linux/drivers/irqchip/irq-armada-370-xp.c

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/*
* Marvell Armada 370 and Armada XP SoC IRQ handling
*
* Copyright (C) 2012 Marvell
*
* Lior Amsalem <alior@marvell.com>
* Gregory CLEMENT <gregory.clement@free-electrons.com>
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
* Ben Dooks <ben.dooks@codethink.co.uk>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/cpu.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/irqdomain.h>
#include <linux/slab.h>
#include <linux/msi.h>
#include <asm/mach/arch.h>
#include <asm/exception.h>
#include <asm/smp_plat.h>
#include <asm/mach/irq.h>
#include "irqchip.h"
/* Interrupt Controller Registers Map */
#define ARMADA_370_XP_INT_SET_MASK_OFFS (0x48)
#define ARMADA_370_XP_INT_CLEAR_MASK_OFFS (0x4C)
#define ARMADA_370_XP_INT_CONTROL (0x00)
#define ARMADA_370_XP_INT_SET_ENABLE_OFFS (0x30)
#define ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS (0x34)
#define ARMADA_370_XP_INT_SOURCE_CTL(irq) (0x100 + irq*4)
#define ARMADA_370_XP_INT_SOURCE_CPU_MASK 0xF
#define ARMADA_370_XP_CPU_INTACK_OFFS (0x44)
#define ARMADA_375_PPI_CAUSE (0x10)
#define ARMADA_370_XP_SW_TRIG_INT_OFFS (0x4)
#define ARMADA_370_XP_IN_DRBEL_MSK_OFFS (0xc)
#define ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS (0x8)
#define ARMADA_370_XP_MAX_PER_CPU_IRQS (28)
#define ARMADA_370_XP_TIMER0_PER_CPU_IRQ (5)
#define IPI_DOORBELL_START (0)
#define IPI_DOORBELL_END (8)
#define IPI_DOORBELL_MASK 0xFF
#define PCI_MSI_DOORBELL_START (16)
#define PCI_MSI_DOORBELL_NR (16)
#define PCI_MSI_DOORBELL_END (32)
#define PCI_MSI_DOORBELL_MASK 0xFFFF0000
static void __iomem *per_cpu_int_base;
static void __iomem *main_int_base;
static struct irq_domain *armada_370_xp_mpic_domain;
#ifdef CONFIG_PCI_MSI
static struct irq_domain *armada_370_xp_msi_domain;
static DECLARE_BITMAP(msi_used, PCI_MSI_DOORBELL_NR);
static DEFINE_MUTEX(msi_used_lock);
static phys_addr_t msi_doorbell_addr;
#endif
/*
* In SMP mode:
* For shared global interrupts, mask/unmask global enable bit
* For CPU interrupts, mask/unmask the calling CPU's bit
*/
static void armada_370_xp_irq_mask(struct irq_data *d)
{
irq_hw_number_t hwirq = irqd_to_hwirq(d);
if (hwirq != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
writel(hwirq, main_int_base +
ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS);
else
writel(hwirq, per_cpu_int_base +
ARMADA_370_XP_INT_SET_MASK_OFFS);
}
static void armada_370_xp_irq_unmask(struct irq_data *d)
{
irq_hw_number_t hwirq = irqd_to_hwirq(d);
if (hwirq != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
writel(hwirq, main_int_base +
ARMADA_370_XP_INT_SET_ENABLE_OFFS);
else
writel(hwirq, per_cpu_int_base +
ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
}
#ifdef CONFIG_PCI_MSI
static int armada_370_xp_alloc_msi(void)
{
int hwirq;
mutex_lock(&msi_used_lock);
hwirq = find_first_zero_bit(&msi_used, PCI_MSI_DOORBELL_NR);
if (hwirq >= PCI_MSI_DOORBELL_NR)
hwirq = -ENOSPC;
else
set_bit(hwirq, msi_used);
mutex_unlock(&msi_used_lock);
return hwirq;
}
static void armada_370_xp_free_msi(int hwirq)
{
mutex_lock(&msi_used_lock);
if (!test_bit(hwirq, msi_used))
pr_err("trying to free unused MSI#%d\n", hwirq);
else
clear_bit(hwirq, msi_used);
mutex_unlock(&msi_used_lock);
}
static int armada_370_xp_setup_msi_irq(struct msi_chip *chip,
struct pci_dev *pdev,
struct msi_desc *desc)
{
struct msi_msg msg;
int virq, hwirq;
hwirq = armada_370_xp_alloc_msi();
if (hwirq < 0)
return hwirq;
virq = irq_create_mapping(armada_370_xp_msi_domain, hwirq);
if (!virq) {
armada_370_xp_free_msi(hwirq);
return -EINVAL;
}
irq_set_msi_desc(virq, desc);
msg.address_lo = msi_doorbell_addr;
msg.address_hi = 0;
msg.data = 0xf00 | (hwirq + 16);
write_msi_msg(virq, &msg);
return 0;
}
static void armada_370_xp_teardown_msi_irq(struct msi_chip *chip,
unsigned int irq)
{
struct irq_data *d = irq_get_irq_data(irq);
unsigned long hwirq = d->hwirq;
irq_dispose_mapping(irq);
armada_370_xp_free_msi(hwirq);
}
static int armada_370_xp_check_msi_device(struct msi_chip *chip, struct pci_dev *dev,
