[PATCH v2 21/26] x86, irq: Add mp_unregister_ioapic to handle hot-remove ioapic

Yinghai Lu
2013-02-08T19:31:35Z

It will free ioapic related irq_desc and also clear allocated_irqs bits.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
---
arch/x86/include/asm/mpspec.h | 1 +
arch/x86/kernel/apic/io_apic.c | 42 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+)

diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index 11bb6ea..e70b7e5 100644
--- a/arch/x86/include/asm/mpspec.h
+++ b/arch/x86/include/asm/mpspec.h
@@ -97,6 +97,7 @@ static inline void early_reserve_e820_mpc_new(void) { }
void __cpuinit generic_processor_info(int apicid, int version);
#ifdef CONFIG_ACPI
int __mp_register_ioapic(int id, u32 address, u32 gsi_base, bool hot);
+int mp_unregister_ioapic(u32 gsi_base);
extern void mp_register_ioapic(int id, u32 address, u32 gsi_base);
extern void mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
u32 gsi);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index d3b3c14..4a9ccf6 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -256,6 +256,14 @@ static void free_irq_at(unsigned int at, struct irq_cfg *cfg)
irq_free_desc(at);
}

+static void free_irqs(unsigned int from, int cnt)
+{
+ int i;
+
+ for (i = from; i < from + cnt; i++)
+ free_irq_at(i, irq_get_chip_data(i));
+}
+
static struct irq_cfg *realloc_irq_and_cfg_at(unsigned int at, int node)
{
struct irq_desc *desc = irq_to_desc(at);
@@ -329,6 +337,16 @@ static void __init reserve_ioapic_gsi_irq_extra(void)
}
}

+static void free_ioapic_gsi_irq_base(int idx)
+{
+ struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(idx);
+ int irq_base = gsi_cfg->irq_base;
+ int irq_cnt = gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
+
+ if (irq_base > 0)
+ free_irqs(irq_base, irq_cnt);
+}
+
static void alloc_ioapic_saved_registers(int idx)
{
if (ioapics[idx].saved_registers)
@@ -342,6 +360,11 @@ static void alloc_ioapic_saved_registers(int idx)
pr_err("IOAPIC %d: suspend/resume impossible!\n", idx);
}

+static void free_ioapic_saved_registers(int idx)
+{
+ kfree(ioapics[idx].saved_registers);
+}
+
int __init arch_early_irq_init(void)
{
int node = cpu_to_node(0);
@@ -3983,6 +4006,25 @@ void mp_register_ioapic(int id, u32 address, u32 gsi_base)
__mp_register_ioapic(id, address, gsi_base, false);
}

+int mp_unregister_ioapic(u32 gsi_base)
+{
+ int idx;
+
+ idx = mp_find_ioapic(gsi_base);
+ if (idx < 0)
+ return -EINVAL;
+
+ free_ioapic_saved_registers(idx);
+
+ free_ioapic_gsi_irq_base(idx);
+
+ clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+ memset(&ioapics[idx], 0, sizeof(struct ioapic));
+ ioapics[idx].mp_config.apicid = 0xff;
+
+ return 0;
+}
+
/* Enable IOAPIC early just for system timer */
void __init pre_init_apic_IRQ0(void)
{
--
1.7.10.4