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linux_dsm_epyc7002/arch/arm/mach-sa1100/neponset.c
Russell King d782f33df7 [ARM] Fix Neponset IRQ handling 
While testing the genirq code on ARM, a condition was found whereby
the Neponset IRQ handler was being re-entered, causing the system
to deadlock.

Under the ARM IRQ code, this would not have been a visible problem
because the "simple" IRQ handling had no re-entrancy protection.

Resolve this by acknowledging the parent interrupt after we mask it
when we are going to handle one of our "special" level-based sources
(from ethernet or USAR chip.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-08 17:59:31 +01:00

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/*
* linux/arch/arm/mach-sa1100/neponset.c
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ptrace.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/serial_core.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/hardware.h>
#include <asm/mach-types.h>
#include <asm/irq.h>
#include <asm/mach/map.h>
#include <asm/mach/irq.h>
#include <asm/mach/serial_sa1100.h>
#include <asm/arch/assabet.h>
#include <asm/arch/neponset.h>
#include <asm/hardware/sa1111.h>
#include <asm/sizes.h>
/*
* Install handler for Neponset IRQ. Note that we have to loop here
* since the ETHERNET and USAR IRQs are level based, and we need to
* ensure that the IRQ signal is deasserted before returning. This
* is rather unfortunate.
*/
static void
neponset_irq_handler(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
{
unsigned int irr;
while (1) {
struct irqdesc *d;
/*
* Acknowledge the parent IRQ.
*/
desc->chip->ack(irq);
/*
* Read the interrupt reason register. Let's have all
* active IRQ bits high. Note: there is a typo in the
* Neponset user's guide for the SA1111 IRR level.
*/
irr = IRR ^ (IRR_ETHERNET | IRR_USAR);
if ((irr & (IRR_ETHERNET | IRR_USAR | IRR_SA1111)) == 0)
break;
/*
* Since there is no individual mask, we have to
* mask the parent IRQ. This is safe, since we'll
* recheck the register for any pending IRQs.
*/
if (irr & (IRR_ETHERNET | IRR_USAR)) {
desc->chip->mask(irq);
/*
* Ack the interrupt now to prevent re-entering
* this neponset handler. Again, this is safe
* since we'll check the IRR register prior to
* leaving.
*/
desc->chip->ack(irq);
if (irr & IRR_ETHERNET) {
d = irq_desc + IRQ_NEPONSET_SMC9196;
desc_handle_irq(IRQ_NEPONSET_SMC9196, d, regs);
}
if (irr & IRR_USAR) {
d = irq_desc + IRQ_NEPONSET_USAR;
desc_handle_irq(IRQ_NEPONSET_USAR, d, regs);
}
desc->chip->unmask(irq);
}
if (irr & IRR_SA1111) {
d = irq_desc + IRQ_NEPONSET_SA1111;
desc_handle_irq(IRQ_NEPONSET_SA1111, d, regs);
}
}
}
static void neponset_set_mctrl(struct uart_port *port, u_int mctrl)
{
u_int mdm_ctl0 = MDM_CTL_0;
if (port->mapbase == _Ser1UTCR0) {
if (mctrl & TIOCM_RTS)
mdm_ctl0 &= ~MDM_CTL0_RTS2;
else
mdm_ctl0 |= MDM_CTL0_RTS2;
if (mctrl & TIOCM_DTR)
mdm_ctl0 &= ~MDM_CTL0_DTR2;
else
mdm_ctl0 |= MDM_CTL0_DTR2;
} else if (port->mapbase == _Ser3UTCR0) {
if (mctrl & TIOCM_RTS)
mdm_ctl0 &= ~MDM_CTL0_RTS1;
else
mdm_ctl0 |= MDM_CTL0_RTS1;
if (mctrl & TIOCM_DTR)
mdm_ctl0 &= ~MDM_CTL0_DTR1;
else
mdm_ctl0 |= MDM_CTL0_DTR1;
}
MDM_CTL_0 = mdm_ctl0;
}
static u_int neponset_get_mctrl(struct uart_port *port)
{
u_int ret = TIOCM_CD | TIOCM_CTS | TIOCM_DSR;
u_int mdm_ctl1 = MDM_CTL_1;
if (port->mapbase == _Ser1UTCR0) {
if (mdm_ctl1 & MDM_CTL1_DCD2)
ret &= ~TIOCM_CD;
if (mdm_ctl1 & MDM_CTL1_CTS2)
ret &= ~TIOCM_CTS;
if (mdm_ctl1 & MDM_CTL1_DSR2)
ret &= ~TIOCM_DSR;
} else if (port->mapbase == _Ser3UTCR0) {
if (mdm_ctl1 & MDM_CTL1_DCD1)
ret &= ~TIOCM_CD;
if (mdm_ctl1 & MDM_CTL1_CTS1)
ret &= ~TIOCM_CTS;
if (mdm_ctl1 & MDM_CTL1_DSR1)
ret &= ~TIOCM_DSR;
}
return ret;
}
static struct sa1100_port_fns neponset_port_fns __initdata = {
.set_mctrl = neponset_set_mctrl,
.get_mctrl = neponset_get_mctrl,
};
static int neponset_probe(struct platform_device *dev)
{
sa1100_register_uart_fns(&neponset_port_fns);
/*
* Install handler for GPIO25.
*/
set_irq_type(IRQ_GPIO25, IRQT_RISING);
set_irq_chained_handler(IRQ_GPIO25, neponset_irq_handler);
