zpci_dev *zdev, u32 fh)
+{
+ if (!fh || zdev->fh == fh)
+ return;
+
+ zdev->fh = fh;
+ if (zpci_use_mio(zdev))
+ return;
+ if (zdev->has_resources && zdev_enabled(zdev))
+ zpci_do_update_iomap_fh(zdev, fh);
+}
+
static struct resource *__alloc_res(struct zpci_dev *zdev, unsigned long start,
unsigned long size, unsigned long flags)
{
@@ -668,7 +696,7 @@ int zpci_enable_device(struct zpci_dev *zdev)
if (clp_enable_fh(zdev, &fh, ZPCI_NR_DMA_SPACES))
rc = -EIO;
else
- zdev->fh = fh;
+ zpci_update_fh(zdev, fh);
return rc;
}
@@ -679,14 +707,14 @@ int zpci_disable_device(struct zpci_dev *zdev)
cc = clp_disable_fh(zdev, &fh);
if (!cc) {
- zdev->fh = fh;
+ zpci_update_fh(zdev, fh);
} else if (cc == CLP_RC_SETPCIFN_ALRDY) {
pr_info("Disabling PCI function %08x had no effect as it was already disabled\n",
zdev->fid);
/* Function is already disabled - update handle */
rc = clp_refresh_fh(zdev->fid, &fh);
if (!rc) {
- zdev->fh = fh;
+ zpci_update_fh(zdev, fh);
rc = -EINVAL;
}
} else {
@@ -696,6 +724,65 @@ int zpci_disable_device(struct zpci_dev *zdev)
}
/**
+ * zpci_hot_reset_device - perform a reset of the given zPCI function
+ * @zdev: the slot which should be reset
+ *
+ * Performs a low level reset of the zPCI function. The reset is low level in
+ * the sense that the zPCI function can be reset without detaching it from the
+ * common PCI subsystem. The reset may be performed while under control of
+ * either DMA or IOMMU APIs in which case the existing DMA/IOMMU translation
+ * table is reinstated at the end of the reset.
+ *
+ * After the reset the functions internal state is reset to an initial state
+ * equivalent to its state during boot when first probing a driver.
+ * Consequently after reset the PCI function requires re-initialization via the
+ * common PCI code including re-enabling IRQs via pci_alloc_irq_vectors()
+ * and enabling the function via e.g.pci_enablde_device_flags().The caller
+ * must guard against concurrent reset attempts.
+ *
+ * In most cases this function should not be called directly but through
+ * pci_reset_function() or pci_reset_bus() which handle the save/restore and
+ * locking.
+ *
+ * Return: 0 on success and an error value otherwise
+ */
+int zpci_hot_reset_device(struct zpci_dev *zdev)
+{
+ int rc;
+
+ zpci_dbg(3, "rst fid:%x, fh:%x\n", zdev->fid, zdev->fh);
+ if (zdev_enabled(zdev)) {
+ /* Disables device access, DMAs and IRQs (reset state) */
+ rc = zpci_disable_device(zdev);
+ /*
+ * Due to a z/VM vs LPAR inconsistency in the error state the
+ * FH may indicate an enabled device but disable says the
+ * device is already disabled don't treat it as an error here.
+ */
+ if (rc == -EINVAL)
+ rc = 0;
+ if (rc)
+ return rc;
+ }
+
+ rc = zpci_enable_device(zdev);
+ if (rc)
+ return rc;
+
+ if (zdev->dma_table)
+ rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
+ (u64)zdev->dma_table);
+ else
+ rc = zpci_dma_init_device(zdev);
+ if (rc) {
+ zpci_disable_device(zdev);
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
* zpci_create_device() - Create a new zpci_dev and add it to the zbus
* @fid: Function ID of the device to be created
* @fh: Current Function Handle of the device to be created
@@ -776,7 +863,7 @@ int zpci_scan_configured_device(struct zpci_dev *zdev, u32 fh)
{
int rc;
- zdev->fh = fh;
+ zpci_update_fh(zdev, fh);
/* the PCI function will be scanned once function 0 appears */
if (!zdev->zbus->bus)
return 0;
@@ -903,6 +990,59 @@ int zpci_report_error(struct pci_dev *pdev,
}
EXPORT_SYMBOL(zpci_report_error);
+/**
+ * zpci_clear_error_state() - Clears the zPCI error state of the device
+ * @zdev: The zdev for which the zPCI error state should be reset
+ *
+ * Clear the zPCI error state of the device. If clearing the zPCI error state
+ * fails the device is left in the error state. In this case it may make sense
+ * to call zpci_io_perm_failure() on the associated pdev if it exists.
