linux/arch/arm/mach-omap2/omap4-common.c
Tony Lindgren f4b9f40ae9 ARM: OMAP4+: Initialize SAR RAM base early for proper CPU1 reset for kexec
Prepare things for making kexec work on SMP omap variants by initializing
SARM RAM base early. This allows us to configure CPU1 for kexec in case
the previous kernel has put CPU1 in low power mode.

Note that this should not prevent moving other SAR RAM code to live
under drivers. However for kexec, we will need this very early.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 22:55:47 -07:00

351 lines
9.1 KiB
C

/*
* OMAP4 specific common source file.
*
* Copyright (C) 2010 Texas Instruments, Inc.
* Author:
* Santosh Shilimkar <santosh.shilimkar@ti.com>
*
*
* This program is free software,you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/platform_device.h>
#include <linux/memblock.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/export.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/of_address.h>
#include <linux/reboot.h>
#include <linux/genalloc.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/map.h>
#include <asm/memblock.h>
#include <asm/smp_twd.h>
#include "omap-wakeupgen.h"
#include "soc.h"
#include "iomap.h"
#include "common.h"
#include "prminst44xx.h"
#include "prcm_mpu44xx.h"
#include "omap4-sar-layout.h"
#include "omap-secure.h"
#include "sram.h"
#ifdef CONFIG_CACHE_L2X0
static void __iomem *l2cache_base;
#endif
static void __iomem *sar_ram_base;
static void __iomem *gic_dist_base_addr;
static void __iomem *twd_base;
#define IRQ_LOCALTIMER 29
#ifdef CONFIG_OMAP_INTERCONNECT_BARRIER
/* Used to implement memory barrier on DRAM path */
#define OMAP4_DRAM_BARRIER_VA 0xfe600000
static void __iomem *dram_sync, *sram_sync;
static phys_addr_t dram_sync_paddr;
static u32 dram_sync_size;
/*
* The OMAP4 bus structure contains asynchronous bridges which can buffer
* data writes from the MPU. These asynchronous bridges can be found on
* paths between the MPU to EMIF, and the MPU to L3 interconnects.
*
* We need to be careful about re-ordering which can happen as a result
* of different accesses being performed via different paths, and
* therefore different asynchronous bridges.
*/
/*
* OMAP4 interconnect barrier which is called for each mb() and wmb().
* This is to ensure that normal paths to DRAM (normal memory, cacheable
* accesses) are properly synchronised with writes to DMA coherent memory
* (normal memory, uncacheable) and device writes.
*
* The mb() and wmb() barriers only operate only on the MPU->MA->EMIF
* path, as we need to ensure that data is visible to other system
* masters prior to writes to those system masters being seen.
*
* Note: the SRAM path is not synchronised via mb() and wmb().
*/
static void omap4_mb(void)
{
if (dram_sync)
writel_relaxed(0, dram_sync);
}
/*
* OMAP4 Errata i688 - asynchronous bridge corruption when entering WFI.
*
* If a data is stalled inside asynchronous bridge because of back
* pressure, it may be accepted multiple times, creating pointer
* misalignment that will corrupt next transfers on that data path until
* next reset of the system. No recovery procedure once the issue is hit,
* the path remains consistently broken.
*
* Async bridges can be found on paths between MPU to EMIF and MPU to L3
* interconnects.
*
* This situation can happen only when the idle is initiated by a Master
* Request Disconnection (which is trigged by software when executing WFI
* on the CPU).
*
* The work-around for this errata needs all the initiators connected
* through an async bridge to ensure that data path is properly drained
* before issuing WFI. This condition will be met if one Strongly ordered
* access is performed to the target right before executing the WFI.
*
* In MPU case, L3 T2ASYNC FIFO and DDR T2ASYNC FIFO needs to be drained.
* IO barrier ensure that there is no synchronisation loss on initiators
* operating on both interconnect port simultaneously.
*
* This is a stronger version of the OMAP4 memory barrier below, and
* operates on both the MPU->MA->EMIF path but also the MPU->OCP path
* as well, and is necessary prior to executing a WFI.
*/
void omap_interconnect_sync(void)
{
if (dram_sync && sram_sync) {
writel_relaxed(readl_relaxed(dram_sync), dram_sync);
writel_relaxed(readl_relaxed(sram_sync), sram_sync);
isb();
}
}
static int __init omap4_sram_init(void)
{
struct device_node *np;
struct gen_pool *sram_pool;
np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
if (!np)
pr_warn("%s:Unable to allocate sram needed to handle errata I688\n",
__func__);
sram_pool = of_gen_pool_get(np, "sram", 0);
if (!sram_pool)
pr_warn("%s:Unable to get sram pool needed to handle errata I688\n",