/*
* We would set IRQ_GPIO25 to be a wake-up IRQ, but
* unfortunately something on the Neponset activates
* this IRQ on sleep (ethernet?)
*/
#if 0
enable_irq_wake(IRQ_GPIO25);
#endif
/*
* Setup other Neponset IRQs. SA1111 will be done by the
* generic SA1111 code.
*/
set_irq_handler(IRQ_NEPONSET_SMC9196, do_simple_IRQ);
set_irq_flags(IRQ_NEPONSET_SMC9196, IRQF_VALID | IRQF_PROBE);
set_irq_handler(IRQ_NEPONSET_USAR, do_simple_IRQ);
set_irq_flags(IRQ_NEPONSET_USAR, IRQF_VALID | IRQF_PROBE);
/*
* Disable GPIO 0/1 drivers so the buttons work on the module.
*/
NCR_0 = NCR_GP01_OFF;
return 0;
}
#ifdef CONFIG_PM
/*
* LDM power management.
*/
static int neponset_suspend(struct platform_device *dev, pm_message_t state)
{
/*
* Save state.
*/
if (!dev->dev.power.saved_state)
dev->dev.power.saved_state = kmalloc(sizeof(unsigned int), GFP_KERNEL);
if (!dev->dev.power.saved_state)
return -ENOMEM;
*(unsigned int *)dev->dev.power.saved_state = NCR_0;
return 0;
}
static int neponset_resume(struct platform_device *dev)
{
if (dev->dev.power.saved_state) {
NCR_0 = *(unsigned int *)dev->dev.power.saved_state;
kfree(dev->dev.power.saved_state);
dev->dev.power.saved_state = NULL;
}
return 0;
}
#else
#define neponset_suspend NULL
#define neponset_resume NULL
#endif
static struct platform_driver neponset_device_driver = {
.probe = neponset_probe,
.suspend = neponset_suspend,
.resume = neponset_resume,
.driver = {
.name = "neponset",
},
};
static struct resource neponset_resources[] = {
[0] = {
.start = 0x10000000,
.end = 0x17ffffff,
.flags = IORESOURCE_MEM,
},
};
static struct platform_device neponset_device = {
.name = "neponset",
.id = 0,
.num_resources = ARRAY_SIZE(neponset_resources),
.resource = neponset_resources,
};
static struct resource sa1111_resources[] = {
[0] = {
.start = 0x40000000,
.end = 0x40001fff,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_NEPONSET_SA1111,
.end = IRQ_NEPONSET_SA1111,
.flags = IORESOURCE_IRQ,
},
};
static u64 sa1111_dmamask = 0xffffffffUL;
static struct platform_device sa1111_device = {
.name = "sa1111",
.id = 0,
.dev = {
.dma_mask = &sa1111_dmamask,
.coherent_dma_mask = 0xffffffff,
},
.num_resources = ARRAY_SIZE(sa1111_resources),
.resource = sa1111_resources,
};
static struct resource smc91x_resources[] = {
[0] = {
.name = "smc91x-regs",
.start = SA1100_CS3_PHYS,
.end = SA1100_CS3_PHYS + 0x01ffffff,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_NEPONSET_SMC9196,
.end = IRQ_NEPONSET_SMC9196,
.flags = IORESOURCE_IRQ,
},
[2] = {
.name = "smc91x-attrib",
.start = SA1100_CS3_PHYS + 0x02000000,
.end = SA1100_CS3_PHYS + 0x03ffffff,
.flags = IORESOURCE_MEM,
},
};
static struct platform_device smc91x_device = {
.name = "smc91x",
.id = 0,
.num_resources = ARRAY_SIZE(smc91x_resources),
.resource = smc91x_resources,
};
static struct platform_device *devices[] __initdata = {
&neponset_device,
&sa1111_device,
&smc91x_device,
};
static int __init neponset_init(void)
{
platform_driver_register(&neponset_device_driver);
/*
* The Neponset is only present on the Assabet machine type.
*/
if (!machine_is_assabet())
return -ENODEV;
/*
* Ensure that the memory bus request/grant signals are setup,
* and the grant is held in its inactive state, whether or not
* we actually have a Neponset attached.
*/
sa1110_mb_disable();
if (!machine_has_neponset()) {
printk(KERN_DEBUG "Neponset expansion board not present\n");
return -ENODEV;
}
if (WHOAMI != 0x11) {
printk(KERN_WARNING "Neponset board detected, but "
"wrong ID: %02x\n", WHOAMI);
return -ENODEV;
}
return platform_add_devices(devices, ARRAY_SIZE(devices));
}
subsys_initcall(neponset_init);
static struct map_desc neponset_io_desc[] __initdata = {
{ /* System Registers */
.virtual = 0xf3000000,
.pfn = __phys_to_pfn(0x10000000),
.length = SZ_1M,
.type = MT_DEVICE
}, { /* SA-1111 */
.virtual = 0xf4000000,
.pfn = __phys_to_pfn(0x40000000),
.length = SZ_1M,
.type = MT_DEVICE
}
};
void __init neponset_map_io(void)
{
iotable_init(neponset_io_desc, ARRAY_SIZE(neponset_io_desc));
}
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