[PATCH 0/5] Add device tree support for on-chip SRAM

[PATCH 0/5] Add device tree support for on-chip SRAM

[Philipp Zabel]

These patches add support to configure the on-chip SRAM via device-tree
node and to obtain the resulting genalloc pool from a phandle pointing   
at the node.
This allows drivers to allocate SRAM with the genalloc API without
hard-coding the genalloc pool address.

regards
Philipp

---
 arch/arm/boot/dts/imx53.dtsi          |    5 ++
 arch/arm/boot/dts/imx6q.dtsi          |    5 ++
 arch/arm/plat-mxc/include/mach/iram.h |   41 -----------------
 arch/arm/plat-mxc/iram_alloc.c        |   81 ++++++++++++++++++++-------------
 include/linux/genalloc.h              |   14 ++++++
 lib/genalloc.c                        |   77 +++++++++++++++++++++++++++++++
 6 files changed, 150 insertions(+), 73 deletions(-)

[PATCH 1/5] ARM i.MX: Switch IRAM allocator to device tree initialization

[Philipp Zabel]

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 arch/arm/plat-mxc/include/mach/iram.h |    6 -----
 arch/arm/plat-mxc/iram_alloc.c        |   44 ++++++++++++++++++++++++++++++---
 2 files changed, 41 insertions(+), 9 deletions(-)

diff --git a/arch/arm/plat-mxc/include/mach/iram.h b/arch/arm/plat-mxc/include/mach/iram.h
index 022690c..d5c863f 100644
--- a/arch/arm/plat-mxc/include/mach/iram.h
+++ b/arch/arm/plat-mxc/include/mach/iram.h
@@ -20,17 +20,11 @@
 
 #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;
diff --git a/arch/arm/plat-mxc/iram_alloc.c b/arch/arm/plat-mxc/iram_alloc.c
index 074c386..673deb4 100644
--- a/arch/arm/plat-mxc/iram_alloc.c
+++ b/arch/arm/plat-mxc/iram_alloc.c
@@ -22,6 +22,8 @@
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/genalloc.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
 #include <mach/iram.h>
 
 static unsigned long iram_phys_base;
@@ -55,15 +57,26 @@ void iram_free(unsigned long addr, unsigned int size)
 }
 EXPORT_SYMBOL(iram_free);
 
-int __init iram_init(unsigned long base, unsigned long size)
+static int __devinit iram_probe(struct platform_device *pdev)
 {
-	iram_phys_base = base;
+	struct resource *res;
+	unsigned long size;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	if (iram_phys_base)
+		return -EBUSY;
+
+	iram_phys_base = res->start;
+	size = resource_size(res);
 
 	iram_pool = gen_pool_create(PAGE_SHIFT, -1);
 	if (!iram_pool)
 		return -ENOMEM;
 
-	gen_pool_add(iram_pool, base, size, -1);
+	gen_pool_add(iram_pool, res->start, size, -1);
 	iram_virt_base = ioremap(iram_phys_base, size);
 	if (!iram_virt_base)
 		return -EIO;
@@ -71,3 +84,28 @@ int __init iram_init(unsigned long base, unsigned long size)
 	pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, iram_virt_base);
 	return 0;
 }
+
+static int __devexit iram_remove(struct platform_device *pdev)
+{
+	gen_pool_destroy(iram_pool);
+	iram_pool = NULL;
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id iram_dt_ids[] = {
+	{ .compatible = "fsl,imx-iram" },
+	{ /* sentinel */ }
+};
+#endif
+
+static struct platform_driver iram_driver = {
+	.driver = {
+		.name = "imx-iram",
+		.of_match_table = of_match_ptr(iram_dt_ids),
+	},
+	.probe = iram_probe,
+	.remove = __devexit_p(iram_remove),
+};
+
+module_platform_driver(iram_driver);
-- 
1.7.10.4

[PATCH 2/5] ARM i.MX53, i.MX6q: Add IRAM to device tree

[Philipp Zabel]