int nvec, int type)
{
/* We support MSI, but not MSI-X */
if (type == PCI_CAP_ID_MSI)
return 0;
return -EINVAL;
}
static struct irq_chip armada_370_xp_msi_irq_chip = {
.name = "armada_370_xp_msi_irq",
.irq_enable = unmask_msi_irq,
.irq_disable = mask_msi_irq,
.irq_mask = mask_msi_irq,
.irq_unmask = unmask_msi_irq,
};
static int armada_370_xp_msi_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hw)
{
irq_set_chip_and_handler(virq, &armada_370_xp_msi_irq_chip,
handle_simple_irq);
set_irq_flags(virq, IRQF_VALID);
return 0;
}
static const struct irq_domain_ops armada_370_xp_msi_irq_ops = {
.map = armada_370_xp_msi_map,
};
static int armada_370_xp_msi_init(struct device_node *node,
phys_addr_t main_int_phys_base)
{
struct msi_chip *msi_chip;
u32 reg;
int ret;
msi_doorbell_addr = main_int_phys_base +
ARMADA_370_XP_SW_TRIG_INT_OFFS;
msi_chip = kzalloc(sizeof(*msi_chip), GFP_KERNEL);
if (!msi_chip)
return -ENOMEM;
msi_chip->setup_irq = armada_370_xp_setup_msi_irq;
msi_chip->teardown_irq = armada_370_xp_teardown_msi_irq;
msi_chip->check_device = armada_370_xp_check_msi_device;
msi_chip->of_node = node;
armada_370_xp_msi_domain =
irq_domain_add_linear(NULL, PCI_MSI_DOORBELL_NR,
&armada_370_xp_msi_irq_ops,
NULL);
if (!armada_370_xp_msi_domain) {
kfree(msi_chip);
return -ENOMEM;
}
ret = of_pci_msi_chip_add(msi_chip);
if (ret < 0) {
irq_domain_remove(armada_370_xp_msi_domain);
kfree(msi_chip);
return ret;
}
reg = readl(per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_MSK_OFFS)
| PCI_MSI_DOORBELL_MASK;
writel(reg, per_cpu_int_base +
ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
/* Unmask IPI interrupt */
writel(1, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
return 0;
}
#else
static inline int armada_370_xp_msi_init(struct device_node *node,
phys_addr_t main_int_phys_base)
{
return 0;
}
#endif
#ifdef CONFIG_SMP
static DEFINE_RAW_SPINLOCK(irq_controller_lock);
static int armada_xp_set_affinity(struct irq_data *d,
const struct cpumask *mask_val, bool force)
{
irq_hw_number_t hwirq = irqd_to_hwirq(d);
unsigned long reg, mask;
int cpu;
/* Select a single core from the affinity mask which is online */
cpu = cpumask_any_and(mask_val, cpu_online_mask);
mask = 1UL << cpu_logical_map(cpu);
raw_spin_lock(&irq_controller_lock);
reg = readl(main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
reg = (reg & (~ARMADA_370_XP_INT_SOURCE_CPU_MASK)) | mask;
writel(reg, main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
raw_spin_unlock(&irq_controller_lock);
return 0;
}
#endif
static struct irq_chip armada_370_xp_irq_chip = {
.name = "armada_370_xp_irq",
.irq_mask = armada_370_xp_irq_mask,
.irq_mask_ack = armada_370_xp_irq_mask,
.irq_unmask = armada_370_xp_irq_unmask,
#ifdef CONFIG_SMP
.irq_set_affinity = armada_xp_set_affinity,
#endif
};
static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
unsigned int virq, irq_hw_number_t hw)
{
armada_370_xp_irq_mask(irq_get_irq_data(virq));
arm: mvebu: Fix the irq map function in SMP mode This patch fix the regression introduced by the commit 3202bf0157ccb "arm: mvebu: Improve the SMP support of the interrupt controller": GPIO IRQ were no longer delivered to the CPUs. To be delivered to a CPU an interrupt must be enabled at CPU level and at interrupt source level. Before the offending patch, all the interrupts were enabled at source level during map() function. Mask() and unmask() was done by handling the per-CPU part. It was fine when running in UP with only one CPU. The offending patch added support for SMP, in this case mask() and unmask() was done by handling the interrupt source level part. The per-CPU level part was handled by the affinity API to select the CPU which will receive the interrupt. (Due to some hardware limitation only one CPU at a time can received a given interrupt). For "normal" interrupt __setup_irq() was called when an irq was registered. irq_set_affinity() is called from this function, which enabled the interrupt on one of the CPUs. Whereas for GPIO IRQ which were chained interrupts, the irq_set_affinity() was never called and none of the CPUs was selected to receive the interrupt. With this patch all the interrupt are enable on the current CPU during map() function. Enabling the interrupts on a CPU doesn't depend anymore on irq_set_affinity() and then the chained irq are not anymore a special case. However the CPU which will receive the irq can still be modify later using irq_set_affinity(). Tested with Mirabox (A370) and Openblocks AX3 (AXP), rootfs mounted over NFS, compiled with CONFIG_SMP=y/N. