/**
 *
 * @file sysfs.c
 * @brief This file contains the functions providing the SysFS-interface.
 * @author Guillermo Marcus
 * @date 2010-03-01
 *
 */
#include <linux/version.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/cdev.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/kernel.h>

#include "compat.h"
#include "config.h"
#include "pciDriver.h"
#include "common.h"
#include "umem.h"
#include "kmem.h"
#include "sysfs.h"

static SYSFS_GET_FUNCTION(pcidriver_show_kmem_entry);
static SYSFS_GET_FUNCTION(pcidriver_show_umem_entry);

/**
 *
 * Initializes the sysfs attributes for an kmem/umem-entry
 *
 */
static int _pcidriver_sysfs_initialize(pcidriver_privdata_t *privdata,
					int id,
					struct class_device_attribute *sysfs_attr,
					const char *fmtstring,
					SYSFS_GET_FUNCTION((*callback)))
{
	/* sysfs attributes for kmem buffers don’t make sense before 2.6.13, as
	   we have no mmap support before */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,13)
	char namebuffer[16];

	/* allocate space for the name of the attribute */
	snprintf(namebuffer, sizeof(namebuffer), fmtstring, id);

	if ((sysfs_attr->attr.name = kstrdup(namebuffer, GFP_KERNEL)) == NULL)
		return -ENOMEM;

	sysfs_attr->attr.mode = S_IRUGO;
	sysfs_attr->attr.owner = THIS_MODULE;
	sysfs_attr->show = callback;
	sysfs_attr->store = NULL;
			
	/* name and add attribute */
	if (class_device_create_file(privdata->class_dev, sysfs_attr) != 0)
		return -ENXIO; /* Device not configured. Not the really best choice, but hm. */
#endif

	return 0;
}

int pcidriver_sysfs_initialize_kmem(pcidriver_privdata_t *privdata, int id, struct class_device_attribute *sysfs_attr)
{
	return _pcidriver_sysfs_initialize(privdata, id, sysfs_attr, "kbuf%d", pcidriver_show_kmem_entry);
}

int pcidriver_sysfs_initialize_umem(pcidriver_privdata_t *privdata, int id, struct class_device_attribute *sysfs_attr)
{
	return _pcidriver_sysfs_initialize(privdata, id, sysfs_attr, "umem%d", pcidriver_show_umem_entry);
}

/**
 *
 * Removes the file from sysfs and frees the allocated (kstrdup()) memory.
 *
 */
void pcidriver_sysfs_remove(pcidriver_privdata_t *privdata, struct class_device_attribute *sysfs_attr)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,13)
	class_device_remove_file(privdata->class_dev, sysfs_attr);
	kfree(sysfs_attr->attr.name);
#endif
}

static SYSFS_GET_FUNCTION(pcidriver_show_kmem_entry)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,13)
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;

        /* As we can be sure that attr.name contains a filename which we
         * created (see _pcidriver_sysfs_initialize), we do not need to have
         * sanity checks but can directly call simple_strtol() */
        int id = simple_strtol(attr->attr.name + strlen("kbuf"), NULL, 10);
	pcidriver_kmem_entry_t *entry = pcidriver_kmem_find_entry_id(privdata, id);
	if (entry)
	    return snprintf(buf, PAGE_SIZE, "buffer: %d\ntype: %lu\nuse: 0x%lx\nitem: %lu\nsize: %lu\n", id, entry->type, entry->use, entry->item, entry->size);
	else
	    return snprintf(buf, PAGE_SIZE, "I am in the kmem_entry show function for buffer %d\n", id);
#else
	return 0;
#endif
}

static SYSFS_GET_FUNCTION(pcidriver_show_umem_entry)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,13)
#if 0
	pcidriver_privdata_t *privdata = (pcidriver_privdata_t *)cls->class_data;

	return snprintf(buf, PAGE_SIZE, "I am in the umem_entry show function, class_device_kobj_name: %s\n", cls->kobj.name);
#endif
	return 0;
#else
	return 0;
#endif
}

#ifdef ENABLE_IRQ
SYSFS_GET_FUNCTION(pcidriver_show_irq_count)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;

	return snprintf(buf, PAGE_SIZE, "%d\n", privdata->irq_count);
}

SYSFS_GET_FUNCTION(pcidriver_show_irq_queues)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	int i, offset;

	/* output will be truncated to PAGE_SIZE */
	offset = snprintf(buf, PAGE_SIZE, "Queue\tOutstanding IRQs\n");
	for (i = 0; i < PCIDRIVER_INT_MAXSOURCES; i++)
		offset += snprintf(buf+offset, PAGE_SIZE-offset, "%d\t%d\n", i, atomic_read(&(privdata->irq_outstanding[i])) );

	return (offset > PAGE_SIZE ? PAGE_SIZE : offset+1);
}
#endif

SYSFS_GET_FUNCTION(pcidriver_show_mmap_mode)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;

	return snprintf(buf, PAGE_SIZE, "%d\n", privdata->mmap_mode);
}

SYSFS_SET_FUNCTION(pcidriver_store_mmap_mode)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	int mode = -1;

