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linux-next/arch/arm/mach-zynq/common.c
Thomas Betker 6632d4fdd7 ARM: zynq: Set bit 22 in PL310 AuxCtrl register (6395/1)
This patch is based on the
commit 1a8e41cd67 ("ARM: 6395/1: VExpress: Set bit 22 in the PL310
(cache controller) AuxCtlr register")

Clearing bit 22 in the PL310 Auxiliary Control register (shared
attribute override enable) has the side effect of transforming Normal
Shared Non-cacheable reads into Cacheable no-allocate reads.

Coherent DMA buffers in Linux always have a cacheable alias via the
kernel linear mapping and the processor can speculatively load cache
lines into the PL310 controller. With bit 22 cleared, Non-cacheable
reads would unexpectedly hit such cache lines leading to buffer
corruption.

For Zynq, this fix avoids memory inconsistencies between Gigabit
Ethernet controller (GEM) and CPU when DMA_CMA is disabled.

Suggested-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2015-07-22 09:37:58 +02:00

211 lines
5.1 KiB
C

/*
* This file contains common code that is intended to be used across
* boards so that it's not replicated.
*
* Copyright (C) 2011 Xilinx
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/cpumask.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clk/zynq.h>
#include <linux/clocksource.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/of.h>
#include <linux/memblock.h>
#include <linux/irqchip.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/mach/time.h>
#include <asm/mach-types.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/smp_scu.h>
#include <asm/system_info.h>
#include <asm/hardware/cache-l2x0.h>
#include "common.h"
#define ZYNQ_DEVCFG_MCTRL 0x80
#define ZYNQ_DEVCFG_PS_VERSION_SHIFT 28
#define ZYNQ_DEVCFG_PS_VERSION_MASK 0xF
void __iomem *zynq_scu_base;
/**
* zynq_memory_init - Initialize special memory
*
* We need to stop things allocating the low memory as DMA can't work in
* the 1st 512K of memory.
*/
static void __init zynq_memory_init(void)
{
if (!__pa(PAGE_OFFSET))
memblock_reserve(__pa(PAGE_OFFSET), __pa(swapper_pg_dir));
}
static struct platform_device zynq_cpuidle_device = {
.name = "cpuidle-zynq",
};
/**
* zynq_get_revision - Get Zynq silicon revision
*
* Return: Silicon version or -1 otherwise
*/
static int __init zynq_get_revision(void)
{
struct device_node *np;
void __iomem *zynq_devcfg_base;
u32 revision;
np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-devcfg-1.0");
if (!np) {
pr_err("%s: no devcfg node found\n", __func__);
return -1;
}
zynq_devcfg_base = of_iomap(np, 0);
if (!zynq_devcfg_base) {
pr_err("%s: Unable to map I/O memory\n", __func__);
return -1;
}
revision = readl(zynq_devcfg_base + ZYNQ_DEVCFG_MCTRL);
revision >>= ZYNQ_DEVCFG_PS_VERSION_SHIFT;
revision &= ZYNQ_DEVCFG_PS_VERSION_MASK;
iounmap(zynq_devcfg_base);
return revision;
}
static void __init zynq_init_late(void)
{
zynq_core_pm_init();
zynq_pm_late_init();
}
/**
* zynq_init_machine - System specific initialization, intended to be
* called from board specific initialization.
*/
static void __init zynq_init_machine(void)
{
struct platform_device_info devinfo = { .name = "cpufreq-dt", };
struct soc_device_attribute *soc_dev_attr;
struct soc_device *soc_dev;
struct device *parent = NULL;
soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
if (!soc_dev_attr)
goto out;
system_rev = zynq_get_revision();
soc_dev_attr->family = kasprintf(GFP_KERNEL, "Xilinx Zynq");
soc_dev_attr->revision = kasprintf(GFP_KERNEL, "0x%x", system_rev);
soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "0x%x",
zynq_slcr_get_device_id());
soc_dev = soc_device_register(soc_dev_attr);
if (IS_ERR(soc_dev)) {
kfree(soc_dev_attr->family);
kfree(soc_dev_attr->revision);
kfree(soc_dev_attr->soc_id);
kfree(soc_dev_attr);
goto out;
}
parent = soc_device_to_device(soc_dev);
out:
/*
* Finished with the static registrations now; fill in the missing
* devices
*/
of_platform_populate(NULL, of_default_bus_match_table, NULL, parent);
platform_device_register(&zynq_cpuidle_device);
platform_device_register_full(&devinfo);
}
static void __init zynq_timer_init(void)
{
zynq_early_slcr_init();
zynq_clock_init();
of_clk_init(NULL);
clocksource_of_init();
}
static struct map_desc zynq_cortex_a9_scu_map __initdata = {
.length = SZ_256,
.type = MT_DEVICE,
};
static void __init zynq_scu_map_io(void)
{
unsigned long base;
base = scu_a9_get_base();
zynq_cortex_a9_scu_map.pfn = __phys_to_pfn(base);
/* Expected address is in vmalloc area that's why simple assign here */
zynq_cortex_a9_scu_map.virtual = base;
iotable_init(&zynq_cortex_a9_scu_map, 1);
zynq_scu_base = (void __iomem *)base;
BUG_ON(!zynq_scu_base);
}
/**
* zynq_map_io - Create memory mappings needed for early I/O.
*/
static void __init zynq_map_io(void)
{
debug_ll_io_init();
zynq_scu_map_io();
}
static void __init zynq_irq_init(void)
{
gic_set_irqchip_flags(IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND);
irqchip_init();
}
static const char * const zynq_dt_match[] = {
"xlnx,zynq-7000",
NULL
};
DT_MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform")
/* 64KB way size, 8-way associativity, parity disabled */
.l2c_aux_val = 0x00400000,
.l2c_aux_mask = 0xffbfffff,
.smp = smp_ops(zynq_smp_ops),
.map_io = zynq_map_io,
.init_irq = zynq_irq_init,
.init_machine = zynq_init_machine,
.init_late = zynq_init_late,
.init_time = zynq_timer_init,
.dt_compat = zynq_dt_match,
.reserve = zynq_memory_init,
MACHINE_END