linux-kernel - [PATCH] tile: do less L1 I-cache eviction

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Message-ID: <201308092100.r79L00P9011261@lab-41.internal.tilera.com>
Date:	Fri, 9 Aug 2013 16:09:41 -0400
From:	Chris Metcalf <cmetcalf@...era.com>
To:	<linux-kernel@...r.kernel.org>
Subject: [PATCH] tile: do less L1 I-cache eviction

We had been doing an automatic full eviction of the L1 I$
everywhere whenever we did a kernel-space TLB flush.  It turns
out this isn't necessary, since all the callers already handle
doing a flush if necessary.

Signed-off-by: Chris Metcalf <cmetcalf@...era.com>
---
 arch/tile/kernel/tlb.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/tile/kernel/tlb.c b/arch/tile/kernel/tlb.c
index 3fd54d5..f23b535 100644
--- a/arch/tile/kernel/tlb.c
+++ b/arch/tile/kernel/tlb.c
@@ -91,8 +91,14 @@ void flush_tlb_all(void)
 	}
 }
 
+/*
+ * Callers need to flush the L1I themselves if necessary, e.g. for
+ * kernel module unload.  Otherwise we assume callers are not using
+ * executable pgprot_t's.  Using EVICT_L1I means that dataplane cpus
+ * will get an unnecessary interrupt otherwise.
+ */
 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 {
-	flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
+	flush_remote(0, 0, NULL,
 		     start, end - start, PAGE_SIZE, cpu_online_mask, NULL, 0);
 }
-- 
1.8.3.1

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