OMAP: iommu: add initial debugfs support

This enables to peek the following data.

$ /debug/iommu/isp# ls
mem             nr_tlb_entries  regs
mmap            pagetable       tlb
$ /debug/iommu/isp# head pagetable
L:      da:      pa:
-----------------------------------------
2: 00001000 8ae4a002
2: 00002000 8e7bb002
2: 00003000 8ae49002
2: 00004000 8ae65002
.....

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

6 files changed, 449 insertions, 19 deletions

diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
index 015f22a53ead..2d9b5cc981cd 100644
--- a/arch/arm/mach-omap2/iommu2.c
+++ b/arch/arm/mach-omap2/iommu2.c
@@ -217,10 +217,19 @@ static ssize_t omap2_dump_cr(struct iommu *obj, struct cr_regs *cr, char *buf)
 }
 
 #define pr_reg(name)                                                    \
-        p += sprintf(p, "%20s: %08x\n",                                 \
-                     __stringify(name), iommu_read_reg(obj, MMU_##name));
-
-static ssize_t omap2_iommu_dump_ctx(struct iommu *obj, char *buf)
+        do {                                                            \
+                ssize_t bytes;                                          \
+                const char *str = "%20s: %08x\n";                       \
+                const int maxcol = 32;                                  \
+                bytes = snprintf(p, maxcol, str, __stringify(name),     \
+                                 iommu_read_reg(obj, MMU_##name));      \
+                p += bytes;                                             \
+                len -= bytes;                                           \
+                if (len < maxcol)                                       \
+                        goto out;                                       \
+        } while (0)
+
+static ssize_t omap2_iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t len)
 {
         char *p = buf;
 
@@ -242,7 +251,7 @@ static ssize_t omap2_iommu_dump_ctx(struct iommu *obj, char *buf)
         pr_reg(READ_CAM);
         pr_reg(READ_RAM);
         pr_reg(EMU_FAULT_AD);
-
+out:
         return p - buf;
 }
 
diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index efe85d095190..ab9f9efc9b62 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -120,6 +120,10 @@ config OMAP_MBOX_FWK
 config OMAP_IOMMU
         tristate
 
+config OMAP_IOMMU_DEBUG
+        depends on OMAP_IOMMU
+        tristate
+
 choice
         prompt "System timer"
         default OMAP_MPU_TIMER
diff --git a/arch/arm/plat-omap/Makefile b/arch/arm/plat-omap/Makefile
index a83279523958..769a4c200364 100644
--- a/arch/arm/plat-omap/Makefile
+++ b/arch/arm/plat-omap/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_ARCH_OMAP16XX) += ocpi.o
 
 obj-$(CONFIG_OMAP_MCBSP) += mcbsp.o
 obj-$(CONFIG_OMAP_IOMMU) += iommu.o iovmm.o
+obj-$(CONFIG_OMAP_IOMMU_DEBUG) += iommu-debug.o
 
 obj-$(CONFIG_CPU_FREQ) += cpu-omap.o
 obj-$(CONFIG_OMAP_DM_TIMER) += dmtimer.o
diff --git a/arch/arm/plat-omap/include/mach/iommu.h b/arch/arm/plat-omap/include/mach/iommu.h
index 769b00b4c34a..46d41ac83dbf 100644
--- a/arch/arm/plat-omap/include/mach/iommu.h
+++ b/arch/arm/plat-omap/include/mach/iommu.h
@@ -95,7 +95,7 @@ struct iommu_functions {
 
         void (*save_ctx)(struct iommu *obj);
         void (*restore_ctx)(struct iommu *obj);
-        ssize_t (*dump_ctx)(struct iommu *obj, char *buf);
+        ssize_t (*dump_ctx)(struct iommu *obj, char *buf, ssize_t len);
 };
 
 struct iommu_platform_data {
@@ -162,7 +162,7 @@ extern void uninstall_iommu_arch(const struct iommu_functions *ops);
 extern int foreach_iommu_device(void *data,
                                 int (*fn)(struct device *, void *));
 
-extern ssize_t iommu_dump_ctx(struct iommu *obj, char *buf);
-extern size_t dump_tlb_entries(struct iommu *obj, char *buf);
+extern ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t len);
+extern size_t dump_tlb_entries(struct iommu *obj, char *buf, ssize_t len);
 
