ARM: imx: Add iram allocator functions

Add IRAM(Internal RAM) allocation functions using GENERIC_ALLOCATOR.
The allocation size is 4KB multiples to guarantee alignment. The
idea for these functions is for i.MX platforms to use them
to dynamically allocate IRAM usage.

Applies on 2.6.36-rc7

Signed-off-by: Dinh Nguyen <Dinh.Nguyen@freescale.com>
Reviewed-by: Amit Kucheria <amit.kucheria@canonical.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

4 files changed, 119 insertions, 0 deletions

diff --git a/arch/arm/plat-mxc/Kconfig b/arch/arm/plat-mxc/Kconfig
index 95f8d614d4fc..64e3a64520e0 100644
--- a/arch/arm/plat-mxc/Kconfig
+++ b/arch/arm/plat-mxc/Kconfig
@@ -122,4 +122,8 @@ config ARCH_MXC_AUDMUX_V1
 config ARCH_MXC_AUDMUX_V2
         bool
 
+config IRAM_ALLOC
+        bool
+        select GENERIC_ALLOCATOR
+
 endif
diff --git a/arch/arm/plat-mxc/Makefile b/arch/arm/plat-mxc/Makefile
index bb3443f9751a..06875b4dd70f 100644
--- a/arch/arm/plat-mxc/Makefile
+++ b/arch/arm/plat-mxc/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_MXC_TZIC) += tzic.o
 
 obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o
 obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o
+obj-$(CONFIG_IRAM_ALLOC) += iram_alloc.o
 obj-$(CONFIG_MXC_PWM)  += pwm.o
 obj-$(CONFIG_USB_EHCI_MXC) += ehci.o
 obj-$(CONFIG_MXC_ULPI) += ulpi.o
diff --git a/arch/arm/plat-mxc/include/mach/iram.h b/arch/arm/plat-mxc/include/mach/iram.h
new file mode 100644
index 000000000000..022690c33702
--- /dev/null
+++ b/arch/arm/plat-mxc/include/mach/iram.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include <linux/errno.h>
+
+#ifdef CONFIG_IRAM_ALLOC
+
+int __init iram_init(unsigned long base, unsigned long size);
+void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr);
+void iram_free(unsigned long dma_addr, unsigned int size);
+
+#else
+
+static inline int __init iram_init(unsigned long base, unsigned long size)
+{
+        return -ENOMEM;
+}
+
+static inline void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr)
+{
+        return NULL;
+}
+
+static inline void iram_free(unsigned long base, unsigned long size) {}
+
+#endif
diff --git a/arch/arm/plat-mxc/iram_alloc.c b/arch/arm/plat-mxc/iram_alloc.c
new file mode 100644
index 000000000000..074c3869626a
--- /dev/null
+++ b/arch/arm/plat-mxc/iram_alloc.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/genalloc.h>
+#include <mach/iram.h>
+
+static unsigned long iram_phys_base;
+static void __iomem *iram_virt_base;
+static struct gen_pool *iram_pool;
+
+static inline void __iomem *iram_phys_to_virt(unsigned long p)
+{
+        return iram_virt_base + (p - iram_phys_base);
+}
+
+void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr)
+{
+        if (!iram_pool)
+                return NULL;
+
+        *dma_addr = gen_pool_alloc(iram_pool, size);
+        pr_debug("iram alloc - %dB@0x%lX\n", size, *dma_addr);
+        if (!*dma_addr)
+                return NULL;
+        return iram_phys_to_virt(*dma_addr);
+}
+EXPORT_SYMBOL(iram_alloc);
+
+void iram_free(unsigned long addr, unsigned int size)
+{
+        if (!iram_pool)
+                return;
+
+        gen_pool_free(iram_pool, addr, size);
+}
+EXPORT_SYMBOL(iram_free);
+
+int __init iram_init(unsigned long base, unsigned long size)
+{
+        iram_phys_base = base;
+
+        iram_pool = gen_pool_create(PAGE_SHIFT, -1);
+        if (!iram_pool)
+                return -ENOMEM;
+
+        gen_pool_add(iram_pool, base, size, -1);
+        iram_virt_base = ioremap(iram_phys_base, size);
+        if (!iram_virt_base)
+                return -EIO;
+
+        pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, iram_virt_base);
+        return 0;
+}