linux-kernel - [PATCH v5 4/7] ARM: l2c: Add support for overriding prefetch settings

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <1411556741-5810-5-git-send-email-m.szyprowski@samsung.com>
Date:	Wed, 24 Sep 2014 13:05:38 +0200
From:	Marek Szyprowski <m.szyprowski@...sung.com>
To:	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-samsung-soc@...r.kernel.org
Cc:	Marek Szyprowski <m.szyprowski@...sung.com>,
	Tomasz Figa <tomasz.figa@...il.com>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Russell King - ARM Linux <linux@....linux.org.uk>,
	Kukjin Kim <kgene.kim@...sung.com>, lauraa@...eaurora.org,
	linux-omap@...r.kernel.org, linus.walleij@...aro.org,
	santosh.shilimkar@...com, tony@...mide.com, drake@...lessm.com,
	loeliger@...il.com
Subject: [PATCH v5 4/7] ARM: l2c: Add support for overriding prefetch settings

From: Tomasz Figa <t.figa@...sung.com>

Firmware on certain boards (e.g. ODROID-U3) can leave incorrect L2C prefetch
settings configured in registers leading to crashes if L2C is enabled
without overriding them. This patch introduces bindings to enable
prefetch settings to be specified from DT and necessary support in the
driver.

Signed-off-by: Tomasz Figa <t.figa@...sung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@...sung.com>
---
 Documentation/devicetree/bindings/arm/l2cc.txt | 10 +++++++
 arch/arm/mm/cache-l2x0.c                       | 39 ++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt
index af527ee111c2..3443d2d76788 100644
--- a/Documentation/devicetree/bindings/arm/l2cc.txt
+++ b/Documentation/devicetree/bindings/arm/l2cc.txt
@@ -47,6 +47,16 @@ Optional properties:
 - cache-id-part: cache id part number to be used if it is not present
   on hardware
 - wt-override: If present then L2 is forced to Write through mode
+- arm,double-linefill : Override double linefill enable setting. Enable if
+  non-zero, disable if zero.
+- arm,double-linefill-incr : Override double linefill on INCR read. Enable
+  if non-zero, disable if zero.
+- arm,double-linefill-wrap : Override double linefill on WRAP read. Enable
+  if non-zero, disable if zero.
+- arm,prefetch-drop : Override prefetch drop enable setting. Enable if non-zero,
+  disable if zero.
+- arm,prefetch-offset : Override prefetch offset value. Valid values are
+  0-7, 15, 23, and 31.
 
 Example:
 
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 84c6c55ab896..af90a6ff6b49 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1059,6 +1059,8 @@ static void __init l2c310_of_parse(const struct device_node *np,
 	u32 data[3] = { 0, 0, 0 };
 	u32 tag[3] = { 0, 0, 0 };
 	u32 filter[2] = { 0, 0 };
+	u32 prefetch;
+	u32 val;
 
 	of_property_read_u32_array(np, "arm,tag-latency", tag, ARRAY_SIZE(tag));
 	if (tag[0] && tag[1] && tag[2])
@@ -1083,6 +1085,43 @@ static void __init l2c310_of_parse(const struct device_node *np,
 		l2x0_saved_regs.filter_start = (filter[0] & ~(SZ_1M - 1))
 					| L310_ADDR_FILTER_EN;
 	}
+
+	prefetch = l2x0_saved_regs.prefetch_ctrl;
+
+	if (!of_property_read_u32(np, "arm,double-linefill", &val)) {
+		if (val)
+			prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL;
+		else
+			prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL;
+	}
+
+	if (!of_property_read_u32(np, "arm,double-linefill-incr", &val)) {
+		if (val)
+			prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL_INCR;
+		else
+			prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL_INCR;
+	}
+
+	if (!of_property_read_u32(np, "arm,double-linefill-wrap", &val)) {
+		if (!val)
+			prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL_WRAP;
+		else
+			prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL_WRAP;
+	}
+
+	if (!of_property_read_u32(np, "arm,prefetch-drop", &val)) {
+		if (val)
+			prefetch |= L310_PREFETCH_CTRL_PREFETCH_DROP;
+		else
+			prefetch &= ~L310_PREFETCH_CTRL_PREFETCH_DROP;
+	}
+
+	if (!of_property_read_u32(np, "arm,prefetch-offset", &val)) {
+		prefetch &= ~L310_PREFETCH_CTRL_OFFSET_MASK;
+		prefetch |= val & L310_PREFETCH_CTRL_OFFSET_MASK;
+	}
+
+	l2x0_saved_regs.prefetch_ctrl = prefetch;
 }
 
 static const struct l2c_init_data of_l2c310_data __initconst = {
-- 
1.9.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/