 #endif /* __MACH_IOMMU_H */
diff --git a/arch/arm/plat-omap/iommu-debug.c b/arch/arm/plat-omap/iommu-debug.c
new file mode 100644
index 000000000000..c799b3b0d709
--- /dev/null
+++ b/arch/arm/plat-omap/iommu-debug.c
@@ -0,0 +1,415 @@
+/*
+ * omap iommu: debugfs interface
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/debugfs.h>
+
+#include <mach/iommu.h>
+#include <mach/iovmm.h>
+
+#include "iopgtable.h"
+
+#define MAXCOLUMN 100 /* for short messages */
+
+static DEFINE_MUTEX(iommu_debug_lock);
+
+static struct dentry *iommu_debug_root;
+
+static ssize_t debug_read_ver(struct file *file, char __user *userbuf,
+                              size_t count, loff_t *ppos)
+{
+        u32 ver = iommu_arch_version();
+        char buf[MAXCOLUMN], *p = buf;
+
+        p += sprintf(p, "H/W version: %d.%d\n", (ver >> 4) & 0xf , ver & 0xf);
+
+        return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+}
+
+static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
+                               size_t count, loff_t *ppos)
+{
+        struct iommu *obj = file->private_data;
+        char *p, *buf;
+        ssize_t bytes;
+
+        buf = kmalloc(count, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        p = buf;
+
+        mutex_lock(&iommu_debug_lock);
+
+        bytes = iommu_dump_ctx(obj, p, count);
+        bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
+
+        mutex_unlock(&iommu_debug_lock);
+        kfree(buf);
+
+        return bytes;
+}
+
+static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
+                              size_t count, loff_t *ppos)
+{
+        struct iommu *obj = file->private_data;
+        char *p, *buf;
+        ssize_t bytes, rest;
+
+        buf = kmalloc(count, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        p = buf;
+
+        mutex_lock(&iommu_debug_lock);
+
+        p += sprintf(p, "%8s %8s\n", "cam:", "ram:");
+        p += sprintf(p, "-----------------------------------------\n");
+        rest = count - (p - buf);
+        p += dump_tlb_entries(obj, p, rest);
+
+        bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+
+        mutex_unlock(&iommu_debug_lock);
+        kfree(buf);
+
+        return bytes;
+}
+
+static ssize_t debug_write_pagetable(struct file *file,
+                     const char __user *userbuf, size_t count, loff_t *ppos)
+{
+        struct iotlb_entry e;
+        struct cr_regs cr;
+        int err;
+        struct iommu *obj = file->private_data;
+        char buf[MAXCOLUMN], *p = buf;
+
+        count = min(count, sizeof(buf));
+
+        mutex_lock(&iommu_debug_lock);
+        if (copy_from_user(p, userbuf, count)) {
+                mutex_unlock(&iommu_debug_lock);
+                return -EFAULT;
+        }
+
+        sscanf(p, "%x %x", &cr.cam, &cr.ram);
+        if (!cr.cam || !cr.ram) {
+                mutex_unlock(&iommu_debug_lock);
+                return -EINVAL;
+        }
+
+        iotlb_cr_to_e(&cr, &e);
+        err = iopgtable_store_entry(obj, &e);
+        if (err)
+                dev_err(obj->dev, "%s: fail to store cr\n", __func__);
+
+        mutex_unlock(&iommu_debug_lock);
+        return count;
+}
+
+#define dump_ioptable_entry_one(lv, da, val)                    \
+        ({                                                      \
+                int __err = 0;                                  \
+                ssize_t bytes;                                  \
+                const int maxcol = 22;                          \
+                const char *str = "%d: %08x %08x\n";            \
+                bytes = snprintf(p, maxcol, str, lv, da, val);  \
+                p += bytes;                                     \
+                len -= bytes;                                   \
+                if (len < maxcol)                               \
+                        __err = -ENOMEM;                        \
+                __err;                                          \
+        })
+
+static ssize_t dump_ioptable(struct iommu *obj, char *buf, ssize_t len)
+{
+        int i;
+        u32 *iopgd;
+        char *p = buf;
+
+        spin_lock(&obj->page_table_lock);
+
+        iopgd = iopgd_offset(obj, 0);
+        for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
+                int j, err;
+                u32 *iopte;
+                u32 da;
+
+                if (!*iopgd)
+                        continue;
+
+                if (!(*iopgd & IOPGD_TABLE)) {
+                        da = i << IOPGD_SHIFT;
+
+                        err = dump_ioptable_entry_one(1, da, *iopgd);
+                        if (err)
+                                goto out;
+                        continue;
+                }
+
+                iopte = iopte_offset(iopgd, 0);
+
+                for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
+                        if (!*iopte)
+                                continue;
+
+                        da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
+                        err = dump_ioptable_entry_one(2, da, *iopgd);
+                        if (err)
+                                goto out;
+                }
+        }
+out:
+        spin_unlock(&obj->page_table_lock);
+
+        return p - buf;
+}
+
+static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
+                                    size_t count, loff_t *ppos)
+{
+        struct iommu *obj = file->private_data;
+        char *p, *buf;
+        size_t bytes;
+
+        buf = (char *)__get_free_page(GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        p = buf;
+
+        p += sprintf(p, "L: %8s %8s\n", "da:", "pa:");
+        p += sprintf(p, "-----------------------------------------\n");
+
+        mutex_lock(&iommu_debug_lock);
+
+        bytes = PAGE_SIZE - (p - buf);
+        p += dump_ioptable(obj, p, bytes);
+
+        bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+
+        mutex_unlock(&iommu_debug_lock);
+        free_page((unsigned long)buf);
+
+        return bytes;
+}
+
+static ssize_t debug_read_mmap(struct file *file, char __user *userbuf,
+                               size_t count, loff_t *ppos)
+{
+        struct iommu *obj = file->private_data;
