Skip to content

Commit 6ac3484

Browse files
wxiong66martinkpetersen
wxiong66
authored and
martinkpetersen
committed
scsi: ipr: Enable/disable IRQD_NO_BALANCING during reset
A dynamic remove/add storage adapter test hits EEH on PowerPC: EEH: [c00000000004f75c] __eeh_send_failure_event+0x7c/0x160 EEH: [c000000000048444] eeh_dev_check_failure.part.0+0x254/0x650 EEH: [c008000001650678] eeh_readl+0x60/0x90 [ipr] EEH: [c00800000166746c] ipr_cancel_op+0x2b8/0x524 [ipr] EEH: [c008000001656524] ipr_eh_abort+0x6c/0x130 [ipr] EEH: [c000000000ab0d20] scmd_eh_abort_handler+0x140/0x440 EEH: [c00000000017e558] process_one_work+0x298/0x590 EEH: [c00000000017eef8] worker_thread+0xa8/0x620 EEH: [c00000000018be34] kthread+0x124/0x130 EEH: [c00000000000cd64] ret_from_kernel_thread+0x5c/0x64 A PCIe bus trace reveals that a vector of MSI-X is cleared to 0 by irqbalance daemon. If we disable irqbalance daemon, we won't see the issue. With debug enabled in ipr driver: [ 44.103071] ipr: Entering __ipr_remove [ 44.103083] ipr: Entering ipr_initiate_ioa_bringdown [ 44.103091] ipr: Entering ipr_reset_shutdown_ioa [ 44.103099] ipr: Leaving ipr_reset_shutdown_ioa [ 44.103105] ipr: Leaving ipr_initiate_ioa_bringdown [ 44.149918] ipr: Entering ipr_reset_ucode_download [ 44.149935] ipr: Entering ipr_reset_alert [ 44.150032] ipr: Entering ipr_reset_start_timer [ 44.150038] ipr: Leaving ipr_reset_alert [ 44.244343] scsi 1:2:3:0: alua: Detached [ 44.254300] ipr: Entering ipr_reset_start_bist [ 44.254320] ipr: Entering ipr_reset_start_timer [ 44.254325] ipr: Leaving ipr_reset_start_bist [ 44.364329] scsi 1:2:4:0: alua: Detached [ 45.134341] scsi 1:2:5:0: alua: Detached [ 45.860949] ipr: Entering ipr_reset_shutdown_ioa [ 45.860962] ipr: Leaving ipr_reset_shutdown_ioa [ 45.860966] ipr: Entering ipr_reset_alert [ 45.861028] ipr: Entering ipr_reset_start_timer [ 45.861035] ipr: Leaving ipr_reset_alert [ 45.964302] ipr: Entering ipr_reset_start_bist [ 45.964309] ipr: Entering ipr_reset_start_timer [ 45.964313] ipr: Leaving ipr_reset_start_bist [ 46.264301] ipr: Entering ipr_reset_bist_done [ 46.264309] ipr: Leaving ipr_reset_bist_done During adapter reset, ipr device driver blocks config space access but can't block MMIO access for MSI-X entries. There is very small window: irqbalance daemon kicks in during adapter reset before ipr driver calls pci_restore_state(pdev) to restore MSI-X table. irqbalance daemon reads back all 0 for that MSI-X vector in __pci_read_msi_msg(). irqbalance daemon: msi_domain_set_affinity() ->irq_chip_set_affinity_patent() ->xive_irq_set_affinity() ->irq_chip_compose_msi_msg() ->pseries_msi_compose_msg() ->__pci_read_msi_msg(): read all 0 since didn't call pci_restore_state ->irq_chip_write_msi_msg() -> pci_write_msg_msi(): write 0 to the msix vector entry When ipr driver calls pci_restore_state(pdev) in ipr_reset_restore_cfg_space(), the MSI-X vector entry has been cleared by irqbalance daemon in pci_write_msg_msix(). pci_restore_state() ->__pci_restore_msix_state() Below is the MSI-X table for ipr adapter after irqbalance daemon kicked in during adapter reset: Dump MSIx table: index=0 address_lo=c800 address_hi=10000000 msg_data=0 Dump MSIx table: index=1 address_lo=c810 address_hi=10000000 msg_data=0 Dump MSIx table: index=2 address_lo=c820 address_hi=10000000 msg_data=0 Dump MSIx table: index=3 address_lo=c830 address_hi=10000000 msg_data=0 Dump MSIx table: index=4 address_lo=c840 address_hi=10000000 msg_data=0 Dump MSIx table: index=5 address_lo=c850 address_hi=10000000 msg_data=0 Dump MSIx table: index=6 address_lo=c860 address_hi=10000000 msg_data=0 Dump MSIx table: index=7 address_lo=c870 address_hi=10000000 msg_data=0 Dump MSIx table: index=8 address_lo=0 address_hi=0 msg_data=0 ---------> Hit EEH since msix vector of index=8 are 0 Dump MSIx table: index=9 address_lo=c890 address_hi=10000000 msg_data=0 Dump MSIx table: index=10 address_lo=c8a0 address_hi=10000000 msg_data=0 Dump MSIx table: index=11 address_lo=c8b0 address_hi=10000000 msg_data=0 Dump MSIx table: index=12 address_lo=c8c0 address_hi=10000000 msg_data=0 Dump MSIx table: index=13 address_lo=c8d0 address_hi=10000000 msg_data=0 Dump MSIx table: index=14 address_lo=c8e0 address_hi=10000000 msg_data=0 Dump MSIx table: index=15 address_lo=c8f0 address_hi=10000000 msg_data=0 [ 46.264312] ipr: Entering ipr_reset_restore_cfg_space [ 46.267439] ipr: Entering ipr_fail_all_ops [ 46.267447] ipr: Leaving ipr_fail_all_ops [ 46.267451] ipr: Leaving ipr_reset_restore_cfg_space [ 46.267454] ipr: Entering ipr_ioa_bringdown_done [ 46.267458] ipr: Leaving ipr_ioa_bringdown_done [ 46.267467] ipr: Entering ipr_worker_thread [ 46.267470] ipr: Leaving ipr_worker_thread IRQ balancing is not required during adapter reset. Enable "IRQ_NO_BALANCING" flag before starting adapter reset and disable it after calling pci_restore_state(). The irqbalance daemon is disabled for this short period of time (~2s). Co-developed-by: Kyle Mahlkuch <Kyle.Mahlkuch@ibm.com> Signed-off-by: Kyle Mahlkuch <Kyle.Mahlkuch@ibm.com> Signed-off-by: Wen Xiong <wenxiong@linux.ibm.com> Link: https://patch.msgid.link/20251028142427.3969819-2-wenxiong@linux.ibm.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
1 parent ab58153 commit 6ac3484

