Date:	Wed,  7 Mar 2012 17:34:34 -0800
From:	John Stultz <john.stultz@...aro.org>
To:	lkml <linux-kernel@...r.kernel.org>
Cc:	Colin Cross <ccross@...roid.com>,
	Greg KH <gregkh@...uxfoundation.org>,
	Android Kernel Team <kernel-team@...roid.com>,
	John Stultz <john.stultz@...aro.org>
Subject: [PATCH 07/11] android: persistent_ram: handle reserving and mapping memory

From: Colin Cross <ccross@...roid.com>

Replace the ioremapped memory passed in from the drivers with
a memblock_reserve and vmap.  Adds a new function,
persistent_ram_early_init, designed to be called from the machine
init_early callback, that calls memblock_remove and saves the
provided persistent ram area layout.

Drivers only pass in their struct device * and ecc settings.
Locating and mapping the memory is now handled entirely within
persistent_ram.

Also, convert ram_console to the new persistent_ram_init
parameters that only take a struct device * and ecc settings.

[jstultz: Fix pr_info casting issues on 64bit, folded two
patches as the build breaks if they are apart. Also replaced
phys_to_page() w/ pfn_to_page(addr>>PAGE_SHIFT), as phys_to_page
is only on a few arches.]
CC: Greg KH <gregkh@...uxfoundation.org>
CC: Android Kernel Team <kernel-team@...roid.com>
Signed-off-by: Colin Cross <ccross@...roid.com>
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
 drivers/staging/android/persistent_ram.c |  139 ++++++++++++++++++++++++------
 drivers/staging/android/persistent_ram.h |   24 +++++-
 drivers/staging/android/ram_console.c    |   42 ++-------
 3 files changed, 144 insertions(+), 61 deletions(-)

diff --git a/drivers/staging/android/persistent_ram.c b/drivers/staging/android/persistent_ram.c
index 35c57a0..81950e6 100644
--- a/drivers/staging/android/persistent_ram.c
+++ b/drivers/staging/android/persistent_ram.c
@@ -12,12 +12,17 @@
  *
  */
 
+#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
 #include <linux/rslib.h>
 #include <linux/slab.h>
+#include <linux/vmalloc.h>
 #include "persistent_ram.h"
 
 struct persistent_ram_buffer {
@@ -29,7 +34,7 @@ struct persistent_ram_buffer {
 
 #define PERSISTENT_RAM_SIG (0x43474244) /* DBGC */
 
-static LIST_HEAD(zone_list);
+static __initdata LIST_HEAD(persistent_ram_list);
 
 static void persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
 	uint8_t *data, size_t len, uint8_t *ecc)
@@ -270,54 +275,134 @@ void persistent_ram_free_old(struct persistent_ram_zone *prz)
 	prz->old_log_size = 0;
 }
 
-static int __init __persistent_ram_init(struct persistent_ram_zone *prz,
-			       void __iomem *mem, size_t buffer_size, bool ecc)
+static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
+		struct persistent_ram_zone *prz)
 {
-	struct persistent_ram_buffer *buffer = mem;
+	struct page **pages;
+	phys_addr_t page_start;
+	unsigned int page_count;
+	pgprot_t prot;
+	unsigned int i;
+
+	page_start = start - offset_in_page(start);
+	page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
+
+	prot = pgprot_noncached(PAGE_KERNEL);
+
+	pages = kmalloc(sizeof(struct page *) * page_count, GFP_KERNEL);
+	if (!pages) {
+		pr_err("%s: Failed to allocate array for %u pages\n", __func__,
+			page_count);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < page_count; i++) {
+		phys_addr_t addr = page_start + i * PAGE_SIZE;
+		pages[i] = pfn_to_page(addr >> PAGE_SHIFT);
+	}
+	prz->vaddr = vmap(pages, page_count, VM_MAP, prot);
+	kfree(pages);
+	if (!prz->vaddr) {
+		pr_err("%s: Failed to map %u pages\n", __func__, page_count);
+		return -ENOMEM;
+	}
+
+	prz->buffer = prz->vaddr + offset_in_page(start);
+	prz->buffer_size = size - sizeof(struct persistent_ram_buffer);
+
+	return 0;
+}
+
+static int __init persistent_ram_buffer_init(const char *name,
+		struct persistent_ram_zone *prz)
+{
+	int i;
+	struct persistent_ram *ram;
+	struct persistent_ram_descriptor *desc;
+	phys_addr_t start;
+
+	list_for_each_entry(ram, &persistent_ram_list, node) {
+		start = ram->start;
+		for (i = 0; i < ram->num_descs; i++) {
+			desc = &ram->descs[i];
+			if (!strcmp(desc->name, name))
+				return persistent_ram_buffer_map(start,
+						desc->size, prz);
+			start += desc->size;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static  __init
+struct persistent_ram_zone *__persistent_ram_init(struct device *dev, bool ecc)
+{
+	struct persistent_ram_zone *prz;
 	int ret;
 
