Re: [PATCH v6 3/3] qe_common: add qe_muram_ functions to manage muram
From: Laura Abbott
Date: Mon Aug 24 2015 - 19:32:43 EST
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 <scottwood@xxxxxxxxxxxxx>
+ *
+ * copyright 2007-2008,2010 freescale Semiconductor, Inc.
+ *
+ * some parts derived from commproc.c/qe2_common.c, which is:
+ * copyright (c) 1997 dan error_act (dmalek@xxxxxxx)
+ * copyright (c) 1999-2001 dan Malek <dan@xxxxxxxxxxxxxxxxx>
+ * copyright (c) 2000 montavista Software, Inc (source@xxxxxxxxxx)
+ * 2006 (c) montavista software, Inc.
+ * vitaly bordug <vbordug@xxxxxxxxxxxxx>
+ *
+ * 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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