__func__);
else
sram_sync = (void *)gen_pool_alloc(sram_pool, PAGE_SIZE);
return 0;
}
omap_arch_initcall(omap4_sram_init);
/* Steal one page physical memory for barrier implementation */
void __init omap_barrier_reserve_memblock(void)
{
dram_sync_size = ALIGN(PAGE_SIZE, SZ_1M);
dram_sync_paddr = arm_memblock_steal(dram_sync_size, SZ_1M);
}
void __init omap_barriers_init(void)
{
struct map_desc dram_io_desc[1];
dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
dram_io_desc[0].pfn = __phys_to_pfn(dram_sync_paddr);
dram_io_desc[0].length = dram_sync_size;
dram_io_desc[0].type = MT_MEMORY_RW_SO;
iotable_init(dram_io_desc, ARRAY_SIZE(dram_io_desc));
dram_sync = (void __iomem *) dram_io_desc[0].virtual;
pr_info("OMAP4: Map %pa to %p for dram barrier\n",
&dram_sync_paddr, dram_sync);
soc_mb = omap4_mb;
}
#endif
void gic_dist_disable(void)
{
if (gic_dist_base_addr)
writel_relaxed(0x0, gic_dist_base_addr + GIC_DIST_CTRL);
}
void gic_dist_enable(void)
{
if (gic_dist_base_addr)
writel_relaxed(0x1, gic_dist_base_addr + GIC_DIST_CTRL);
}
bool gic_dist_disabled(void)
{
return !(readl_relaxed(gic_dist_base_addr + GIC_DIST_CTRL) & 0x1);
}
void gic_timer_retrigger(void)
{
u32 twd_int = readl_relaxed(twd_base + TWD_TIMER_INTSTAT);
u32 gic_int = readl_relaxed(gic_dist_base_addr + GIC_DIST_PENDING_SET);
u32 twd_ctrl = readl_relaxed(twd_base + TWD_TIMER_CONTROL);
if (twd_int && !(gic_int & BIT(IRQ_LOCALTIMER))) {
/*
* The local timer interrupt got lost while the distributor was
* disabled. Ack the pending interrupt, and retrigger it.
*/
pr_warn("%s: lost localtimer interrupt\n", __func__);
writel_relaxed(1, twd_base + TWD_TIMER_INTSTAT);
if (!(twd_ctrl & TWD_TIMER_CONTROL_PERIODIC)) {
writel_relaxed(1, twd_base + TWD_TIMER_COUNTER);
twd_ctrl |= TWD_TIMER_CONTROL_ENABLE;
writel_relaxed(twd_ctrl, twd_base + TWD_TIMER_CONTROL);
}
}
}
#ifdef CONFIG_CACHE_L2X0
void __iomem *omap4_get_l2cache_base(void)
{
return l2cache_base;
}
void omap4_l2c310_write_sec(unsigned long val, unsigned reg)
{
unsigned smc_op;
switch (reg) {
case L2X0_CTRL:
smc_op = OMAP4_MON_L2X0_CTRL_INDEX;
break;
case L2X0_AUX_CTRL:
smc_op = OMAP4_MON_L2X0_AUXCTRL_INDEX;
break;
case L2X0_DEBUG_CTRL:
smc_op = OMAP4_MON_L2X0_DBG_CTRL_INDEX;
break;
case L310_PREFETCH_CTRL:
smc_op = OMAP4_MON_L2X0_PREFETCH_INDEX;
break;
case L310_POWER_CTRL:
pr_info_once("OMAP L2C310: ROM does not support power control setting\n");
return;
default:
WARN_ONCE(1, "OMAP L2C310: ignoring write to reg 0x%x\n", reg);
return;
}
omap_smc1(smc_op, val);
}
int __init omap_l2_cache_init(void)
{
/* Static mapping, never released */
l2cache_base = ioremap(OMAP44XX_L2CACHE_BASE, SZ_4K);
if (WARN_ON(!l2cache_base))
return -ENOMEM;
return 0;
}
#endif
void __iomem *omap4_get_sar_ram_base(void)
{
return sar_ram_base;
}
/*
* SAR RAM used to save and restore the HW context in low power modes.
* Note that we need to initialize this very early for kexec. See
* omap4_mpuss_early_init().
*/
void __init omap4_sar_ram_init(void)
{
unsigned long sar_base;
/*
* To avoid code running on other OMAPs in
* multi-omap builds
*/
if (cpu_is_omap44xx())
sar_base = OMAP44XX_SAR_RAM_BASE;
else if (soc_is_omap54xx())
sar_base = OMAP54XX_SAR_RAM_BASE;
else
return;
/* Static mapping, never released */
sar_ram_base = ioremap(sar_base, SZ_16K);
if (WARN_ON(!sar_ram_base))
return;
}
static const struct of_device_id intc_match[] = {
{ .compatible = "ti,omap4-wugen-mpu", },
{ .compatible = "ti,omap5-wugen-mpu", },
{ },
};
static struct device_node *intc_node;
unsigned int omap4_xlate_irq(unsigned int hwirq)
{
struct of_phandle_args irq_data;
unsigned int irq;
if (!intc_node)
intc_node = of_find_matching_node(NULL, intc_match);
if (WARN_ON(!intc_node))
return hwirq;
irq_data.np = intc_node;
irq_data.args_count = 3;
irq_data.args[0] = 0;
irq_data.args[1] = hwirq - OMAP44XX_IRQ_GIC_START;
irq_data.args[2] = IRQ_TYPE_LEVEL_HIGH;
irq = irq_create_of_mapping(&irq_data);
if (WARN_ON(!irq))
irq = hwirq;
return irq;
}
void __init omap_gic_of_init(void)
{
struct device_node *np;
intc_node = of_find_matching_node(NULL, intc_match);
if (WARN_ON(!intc_node)) {
pr_err("No WUGEN found in DT, system will misbehave.\n");
pr_err("UPDATE YOUR DEVICE TREE!\n");
}
/* Extract GIC distributor and TWD bases for OMAP4460 ROM Errata WA */
if (!cpu_is_omap446x())
goto skip_errata_init;
np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-gic");
gic_dist_base_addr = of_iomap(np, 0);
WARN_ON(!gic_dist_base_addr);
np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-twd-timer");
twd_base = of_iomap(np, 0);
WARN_ON(!twd_base);
skip_errata_init:
irqchip_init();
}