[PATCH 5.15 37/73] misc: sgi-gru: Dont disable preemption in GRU driver

5.15-stable review patch. If anyone has any objections, please let me know.

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From: Dimitri Sivanich sivanich@hpe.com

[ Upstream commit b983b271662bd6104d429b0fd97af3333ba760bf ]

Disabling preemption in the GRU driver is unnecessary, and clashes with sleeping locks in several code paths. Remove preempt_disable and preempt_enable from the GRU driver.

Signed-off-by: Dimitri Sivanich sivanich@hpe.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/misc/sgi-gru/grukservices.c | 2 -- drivers/misc/sgi-gru/grumain.c | 4 ---- drivers/misc/sgi-gru/grutlbpurge.c | 2 -- 3 files changed, 8 deletions(-)

diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c index 0ea923fe6371b..e2bdba4742930 100644 --- a/drivers/misc/sgi-gru/grukservices.c +++ b/drivers/misc/sgi-gru/grukservices.c @@ -258,7 +258,6 @@ static int gru_get_cpu_resources(int dsr_bytes, void **cb, void **dsr) int lcpu;

BUG_ON(dsr_bytes > GRU_NUM_KERNEL_DSR_BYTES); - preempt_disable(); bs = gru_lock_kernel_context(-1); lcpu = uv_blade_processor_id(); *cb = bs->kernel_cb + lcpu * GRU_HANDLE_STRIDE; @@ -272,7 +271,6 @@ static int gru_get_cpu_resources(int dsr_bytes, void **cb, void **dsr) static void gru_free_cpu_resources(void *cb, void *dsr) { gru_unlock_kernel_context(uv_numa_blade_id()); - preempt_enable(); }

/* diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c index 3a16eb8e03f73..9b8bdd57ec854 100644 --- a/drivers/misc/sgi-gru/grumain.c +++ b/drivers/misc/sgi-gru/grumain.c @@ -941,10 +941,8 @@ vm_fault_t gru_fault(struct vm_fault *vmf)

again: mutex_lock(&gts->ts_ctxlock); - preempt_disable();

if (gru_check_context_placement(gts)) { - preempt_enable(); mutex_unlock(&gts->ts_ctxlock); gru_unload_context(gts, 1); return VM_FAULT_NOPAGE; @@ -953,7 +951,6 @@ vm_fault_t gru_fault(struct vm_fault *vmf) if (!gts->ts_gru) { STAT(load_user_context); if (!gru_assign_gru_context(gts)) { - preempt_enable(); mutex_unlock(&gts->ts_ctxlock); set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(GRU_ASSIGN_DELAY); /* true hack ZZZ */ @@ -969,7 +966,6 @@ vm_fault_t gru_fault(struct vm_fault *vmf) vma->vm_page_prot); }

- preempt_enable(); mutex_unlock(&gts->ts_ctxlock);

return VM_FAULT_NOPAGE; diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c index 10921cd2608df..1107dd3e2e9fa 100644 --- a/drivers/misc/sgi-gru/grutlbpurge.c +++ b/drivers/misc/sgi-gru/grutlbpurge.c @@ -65,7 +65,6 @@ static struct gru_tlb_global_handle *get_lock_tgh_handle(struct gru_state struct gru_tlb_global_handle *tgh; int n;

- preempt_disable(); if (uv_numa_blade_id() == gru->gs_blade_id) n = get_on_blade_tgh(gru); else @@ -79,7 +78,6 @@ static struct gru_tlb_global_handle *get_lock_tgh_handle(struct gru_state static void get_unlock_tgh_handle(struct gru_tlb_global_handle *tgh) { unlock_tgh_handle(tgh); - preempt_enable(); }

/*