1 file changed

Lines changed: 27 additions & 1 deletion

File tree

‎drivers/scsi/ipr.c‎

Lines changed: 27 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -61,8 +61,8 @@
6161
#include <linux/hdreg.h>
6262
#include <linux/reboot.h>
6363
#include <linux/stringify.h>
64+
#include <linux/irq.h>
6465
#include <asm/io.h>
65-
#include <asm/irq.h>
6666
#include <asm/processor.h>
6767
#include <scsi/scsi.h>
6868
#include <scsi/scsi_host.h>
@@ -7843,6 +7843,30 @@ static int ipr_dump_mailbox_wait(struct ipr_cmnd *ipr_cmd)
78437843
return IPR_RC_JOB_RETURN;
78447844
}
78457845

7846+
/**
7847+
* ipr_set_affinity_nobalance
7848+
* @ioa_cfg: ipr_ioa_cfg struct for an ipr device
7849+
* @flag: bool
7850+
* true: ensable "IRQ_NO_BALANCING" bit for msix interrupt
7851+
* false: disable "IRQ_NO_BALANCING" bit for msix interrupt
7852+
* Description: This function will be called to disable/enable
7853+
* "IRQ_NO_BALANCING" to avoid irqbalance daemon
7854+
* kicking in during adapter reset.
7855+
**/
7856+
static void ipr_set_affinity_nobalance(struct ipr_ioa_cfg *ioa_cfg, bool flag)
7857+
{
7858+
int irq, i;
7859+
7860+
for (i = 0; i < ioa_cfg->nvectors; i++) {
7861+
irq = pci_irq_vector(ioa_cfg->pdev, i);
7862+
7863+
if (flag)
7864+
irq_set_status_flags(irq, IRQ_NO_BALANCING);
7865+
else
7866+
irq_clear_status_flags(irq, IRQ_NO_BALANCING);
7867+
}
7868+
}
7869+
78467870
/**
78477871
* ipr_reset_restore_cfg_space - Restore PCI config space.
78487872
* @ipr_cmd: ipr command struct
@@ -7867,6 +7891,7 @@ static int ipr_reset_restore_cfg_space(struct ipr_cmnd *ipr_cmd)
78677891
return IPR_RC_JOB_CONTINUE;
78687892
}
78697893

7894+
ipr_set_affinity_nobalance(ioa_cfg, false);
78707895
ipr_fail_all_ops(ioa_cfg);
78717896

78727897
if (ioa_cfg->sis64) {
@@ -7946,6 +7971,7 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd)
79467971
rc = pci_write_config_byte(ioa_cfg->pdev, PCI_BIST, PCI_BIST_START);
79477972

79487973
if (rc == PCIBIOS_SUCCESSFUL) {
7974+
ipr_set_affinity_nobalance(ioa_cfg, true);
79497975
ipr_cmd->job_step = ipr_reset_bist_done;
79507976
ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT);
79517977
rc = IPR_RC_JOB_RETURN;

0 commit comments

Comments
 (0)