+        char *p, *buf;
+        struct iovm_struct *tmp;
+        int uninitialized_var(i);
+        ssize_t bytes;
+
+        buf = (char *)__get_free_page(GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        p = buf;
+
+        p += sprintf(p, "%-3s %-8s %-8s %6s %8s\n",
+                     "No", "start", "end", "size", "flags");
+        p += sprintf(p, "-------------------------------------------------\n");
+
+        mutex_lock(&iommu_debug_lock);
+
+        list_for_each_entry(tmp, &obj->mmap, list) {
+                size_t len;
+                const char *str = "%3d %08x-%08x %6x %8x\n";
+                const int maxcol = 39;
+
+                len = tmp->da_end - tmp->da_start;
+                p += snprintf(p, maxcol, str,
+                              i, tmp->da_start, tmp->da_end, len, tmp->flags);
+
+                if (PAGE_SIZE - (p - buf) < maxcol)
+                        break;
+                i++;
+        }
+
+        bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+
+        mutex_unlock(&iommu_debug_lock);
+        free_page((unsigned long)buf);
+
+        return bytes;
+}
+
+static ssize_t debug_read_mem(struct file *file, char __user *userbuf,
+                              size_t count, loff_t *ppos)
+{
+        struct iommu *obj = file->private_data;
+        char *p, *buf;
+        struct iovm_struct *area;
+        ssize_t bytes;
+
+        count = min_t(ssize_t, count, PAGE_SIZE);
+
+        buf = (char *)__get_free_page(GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        p = buf;
+
+        mutex_lock(&iommu_debug_lock);
+
+        area = find_iovm_area(obj, (u32)ppos);
+        if (IS_ERR(area)) {
+                bytes = -EINVAL;
+                goto err_out;
+        }
+        memcpy(p, area->va, count);
+        p += count;
+
+        bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+err_out:
+        mutex_unlock(&iommu_debug_lock);
+        free_page((unsigned long)buf);
+
+        return bytes;
+}
+
+static ssize_t debug_write_mem(struct file *file, const char __user *userbuf,
+                               size_t count, loff_t *ppos)
+{
+        struct iommu *obj = file->private_data;
+        struct iovm_struct *area;
+        char *p, *buf;
+
+        count = min_t(size_t, count, PAGE_SIZE);
+
+        buf = (char *)__get_free_page(GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        p = buf;
+
+        mutex_lock(&iommu_debug_lock);
+
+        if (copy_from_user(p, userbuf, count)) {
+                count =  -EFAULT;
+                goto err_out;
+        }
+
+        area = find_iovm_area(obj, (u32)ppos);
+        if (IS_ERR(area)) {
+                count = -EINVAL;
+                goto err_out;
+        }
+        memcpy(area->va, p, count);
+err_out:
+        mutex_unlock(&iommu_debug_lock);
+        free_page((unsigned long)buf);
+
+        return count;
+}
+
+static int debug_open_generic(struct inode *inode, struct file *file)
+{
+        file->private_data = inode->i_private;
+        return 0;
+}
+
+#define DEBUG_FOPS(name)                                                \
+        static const struct file_operations debug_##name##_fops = {     \
+                .open = debug_open_generic,                             \
+                .read = debug_read_##name,                              \
+                .write = debug_write_##name,                            \
+        };
+
+#define DEBUG_FOPS_RO(name)                                             \
+        static const struct file_operations debug_##name##_fops = {     \
+                .open = debug_open_generic,                             \
+                .read = debug_read_##name,                              \
+        };
+
+DEBUG_FOPS_RO(ver);
+DEBUG_FOPS_RO(regs);
+DEBUG_FOPS_RO(tlb);
+DEBUG_FOPS(pagetable);
+DEBUG_FOPS_RO(mmap);
+DEBUG_FOPS(mem);
+
+#define __DEBUG_ADD_FILE(attr, mode)                                    \
+        {                                                               \
+                struct dentry *dent;                                    \
+                dent = debugfs_create_file(#attr, mode, parent,         \
+                                           obj, &debug_##attr##_fops);  \
+                if (!dent)                                              \
+                        return -ENOMEM;                                 \
+        }
+
+#define DEBUG_ADD_FILE(name) __DEBUG_ADD_FILE(name, 600)
+#define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 400)
+
+static int iommu_debug_register(struct device *dev, void *data)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct iommu *obj = platform_get_drvdata(pdev);
+        struct dentry *d, *parent;
+
+        if (!obj || !obj->dev)
+                return -EINVAL;
+
+        d = debugfs_create_dir(obj->name, iommu_debug_root);
+        if (!d)
+                return -ENOMEM;
+        parent = d;
+
+        d = debugfs_create_u8("nr_tlb_entries", 400, parent,
+                              (u8 *)&obj->nr_tlb_entries);
+        if (!d)
+                return -ENOMEM;
+
+        DEBUG_ADD_FILE_RO(ver);
+        DEBUG_ADD_FILE_RO(regs);
+        DEBUG_ADD_FILE_RO(tlb);
+        DEBUG_ADD_FILE(pagetable);
+        DEBUG_ADD_FILE_RO(mmap);
+        DEBUG_ADD_FILE(mem);
+
+        return 0;
+}
+
+static int __init iommu_debug_init(void)
+{
+        struct dentry *d;
+        int err;
+
+        d = debugfs_create_dir("iommu", NULL);
+        if (!d)
+                return -ENOMEM;
+        iommu_debug_root = d;
+
+        err = foreach_iommu_device(d, iommu_debug_register);
+        if (err)
+                goto err_out;
+        return 0;
+
+err_out:
+        debugfs_remove_recursive(iommu_debug_root);
+        return err;
+}
+module_init(iommu_debug_init)
+
+static void __exit iommu_debugfs_exit(void)
+{
+        debugfs_remove_recursive(iommu_debug_root);
+}
+module_exit(iommu_debugfs_exit)
+
+MODULE_DESCRIPTION("omap iommu: debugfs interface");
+MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index 4a0301399013..4b6012707307 100644
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -351,16 +351,14 @@ EXPORT_SYMBOL_GPL(flush_iotlb_all);
 
