powerpc/85xx: add cache-sram support

It adds cache-sram support in P1/P2 QorIQ platforms as under:

* A small abstraction over powerpc's remote heap allocator
* Exports mpc85xx_cache_sram_alloc()/free() APIs
* Supports only one contiguous SRAM window
* Drivers can do the following in Kconfig to use these APIs
    "select FSL_85XX_CACHE_SRAM if MPC85xx"
* Required SRAM size and the offset where SRAM should be mapped must be
  provided at kernel command line as :
    cache-sram-size=<value>
    cache-sram-offset=<offset>

Signed-off-by: Harninder Rai <harninder.rai@freescale.com>
Signed-off-by: Vivek Mahajan <vivek.mahajan@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 231 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/fsl_85xx_l2ctlr.c b/arch/powerpc/sysdev/fsl_85xx_l2ctlr.c
new file mode 100644
index 00000000000..cc8d6556d79
--- /dev/null
+++ b/arch/powerpc/sysdev/fsl_85xx_l2ctlr.c
@@ -0,0 +1,231 @@
+/*
+ * Copyright 2009-2010 Freescale Semiconductor, Inc.
+ *
+ * QorIQ (P1/P2) L2 controller init for Cache-SRAM instantiation
+ *
+ * Author: Vivek Mahajan <vivek.mahajan@freescale.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/of_platform.h>
+#include <asm/io.h>
+
+#include "fsl_85xx_cache_ctlr.h"
+
+static char *sram_size;
+static char *sram_offset;
+struct mpc85xx_l2ctlr __iomem *l2ctlr;
+
+static long get_cache_sram_size(void)
+{
+	unsigned long val;
+
+	if (!sram_size || (strict_strtoul(sram_size, 0, &val) < 0))
+		return -EINVAL;
+
+	return val;
+}
+
+static long get_cache_sram_offset(void)
+{
+	unsigned long val;
+
+	if (!sram_offset || (strict_strtoul(sram_offset, 0, &val) < 0))
+		return -EINVAL;
+
+	return val;
+}
+
+static int __init get_size_from_cmdline(char *str)
+{
+	if (!str)
+		return 0;
+
+	sram_size = str;
+	return 1;
+}
+
+static int __init get_offset_from_cmdline(char *str)
+{
+	if (!str)
+		return 0;
+
+	sram_offset = str;
+	return 1;
+}
+
+__setup("cache-sram-size=", get_size_from_cmdline);
+__setup("cache-sram-offset=", get_offset_from_cmdline);
+
+static int __devinit mpc85xx_l2ctlr_of_probe(struct platform_device *dev,
+					  const struct of_device_id *match)
+{
+	long rval;
+	unsigned int rem;
+	unsigned char ways;
+	const unsigned int *prop;
+	unsigned int l2cache_size;
+	struct sram_parameters sram_params;
+
+	if (!dev->dev.of_node) {
+		dev_err(&dev->dev, "Device's OF-node is NULL\n");
+		return -EINVAL;
+	}
+
+	prop = of_get_property(dev->dev.of_node, "cache-size", NULL);
+	if (!prop) {
+		dev_err(&dev->dev, "Missing L2 cache-size\n");
+		return -EINVAL;
+	}
+	l2cache_size = *prop;
+
+	sram_params.sram_size  = get_cache_sram_size();
+	if (sram_params.sram_size <= 0) {
+		dev_err(&dev->dev,
+			"Entire L2 as cache, Aborting Cache-SRAM stuff\n");
+		return -EINVAL;
+	}
+
+	sram_params.sram_offset  = get_cache_sram_offset();
+	if (sram_params.sram_offset <= 0) {
