Re: [PATCH v9 3/5] qe_common: add qe_muram_ functions to manage muram

[Scott Wood]

On Mon, 2015-09-14 at 09:38 +0800, Zhao Qiang wrote:
> diff --git a/arch/powerpc/sysdev/qe_lib/qe_common.c 
> b/arch/powerpc/sysdev/qe_lib/qe_common.c
> new file mode 100644
> index 0000000..1213458
> --- /dev/null
> +++ b/arch/powerpc/sysdev/qe_lib/qe_common.c
> @@ -0,0 +1,242 @@
> +/*
> + * Freescale QE common code
> + *
> + * Author: Zhao Qiang  <qiang.zhao@xxxxxxxxxxxxx>
> + *
> + * Copyright 2015 Freescale Semiconductor, Inc.
> + *
> + * 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/genalloc.h>
> +#include <linux/list.h>
> +#include <linux/init.h>
> +#include <linux/of_device.h>
> +#include <linux/spinlock.h>
> +#include <linux/export.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +
> +#include <linux/io.h>
> +#include <asm/qe.h>
> +
> +static struct gen_pool *muram_pool;
> +static struct genpool_data_align muram_pool_data;
> +static struct genpool_data_fixed muram_pool_data_fixed;
> +static spinlock_t qe_muram_lock;
> +static u8 __iomem *muram_vbase;
> +static phys_addr_t muram_pbase;
> +
> +struct muram_block {
> +     struct list_head head;
> +     unsigned long start;
> +     int size;
> +};
> +
> +static LIST_HEAD(muram_block_list);
> +
> +/* max address size we deal with */
> +#define OF_MAX_ADDR_CELLS    4
> +#define GENPOOL_OFFSET               4096
> +
> +int qe_muram_init(void)
> +{
> +     struct device_node *np;
> +     struct resource r;
> +     u32 zero[OF_MAX_ADDR_CELLS] = {};
> +     resource_size_t max = 0;
> +     int i = 0;
> +     int ret = 0;
> +
> +     if (muram_pbase)
> +             return 0;
> +
> +     np = of_find_compatible_node(NULL, NULL, "fsl,qe-muram-data");
> +     if (!np) {
> +             /* try legacy bindings */
> +             np = of_find_node_by_name(NULL, "data-only");
> +             if (!np) {
> +                     pr_err("Cannot find CPM muram data node");
> +                     ret = -ENODEV;
> +                     goto out;
> +             }
> +     }
> +
> +     muram_pool = gen_pool_create(1, -1);
> +     muram_pbase = of_translate_address(np, zero);
> +     if (muram_pbase == (phys_addr_t)OF_BAD_ADDR) {
> +             pr_err("Cannot translate zero through CPM muram node");
> +             ret = -ENODEV;
> +             goto err;
> +     }
> +
> +     while (of_address_to_resource(np, i++, &r) == 0) {
> +             if (r.end > max)
> +                     max = r.end;
> +             ret = gen_pool_add(muram_pool, r.start - muram_pbase +
> +                                GENPOOL_OFFSET, resource_size(&r), -1);
> +             if (ret) {
> +                             pr_err("QE: couldn't add muram to pool!\n");
> +                             goto err;
> +                     }
> +
> +     }
> +
> +     muram_vbase = ioremap(muram_pbase, max - muram_pbase + 1);
> +     if (!muram_vbase) {
> +             pr_err("Cannot map QE muram");
> +             ret = -ENOMEM;
> +             goto err;
> +     }
> +     goto out;
> +err:
> +     gen_pool_destroy(muram_pool);
> +out:
> +     of_node_put(np);
> +     return ret;
> +}
> +
> +/*
> + * qe_muram_alloc - allocate the requested size worth of multi-user ram
> + * @size: number of bytes to allocate
> + * @align: requested alignment, in bytes
> + *
> + * This function returns an offset into the muram area.
> + */
> +unsigned long qe_muram_alloc(unsigned long size, unsigned long align)
> +{
> +     unsigned long start;
> +     unsigned long flags;
> +     struct muram_block *entry;
> +
> +     spin_lock_irqsave(&qe_muram_lock, flags);
> +     muram_pool_data.align = align;
> +     gen_pool_set_algo(muram_pool, gen_pool_first_fit_align,
> +                       &muram_pool_data);
> +     start = gen_pool_alloc(muram_pool, size);
> +     if (!start)
> +             goto out2;
> +     start = start - GENPOOL_OFFSET;
> +     memset(qe_muram_addr(start), 0, size);
> +     entry = kmalloc(sizeof(*entry), GFP_KERNEL);
> +     if (!entry)
> +             goto out1;
