From:   Eliav Farber <farbere@amazon.com>
To:     <bp@alien8.de>
CC:     <mchehab@kernel.org>, <linux-edac@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <ronenk@amazon.com>,
        <talel@amazon.com>, <hhhawa@amazon.com>, <jonnyc@amazon.com>,
        <hanochu@amazon.com>, <farbere@amazon.com>
Subject: [PATCH 4/4] EDAC: Refactor edac_align_ptr() flow
Date:   Thu, 13 Jan 2022 10:06:22 +0000
Message-ID: <20220113100622.12783-5-farbere@amazon.com>
In-Reply-To: <20220113100622.12783-1-farbere@amazon.com>
References: <20220113100622.12783-1-farbere@amazon.com>
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Modify flow to be more clear:
 - Calculate required alignment based on size.
 - Check if *p is aligned and fix if not.
 - Set return ptr to to be *p.
 - Increase *p by new size for the next call.

Signed-off-by: Eliav Farber <farbere@amazon.com>
---
 drivers/edac/edac_mc.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 3367bf997b73..a3ff5a019fc7 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -241,9 +241,7 @@ EXPORT_SYMBOL_GPL(edac_mem_types);
 void *edac_align_ptr(void **p, unsigned size, int n_elems)
 {
 	unsigned align, r;
-	void *ptr = *p;
-
-	*p += size * n_elems;
+	void *ptr;
 
 	/*
 	 * 'p' can possibly be an unaligned item X such that sizeof(X) is
@@ -258,16 +256,22 @@ void *edac_align_ptr(void **p, unsigned size, int n_elems)
 	else if (size > sizeof(u8))
 		align = sizeof(u16);
 	else
-		return ptr;
-
-	r = (unsigned long)ptr % align;
+		goto out;
 
-	if (r == 0)
-		return ptr;
+	/* Calculate alignment, and fix *p if not aligned. */
+	r = (unsigned long)*p % align;
+	if (r)
+		*p += align - r;
 
-	*p += align - r;
+out:
+	/*
+	 * Set return ptr to to be *p (after alignment if it was needed),
+	 * and increase *p by new size for the next call.
+	 */
+	ptr = *p;
+	*p += size * n_elems;
 
-	return (void *)(((unsigned long)ptr) + align - r);
+	return ptr;
 }
 
 static void _edac_mc_free(struct mem_ctl_info *mci)
-- 
2.32.0