On 08/24/2015 02:31 AM, Zhao Qiang wrote:

diff --git a/drivers/soc/fsl/qe/qe_common.c b/drivers/soc/fsl/qe/qe_common.c
new file mode 100644
index 0000000..7f1762c
--- /dev/null
+++ b/drivers/soc/fsl/qe/qe_common.c
@@ -0,0 +1,193 @@
+/*
+ * common qe code
+ *
+ * author: scott wood <scottw...@freescale.com>
+ *
+ * copyright 2007-2008,2010 freescale Semiconductor, Inc.
+ *
+ * some parts derived from commproc.c/qe2_common.c, which is:
+ * copyright (c) 1997 dan error_act (dma...@jlc.net)
+ * copyright (c) 1999-2001 dan Malek <d...@embeddedalley.com>
+ * copyright (c) 2000 montavista Software, Inc (sou...@mvista.com)
+ * 2006 (c) montavista software, Inc.
+ * vitaly bordug <vbor...@ru.mvista.com>
+ *
+ * this program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the free software Foundation.
+ */
+
+#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 <soc/fsl/qe/qe.h>
+
+static struct gen_pool *muram_pool;
+static struct genpool_data_align muram_pool_data;
+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
+
+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;
+
+       muram_pool = gen_pool_create(1, -1);
+       gen_pool_set_algo(muram_pool, gen_pool_first_fit_align,
+                         &muram_pool_data);
+
+       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_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 out;
+       }
+
+       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,
+                                  resource_size(&r), -1);
+               if (ret) {
+                               pr_err("QE MURAM: could not add muram ");
+                               pr_err("remainder to pool!\n");

Don't split the error string over two lines

+                               return ret;

returning here misses the error path

+                       }
+
+       }
+
+       muram_vbase = ioremap(muram_pbase, max - muram_pbase + 1);
+       if (!muram_vbase) {
+               pr_err("Cannot map CPM muram");
+               ret = -ENOMEM;
+       }
+

gen_pool_destroy on the error path

+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.
+ * Use qe_dpram_addr() to get the virtual address of the area.
+ * Use qe_muram_free() to free the allocation.
+ */
+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;
+       start = gen_pool_alloc(muram_pool, size);

The advantage of creating gen_pool_alloc_data was so that you could
pass in the align automatically without having to modify the structure.
Is there a reason you aren't using that?

+       memset(qe_muram_addr(start), 0, size);

There doesn't seem to be a check for allocation failure from the
gen_alloc.

+       entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+       if (!entry)
+               goto out;
+       entry->start = start;
+       entry->size = size;
+       list_add(&entry->head, &muram_block_list);

What's the point of keeping the block list anyway? It's used only in
this file and it only seems to duplicate what gen_alloc is doing internally.
Is there some lookup functionality you still need? Could you use a gen_alloc
API to do so?

+       spin_unlock_irqrestore(&qe_muram_lock, flags);
+
+       return start;
+out:
+       gen_pool_free(muram_pool, start, size);
+       return (unsigned long) -ENOMEM;
+}
+EXPORT_SYMBOL(qe_muram_alloc);
+
+/**
+ * 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, 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);

Thanks,
Laura

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