From: Kevin Hao haokexin@gmail.com
commit 55ba18dc62deff5910c0fa64486dea1ff20832ff upstream.
The commit 4af1b64f80fb ("octeontx2-pf: Fix lmtst ID used in aura free") uses the get/put_cpu() to protect the usage of percpu pointer in ->aura_freeptr() callback, but it also unnecessarily disable the preemption for the blockable memory allocation. The commit 87b93b678e95 ("octeontx2-pf: Avoid use of GFP_KERNEL in atomic context") tried to fix these sleep inside atomic warnings. But it only fix the one for the non-rt kernel. For the rt kernel, we still get the similar warnings like below. BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by swapper/0/1: #0: ffff800009fc5fe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x24/0x30 #1: ffff000100c276c0 (&mbox->lock){+.+.}-{3:3}, at: otx2_init_hw_resources+0x8c/0x3a4 #2: ffffffbfef6537e0 (&cpu_rcache->lock){+.+.}-{2:2}, at: alloc_iova_fast+0x1ac/0x2ac Preemption disabled at: [<ffff800008b1908c>] otx2_rq_aura_pool_init+0x14c/0x284 CPU: 20 PID: 1 Comm: swapper/0 Tainted: G W 6.2.0-rc3-rt1-yocto-preempt-rt #1 Hardware name: Marvell OcteonTX CN96XX board (DT) Call trace: dump_backtrace.part.0+0xe8/0xf4 show_stack+0x20/0x30 dump_stack_lvl+0x9c/0xd8 dump_stack+0x18/0x34 __might_resched+0x188/0x224 rt_spin_lock+0x64/0x110 alloc_iova_fast+0x1ac/0x2ac iommu_dma_alloc_iova+0xd4/0x110 __iommu_dma_map+0x80/0x144 iommu_dma_map_page+0xe8/0x260 dma_map_page_attrs+0xb4/0xc0 __otx2_alloc_rbuf+0x90/0x150 otx2_rq_aura_pool_init+0x1c8/0x284 otx2_init_hw_resources+0xe4/0x3a4 otx2_open+0xf0/0x610 __dev_open+0x104/0x224 __dev_change_flags+0x1e4/0x274 dev_change_flags+0x2c/0x7c ic_open_devs+0x124/0x2f8 ip_auto_config+0x180/0x42c do_one_initcall+0x90/0x4dc do_basic_setup+0x10c/0x14c kernel_init_freeable+0x10c/0x13c kernel_init+0x2c/0x140 ret_from_fork+0x10/0x20
Of course, we can shuffle the get/put_cpu() to only wrap the invocation of ->aura_freeptr() as what commit 87b93b678e95 does. But there are only two ->aura_freeptr() callbacks, otx2_aura_freeptr() and cn10k_aura_freeptr(). There is no usage of perpcu variable in the otx2_aura_freeptr() at all, so the get/put_cpu() seems redundant to it. We can move the get/put_cpu() into the corresponding callback which really has the percpu variable usage and avoid the sprinkling of get/put_cpu() in several places.
Fixes: 4af1b64f80fb ("octeontx2-pf: Fix lmtst ID used in aura free") Signed-off-by: Kevin Hao haokexin@gmail.com Link: https://lore.kernel.org/r/20230118071300.3271125-1-haokexin@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c | 11 ++--------- drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h | 2 ++ 2 files changed, 4 insertions(+), 9 deletions(-)
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c @@ -1012,7 +1012,6 @@ static void otx2_pool_refill_task(struct rbpool = cq->rbpool; free_ptrs = cq->pool_ptrs;
- get_cpu(); while (cq->pool_ptrs) { if (otx2_alloc_rbuf(pfvf, rbpool, &bufptr)) { /* Schedule a WQ if we fails to free atleast half of the @@ -1032,7 +1031,6 @@ static void otx2_pool_refill_task(struct pfvf->hw_ops->aura_freeptr(pfvf, qidx, bufptr + OTX2_HEAD_ROOM); cq->pool_ptrs--; } - put_cpu(); cq->refill_task_sched = false; }
@@ -1387,9 +1385,7 @@ int otx2_sq_aura_pool_init(struct otx2_n err = otx2_alloc_rbuf(pfvf, pool, &bufptr); if (err) goto err_mem; - get_cpu(); pfvf->hw_ops->aura_freeptr(pfvf, pool_id, bufptr); - put_cpu(); sq->sqb_ptrs[sq->sqb_count++] = (u64)bufptr; } } @@ -1435,21 +1431,18 @@ int otx2_rq_aura_pool_init(struct otx2_n if (err) goto fail;
- get_cpu(); /* Allocate pointers and free them to aura/pool */ for (pool_id = 0; pool_id < hw->rqpool_cnt; pool_id++) { pool = &pfvf->qset.pool[pool_id]; for (ptr = 0; ptr < num_ptrs; ptr++) { err = otx2_alloc_rbuf(pfvf, pool, &bufptr); if (err) - goto err_mem; + return -ENOMEM; pfvf->hw_ops->aura_freeptr(pfvf, pool_id, bufptr + OTX2_HEAD_ROOM); } } -err_mem: - put_cpu(); - return err ? -ENOMEM : 0; + return 0; fail: otx2_mbox_reset(&pfvf->mbox.mbox, 0); otx2_aura_pool_free(pfvf); --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h @@ -733,8 +733,10 @@ static inline void cn10k_aura_freeptr(vo u64 ptrs[2];
ptrs[1] = buf; + get_cpu(); /* Free only one buffer at time during init and teardown */ __cn10k_aura_freeptr(pfvf, aura, ptrs, 2); + put_cpu(); }
/* Alloc pointer from pool/aura */