From 9c78a73a5fd3aff694ddcaeefdae4ec78a3573be Mon Sep 17 00:00:00 2001
From: Stefan Wahren <stefan.wahren@i2se.com>
Date: Sun, 23 Jan 2022 21:02:08 +0100
Subject: [PATCH] staging: vchiq_arm: introduce is_adjacent_block
The check for an adjacent block is hard to read. So move it into a separate
inline function.
Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1642968143-19281-4-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
.../interface/vchiq_arm/vchiq_arm.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index 6759a6261500..974804447935 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -189,6 +189,20 @@ cleanup_pagelistinfo(struct vchiq_pagelist_info *pagelistinfo)
pagelistinfo->pagelist, pagelistinfo->dma_addr);
}
+static inline bool
+is_adjacent_block(u32 *addrs, u32 addr, unsigned int k)
+{
+ u32 tmp;
+
+ if (!k)
+ return false;
+
+ tmp = (addrs[k - 1] & PAGE_MASK) +
+ (((addrs[k - 1] & ~PAGE_MASK) + 1) << PAGE_SHIFT);
+
+ return tmp == (addr & PAGE_MASK);
+}
+
/* There is a potential problem with partial cache lines (pages?)
* at the ends of the block when reading. If the CPU accessed anything in
* the same line (page?) then it may have pulled old data into the cache,
@@ -349,10 +363,7 @@ create_pagelist(char *buf, char __user *ubuf,
WARN_ON(len == 0);
WARN_ON(i && (i != (dma_buffers - 1)) && (len & ~PAGE_MASK));
WARN_ON(i && (addr & ~PAGE_MASK));
- if (k > 0 &&
- ((addrs[k - 1] & PAGE_MASK) +
- (((addrs[k - 1] & ~PAGE_MASK) + 1) << PAGE_SHIFT))
- == (addr & PAGE_MASK))
+ if (is_adjacent_block(addrs, addr, k))
addrs[k - 1] += ((len + PAGE_SIZE - 1) >> PAGE_SHIFT);
else
addrs[k++] = (addr & PAGE_MASK) |
--
2.30.9