cpm_common.c

linux 内核源代码

/*
 * Common CPM code
 *
 * Author: Scott Wood <[e-mail]>
 *
 * Copyright 2007 Freescale Semiconductor, Inc.
 *
 * Some parts derived from commproc.c/cpm2_common.c, which is:
 * Copyright (c) 1997 Dan error_act ([e-mail])
 * Copyright (c) 1999-2001 Dan Malek <[e-mail]>
 * Copyright (c) 2000 MontaVista Software, Inc ([e-mail])
 * 2006 (c) MontaVista Software, Inc.
 * Vitaly Bordug <[e-mail]>
 *
 * 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/init.h>
#include <linux/of_device.h>

#include <asm/udbg.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/rheap.h>
#include <asm/cpm.h>

#include <mm/mmu_decl.h>

#ifdef CONFIG_PPC_EARLY_DEBUG_CPM
static u32 __iomem *cpm_udbg_txdesc =
	(u32 __iomem __force *)CONFIG_PPC_EARLY_DEBUG_CPM_ADDR;

static void udbg_putc_cpm(char c)
{
	u8 __iomem *txbuf = (u8 __iomem __force *)in_be32(&cpm_udbg_txdesc[1]);

	if (c == '\n')
		udbg_putc('\r');

	while (in_be32(&cpm_udbg_txdesc[0]) & 0x80000000)
		;

	out_8(txbuf, c);
	out_be32(&cpm_udbg_txdesc[0], 0xa0000001);
}

void __init udbg_init_cpm(void)
{
	if (cpm_udbg_txdesc) {
#ifdef CONFIG_CPM2
		setbat(1, 0xf0000000, 0xf0000000, 1024*1024, _PAGE_IO);
#endif
		udbg_putc = udbg_putc_cpm;
		udbg_putc('X');
	}
}
#endif

#ifdef CONFIG_PPC_CPM_NEW_BINDING
static spinlock_t cpm_muram_lock;
static rh_block_t cpm_boot_muram_rh_block[16];
static rh_info_t cpm_muram_info;
static u8 __iomem *muram_vbase;
static phys_addr_t muram_pbase;

/* Max address size we deal with */
#define OF_MAX_ADDR_CELLS	4

int __init cpm_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;

	spin_lock_init(&cpm_muram_lock);
	/* initialize the info header */
	rh_init(&cpm_muram_info, 1,
	        sizeof(cpm_boot_muram_rh_block) /
	        sizeof(cpm_boot_muram_rh_block[0]),
	        cpm_boot_muram_rh_block);

	np = of_find_compatible_node(NULL, NULL, "fsl,cpm-muram-data");
	if (!np) {
		printk(KERN_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) {
		printk(KERN_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;

		rh_attach_region(&cpm_muram_info, r.start - muram_pbase,
		                 r.end - r.start + 1);
	}

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

out:
	of_node_put(np);
	return ret;
}

/**
 * cpm_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 cpm_dpram_addr() to get the virtual address of the area.
 * Use cpm_muram_free() to free the allocation.
 */
unsigned long cpm_muram_alloc(unsigned long size, unsigned long align)
{
	unsigned long start;
	unsigned long flags;

	spin_lock_irqsave(&cpm_muram_lock, flags);
	cpm_muram_info.alignment = align;
	start = rh_alloc(&cpm_muram_info, size, "commproc");
	spin_unlock_irqrestore(&cpm_muram_lock, flags);

	return start;
}
EXPORT_SYMBOL(cpm_muram_alloc);

/**
 * cpm_muram_free - free a chunk of multi-user ram
 * @offset: The beginning of the chunk as returned by cpm_muram_alloc().
 */
int cpm_muram_free(unsigned long offset)
{
	int ret;
	unsigned long flags;

	spin_lock_irqsave(&cpm_muram_lock, flags);
	ret = rh_free(&cpm_muram_info, offset);
	spin_unlock_irqrestore(&cpm_muram_lock, flags);

	return ret;
}
EXPORT_SYMBOL(cpm_muram_free);

/**
 * cpm_muram_alloc_fixed - reserve a specific region of multi-user ram
 * @offset: the offset into the muram area to reserve
 * @size: the number of bytes to reserve
 *
 * This function returns "start" on success, -ENOMEM on failure.
 * Use cpm_dpram_addr() to get the virtual address of the area.
 * Use cpm_muram_free() to free the allocation.
 */
unsigned long cpm_muram_alloc_fixed(unsigned long offset, unsigned long size)
{
	unsigned long start;
	unsigned long flags;

	spin_lock_irqsave(&cpm_muram_lock, flags);
	cpm_muram_info.alignment = 1;
	start = rh_alloc_fixed(&cpm_muram_info, offset, size, "commproc");
	spin_unlock_irqrestore(&cpm_muram_lock, flags);

	return start;
}
EXPORT_SYMBOL(cpm_muram_alloc_fixed);

/**
 * cpm_muram_addr - turn a muram offset into a virtual address
 * @offset: muram offset to convert
 */
void __iomem *cpm_muram_addr(unsigned long offset)
{
	return muram_vbase + offset;
}
EXPORT_SYMBOL(cpm_muram_addr);

/**
 * cpm_muram_dma - turn a muram virtual address into a DMA address
 * @offset: virtual address from cpm_muram_addr() to convert
 */
dma_addr_t cpm_muram_dma(void __iomem *addr)
{
	return muram_pbase + ((u8 __iomem *)addr - muram_vbase);
}
EXPORT_SYMBOL(cpm_muram_dma);

#endif /* CONFIG_PPC_CPM_NEW_BINDING */