 #if defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE)
 
-ssize_t iommu_dump_ctx(struct iommu *obj, char *buf)
+ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t bytes)
 {
-        ssize_t bytes;
-
         if (!obj || !buf)
                 return -EINVAL;
 
         clk_enable(obj->clk);
 
-        bytes = arch_iommu->dump_ctx(obj, buf);
+        bytes = arch_iommu->dump_ctx(obj, buf, bytes);
 
         clk_disable(obj->clk);
 
@@ -368,7 +366,7 @@ ssize_t iommu_dump_ctx(struct iommu *obj, char *buf)
 }
 EXPORT_SYMBOL_GPL(iommu_dump_ctx);
 
-static int __dump_tlb_entries(struct iommu *obj, struct cr_regs *crs)
+static int __dump_tlb_entries(struct iommu *obj, struct cr_regs *crs, int num)
 {
         int i;
         struct iotlb_lock saved, l;
@@ -379,7 +377,7 @@ static int __dump_tlb_entries(struct iommu *obj, struct cr_regs *crs)
         iotlb_lock_get(obj, &saved);
         memcpy(&l, &saved, sizeof(saved));
 
-        for (i = 0; i < obj->nr_tlb_entries; i++) {
+        for (i = 0; i < num; i++) {
                 struct cr_regs tmp;
 
                 iotlb_lock_get(obj, &l);
@@ -402,18 +400,21 @@ static int __dump_tlb_entries(struct iommu *obj, struct cr_regs *crs)
  * @obj:        target iommu
  * @buf:        output buffer
  **/
-size_t dump_tlb_entries(struct iommu *obj, char *buf)
+size_t dump_tlb_entries(struct iommu *obj, char *buf, ssize_t bytes)
 {
-        int i, n;
+        int i, num;
         struct cr_regs *cr;
         char *p = buf;
 
-        cr = kcalloc(obj->nr_tlb_entries, sizeof(*cr), GFP_KERNEL);
+        num = bytes / sizeof(*cr);
+        num = min(obj->nr_tlb_entries, num);
+
+        cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
         if (!cr)
                 return 0;
 
-        n = __dump_tlb_entries(obj, cr);
-        for (i = 0; i < n; i++)
+        num = __dump_tlb_entries(obj, cr, num);
+        for (i = 0; i < num; i++)
                 p += iotlb_dump_cr(obj, cr + i, p);
         kfree(cr);