+ *
+ * Returns: 0 on success, -EIO otherwise
+ */
+int zpci_clear_error_state(struct zpci_dev *zdev)
+{
+ u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_RESET_ERROR);
+ struct zpci_fib fib = {0};
+ u8 status;
+ int cc;
+
+ cc = zpci_mod_fc(req, &fib, &status);
+ if (cc) {
+ zpci_dbg(3, "ces fid:%x, cc:%d, status:%x\n", zdev->fid, cc, status);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/**
+ * zpci_reset_load_store_blocked() - Re-enables L/S from error state
+ * @zdev: The zdev for which to unblock load/store access
+ *
+ * Re-enables load/store access for a PCI function in the error state while
+ * keeping DMA blocked. In this state drivers can poke MMIO space to determine
+ * if error recovery is possible while catching any rogue DMA access from the
+ * device.
+ *
+ * Returns: 0 on success, -EIO otherwise
+ */
+int zpci_reset_load_store_blocked(struct zpci_dev *zdev)
+{
+ u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_RESET_BLOCK);
+ struct zpci_fib fib = {0};
+ u8 status;
+ int cc;
+
+ cc = zpci_mod_fc(req, &fib, &status);
+ if (cc) {
+ zpci_dbg(3, "rls fid:%x, cc:%d, status:%x\n", zdev->fid, cc, status);
+ return -EIO;
+ }
+
+ return 0;
+}
+
static int zpci_mem_init(void)
{
BUILD_BUG_ON(!is_power_of_2(__alignof__(struct zpci_fmb)) ||
diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index 6a5bfa9dc1f2..2e3e5b278925 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -47,18 +47,223 @@ struct zpci_ccdf_avail {
u16 pec; /* PCI event code */
} __packed;
+static inline bool ers_result_indicates_abort(pci_ers_result_t ers_res)
+{
+ switch (ers_res) {
+ case PCI_ERS_RESULT_CAN_RECOVER:
+ case PCI_ERS_RESULT_RECOVERED:
+ case PCI_ERS_RESULT_NEED_RESET:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static bool is_passed_through(struct zpci_dev *zdev)
+{
+ return zdev->s390_domain;
+}
+
+static bool is_driver_supported(struct pci_driver *driver)
+{
+ if (!driver || !driver->err_handler)
+ return false;
+ if (!driver->err_handler->error_detected)
+ return false;
+ if (!driver->err_handler->slot_reset)
+ return false;
+ if (!driver->err_handler->resume)
+ return false;
+ return true;
+}
+
+static pci_ers_result_t zpci_event_notify_error_detected(struct pci_dev *pdev,
+ struct pci_driver *driver)
+{
+ pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
+
+ ers_res = driver->err_handler->error_detected(pdev, pdev->error_state);
+ if (ers_result_indicates_abort(ers_res))
+ pr_info("%s: Automatic recovery failed after initial reporting\n", pci_name(pdev));
+ else if (ers_res == PCI_ERS_RESULT_NEED_RESET)
+ pr_debug("%s: Driver needs reset to recover\n", pci_name(pdev));
+
+ return ers_res;
+}
+
+static pci_ers_result_t zpci_event_do_error_state_clear(struct pci_dev *pdev,
+ struct pci_driver *driver)
+{
+ pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
+ struct zpci_dev *zdev = to_zpci(pdev);
+ int rc;
+
+ pr_info("%s: Unblocking device access for examination\n", pci_name(pdev));
+ rc = zpci_reset_load_store_blocked(zdev);
+ if (rc) {
+ pr_err("%s: Unblocking device access failed\n", pci_name(pdev));
+ /* Let's try a full reset instead */
+ return PCI_ERS_RESULT_NEED_RESET;
+ }
+
+ if (driver->err_handler->mmio_enabled) {
+ ers_res = driver->err_handler->mmio_enabled(pdev);
+ if (ers_result_indicates_abort(ers_res)) {
+ pr_info("%s: Automatic recovery failed after MMIO re-enable\n",
+ pci_name(pdev));
+ return ers_res;
+ } else if (ers_res == PCI_ERS_RESULT_NEED_RESET) {
+ pr_debug("%s: Driver needs reset to recover\n", pci_name(pdev));
+ return ers_res;
+ }
+ }
+
+ pr_debug("%s: Unblocking DMA\n", pci_name(pdev));
+ rc = zpci_clear_error_state(zdev);
+ if (!rc) {
+ pdev->error_state = pci_channel_io_normal;
+ } else {
+ pr_err("%s: Unblocking DMA failed\n", pci_name(pdev));
+ /* Let's try a full reset instead */
+ return PCI_ERS_RESULT_NEED_RESET;
+ }
+
+ return ers_res;
+}
+
+static pci_ers_result_t zpci_event_do_reset(struct pci_dev *pdev,
+ struct pci_driver *driver)
+{
+ pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
+
+ pr_info("%s: Initiating reset\n", pci_name(pdev));
+ if (zpci_hot_reset_device(to_zpci(pdev))) {
+ pr_err("%s: The reset request failed\n", pci_name(pdev));
+ return ers_res;
+ }
+ pdev->error_state = pci_channel_io_normal;
+ ers_res = driver->err_handler->slot_reset(pdev);
+ if (ers_result_indicates_abort(ers_res)) {
+ pr_info("%s: Automatic recovery failed after slot reset\n", pci_name(pdev));
+ return ers_res;
+ }
+
+ return ers_res;
+}
+
+/* zpci_event_attempt_error_recovery - Try to recover the given PCI function
+ * @pdev: PCI function to recover currently in the error state
+ *
+ * We follow the scheme outlined in Documentation/PCI/pci-error-recovery.rst.