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 arch/arm/boot/dts/imx53.dtsi |    5 +++++
 arch/arm/boot/dts/imx6q.dtsi |    5 +++++
 2 files changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/imx53.dtsi b/arch/arm/boot/dts/imx53.dtsi
index e3e8694..6d99d8a 100644
--- a/arch/arm/boot/dts/imx53.dtsi
+++ b/arch/arm/boot/dts/imx53.dtsi
@@ -330,5 +330,10 @@
 				status = "disabled";
 			};
 		};
+
+		iram@f8000000 {
+			compatible = "fsl,imx-iram";
+			reg = <0xf8000000 0x20000>;
+		};
 	};
 };
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index 8c90cba..bb34a28 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -87,6 +87,11 @@
 		interrupt-parent = <&intc>;
 		ranges;
 
+		iram@00900000 {
+			compatible = "fsl,imx-iram";
+			reg = <0x00900000 0x3f000>;
+		};
+
 		timer@00a00600 {
 			compatible = "arm,cortex-a9-twd-timer";
 			reg = <0x00a00600 0x20>;
-- 
1.7.10.4

[PATCH 3/5] iram_alloc: store the virt and phys mem address in gen_pool chunks

[Philipp Zabel]

This improves the symmetry of iram_alloc and iram_free in that
iram_free has to be called with the virtual address now.
Also, gen_pool_virt_to_phys is now functional.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 arch/arm/plat-mxc/iram_alloc.c |   39 ++++++++++++++++++++++-----------------
 1 file changed, 22 insertions(+), 17 deletions(-)

diff --git a/arch/arm/plat-mxc/iram_alloc.c b/arch/arm/plat-mxc/iram_alloc.c
index 673deb4..343e96d 100644
--- a/arch/arm/plat-mxc/iram_alloc.c
+++ b/arch/arm/plat-mxc/iram_alloc.c
@@ -26,25 +26,22 @@
 #include <linux/platform_device.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)
 {
+	unsigned long virt;
+
 	if (!iram_pool)
 		return NULL;
 
-	*dma_addr = gen_pool_alloc(iram_pool, size);
+	virt = gen_pool_alloc(iram_pool, size);
 	pr_debug("iram alloc - %dB@0x%lX\n", size, *dma_addr);
-	if (!*dma_addr)
+	if (!virt)
 		return NULL;
-	return iram_phys_to_virt(*dma_addr);
+
+	*dma_addr = gen_pool_virt_to_phys(iram_pool, virt);
+	return (void __iomem *)virt;
 }
 EXPORT_SYMBOL(iram_alloc);
 
@@ -59,29 +56,37 @@ EXPORT_SYMBOL(iram_free);
 
 static int __devinit iram_probe(struct platform_device *pdev)
 {
+	void __iomem *virt_base;
 	struct resource *res;
 	unsigned long size;
+	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -EINVAL;
 
-	if (iram_phys_base)
+	if (iram_pool)
 		return -EBUSY;
 
-	iram_phys_base = res->start;
 	size = resource_size(res);
 
+	virt_base = devm_ioremap(&pdev->dev, res->start, size);
+	if (!virt_base)
+		return -ENOMEM;
+
 	iram_pool = gen_pool_create(PAGE_SHIFT, -1);
 	if (!iram_pool)
 		return -ENOMEM;
 
-	gen_pool_add(iram_pool, res->start, size, -1);
-	iram_virt_base = ioremap(iram_phys_base, size);
-	if (!iram_virt_base)
-		return -EIO;
+	ret = gen_pool_add_virt(iram_pool, (unsigned long)virt_base,
+				res->start, size, -1);
+	if (ret < 0) {
+		gen_pool_destroy(iram_pool);
+		iram_pool = NULL;
+		return ret;
+	}
 
-	pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, iram_virt_base);
+	pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, virt_base);
 	return 0;
 }
 
