[RFC 03/12] powerpc/pseries: Rework hash flush to remove conditional locking

[Ritesh Harjani (IBM)]

Clang's compiler based static context analysis does not work with locks
that are conditionally taken like in pSeries_lpar_flush_hash_range().

This also simplifies the function definition in my opinion - so this
is also a win.

No functional change intended.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
---
 arch/powerpc/platforms/pseries/lpar.c | 31 ++++++++++++++++-----------
 1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index abd77c45cbf4..5dbf447d3a83 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -1526,28 +1526,19 @@ void __init pseries_lpar_read_hblkrm_characteristics(void)
 					bpsize, idx, hblkrm_size[bpsize][idx]);
 }
 
-/*
- * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
- * lock.
- */
-static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
+static void pSeries_lpar_flush_hash_range_unlocked(unsigned long number, int local)
 {
 	unsigned long vpn;
 	unsigned long i, pix, rc;
-	unsigned long flags = 0;
 	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
-	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 	unsigned long param[PLPAR_HCALL9_BUFSIZE];
 	unsigned long index, shift, slot;
 	real_pte_t pte;
 	int psize, ssize;
 
-	if (lock_tlbie)
-		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
-
 	if (is_supported_hlbkrm(batch->psize, batch->psize)) {
 		do_block_remove(number, batch, param);
-		goto out;
+		return;
 	}
 
 	psize = batch->psize;
@@ -1587,10 +1578,24 @@ static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
 				  param[6], param[7]);
 		BUG_ON(rc != H_SUCCESS);
 	}
+}
 
-out:
-	if (lock_tlbie)
+/*
+ * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
+ * lock. Firmware with MMU_FTR_LOCKLESS_TLBIE does not need it.
+ */
+static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
+{
+	unsigned long flags;
+
+	if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE)) {
+		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
+		pSeries_lpar_flush_hash_range_unlocked(number, local);
 		spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
+		return;
+	}
+
+	pSeries_lpar_flush_hash_range_unlocked(number, local);
 }
 
 static int __init disable_bulk_remove(char *str)
-- 
2.39.5