linux-stable/drivers/soc/fsl/qe/qe_common.c
Christophe Leroy 4d486e0083 soc/fsl/qe: fix Oops on CPM1 (and likely CPM2)
Commit 0e6e01ff69 ("CPM/QE: use genalloc to manage CPM/QE muram")
has changed the way muram is managed.
genalloc uses kmalloc(), hence requires the SLAB to be up and running.

On powerpc 8xx, cpm_reset() is called early during startup.
cpm_reset() then calls cpm_muram_init() before SLAB is available,
hence the following Oops.

cpm_reset() cannot be called during initcalls because the CPM is
needed for console.

This patch removes the call to cpm_muram_init() from cpm_reset().
cpm_muram_init() will be called from a new function called cpm_init()
which is declared as subsys_initcall, unless cpm_muram_alloc() is
called earlier for the serial console in which case cpm_muram_init()
will be called from there.

The reason for calling it from two places is that some drivers
(e.g. i2c-cpm) need some of the initialisations done by
cpm_muram_init() but don't call cpm_muram_alloc(). The console
driver calls cpm_muram_alloc() but some platforms might not use
the CPM serial ports for console.

[    0.000000] Unable to handle kernel paging request for data at address 0x00000008
[    0.000000] Faulting instruction address: 0xc01acce0
[    0.000000] Oops: Kernel access of bad area, sig: 11 [#1]
[    0.000000] PREEMPT CMPC885
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.14-g0886ed8 #5
[    0.000000] task: c05183e0 ti: c0536000 task.ti: c0536000
[    0.000000] NIP: c01acce0 LR: c0011068 CTR: 00000000
[    0.000000] REGS: c0537e50 TRAP: 0300   Not tainted (4.4.14-s3k-dev-g0886ed8-svn)
[    0.000000] MSR: 00001032 <ME,IR,DR,RI>  CR: 28044428  XER: 00000000
[    0.000000] DAR: 00000008 DSISR: c0000000
GPR00: c0011068 c0537f00 c05183e0 00000000 00009000 ffffffff 00000bc0 ffffffff
GPR08: ff003000 ff00b000 ff003bbf 00000000 22044422 100d43a8 00000000 07ff94e8
GPR16: 00000000 07bb5d70 00000000 07ff81f4 07ff81f4 07ff81f4 00000000 00000000
GPR24: 07ffb3a0 07fe7628 c0550000 c7ffa190 c0540000 ff003bbf 00000000 00000001
[    0.000000] NIP [c01acce0] gen_pool_add_virt+0x14/0xdc
[    0.000000] LR [c0011068] cpm_muram_init+0xd4/0x18c
[    0.000000] Call Trace:
[    0.000000] [c0537f00] [00000200] 0x200 (unreliable)
[    0.000000] [c0537f20] [c0011068] cpm_muram_init+0xd4/0x18c
[    0.000000] [c0537f70] [c0494684] cpm_reset+0xb4/0xc8
[    0.000000] [c0537f90] [c0494c64] cmpc885_setup_arch+0x10/0x30
[    0.000000] [c0537fa0] [c0493cd4] setup_arch+0x130/0x168
[    0.000000] [c0537fb0] [c04906bc] start_kernel+0x88/0x380
[    0.000000] [c0537ff0] [c0002224] start_here+0x38/0x98
[    0.000000] Instruction dump:
[    0.000000] 91430010 91430014 80010014 83e1000c 7c0803a6 38210010 4e800020 7c0802a6
[    0.000000] 9421ffe0 bf61000c 90010024 7c7e1b78 <80630008> 7c9c2378 7cc31c30 3863001f
[    0.000000] ---[ end trace dc8fa200cb88537f ]---

fixes: 0e6e01ff69 ("CPM/QE: use genalloc to manage CPM/QE muram")
Cc: stable@vger.linux.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[scottwood: Removed some string changes unrelated to bugfix]
Signed-off-by: Scott Wood <oss@buserror.net>
2016-09-25 02:38:52 -05:00

243 lines
6.2 KiB
C

/*
* Common CPM code
*
* Author: Scott Wood <scottwood@freescale.com>
*
* Copyright 2007-2008,2010 Freescale Semiconductor, Inc.
*
* Some parts derived from commproc.c/cpm2_common.c, which is:
* Copyright (c) 1997 Dan error_act (dmalek@jlc.net)
* Copyright (c) 1999-2001 Dan Malek <dan@embeddedalley.com>
* Copyright (c) 2000 MontaVista Software, Inc (source@mvista.com)
* 2006 (c) MontaVista Software, Inc.
* Vitaly Bordug <vbordug@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/init.h>
#include <linux/list.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 spinlock_t cpm_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 * 8)
int 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;
if (muram_pbase)
return 0;
spin_lock_init(&cpm_muram_lock);
np = of_find_compatible_node(NULL, NULL, "fsl,cpm-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;
}
}
muram_pool = gen_pool_create(0, -1);
if (!muram_pool) {
pr_err("Cannot allocate memory pool for CPM/QE muram");
ret = -ENOMEM;
goto out_muram;
}
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_pool;
}
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 out_pool;
}
}
muram_vbase = ioremap(muram_pbase, max - muram_pbase + 1);
if (!muram_vbase) {
pr_err("Cannot map QE muram");
ret = -ENOMEM;
goto out_pool;
}
goto out_muram;
out_pool:
gen_pool_destroy(muram_pool);
out_muram:
of_node_put(np);
return ret;
}
/*
* cpm_muram_alloc_common - cpm_muram_alloc common code
* @size: number of bytes to allocate
* @algo: algorithm for alloc.
* @data: data for genalloc's algorithm.
*
* This function returns an offset into the muram area.
*/
static unsigned long cpm_muram_alloc_common(unsigned long size,
genpool_algo_t algo, void *data)
{
struct muram_block *entry;
unsigned long start;
if (!muram_pool && cpm_muram_init())
goto out2;
start = gen_pool_alloc_algo(muram_pool, size, algo, data);
if (!start)
goto out2;
start = start - GENPOOL_OFFSET;
memset_io(cpm_muram_addr(start), 0, size);
entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
if (!entry)
goto out1;
entry->start = start;
entry->size = size;
list_add(&entry->head, &muram_block_list);
return start;
out1:
gen_pool_free(muram_pool, start, size);
out2:
return (unsigned long)-ENOMEM;
}
/*
* 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;
struct genpool_data_align muram_pool_data;
spin_lock_irqsave(&cpm_muram_lock, flags);
muram_pool_data.align = align;
start = cpm_muram_alloc_common(size, gen_pool_first_fit_align,
&muram_pool_data);
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)
{
unsigned long flags;
int size;
struct muram_block *tmp;
size = 0;
spin_lock_irqsave(&cpm_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(&cpm_muram_lock, flags);
return size;
}
EXPORT_SYMBOL(cpm_muram_free);
/*
* cpm_muram_alloc_fixed - reserve a specific region of multi-user ram
* @offset: offset of allocation start address
* @size: number of bytes to allocate
* 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_fixed(unsigned long offset, unsigned long size)
{
unsigned long start;
unsigned long flags;
struct genpool_data_fixed muram_pool_data_fixed;
spin_lock_irqsave(&cpm_muram_lock, flags);
muram_pool_data_fixed.offset = offset + GENPOOL_OFFSET;
start = cpm_muram_alloc_common(size, gen_pool_fixed_alloc,
&muram_pool_data_fixed);
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);
unsigned long cpm_muram_offset(void __iomem *addr)
{
return addr - (void __iomem *)muram_vbase;
}
EXPORT_SYMBOL(cpm_muram_offset);
/**
* 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);