-	INIT_LIST_HEAD(&prz->node);
+	prz = kzalloc(sizeof(struct persistent_ram_zone), GFP_KERNEL);
+	if (!prz) {
+		pr_err("persistent_ram: failed to allocate persistent ram zone\n");
+		return ERR_PTR(-ENOMEM);
+	}
 
-	prz->buffer = buffer;
-	prz->buffer_size = buffer_size - sizeof(struct persistent_ram_buffer);
+	INIT_LIST_HEAD(&prz->node);
 
-	if (prz->buffer_size > buffer_size) {
-		pr_err("persistent_ram: buffer %p, invalid size %zu, datasize %zu\n",
-		       buffer, buffer_size, prz->buffer_size);
-		return -EINVAL;
+	ret = persistent_ram_buffer_init(dev_name(dev), prz);
+	if (ret) {
+		pr_err("persistent_ram: failed to initialize buffer\n");
+		return ERR_PTR(ret);
 	}
 
 	prz->ecc = ecc;
-	ret = persistent_ram_init_ecc(prz, buffer_size);
+	ret = persistent_ram_init_ecc(prz, prz->buffer_size);
 	if (ret)
-		return ret;
+		return ERR_PTR(ret);
 
-	if (buffer->sig == PERSISTENT_RAM_SIG) {
-		if (buffer->size > prz->buffer_size
-		    || buffer->start > buffer->size)
+	if (prz->buffer->sig == PERSISTENT_RAM_SIG) {
+		if (prz->buffer->size > prz->buffer_size
+		    || prz->buffer->start > prz->buffer->size)
 			pr_info("persistent_ram: found existing invalid buffer, size %d, start %d\n",
-			       buffer->size, buffer->start);
+			       prz->buffer->size, prz->buffer->start);
 		else {
 			pr_info("persistent_ram: found existing buffer, size %d, start %d\n",
-			       buffer->size, buffer->start);
+			       prz->buffer->size, prz->buffer->start);
 			persistent_ram_save_old(prz);
 		}
 	} else {
 		pr_info("persistent_ram: no valid data in buffer (sig = 0x%08x)\n",
-			buffer->sig);
+			prz->buffer->sig);
 	}
 
-	buffer->sig = PERSISTENT_RAM_SIG;
-	buffer->start = 0;
-	buffer->size = 0;
+	prz->buffer->sig = PERSISTENT_RAM_SIG;
+	prz->buffer->start = 0;
+	prz->buffer->size = 0;
 
-	list_add_tail(&prz->node, &zone_list);
+	return prz;
+}
 
-	return 0;
+struct persistent_ram_zone * __init
+persistent_ram_init_ringbuffer(struct device *dev, bool ecc)
+{
+	return __persistent_ram_init(dev, ecc);
 }
 
-int __init persistent_ram_init_ringbuffer(struct persistent_ram_zone *prz,
-			       void __iomem *mem, size_t buffer_size, bool ecc)
+int __init persistent_ram_early_init(struct persistent_ram *ram)
 {
-	return __persistent_ram_init(prz, mem, buffer_size, true);
+	int ret;
+
+	ret = memblock_reserve(ram->start, ram->size);
+	if (ret) {
+		pr_err("Failed to reserve persistent memory from %08lx-%08lx\n",
+			(long)ram->start, (long)(ram->start + ram->size - 1));
+		return ret;
+	}
+
+	list_add_tail(&ram->node, &persistent_ram_list);
+
+	pr_info("Initialized persistent memory from %08lx-%08lx\n",
+		(long)ram->start, (long)(ram->start + ram->size - 1));
+
+	return 0;
 }
diff --git a/drivers/staging/android/persistent_ram.h b/drivers/staging/android/persistent_ram.h
index ab3995c..f41e208 100644
--- a/drivers/staging/android/persistent_ram.h
+++ b/drivers/staging/android/persistent_ram.h
@@ -15,13 +15,31 @@
 #ifndef __LINUX_PERSISTENT_RAM_H__
 #define __LINUX_PERSISTENT_RAM_H__
 
