[PATCH 07/11] android: persistent_ram: handle reserving and mapping memory

John Stultz
2012-03-08T01:36:29Z

From: Colin Cross <ccross@android.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@linuxfoundation.org>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.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