+ * With the simplification that recovery always happens per function
+ * and the platform determines which functions are affected for
+ * multi-function devices.
+ */
+static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev)
+{
+ pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
+ struct pci_driver *driver;
+
+ /*
+ * Ensure that the PCI function is not removed concurrently, no driver
+ * is unbound or probed and that userspace can't access its
+ * configuration space while we perform recovery.
+ */
+ pci_dev_lock(pdev);
+ if (pdev->error_state == pci_channel_io_perm_failure) {
+ ers_res = PCI_ERS_RESULT_DISCONNECT;
+ goto out_unlock;
+ }
+ pdev->error_state = pci_channel_io_frozen;
+
+ if (is_passed_through(to_zpci(pdev))) {
+ pr_info("%s: Cannot be recovered in the host because it is a pass-through device\n",
+ pci_name(pdev));
+ goto out_unlock;
+ }
+
+ driver = to_pci_driver(pdev->dev.driver);
+ if (!is_driver_supported(driver)) {
+ if (!driver)
+ pr_info("%s: Cannot be recovered because no driver is bound to the device\n",
+ pci_name(pdev));
+ else
+ pr_info("%s: The %s driver bound to the device does not support error recovery\n",
+ pci_name(pdev),
+ driver->name);
+ goto out_unlock;
+ }
+
+ ers_res = zpci_event_notify_error_detected(pdev, driver);
+ if (ers_result_indicates_abort(ers_res))
+ goto out_unlock;
+
+ if (ers_res == PCI_ERS_RESULT_CAN_RECOVER) {
+ ers_res = zpci_event_do_error_state_clear(pdev, driver);
+ if (ers_result_indicates_abort(ers_res))
+ goto out_unlock;
+ }
+
+ if (ers_res == PCI_ERS_RESULT_NEED_RESET)
+ ers_res = zpci_event_do_reset(pdev, driver);
+
+ if (ers_res != PCI_ERS_RESULT_RECOVERED) {
+ pr_err("%s: Automatic recovery failed; operator intervention is required\n",
+ pci_name(pdev));
+ goto out_unlock;
+ }
+
+ pr_info("%s: The device is ready to resume operations\n", pci_name(pdev));
+ if (driver->err_handler->resume)
+ driver->err_handler->resume(pdev);
+out_unlock:
+ pci_dev_unlock(pdev);
+
+ return ers_res;
+}
+
+/* zpci_event_io_failure - Report PCI channel failure state to driver
+ * @pdev: PCI function for which to report
+ * @es: PCI channel failure state to report
+ */
+static void zpci_event_io_failure(struct pci_dev *pdev, pci_channel_state_t es)
+{
+ struct pci_driver *driver;
+
+ pci_dev_lock(pdev);
+ pdev->error_state = es;
+ /**
+ * While vfio-pci's error_detected callback notifies user-space QEMU
+ * reacts to this by freezing the guest. In an s390 environment PCI
+ * errors are rarely fatal so this is overkill. Instead in the future
+ * we will inject the error event and let the guest recover the device
+ * itself.
