[RFC 03/12] powerpc/pseries: Rework hash flush to remove conditional locking
From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Date: 2026-09-27 14:35:05
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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@gmail.com> --- 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)
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2.39.5