	/* Set the mmap-mode if it is either PCIDRIVER_MMAP_PCI or PCIDRIVER_MMAP_KMEM */
	if (sscanf(buf, "%d", &mode) == 1 &&
	    (mode == PCIDRIVER_MMAP_PCI || mode == PCIDRIVER_MMAP_KMEM))
		privdata->mmap_mode = mode;

	return strlen(buf);
}

SYSFS_GET_FUNCTION(pcidriver_show_mmap_area)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;

	return snprintf(buf, PAGE_SIZE, "%d\n", privdata->mmap_area);
}

SYSFS_SET_FUNCTION(pcidriver_store_mmap_area)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	int temp = -1;

	sscanf(buf, "%d", &temp);

	if ((temp >= PCIDRIVER_BAR0) && (temp <= PCIDRIVER_BAR5))
		privdata->mmap_area = temp;

	return strlen(buf);
}

SYSFS_GET_FUNCTION(pcidriver_show_kmem_count)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;

	return snprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&(privdata->kmem_count)));
}

SYSFS_SET_FUNCTION(pcidriver_store_kmem_alloc)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	kmem_handle_t kmem_handle;

	/* FIXME: guillermo: is validation of parsing an unsigned int enough? */
	if (sscanf(buf, "%lu", &kmem_handle.size) == 1)
		pcidriver_kmem_alloc(privdata, &kmem_handle);

	return strlen(buf);
}

SYSFS_SET_FUNCTION(pcidriver_store_kmem_free)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	unsigned int id;
	pcidriver_kmem_entry_t *kmem_entry;

	/* Parse the ID of the kernel memory to be freed, check bounds */
	if (sscanf(buf, "%u", &id) != 1 ||
	    (id >= atomic_read(&(privdata->kmem_count))))
		goto err;

	if ((kmem_entry = pcidriver_kmem_find_entry_id(privdata,id)) == NULL)
		goto err;

	pcidriver_kmem_free_entry(privdata, kmem_entry );
err:
	return strlen(buf);
}

SYSFS_GET_FUNCTION(pcidriver_show_kbuffers)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	int offset = 0;
	struct list_head *ptr;
	pcidriver_kmem_entry_t *entry;

	/* print the header */
	offset += snprintf(buf, PAGE_SIZE, "kbuf#\tcpu addr\tsize\n");

	spin_lock(&(privdata->kmemlist_lock));
	list_for_each(ptr, &(privdata->kmem_list)) {
		entry = list_entry(ptr, pcidriver_kmem_entry_t, list);

		/* print entry info */
		if (offset > PAGE_SIZE) {
			spin_unlock( &(privdata->kmemlist_lock) );
			return PAGE_SIZE;
		}

		offset += snprintf(buf+offset, PAGE_SIZE-offset, "%3d\t%08lx\t%lu\n", entry->id, (unsigned long)(entry->dma_handle), entry->size );
	}

	spin_unlock(&(privdata->kmemlist_lock));

	/* output will be truncated to PAGE_SIZE */
	return (offset > PAGE_SIZE ? PAGE_SIZE : offset+1);
}

SYSFS_GET_FUNCTION(pcidriver_show_umappings)
{
	int offset = 0;
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	struct list_head *ptr;
	pcidriver_umem_entry_t *entry;

	/* print the header */
	offset += snprintf(buf, PAGE_SIZE, "umap#\tn_pages\tsg_ents\n");

	spin_lock( &(privdata->umemlist_lock) );
	list_for_each( ptr, &(privdata->umem_list) ) {
		entry = list_entry(ptr, pcidriver_umem_entry_t, list );

		/* print entry info */
		if (offset > PAGE_SIZE) {
			spin_unlock( &(privdata->umemlist_lock) );
			return PAGE_SIZE;
		}

		offset += snprintf(buf+offset, PAGE_SIZE-offset, "%3d\t%lu\t%lu\n", entry->id,
				(unsigned long)(entry->nr_pages), (unsigned long)(entry->nents));
	}

	spin_unlock( &(privdata->umemlist_lock) );

	/* output will be truncated to PAGE_SIZE */
	return (offset > PAGE_SIZE ? PAGE_SIZE : offset+1);
}

SYSFS_SET_FUNCTION(pcidriver_store_umem_unmap)
{
	pcidriver_privdata_t *privdata = SYSFS_GET_PRIVDATA;
	pcidriver_umem_entry_t *umem_entry;
	unsigned int id;

	if (sscanf(buf, "%u", &id) != 1 ||
	    (id >= atomic_read(&(privdata->umem_count))))
		goto err;

	if ((umem_entry = pcidriver_umem_find_entry_id(privdata, id)) == NULL)
		goto err;

	pcidriver_umem_sgunmap(privdata, umem_entry);
err:
	return strlen(buf);
}