From: Alexey Brodkin <abrodkin@synopsys.com>
Date: Fri, 7 Jul 2017 12:25:14 +0300
Subject: [PATCH] ARCv2: SLC: Make sure busy bit is set properly for region ops
References: bnc#1060662
Patch-mainline: 4.12.10
Git-commit: b37174d95b0251611a80ef60abf03752e9d66d67

commit b37174d95b0251611a80ef60abf03752e9d66d67 upstream.

c70c473396cb "ARCv2: SLC: Make sure busy bit is set properly on SLC flushing"
fixes problem for entire SLC operation where the problem was initially
caught. But given a nature of the issue it is perfectly possible for
busy bit to be read incorrectly even when region operation was started.

So extending initial fix for regional operation as well.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 arch/arc/mm/cache.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index a867575a758b..bebc24cb7912 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -697,6 +697,9 @@ noinline void slc_op(phys_addr_t paddr, unsigned long sz, const int op)
 	write_aux_reg(ARC_REG_SLC_RGN_END, (paddr + sz + l2_line_sz - 1));
 	write_aux_reg(ARC_REG_SLC_RGN_START, paddr);
 
+	/* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */
+	read_aux_reg(ARC_REG_SLC_CTRL);
+
 	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
 
 	spin_unlock_irqrestore(&lock, flags);
-- 
2.14.2