+ */
+ if (is_passed_through(to_zpci(pdev)))
+ goto out;
+ driver = to_pci_driver(pdev->dev.driver);
+ if (driver && driver->err_handler && driver->err_handler->error_detected)
+ driver->err_handler->error_detected(pdev, pdev->error_state);
+out:
+ pci_dev_unlock(pdev);
+}
+
static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
{
struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
struct pci_dev *pdev = NULL;
+ pci_ers_result_t ers_res;
zpci_dbg(3, "err fid:%x, fh:%x, pec:%x\n",
ccdf->fid, ccdf->fh, ccdf->pec);
zpci_err("error CCDF:\n");
zpci_err_hex(ccdf, sizeof(*ccdf));
- if (zdev)
- pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
+ if (zdev) {
+ zpci_update_fh(zdev, ccdf->fh);
+ if (zdev->zbus->bus)
+ pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
+ }
pr_err("%s: Event 0x%x reports an error for PCI function 0x%x\n",
pdev ? pci_name(pdev) : "n/a", ccdf->pec, ccdf->fid);
@@ -66,7 +271,20 @@ static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
if (!pdev)
return;
- pdev->error_state = pci_channel_io_perm_failure;
+ switch (ccdf->pec) {
+ case 0x003a: /* Service Action or Error Recovery Successful */
+ ers_res = zpci_event_attempt_error_recovery(pdev);
+ if (ers_res != PCI_ERS_RESULT_RECOVERED)
+ zpci_event_io_failure(pdev, pci_channel_io_perm_failure);
+ break;
+ default:
+ /*
+ * Mark as frozen not permanently failed because the device
+ * could be subsequently recovered by the platform.
+ */
+ zpci_event_io_failure(pdev, pci_channel_io_frozen);
+ break;
+ }
pci_dev_put(pdev);
}
@@ -78,7 +296,7 @@ void zpci_event_error(void *data)
static void zpci_event_hard_deconfigured(struct zpci_dev *zdev, u32 fh)
{
- zdev->fh = fh;
+ zpci_update_fh(zdev, fh);
/* Give the driver a hint that the function is
* already unusable.
*/
@@ -121,7 +339,7 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
if (!zdev)
zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY);
else
- zdev->fh = ccdf->fh;
+ zpci_update_fh(zdev, ccdf->fh);
break;
case 0x0303: /* Deconfiguration requested */
if (zdev) {
@@ -130,7 +348,7 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
*/
if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
break;
- zdev->fh = ccdf->fh;
+ zpci_update_fh(zdev, ccdf->fh);
zpci_deconfigure_device(zdev);
}
break;
diff --git a/arch/s390/pci/pci_insn.c b/arch/s390/pci/pci_insn.c
index 2e43996159f0..28d863aaafea 100644
--- a/arch/s390/pci/pci_insn.c
+++ b/arch/s390/pci/pci_insn.c
@@ -163,7 +163,7 @@ static inline int zpci_load_fh(u64 *data, const volatile void __iomem *addr,
unsigned long len)
{
struct zpci_iomap_entry *entry = &zpci_iomap_start[ZPCI_IDX(addr)];
- u64 req = ZPCI_CREATE_REQ(entry->fh, entry->bar, len);
+ u64 req = ZPCI_CREATE_REQ(READ_ONCE(entry->fh), entry->bar, len);
return __zpci_load(data, req, ZPCI_OFFSET(addr));
}
@@ -244,7 +244,7 @@ static inline int zpci_store_fh(const volatile void __iomem *addr, u64 data,
unsigned long len)
{
struct zpci_iomap_entry *entry = &zpci_iomap_start[ZPCI_IDX(addr)];
- u64 req = ZPCI_CREATE_REQ(entry->fh, entry->bar, len);
+ u64 req = ZPCI_CREATE_REQ(READ_ONCE(entry->fh), entry->bar, len);
return __zpci_store(data, req, ZPCI_OFFSET(addr));
}
diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c
index 3823e159bf74..954bb7a83124 100644
--- a/arch/s390/pci/pci_irq.c
+++ b/arch/s390/pci/pci_irq.c
@@ -387,6 +387,15 @@ void arch_teardown_msi_irqs(struct pci_dev *pdev)
airq_iv_free(zpci_ibv[0], zdev->msi_first_bit, zdev->msi_nr_irqs);
}
+void arch_restore_msi_irqs(struct pci_dev *pdev)
+{
+ struct zpci_dev *zdev = to_zpci(pdev);
+
+ if (!zdev->irqs_registered)
+ zpci_set_irq(zdev);
+ default_restore_msi_irqs(pdev);
+}
+
static struct airq_struct zpci_airq = {
.handler = zpci_floating_irq_handler,
.isc = PCI_ISC,