+		dev_err(&dev->dev,
+			"Entire L2 as cache, provide a valid sram offset\n");
+		return -EINVAL;
+	}
+
+
+	rem = l2cache_size % sram_params.sram_size;
+	ways = LOCK_WAYS_FULL * sram_params.sram_size / l2cache_size;
+	if (rem || (ways & (ways - 1))) {
+		dev_err(&dev->dev, "Illegal cache-sram-size in command line\n");
+		return -EINVAL;
+	}
+
+	l2ctlr = of_iomap(dev->dev.of_node, 0);
+	if (!l2ctlr) {
+		dev_err(&dev->dev, "Can't map L2 controller\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Write bits[0-17] to srbar0
+	 */
+	out_be32(&l2ctlr->srbar0,
+		sram_params.sram_offset & L2SRAM_BAR_MSK_LO18);
+
+	/*
+	 * Write bits[18-21] to srbare0
+	 */
+#ifdef CONFIG_PHYS_64BIT
+	out_be32(&l2ctlr->srbarea0,
+		(sram_params.sram_offset >> 32) & L2SRAM_BARE_MSK_HI4);
+#endif
+
+	clrsetbits_be32(&l2ctlr->ctl, L2CR_L2E, L2CR_L2FI);
+
+	switch (ways) {
+	case LOCK_WAYS_EIGHTH:
+		setbits32(&l2ctlr->ctl,
+			L2CR_L2E | L2CR_L2FI | L2CR_SRAM_EIGHTH);
+		break;
+
+	case LOCK_WAYS_TWO_EIGHTH:
+		setbits32(&l2ctlr->ctl,
+			L2CR_L2E | L2CR_L2FI | L2CR_SRAM_QUART);
+		break;
+
+	case LOCK_WAYS_HALF:
+		setbits32(&l2ctlr->ctl,
+			L2CR_L2E | L2CR_L2FI | L2CR_SRAM_HALF);
+		break;
+
+	case LOCK_WAYS_FULL:
+	default:
+		setbits32(&l2ctlr->ctl,
+			L2CR_L2E | L2CR_L2FI | L2CR_SRAM_FULL);
+		break;
+	}
+	eieio();
+
+	rval = instantiate_cache_sram(dev, sram_params);
+	if (rval < 0) {
+		dev_err(&dev->dev, "Can't instantiate Cache-SRAM\n");
+		iounmap(l2ctlr);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __devexit mpc85xx_l2ctlr_of_remove(struct platform_device *dev)
+{
+	BUG_ON(!l2ctlr);
+
+	iounmap(l2ctlr);
+	remove_cache_sram(dev);
+	dev_info(&dev->dev, "MPC85xx L2 controller unloaded\n");
+
+	return 0;
+}
+
+static struct of_device_id mpc85xx_l2ctlr_of_match[] = {
+	{
+		.compatible = "fsl,p2020-l2-cache-controller",
+	},
+	{
+		.compatible = "fsl,p2010-l2-cache-controller",
+	},
+	{
+		.compatible = "fsl,p1020-l2-cache-controller",
+	},
+	{
+		.compatible = "fsl,p1011-l2-cache-controller",
+	},
+	{
+		.compatible = "fsl,p1013-l2-cache-controller",
+	},
+	{
+		.compatible = "fsl,p1022-l2-cache-controller",
+	},
+	{},
+};
+
+static struct of_platform_driver mpc85xx_l2ctlr_of_platform_driver = {
+	.driver	= {
+		.name		= "fsl-l2ctlr",
+		.owner		= THIS_MODULE,
+		.of_match_table	= mpc85xx_l2ctlr_of_match,
+	},
+	.probe		= mpc85xx_l2ctlr_of_probe,
+	.remove		= __devexit_p(mpc85xx_l2ctlr_of_remove),
+};
+
+static __init int mpc85xx_l2ctlr_of_init(void)
+{
+	return of_register_platform_driver(&mpc85xx_l2ctlr_of_platform_driver);
+}
+
+static void __exit mpc85xx_l2ctlr_of_exit(void)
+{
+	of_unregister_platform_driver(&mpc85xx_l2ctlr_of_platform_driver);
+}
+
+subsys_initcall(mpc85xx_l2ctlr_of_init);
+module_exit(mpc85xx_l2ctlr_of_exit);
+
+MODULE_DESCRIPTION("Freescale MPC85xx L2 controller init");
+MODULE_LICENSE("GPL v2");