+#include <linux/device.h>
 #include <linux/kernel.h>
+#include <linux/list.h>
 #include <linux/types.h>
 
 struct persistent_ram_buffer;
 
+struct persistent_ram_descriptor {
+	const char	*name;
+	phys_addr_t	size;
+};
+
+struct persistent_ram {
+	phys_addr_t	start;
+	phys_addr_t	size;
+
+	int					num_descs;
+	struct persistent_ram_descriptor	*descs;
+
+	struct list_head node;
+};
+
 struct persistent_ram_zone {
 	struct list_head node;
+	void *vaddr;
 	struct persistent_ram_buffer *buffer;
 	size_t buffer_size;
 
@@ -43,8 +61,10 @@ struct persistent_ram_zone {
 	bool early;
 };
 
-int persistent_ram_init_ringbuffer(struct persistent_ram_zone *prz,
-	void __iomem *buffer, size_t buffer_size, bool ecc);
+int persistent_ram_early_init(struct persistent_ram *ram);
+
+struct persistent_ram_zone *persistent_ram_init_ringbuffer(struct device *dev,
+		bool ecc);
 
 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
 	unsigned int count);
diff --git a/drivers/staging/android/ram_console.c b/drivers/staging/android/ram_console.c
index d920bd7..29d347e 100644
--- a/drivers/staging/android/ram_console.c
+++ b/drivers/staging/android/ram_console.c
@@ -24,7 +24,7 @@
 #include "persistent_ram.h"
 #include "ram_console.h"
 
-static struct persistent_ram_zone ram_console_zone;
+static struct persistent_ram_zone *ram_console_zone;
 static const char *bootinfo;
 static size_t bootinfo_size;
 
@@ -52,33 +52,13 @@ void ram_console_enable_console(int enabled)
 
 static int ram_console_driver_probe(struct platform_device *pdev)
 {
-	struct resource *res = pdev->resource;
-	size_t start;
-	size_t buffer_size;
-	void *buffer;
 	struct ram_console_platform_data *pdata = pdev->dev.platform_data;
-	int ret;
+	struct persistent_ram_zone *prz;
 
-	if (res == NULL || pdev->num_resources != 1 ||
-	    !(res->flags & IORESOURCE_MEM)) {
-		printk(KERN_ERR "ram_console: invalid resource, %p %d flags "
-		       "%lx\n", res, pdev->num_resources, res ? res->flags : 0);
-		return -ENXIO;
-	}
-	buffer_size = resource_size(res);
-	start = res->start;
-	printk(KERN_INFO "ram_console: got buffer at %zx, size %zx\n",
-	       start, buffer_size);
-	buffer = ioremap(res->start, buffer_size);
-	if (buffer == NULL) {
-		printk(KERN_ERR "ram_console: failed to map memory\n");
-		return -ENOMEM;
-	}
+	prz = persistent_ram_init_ringbuffer(&pdev->dev, true);
+	if (IS_ERR(prz))
+		return PTR_ERR(prz);
 
-	ret = persistent_ram_init_ringbuffer(&ram_console_zone, buffer,
-					     buffer_size, true);
-	if (ret)
-		goto err;
 
 	if (pdata) {
 		bootinfo = kstrdup(pdata->bootinfo, GFP_KERNEL);
@@ -86,14 +66,12 @@ static int ram_console_driver_probe(struct platform_device *pdev)
 			bootinfo_size = strlen(bootinfo);
 	}
 
-	ram_console.data = &ram_console_zone;
+	ram_console_zone = prz;
+	ram_console.data = prz;
 
 	register_console(&ram_console);
-	return 0;
 
-err:
-	iounmap(buffer);
-	return ret;
+	return 0;
 }
 
 static struct platform_driver ram_console_driver = {
@@ -115,7 +93,7 @@ static ssize_t ram_console_read_old(struct file *file, char __user *buf,
 {
 	loff_t pos = *offset;
 	ssize_t count;
-	struct persistent_ram_zone *prz = &ram_console_zone;
+	struct persistent_ram_zone *prz = ram_console_zone;
 	size_t old_log_size = persistent_ram_old_size(prz);
 	const char *old_log = persistent_ram_old(prz);
 	char *str;
@@ -170,7 +148,7 @@ static const struct file_operations ram_console_file_ops = {
 static int __init ram_console_late_init(void)
 {
 	struct proc_dir_entry *entry;
-	struct persistent_ram_zone *prz = &ram_console_zone;
+	struct persistent_ram_zone *prz = ram_console_zone;
 
 	if (persistent_ram_old_size(prz) == 0)
 		return 0;
-- 
1.7.3.2.146.gca209

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