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Reported-by: Ryan Press <ryan@presslab.us> Investigated-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Tested-by: Ryan Press <ryan@presslab.us> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2013-04-05 20:32:52 +08:00
if (hw != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
writel(hw, per_cpu_int_base +
ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
else
writel(hw, main_int_base + ARMADA_370_XP_INT_SET_ENABLE_OFFS);
irq_set_status_flags(virq, IRQ_LEVEL);
if (hw == ARMADA_370_XP_TIMER0_PER_CPU_IRQ) {
irq_set_percpu_devid(virq);
irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
handle_percpu_devid_irq);
} else {
irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
handle_level_irq);
}
set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
return 0;
}
#ifdef CONFIG_SMP
static void armada_mpic_send_doorbell(const struct cpumask *mask,
unsigned int irq)
{
int cpu;
unsigned long map = 0;
/* Convert our logical CPU mask into a physical one. */
for_each_cpu(cpu, mask)
map |= 1 << cpu_logical_map(cpu);
/*
* Ensure that stores to Normal memory are visible to the
* other CPUs before issuing the IPI.
*/
dsb();
/* submit softirq */
writel((map << 8) | irq, main_int_base +
ARMADA_370_XP_SW_TRIG_INT_OFFS);
}
static void armada_xp_mpic_smp_cpu_init(void)
{
u32 control;
int nr_irqs, i;
control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
nr_irqs = (control >> 2) & 0x3ff;
for (i = 0; i < nr_irqs; i++)
writel(i, per_cpu_int_base + ARMADA_370_XP_INT_SET_MASK_OFFS);
/* Clear pending IPIs */
writel(0, per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
/* Enable first 8 IPIs */
writel(IPI_DOORBELL_MASK, per_cpu_int_base +
ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
/* Unmask IPI interrupt */
writel(0, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
}
static int armada_xp_mpic_secondary_init(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
armada_xp_mpic_smp_cpu_init();
return NOTIFY_OK;
}
static struct notifier_block armada_370_xp_mpic_cpu_notifier = {
.notifier_call = armada_xp_mpic_secondary_init,
.priority = 100,
};
#endif /* CONFIG_SMP */
static struct irq_domain_ops armada_370_xp_mpic_irq_ops = {
.map = armada_370_xp_mpic_irq_map,
.xlate = irq_domain_xlate_onecell,
};
#ifdef CONFIG_PCI_MSI
static void armada_370_xp_handle_msi_irq(struct pt_regs *regs, bool is_chained)
{
u32 msimask, msinr;
msimask = readl_relaxed(per_cpu_int_base +
ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
& PCI_MSI_DOORBELL_MASK;
writel(~msimask, per_cpu_int_base +
ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
for (msinr = PCI_MSI_DOORBELL_START;
msinr < PCI_MSI_DOORBELL_END; msinr++) {
int irq;
if (!(msimask & BIT(msinr)))
continue;
irq = irq_find_mapping(armada_370_xp_msi_domain,
msinr - 16);
if (is_chained)
generic_handle_irq(irq);
else
handle_IRQ(irq, regs);
}
}
#else
static void armada_370_xp_handle_msi_irq(struct pt_regs *r, bool b) {}
#endif
static void armada_370_xp_mpic_handle_cascade_irq(unsigned int irq,
struct irq_desc *desc)
{
struct irq_chip *chip = irq_get_chip(irq);
unsigned long irqmap, irqn;
unsigned int cascade_irq;
chained_irq_enter(chip, desc);
irqmap = readl_relaxed(per_cpu_int_base + ARMADA_375_PPI_CAUSE);
if (irqmap & BIT(0)) {
armada_370_xp_handle_msi_irq(NULL, true);
irqmap &= ~BIT(0);
}
for_each_set_bit(irqn, &irqmap, BITS_PER_LONG) {
cascade_irq = irq_find_mapping(armada_370_xp_mpic_domain, irqn);
generic_handle_irq(cascade_irq);
}
chained_irq_exit(chip, desc);
}