> +     entry->start = start;
> +     entry->size = size;
> +     list_add(&entry->head, &muram_block_list);
> +     spin_unlock_irqrestore(&qe_muram_lock, flags);
> +
> +     return start;
> +out1:
> +     gen_pool_free(muram_pool, start, size);
> +out2:
> +     spin_unlock_irqrestore(&qe_muram_lock, flags);
> +     return (unsigned long) -ENOMEM;
> +}
> +EXPORT_SYMBOL(qe_muram_alloc);
> +
> +/*
> + * qe_muram_alloc_fixed - reserve a specific region of multi-user ram
> + * @size: number of bytes to allocate
> + * @offset: offset of allocation start address
> + *
> + * This function returns an offset into the muram area.
> + */
> +unsigned long qe_muram_alloc_fixed(unsigned long offset, unsigned long 
> size)
> +{
> +
> +     unsigned long start;
> +     unsigned long flags;
> +     unsigned long size_alloc = size;
> +     struct muram_block *entry;
> +     int end_bit;
> +     int order = muram_pool -> min_alloc_order;
> +
> +     spin_lock_irqsave(&qe_muram_lock, flags);
> +     end_bit = (offset >> order) + ((size + (1UL << order) - 1) >> order);
> +     if ((offset + size) > (end_bit << order))
> +             size_alloc = size + (1UL << order);
> +
> +     muram_pool_data_fixed.offset = offset + GENPOOL_OFFSET;
> +     gen_pool_set_algo(muram_pool, gen_pool_fixed_fit,
> +                       &muram_pool_data_fixed);
> +     start = gen_pool_alloc(muram_pool, size_alloc);
> +     if (!start)
> +             goto out2;
> +     start = start - GENPOOL_OFFSET;
> +     memset(qe_muram_addr(start), 0, size_alloc);
> +     entry = kmalloc(sizeof(*entry), GFP_KERNEL);
> +     if (!entry)
> +             goto out1;
> +     entry->start = start;
> +     entry->size = size_alloc;
> +     list_add(&entry->head, &muram_block_list);
> +     spin_unlock_irqrestore(&qe_muram_lock, flags);
> +
> +     return start;
> +out1:
> +     gen_pool_free(muram_pool, start, size_alloc);
> +out2:
> +     spin_unlock_irqrestore(&qe_muram_lock, flags);
> +     return (unsigned long) -ENOMEM;
> +
> +
> +}
> +EXPORT_SYMBOL(qe_muram_alloc_fixed);
> +
> +/**
> + * qe_muram_free - free a chunk of multi-user ram
> + * @offset: The beginning of the chunk as returned by qe_muram_alloc().
> + */
> +int qe_muram_free(unsigned long offset)
> +{
> +     unsigned long flags;
> +     int size;
> +     struct muram_block *tmp;
> +
> +     size = 0;
> +     spin_lock_irqsave(&qe_muram_lock, flags);
> +     list_for_each_entry(tmp, &muram_block_list, head) {
> +             if (tmp->start == offset) {
> +                     size = tmp->size;
> +                     list_del(&tmp->head);
> +                     kfree(tmp);
> +                     break;
> +             }
> +     }
> +     gen_pool_free(muram_pool, offset + GENPOOL_OFFSET, size);
> +     spin_unlock_irqrestore(&qe_muram_lock, flags);
> +
> +     return size;
> +}
> +EXPORT_SYMBOL(qe_muram_free);
> +
> +/**
> + * qe_muram_addr - turn a muram offset into a virtual address
> + * @offset: muram offset to convert
> + */
> +void __iomem *qe_muram_addr(unsigned long offset)
> +{
> +     return muram_vbase + offset;
> +}
> +EXPORT_SYMBOL(qe_muram_addr);
> +
> +unsigned long qe_muram_offset(void __iomem *addr)
> +{
> +     return addr - (void __iomem *)muram_vbase;
> +}
> +EXPORT_SYMBOL(qe_muram_offset);
> +
> +/**
> + * qe_muram_dma - turn a muram virtual address into a DMA address
> + * @offset: virtual address from qe_muram_addr() to convert
> + */
> +dma_addr_t qe_muram_dma(void __iomem *addr)
> +{
> +     return muram_pbase + ((u8 __iomem *)addr - muram_vbase);
> +}
> +EXPORT_SYMBOL(qe_muram_dma);

Why are you adding new functions rather than replacing the implementation of 
the old ones?

Again, I don't want to see a big addition in one place and a big deletion 
elsewhere.  I want to see the actual code changes as a diff.  Any moving 
around of code must be a separate patch from making changes to it that are 
significant enough that git format-patch doesn't detect it as a move.

-Scott

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