-- 
1.7.10.4

[PATCH 4/5] genalloc: add a global pool list, allow to find pools by phys address

[Philipp Zabel]

This patch keeps all created pools in a global list and adds two
functions that allow to retrieve the gen_pool pointer from a known
physical address and from a device tree node.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 include/linux/genalloc.h |   14 +++++++++
 lib/genalloc.c           |   77 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+)

diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 5e98eeb..46ff435 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -33,6 +33,7 @@
  *  General purpose special memory pool descriptor.
  */
 struct gen_pool {
+	struct list_head next_pool;	/* pool in global list */
 	spinlock_t lock;
 	struct list_head chunks;	/* list of chunks in this pool */
 	int min_alloc_order;		/* minimum allocation order */
@@ -78,4 +79,17 @@ extern void gen_pool_for_each_chunk(struct gen_pool *,
 	void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
 extern size_t gen_pool_avail(struct gen_pool *);
 extern size_t gen_pool_size(struct gen_pool *);
+extern struct gen_pool *gen_pool_find_by_phys(phys_addr_t phys);
+
+#ifdef CONFIG_OF
+struct device_node;
+extern struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+	const char *propname, int index);
+#else
+inline struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+	const char *propname, int index)
+{
+	return NULL;
+}
+#endif
 #endif /* __GENALLOC_H__ */
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 6bc04aa..df2d8f9 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -34,6 +34,11 @@
 #include <linux/rculist.h>
 #include <linux/interrupt.h>
 #include <linux/genalloc.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+
+static LIST_HEAD(pools);
+static DEFINE_SPINLOCK(list_lock);
 
 static int set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
 {
@@ -152,6 +157,9 @@ struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
 		spin_lock_init(&pool->lock);
 		INIT_LIST_HEAD(&pool->chunks);
 		pool->min_alloc_order = min_alloc_order;
+		spin_lock(&list_lock);
+		list_add_rcu(&pool->next_pool, &pools);
+		spin_unlock(&list_lock);
 	}
 	return pool;
 }
@@ -234,6 +242,9 @@ void gen_pool_destroy(struct gen_pool *pool)
 	int order = pool->min_alloc_order;
 	int bit, end_bit;
 
+	spin_lock(&list_lock);
+	list_del_rcu(&pool->next_pool);
+	spin_unlock(&list_lock);
 	list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
 		chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
 		list_del(&chunk->next_chunk);
@@ -400,3 +411,69 @@ size_t gen_pool_size(struct gen_pool *pool)
 	return size;
 }
 EXPORT_SYMBOL_GPL(gen_pool_size);
+
+/**
+ * gen_pool_find_by_phys - find a pool by physical start address
+ * @phys: physical address as added with gen_pool_add_virt
+ *
+ * Returns the pool that contains the chunk starting at phys,
+ * or NULL if not found.
+ */
+struct gen_pool *gen_pool_find_by_phys(phys_addr_t phys)
+{
+	struct gen_pool *pool, *found = NULL;
+	struct gen_pool_chunk *chunk;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pool, &pools, next_pool) {
+		list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
+			if (phys == chunk->phys_addr) {
+				found = pool;
+				break;
+			}
+		}
+	}
+	rcu_read_unlock();
+
+	return found;
+}
+EXPORT_SYMBOL_GPL(gen_pool_find_by_phys);
+
+#ifdef CONFIG_OF
+/**
+ * of_get_named_gen_pool - find a pool by the physical address in
+ * @np: device node
+ *
+ * Returns the pool that contains the chunk starting at the physical
+ * address of the np device node, or NULL if not found.
+ */
+struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+	const char *propname, int index)
+{
+	struct property *prop;
+	const __be32 *list;
+	int size;
+	phandle phandle;
+	struct device_node *np_pool;
+	const u32 *reg;
+	u64 addr;
+
+	prop = of_find_property(np, propname, &size);
+	if (!prop)
+		return NULL;
+	list = prop->value;
+	size /= sizeof(*list);
+	phandle = be32_to_cpup(list);
+	np_pool = of_find_node_by_phandle(phandle);
+	if (!np_pool)
+		return NULL;
+	reg = of_get_property(np_pool, "reg", NULL);
+	if (!reg)
+		return NULL;
+	addr = of_translate_address(np_pool, reg);
+	if (addr == OF_BAD_ADDR)
+		return NULL;
+	return gen_pool_find_by_phys((phys_addr_t) addr);
+}
+EXPORT_SYMBOL_GPL(of_get_named_gen_pool);
+#endif /* CONFIG_OF */
-- 
1.7.10.4