static void __exception_irq_entry
armada_370_xp_handle_irq(struct pt_regs *regs)
{
u32 irqstat, irqnr;
do {
irqstat = readl_relaxed(per_cpu_int_base +
ARMADA_370_XP_CPU_INTACK_OFFS);
irqnr = irqstat & 0x3FF;
if (irqnr > 1022)
break;
if (irqnr > 1) {
irqnr = irq_find_mapping(armada_370_xp_mpic_domain,
irqnr);
handle_IRQ(irqnr, regs);
continue;
}
/* MSI handling */
if (irqnr == 1)
armada_370_xp_handle_msi_irq(regs, false);
#ifdef CONFIG_SMP
/* IPI Handling */
if (irqnr == 0) {
u32 ipimask, ipinr;
ipimask = readl_relaxed(per_cpu_int_base +
ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
& IPI_DOORBELL_MASK;
irqchip: armada-370-xp: fix IPI race condition In the Armada 370/XP driver, when we receive an IRQ 0, we read the list of doorbells that caused the interrupt from register ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS. This gives the list of IPIs that were generated. However, instead of acknowledging only the IPIs that were generated, we acknowledge *all* the IPIs, by writing ~IPI_DOORBELL_MASK in the ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS register. This creates a race condition: if a new IPI that isn't part of the ones read into the temporary "ipimask" variable is fired before we acknowledge all IPIs, then we will simply loose it. This is causing scheduling hangs on SMP intensive workloads. It is important to mention that this ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS register has the following behavior: "A CPU write of 0 clears the bits in this field. A CPU write of 1 has no effect". This is what allows us to simply write ~ipimask to acknoledge the handled IPIs. Notice that the same problem is present in the MSI implementation, but it will be fixed as a separate patch, so that this IPI fix can be pushed to older stable versions as appropriate (all the way to 3.8), while the MSI code only appeared in 3.13. Signed-off-by: Lior Amsalem <alior@marvell.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: stable@vger.kernel.org # v3.8+ Fixes: 344e873e5657e8dc0 'arm: mvebu: Add IPI support via doorbells' Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2013-11-26 00:26:44 +08:00
writel(~ipimask, per_cpu_int_base +
ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
/* Handle all pending doorbells */
for (ipinr = IPI_DOORBELL_START;
ipinr < IPI_DOORBELL_END; ipinr++) {
if (ipimask & (0x1 << ipinr))
handle_IPI(ipinr, regs);
}
continue;
}
#endif
} while (1);
}
static int __init armada_370_xp_mpic_of_init(struct device_node *node,
struct device_node *parent)
{
struct resource main_int_res, per_cpu_int_res;
int parent_irq, nr_irqs, i;
u32 control;
BUG_ON(of_address_to_resource(node, 0, &main_int_res));
BUG_ON(of_address_to_resource(node, 1, &per_cpu_int_res));
BUG_ON(!request_mem_region(main_int_res.start,
resource_size(&main_int_res),
node->full_name));
BUG_ON(!request_mem_region(per_cpu_int_res.start,
resource_size(&per_cpu_int_res),
node->full_name));
main_int_base = ioremap(main_int_res.start,
resource_size(&main_int_res));
BUG_ON(!main_int_base);
per_cpu_int_base = ioremap(per_cpu_int_res.start,
resource_size(&per_cpu_int_res));
BUG_ON(!per_cpu_int_base);
control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
nr_irqs = (control >> 2) & 0x3ff;
for (i = 0; i < nr_irqs; i++)
writel(i, main_int_base + ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS);
armada_370_xp_mpic_domain =
irq_domain_add_linear(node, nr_irqs,
&armada_370_xp_mpic_irq_ops, NULL);
BUG_ON(!armada_370_xp_mpic_domain);
#ifdef CONFIG_SMP
armada_xp_mpic_smp_cpu_init();
#endif
armada_370_xp_msi_init(node, main_int_res.start);
parent_irq = irq_of_parse_and_map(node, 0);
if (parent_irq <= 0) {
irq_set_default_host(armada_370_xp_mpic_domain);
set_handle_irq(armada_370_xp_handle_irq);
#ifdef CONFIG_SMP
set_smp_cross_call(armada_mpic_send_doorbell);
register_cpu_notifier(&armada_370_xp_mpic_cpu_notifier);
#endif
} else {
irq_set_chained_handler(parent_irq,
armada_370_xp_mpic_handle_cascade_irq);
}
return 0;
}
IRQCHIP_DECLARE(armada_370_xp_mpic, "marvell,mpic", armada_370_xp_mpic_of_init);