Patch "ARCv2: PAE40: Explicitly set MSB counterpart of SLC region ops addresses" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

ARCv2: PAE40: Explicitly set MSB counterpart of SLC region ops addresses

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arcv2-pae40-explicitly-set-msb-counterpart-of-slc-region-ops-addresses.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Alexey Brodkin <[email protected]>
Date: Tue, 1 Aug 2017 12:58:47 +0300
Subject: ARCv2: PAE40: Explicitly set MSB counterpart of SLC region ops addresses

From: Alexey Brodkin <[email protected]>

commit 7d79cee2c6540ea64dd917a14e2fd63d4ac3d3c0 upstream.

It is necessary to explicitly set both SLC_AUX_RGN_START1 and SLC_AUX_RGN_END1 which hold MSB bits of the physical address correspondingly of region start and end otherwise SLC region operation is executed in unpredictable manner

Without this patch, SLC flushes on HSDK (IOC disabled) were taking seconds.

---
 arch/arc/include/asm/cache.h |    2 ++
 arch/arc/mm/cache.c          |   13 +++++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

@@ -88,7 +88,9 @@ extern int ioc_exists;
 #define ARC_REG_SLC_FLUSH	0x904
 #define ARC_REG_SLC_INVALIDATE	0x905
 #define ARC_REG_SLC_RGN_START	0x914
+#define ARC_REG_SLC_RGN_START1	0x915
 #define ARC_REG_SLC_RGN_END	0x916
+#define ARC_REG_SLC_RGN_END1	0x917
 
 /* Bit val in SLC_CONTROL */
 #define SLC_CTRL_IM		0x040

@@ -543,6 +543,7 @@ noinline void slc_op(phys_addr_t paddr,
 	static DEFINE_SPINLOCK(lock);
 	unsigned long flags;
 	unsigned int ctrl;
+	phys_addr_t end;
 
 	spin_lock_irqsave(&lock, flags);
 

@@ -572,8 +573,16 @@ noinline void slc_op(phys_addr_t paddr,
 	 * END needs to be setup before START (latter triggers the operation)
 	 * END can't be same as START, so add (l2_line_sz - 1) to sz
 	 */
-	write_aux_reg(ARC_REG_SLC_RGN_END, (paddr + sz + l2_line_sz - 1));
-	write_aux_reg(ARC_REG_SLC_RGN_START, paddr);
+	end = paddr + sz + l2_line_sz - 1;
+	if (is_pae40_enabled())
+		write_aux_reg(ARC_REG_SLC_RGN_END1, upper_32_bits(end));
+
+	write_aux_reg(ARC_REG_SLC_RGN_END, lower_32_bits(end));
+
+	if (is_pae40_enabled())
+		write_aux_reg(ARC_REG_SLC_RGN_START1, upper_32_bits(paddr));
+
+	write_aux_reg(ARC_REG_SLC_RGN_START, lower_32_bits(paddr));
 
 	while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/arcv2-pae40-explicitly-set-msb-counterpart-of-slc-region-ops-addresses.patch