/*
 *      Functions to handle I2O memory
 *
 *      Pulled from the inlines in i2o headers and uninlined
 *
 *
 *      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.
 */

#include <linux/module.h>
#include <linux/i2o.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/slab.h>
#include "core.h"

/* Protects our 32/64bit mask switching */
static DEFINE_MUTEX(mem_lock);

/**
 *      i2o_sg_tablesize - Calculate the maximum number of elements in a SGL
 *      @c: I2O controller for which the calculation should be done
 *      @body_size: maximum body size used for message in 32-bit words.
 *
 *      Return the maximum number of SG elements in a SG list.
 */
u16 i2o_sg_tablesize(struct i2o_controller *c, u16 body_size)
{
        i2o_status_block *sb = c->status_block.virt;
        u16 sg_count =
            (sb->inbound_frame_size - sizeof(struct i2o_message) / 4) -
            body_size;

        if (c->pae_support) {
                /*
                 * for 64-bit a SG attribute element must be added and each
                 * SG element needs 12 bytes instead of 8.
                 */
                sg_count -= 2;
                sg_count /= 3;
        } else
                sg_count /= 2;

        if (c->short_req && (sg_count > 8))
                sg_count = 8;

        return sg_count;
}
EXPORT_SYMBOL_GPL(i2o_sg_tablesize);


/**
 *      i2o_dma_map_single - Map pointer to controller and fill in I2O message.
 *      @c: I2O controller
 *      @ptr: pointer to the data which should be mapped
 *      @size: size of data in bytes
 *      @direction: DMA_TO_DEVICE / DMA_FROM_DEVICE
 *      @sg_ptr: pointer to the SG list inside the I2O message
 *
 *      This function does all necessary DMA handling and also writes the I2O
 *      SGL elements into the I2O message. For details on DMA handling see also
 *      dma_map_single(). The pointer sg_ptr will only be set to the end of the
 *      SG list if the allocation was successful.
 *
 *      Returns DMA address which must be checked for failures using
 *      dma_mapping_error().
 */
dma_addr_t i2o_dma_map_single(struct i2o_controller *c, void *ptr,
                                            size_t size,
                                            enum dma_data_direction direction,
                                            u32 ** sg_ptr)
{
        u32 sg_flags;
        u32 *mptr = *sg_ptr;
        dma_addr_t dma_addr;

        switch (direction) {
        case DMA_TO_DEVICE:
                sg_flags = 0xd4000000;
                break;
        case DMA_FROM_DEVICE:
                sg_flags = 0xd0000000;
                break;
        default:
                return 0;
        }

        dma_addr = dma_map_single(&c->pdev->dev, ptr, size, direction);
        if (!dma_mapping_error(&c->pdev->dev, dma_addr)) {
#ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
                if ((sizeof(dma_addr_t) > 4) && c->pae_support) {
                        *mptr++ = cpu_to_le32(0x7C020002);
                        *mptr++ = cpu_to_le32(PAGE_SIZE);
                }
#endif

                *mptr++ = cpu_to_le32(sg_flags | size);
                *mptr++ = cpu_to_le32(i2o_dma_low(dma_addr));
#ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
                if ((sizeof(dma_addr_t) > 4) && c->pae_support)
                        *mptr++ = cpu_to_le32(i2o_dma_high(dma_addr));
#endif
                *sg_ptr = mptr;
        }
        return dma_addr;
}
EXPORT_SYMBOL_GPL(i2o_dma_map_single);

/**
 *      i2o_dma_map_sg - Map a SG List to controller and fill in I2O message.
 *      @c: I2O controller
 *      @sg: SG list to be mapped
 *      @sg_count: number of elements in the SG list
 *      @direction: DMA_TO_DEVICE / DMA_FROM_DEVICE
 *      @sg_ptr: pointer to the SG list inside the I2O message
 *
 *      This function does all necessary DMA handling and also writes the I2O
 *      SGL elements into the I2O message. For details on DMA handling see also
 *      dma_map_sg(). The pointer sg_ptr will only be set to the end of the SG
 *      list if the allocation was successful.
 *
 *      Returns 0 on failure or 1 on success.
 */
int i2o_dma_map_sg(struct i2o_controller *c, struct scatterlist *sg,
            int sg_count, enum dma_data_direction direction, u32 ** sg_ptr)
{
        u32 sg_flags;
        u32 *mptr = *sg_ptr;

        switch (direction) {
        case DMA_TO_DEVICE:
                sg_flags = 0x14000000;
                break;
        case DMA_FROM_DEVICE:
                sg_flags = 0x10000000;
                break;
        default:
                return 0;
        }

        sg_count = dma_map_sg(&c->pdev->dev, sg, sg_count, direction);
        if (!sg_count)
                return 0;

#ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
        if ((sizeof(dma_addr_t) > 4) && c->pae_support) {
                *mptr++ = cpu_to_le32(0x7C020002);
                *mptr++ = cpu_to_le32(PAGE_SIZE);
        }
#endif

        while (sg_count-- > 0) {
                if (!sg_count)
                        sg_flags |= 0xC0000000;
                *mptr++ = cpu_to_le32(sg_flags | sg_dma_len(sg));
                *mptr++ = cpu_to_le32(i2o_dma_low(sg_dma_address(sg)));
#ifdef CONFIG_I2O_EXT_ADAPTEC_DMA64
                if ((sizeof(dma_addr_t) > 4) && c->pae_support)
                        *mptr++ = cpu_to_le32(i2o_dma_high(sg_dma_address(sg)));
#endif
                sg = sg_next(sg);
        }
        *sg_ptr = mptr;

        return 1;
}
EXPORT_SYMBOL_GPL(i2o_dma_map_sg);

/**
 *      i2o_dma_alloc - Allocate DMA memory
 *      @dev: struct device pointer to the PCI device of the I2O controller
 *      @addr: i2o_dma struct which should get the DMA buffer
 *      @len: length of the new DMA memory
 *
 *      Allocate a coherent DMA memory and write the pointers into addr.
 *
 *      Returns 0 on success or -ENOMEM on failure.
 */
int i2o_dma_alloc(struct device *dev, struct i2o_dma *addr, size_t len)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        int dma_64 = 0;

        mutex_lock(&mem_lock);
        if ((sizeof(dma_addr_t) > 4) && (pdev->dma_mask == DMA_BIT_MASK(64))) {
                dma_64 = 1;
                if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
                        mutex_unlock(&mem_lock);
                        return -ENOMEM;
                }
        }

        addr->virt = dma_alloc_coherent(dev, len, &addr->phys, GFP_KERNEL);

        if ((sizeof(dma_addr_t) > 4) && dma_64)
                if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64)))
                        printk(KERN_WARNING "i2o: unable to set 64-bit DMA");
        mutex_unlock(&mem_lock);

        if (!addr->virt)
                return -ENOMEM;

        memset(addr->virt, 0, len);
        addr->len = len;

        return 0;
}
EXPORT_SYMBOL_GPL(i2o_dma_alloc);


/**
 *      i2o_dma_free - Free DMA memory
 *      @dev: struct device pointer to the PCI device of the I2O controller
 *      @addr: i2o_dma struct which contains the DMA buffer
 *
 *      Free a coherent DMA memory and set virtual address of addr to NULL.
 */
void i2o_dma_free(struct device *dev, struct i2o_dma *addr)
{
        if (addr->virt) {
                if (addr->phys)
                        dma_free_coherent(dev, addr->len, addr->virt,
                                          addr->phys);
                else
                        kfree(addr->virt);
                addr->virt = NULL;
        }
}
EXPORT_SYMBOL_GPL(i2o_dma_free);


/**
 *      i2o_dma_realloc - Realloc DMA memory
 *      @dev: struct device pointer to the PCI device of the I2O controller
 *      @addr: pointer to a i2o_dma struct DMA buffer
 *      @len: new length of memory
 *
 *      If there was something allocated in the addr, free it first. If len > 0
 *      than try to allocate it and write the addresses back to the addr
 *      structure. If len == 0 set the virtual address to NULL.
 *
 *      Returns the 0 on success or negative error code on failure.
 */
int i2o_dma_realloc(struct device *dev, struct i2o_dma *addr, size_t len)
{
        i2o_dma_free(dev, addr);

        if (len)
                return i2o_dma_alloc(dev, addr, len);

        return 0;
}
EXPORT_SYMBOL_GPL(i2o_dma_realloc);

/*
 *      i2o_pool_alloc - Allocate an slab cache and mempool
 *      @mempool: pointer to struct i2o_pool to write data into.
 *      @name: name which is used to identify cache
 *      @size: size of each object
 *      @min_nr: minimum number of objects
 *
 *      First allocates a slab cache with name and size. Then allocates a
 *      mempool which uses the slab cache for allocation and freeing.
 *
 *      Returns 0 on success or negative error code on failure.
 */
int i2o_pool_alloc(struct i2o_pool *pool, const char *name,
                                 size_t size, int min_nr)
{
        pool->name = kmalloc(strlen(name) + 1, GFP_KERNEL);
        if (!pool->name)
                goto exit;
        strcpy(pool->name, name);

        pool->slab =
            kmem_cache_create(pool->name, size, 0, SLAB_HWCACHE_ALIGN, NULL);
        if (!pool->slab)
                goto free_name;

        pool->mempool = mempool_create_slab_pool(min_nr, pool->slab);
        if (!pool->mempool)
                goto free_slab;

        return 0;

free_slab:
        kmem_cache_destroy(pool->slab);

free_name:
        kfree(pool->name);

exit:
        return -ENOMEM;
}
EXPORT_SYMBOL_GPL(i2o_pool_alloc);

/*
 *      i2o_pool_free - Free slab cache and mempool again
 *      @mempool: pointer to struct i2o_pool which should be freed
 *
 *      Note that you have to return all objects to the mempool again before
 *      calling i2o_pool_free().
 */
void i2o_pool_free(struct i2o_pool *pool)
{
        mempool_destroy(pool->mempool);
        kmem_cache_destroy(pool->slab);
        kfree(pool->name);
};
EXPORT_SYMBOL_GPL(i2o_pool_free);