[PATCH 5.17 0707/1126] ice: fix scheduling while atomic on aux critical err interrupt

Greg Kroah-Hartman
2022-04-05T09:52:25Z

From: Alexander Lobakin <alexandr.lobakin@intel.com>

[ Upstream commit 32d53c0aa3a7b727243473949bad2a830b908edc ]

There's a kernel BUG splat on processing aux critical error
interrupts in ice_misc_intr():

[ 2100.917085] BUG: scheduling while atomic: swapper/15/0/0x00010000
...
[ 2101.060770] Call Trace:
[ 2101.063229] <IRQ>
[ 2101.065252] dump_stack+0x41/0x60
[ 2101.068587] __schedule_bug.cold.100+0x4c/0x58
[ 2101.073060] __schedule+0x6a4/0x830
[ 2101.076570] schedule+0x35/0xa0
[ 2101.079727] schedule_preempt_disabled+0xa/0x10
[ 2101.084284] __mutex_lock.isra.7+0x310/0x420
[ 2101.088580] ? ice_misc_intr+0x201/0x2e0 [ice]
[ 2101.093078] ice_send_event_to_aux+0x25/0x70 [ice]
[ 2101.097921] ice_misc_intr+0x220/0x2e0 [ice]
[ 2101.102232] __handle_irq_event_percpu+0x40/0x180
[ 2101.106965] handle_irq_event_percpu+0x30/0x80
[ 2101.111434] handle_irq_event+0x36/0x53
[ 2101.115292] handle_edge_irq+0x82/0x190
[ 2101.119148] handle_irq+0x1c/0x30
[ 2101.122480] do_IRQ+0x49/0xd0
[ 2101.125465] common_interrupt+0xf/0xf
[ 2101.129146] </IRQ>
...

As Andrew correctly mentioned previously[0], the following call
ladder happens:

ice_misc_intr() <- hardirq
ice_send_event_to_aux()
device_lock()
mutex_lock()
might_sleep()
might_resched() <- oops

Add a new PF state bit which indicates that an aux critical error
occurred and serve it in ice_service_task() in process context.
The new ice_pf::oicr_err_reg is read-write in both hardirq and
process contexts, but only 3 bits of non-critical data probably
aren't worth explicit synchronizing (and they're even in the same
byte [31:24]).

[0] https://lore.kernel.org/all/YeSRUVmrdmlUXHDn@lunn.ch

Fixes: 348048e724a0e ("ice: Implement iidc operations")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Tested-by: Michal Kubiak <michal.kubiak@intel.com>
Acked-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/ice/ice.h | 2 ++
drivers/net/ethernet/intel/ice/ice_main.c | 25 ++++++++++++++---------
2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index bea1d1e39fa2..2ca887076dd4 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -290,6 +290,7 @@ enum ice_pf_state {
ICE_LINK_DEFAULT_OVERRIDE_PENDING,
ICE_PHY_INIT_COMPLETE,
ICE_FD_VF_FLUSH_CTX, /* set at FD Rx IRQ or timeout */
+ ICE_AUX_ERR_PENDING,
ICE_STATE_NBITS /* must be last */
};

@@ -559,6 +560,7 @@ struct ice_pf {
wait_queue_head_t reset_wait_queue;

u32 hw_csum_rx_error;
+ u32 oicr_err_reg;
u16 oicr_idx; /* Other interrupt cause MSIX vector index */
u16 num_avail_sw_msix; /* remaining MSIX SW vectors left unclaimed */
u16 max_pf_txqs; /* Total Tx queues PF wide */
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index b7e8744b0c0a..296f9d5f7408 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -2255,6 +2255,19 @@ static void ice_service_task(struct work_struct *work)
return;
}

+ if (test_and_clear_bit(ICE_AUX_ERR_PENDING, pf->state)) {
+ struct iidc_event *event;
+
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
+ if (event) {
+ set_bit(IIDC_EVENT_CRIT_ERR, event->type);
+ /* report the entire OICR value to AUX driver */
+ swap(event->reg, pf->oicr_err_reg);
+ ice_send_event_to_aux(pf, event);
+ kfree(event);
+ }
+ }
+
if (test_bit(ICE_FLAG_PLUG_AUX_DEV, pf->flags)) {
/* Plug aux device per request */
ice_plug_aux_dev(pf);
@@ -3041,17 +3054,9 @@ static irqreturn_t ice_misc_intr(int __always_unused irq, void *data)

#define ICE_AUX_CRIT_ERR (PFINT_OICR_PE_CRITERR_M | PFINT_OICR_HMC_ERR_M | PFINT_OICR_PE_PUSH_M)
if (oicr & ICE_AUX_CRIT_ERR) {
- struct iidc_event *event;
-
+ pf->oicr_err_reg |= oicr;
+ set_bit(ICE_AUX_ERR_PENDING, pf->state);
ena_mask &= ~ICE_AUX_CRIT_ERR;
- event = kzalloc(sizeof(*event), GFP_ATOMIC);
- if (event) {
- set_bit(IIDC_EVENT_CRIT_ERR, event->type);
- /* report the entire OICR value to AUX driver */
- event->reg = oicr;
- ice_send_event_to_aux(pf, event);
- kfree(event);
- }
}

/* Report any remaining unexpected interrupts */
--
2.34.1