[PATCH 5/5] ARM i.MX: Remove iram_alloc/free, as they are unused in-tree

[Philipp Zabel]

Users of the iram_alloc/free API should
convert to the genalloc API instead:

-	virt = iram_alloc(SIZE, &phys);
+	gen_pool_alloc(iram_pool, SIZE);
+	phys = gen_pool_virt_to_phys(iram_pool, virt);
 	/* ... */
-	iram_free(virt, SIZE);
+	gen_pool_free(iram_pool, virt, SIZE);

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 arch/arm/plat-mxc/include/mach/iram.h |   35 ---------------------------------
 arch/arm/plat-mxc/iram_alloc.c        |   26 ------------------------
 2 files changed, 61 deletions(-)
 delete mode 100644 arch/arm/plat-mxc/include/mach/iram.h

diff --git a/arch/arm/plat-mxc/include/mach/iram.h b/arch/arm/plat-mxc/include/mach/iram.h
deleted file mode 100644
index d5c863f..0000000
--- a/arch/arm/plat-mxc/include/mach/iram.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * 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
-
-void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr);
-void iram_free(unsigned long dma_addr, unsigned int size);
-
-#else
-
-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
index 343e96d..0eed213 100644
--- a/arch/arm/plat-mxc/iram_alloc.c
+++ b/arch/arm/plat-mxc/iram_alloc.c
@@ -28,32 +28,6 @@
 
 static struct gen_pool *iram_pool;
 
-void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr)
-{
-	unsigned long virt;
-
-	if (!iram_pool)
-		return NULL;
-
-	virt = gen_pool_alloc(iram_pool, size);
-	pr_debug("iram alloc - %dB@0x%lX\n", size, *dma_addr);
-	if (!virt)
-		return NULL;
-
-	*dma_addr = gen_pool_virt_to_phys(iram_pool, virt);
-	return (void __iomem *)virt;
-}
-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);
-
 static int __devinit iram_probe(struct platform_device *pdev)
 {
 	void __iomem *virt_base;
-- 
1.7.10.4

Re: [PATCH 0/5] Add device tree support for on-chip SRAM

[Shawn Guo]

On Fri, Aug 24, 2012 at 11:17:41AM +0200, Philipp Zabel wrote:
> These patches add support to configure the on-chip SRAM via device-tree
> node and to obtain the resulting genalloc pool from a phandle pointing   
> at the node.
> This allows drivers to allocate SRAM with the genalloc API without
> hard-coding the genalloc pool address.
> 
It looks like a good stuff.  But in the end, there is nothing IMX
specific with iram_alloc.c.  Why do we name it in IMX?

Regards,
Shawn

> regards
> Philipp
> 
> ---
>  arch/arm/boot/dts/imx53.dtsi          |    5 ++
>  arch/arm/boot/dts/imx6q.dtsi          |    5 ++
>  arch/arm/plat-mxc/include/mach/iram.h |   41 -----------------
>  arch/arm/plat-mxc/iram_alloc.c        |   81 ++++++++++++++++++++-------------
>  include/linux/genalloc.h              |   14 ++++++
>  lib/genalloc.c                        |   77 +++++++++++++++++++++++++++++++
>  6 files changed, 150 insertions(+), 73 deletions(-)
>