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From: Kevin Cernekee <cernekee@gmail.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: <linux-mips@linux-mips.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v2 8/9] MIPS: Honor L2 bypass bit
Date: Wed, 20 Oct 2010 20:05:42 -0700	[thread overview]
Message-ID: <74b5d3ba9506b2e6d885546bd6dcdaec@localhost> (raw)

On many of the newer MIPS32 cores, CP0 CONFIG2 bit 12 (L2B) indicates
that the L2 cache is disabled and therefore Linux should not attempt
to use it.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/mm/sc-mips.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c
index 5ab5fa8..f2e2886 100644
--- a/arch/mips/mm/sc-mips.c
+++ b/arch/mips/mm/sc-mips.c
@@ -79,6 +79,17 @@ static inline int __init mips_sc_probe(void)
 		return 0;
 
 	config2 = read_c0_config2();
+
+	/* Check the bypass bit (L2B) */
+	switch (c->cputype) {
+	case CPU_34K:
+	case CPU_74K:
+	case CPU_1004K:
+	case CPU_BMIPS5000:
+		if (config2 & (1 << 12))
+			return 0;
+	}
+
 	tmp = (config2 >> 4) & 0x0f;
 	if (0 < tmp && tmp <= 7)
 		c->scache.linesz = 2 << tmp;
-- 
1.7.0.4

WARNING: multiple messages have this Message-ID (diff)
From: Kevin Cernekee <cernekee@gmail.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 8/9] MIPS: Honor L2 bypass bit
Date: Wed, 20 Oct 2010 20:05:42 -0700	[thread overview]
Message-ID: <74b5d3ba9506b2e6d885546bd6dcdaec@localhost> (raw)
Message-ID: <20101021030542.-rd4HXkTqmquMxs-At-mOCYFkF05EbgtxQEW5maKedM@z> (raw)

On many of the newer MIPS32 cores, CP0 CONFIG2 bit 12 (L2B) indicates
that the L2 cache is disabled and therefore Linux should not attempt
to use it.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
 arch/mips/mm/sc-mips.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c
index 5ab5fa8..f2e2886 100644
--- a/arch/mips/mm/sc-mips.c
+++ b/arch/mips/mm/sc-mips.c
@@ -79,6 +79,17 @@ static inline int __init mips_sc_probe(void)
 		return 0;
 
 	config2 = read_c0_config2();
+
+	/* Check the bypass bit (L2B) */
+	switch (c->cputype) {
+	case CPU_34K:
+	case CPU_74K:
+	case CPU_1004K:
+	case CPU_BMIPS5000:
+		if (config2 & (1 << 12))
+			return 0;
+	}
+
 	tmp = (config2 >> 4) & 0x0f;
 	if (0 < tmp && tmp <= 7)
 		c->scache.linesz = 2 << tmp;
-- 
1.7.0.4

             reply	other threads:[~2010-10-21  3:23 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-21  3:05 Kevin Cernekee [this message]
2010-10-21  3:05 ` [PATCH v2 8/9] MIPS: Honor L2 bypass bit Kevin Cernekee
2010-10-21 12:58 ` Ralf Baechle
2010-10-21 16:25   ` Kevin Cernekee
2010-10-24  2:40     ` Maciej W. Rozycki

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