[PATCH AUTOSEL 4.20 13/42] irqchip/csky: fixup handle_irq_perbit break irq

Sasha Levin
2019-02-09T18:57:08Z

From: Guo Ren <ren_guo@c-sky.com>

[ Upstream commit 56752b21755aef598709d143684cb363db98a7d2 ]

The handle_irq_perbit function loop every bit in hwirq local variable.

handle_irq_perbit(hwirq) {
for_everyt_bit_in(hwirq) {
handle_domain_irq()
->irq_exit()
->invoke_softirq()
->__do_softirq()
->local_irq_enable() // Here will cause new interrupt.
}
}

When new interrupt coming at local_irq_enable, it will finish another
interrupt handler and pull down the interrupt source. But hwirq is the
local variable for handle_irq_perbit(), it can't get new interrupt
controller pending reg status. So we need update hwirq with pending reg
in every loop.

Also change write_relax to writel could prevent stw from fast retire.
When local_irq is enabled, intc regs is really set-in.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Lu Baoquan <lu.baoquan@intellif.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/irqchip/irq-csky-apb-intc.c | 77 ++++++++++++++++-------------
1 file changed, 42 insertions(+), 35 deletions(-)

diff --git a/drivers/irqchip/irq-csky-apb-intc.c b/drivers/irqchip/irq-csky-apb-intc.c
index 2543baba8b1f..5a2ec43b7ddd 100644
--- a/drivers/irqchip/irq-csky-apb-intc.c
+++ b/drivers/irqchip/irq-csky-apb-intc.c
@@ -95,7 +95,7 @@ static inline void setup_irq_channel(u32 magic, void __iomem *reg_addr)

/* Setup 64 channel slots */
for (i = 0; i < INTC_IRQS; i += 4)
- writel_relaxed(build_channel_val(i, magic), reg_addr + i);
+ writel(build_channel_val(i, magic), reg_addr + i);
}

static int __init
@@ -135,16 +135,10 @@ ck_intc_init_comm(struct device_node *node, struct device_node *parent)
static inline bool handle_irq_perbit(struct pt_regs *regs, u32 hwirq,
u32 irq_base)
{
- u32 irq;
-
if (hwirq == 0)
return 0;

- while (hwirq) {
- irq = __ffs(hwirq);
- hwirq &= ~BIT(irq);
- handle_domain_irq(root_domain, irq_base + irq, regs);
- }
+ handle_domain_irq(root_domain, irq_base + __fls(hwirq), regs);

return 1;
}
@@ -154,12 +148,16 @@ static void gx_irq_handler(struct pt_regs *regs)
{
bool ret;

- do {
- ret = handle_irq_perbit(regs,
- readl_relaxed(reg_base + GX_INTC_PEN31_00), 0);
- ret |= handle_irq_perbit(regs,
- readl_relaxed(reg_base + GX_INTC_PEN63_32), 32);
- } while (ret);
+retry:
+ ret = handle_irq_perbit(regs,
+ readl(reg_base + GX_INTC_PEN63_32), 32);
+ if (ret)
+ goto retry;
+
+ ret = handle_irq_perbit(regs,
+ readl(reg_base + GX_INTC_PEN31_00), 0);
+ if (ret)
+ goto retry;
}

static int __init
@@ -174,14 +172,14 @@ gx_intc_init(struct device_node *node, struct device_node *parent)
/*
* Initial enable reg to disable all interrupts
*/
- writel_relaxed(0x0, reg_base + GX_INTC_NEN31_00);
- writel_relaxed(0x0, reg_base + GX_INTC_NEN63_32);
+ writel(0x0, reg_base + GX_INTC_NEN31_00);
+ writel(0x0, reg_base + GX_INTC_NEN63_32);

/*
* Initial mask reg with all unmasked, because we only use enalbe reg
*/
- writel_relaxed(0x0, reg_base + GX_INTC_NMASK31_00);
- writel_relaxed(0x0, reg_base + GX_INTC_NMASK63_32);
+ writel(0x0, reg_base + GX_INTC_NMASK31_00);
+ writel(0x0, reg_base + GX_INTC_NMASK63_32);

setup_irq_channel(0x03020100, reg_base + GX_INTC_SOURCE);

@@ -204,20 +202,29 @@ static void ck_irq_handler(struct pt_regs *regs)
void __iomem *reg_pen_lo = reg_base + CK_INTC_PEN31_00;
void __iomem *reg_pen_hi = reg_base + CK_INTC_PEN63_32;

- do {
- /* handle 0 - 31 irqs */
- ret = handle_irq_perbit(regs, readl_relaxed(reg_pen_lo), 0);
- ret |= handle_irq_perbit(regs, readl_relaxed(reg_pen_hi), 32);
+retry:
+ /* handle 0 - 63 irqs */
+ ret = handle_irq_perbit(regs, readl(reg_pen_hi), 32);
+ if (ret)
+ goto retry;

- if (nr_irq == INTC_IRQS)
- continue;
+ ret = handle_irq_perbit(regs, readl(reg_pen_lo), 0);
+ if (ret)
+ goto retry;
+
+ if (nr_irq == INTC_IRQS)
+ return;

- /* handle 64 - 127 irqs */
- ret |= handle_irq_perbit(regs,
- readl_relaxed(reg_pen_lo + CK_INTC_DUAL_BASE), 64);
- ret |= handle_irq_perbit(regs,
- readl_relaxed(reg_pen_hi + CK_INTC_DUAL_BASE), 96);
- } while (ret);
+ /* handle 64 - 127 irqs */
+ ret = handle_irq_perbit(regs,
+ readl(reg_pen_hi + CK_INTC_DUAL_BASE), 96);
+ if (ret)
+ goto retry;
+
+ ret = handle_irq_perbit(regs,
+ readl(reg_pen_lo + CK_INTC_DUAL_BASE), 64);
+ if (ret)
+ goto retry;
}

static int __init
@@ -230,11 +237,11 @@ ck_intc_init(struct device_node *node, struct device_node *parent)
return ret;

/* Initial enable reg to disable all interrupts */
- writel_relaxed(0, reg_base + CK_INTC_NEN31_00);
- writel_relaxed(0, reg_base + CK_INTC_NEN63_32);
+ writel(0, reg_base + CK_INTC_NEN31_00);
+ writel(0, reg_base + CK_INTC_NEN63_32);

/* Enable irq intc */
- writel_relaxed(BIT(31), reg_base + CK_INTC_ICR);
+ writel(BIT(31), reg_base + CK_INTC_ICR);

ck_set_gc(node, reg_base, CK_INTC_NEN31_00, 0);
ck_set_gc(node, reg_base, CK_INTC_NEN63_32, 32);
@@ -260,8 +267,8 @@ ck_dual_intc_init(struct device_node *node, struct device_node *parent)
return ret;

/* Initial enable reg to disable all interrupts */
- writel_relaxed(0, reg_base + CK_INTC_NEN31_00 + CK_INTC_DUAL_BASE);
- writel_relaxed(0, reg_base + CK_INTC_NEN63_32 + CK_INTC_DUAL_BASE);
+ writel(0, reg_base + CK_INTC_NEN31_00 + CK_INTC_DUAL_BASE);
+ writel(0, reg_base + CK_INTC_NEN63_32 + CK_INTC_DUAL_BASE);

ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN31_00, 64);
ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN63_32, 96);
--
2.19.1