[tip:x86/urgent] x86/ioapic: Add io_apic_ops driver layer to allow interception
From: tip-bot for Jeremy Fitzhardinge
Date: Wed Mar 28 2012 - 05:32:16 EST
Commit-ID: 136d249ef7dbf0fefa292082cc40be1ea864cbd6
Gitweb: http://git.kernel.org/tip/136d249ef7dbf0fefa292082cc40be1ea864cbd6
Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
AuthorDate: Wed, 21 Mar 2012 22:58:08 -0400
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 28 Mar 2012 09:49:29 +0200
x86/ioapic: Add io_apic_ops driver layer to allow interception
Xen dom0 needs to paravirtualize IO operations to the IO APIC,
so add a io_apic_ops for it to intercept. Do this as ops
structure because there's at least some chance that another
paravirtualized environment may want to intercept these.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Acked-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: jwboyer@xxxxxxxxxx
Cc: yinghai@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1332385090-18056-2-git-send-email-konrad.wilk@xxxxxxxxxx
[ Made all the affected code easier on the eyes ]
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/io_apic.h | 9 ++++++
arch/x86/kernel/apic/io_apic.c | 58 +++++++++++++++++++++++++++++++++++-----
2 files changed, 60 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 690d1cc..2c4943d 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -21,6 +21,15 @@
#define IO_APIC_REDIR_LEVEL_TRIGGER (1 << 15)
#define IO_APIC_REDIR_MASKED (1 << 16)
+struct io_apic_ops {
+ void (*init) (void);
+ unsigned int (*read) (unsigned int apic, unsigned int reg);
+ void (*write) (unsigned int apic, unsigned int reg, unsigned int value);
+ void (*modify)(unsigned int apic, unsigned int reg, unsigned int value);
+};
+
+void __init set_io_apic_ops(const struct io_apic_ops *);
+
/*
* The structure of the IO-APIC:
*/
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 2c428c5..e88300d 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -64,9 +64,28 @@
#include <asm/apic.h>
#define __apicdebuginit(type) static type __init
+
#define for_each_irq_pin(entry, head) \
for (entry = head; entry; entry = entry->next)
+static void __init __ioapic_init_mappings(void);
+
+static unsigned int __io_apic_read (unsigned int apic, unsigned int reg);
+static void __io_apic_write (unsigned int apic, unsigned int reg, unsigned int val);
+static void __io_apic_modify(unsigned int apic, unsigned int reg, unsigned int val);
+
+static struct io_apic_ops io_apic_ops = {
+ .init = __ioapic_init_mappings,
+ .read = __io_apic_read,
+ .write = __io_apic_write,
+ .modify = __io_apic_modify,
+};
+
+void __init set_io_apic_ops(const struct io_apic_ops *ops)
+{
+ io_apic_ops = *ops;
+}
+
/*
* Is the SiS APIC rmw bug present ?
* -1 = don't know, 0 = no, 1 = yes
@@ -294,6 +313,22 @@ static void free_irq_at(unsigned int at, struct irq_cfg *cfg)
irq_free_desc(at);
}
+static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
+{
+ return io_apic_ops.read(apic, reg);
+}
+
+static inline void io_apic_write(unsigned int apic, unsigned int reg, unsigned int value)
+{
+ io_apic_ops.write(apic, reg, value);
+}
+
+static inline void io_apic_modify(unsigned int apic, unsigned int reg, unsigned int value)
+{
+ io_apic_ops.modify(apic, reg, value);
+}
+
+
struct io_apic {
unsigned int index;
unsigned int unused[3];
@@ -314,16 +349,17 @@ static inline void io_apic_eoi(unsigned int apic, unsigned int vector)
writel(vector, &io_apic->eoi);
}
-static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
+static unsigned int __io_apic_read(unsigned int apic, unsigned int reg)
{
struct io_apic __iomem *io_apic = io_apic_base(apic);
writel(reg, &io_apic->index);
return readl(&io_apic->data);
}
-static inline void io_apic_write(unsigned int apic, unsigned int reg, unsigned int value)
+static void __io_apic_write(unsigned int apic, unsigned int reg, unsigned int value)
{
struct io_apic __iomem *io_apic = io_apic_base(apic);
+
writel(reg, &io_apic->index);
writel(value, &io_apic->data);
}
@@ -334,7 +370,7 @@ static inline void io_apic_write(unsigned int apic, unsigned int reg, unsigned i
*
* Older SiS APIC requires we rewrite the index register
*/
-static inline void io_apic_modify(unsigned int apic, unsigned int reg, unsigned int value)
+static void __io_apic_modify(unsigned int apic, unsigned int reg, unsigned int value)
{
struct io_apic __iomem *io_apic = io_apic_base(apic);
@@ -377,6 +413,7 @@ static struct IO_APIC_route_entry __ioapic_read_entry(int apic, int pin)
eu.w1 = io_apic_read(apic, 0x10 + 2 * pin);
eu.w2 = io_apic_read(apic, 0x11 + 2 * pin);
+
return eu.entry;
}
@@ -384,9 +421,11 @@ static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
{
union entry_union eu;
unsigned long flags;
+
raw_spin_lock_irqsave(&ioapic_lock, flags);
eu.entry = __ioapic_read_entry(apic, pin);
raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
return eu.entry;
}
@@ -396,8 +435,7 @@ static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
* the interrupt, and we need to make sure the entry is fully populated
* before that happens.
*/
-static void
-__ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
+static void __ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
{
union entry_union eu = {{0, 0}};
@@ -409,6 +447,7 @@ __ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
{
unsigned long flags;
+
raw_spin_lock_irqsave(&ioapic_lock, flags);
__ioapic_write_entry(apic, pin, e);
raw_spin_unlock_irqrestore(&ioapic_lock, flags);
@@ -435,8 +474,7 @@ static void ioapic_mask_entry(int apic, int pin)
* shared ISA-space IRQs, so we have to support them. We are super
* fast in the common case, and fast for shared ISA-space IRQs.
*/
-static int
-__add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
+static int __add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
{
struct irq_pin_list **last, *entry;
@@ -521,6 +559,7 @@ static void io_apic_sync(struct irq_pin_list *entry)
* a dummy read from the IO-APIC
*/
struct io_apic __iomem *io_apic;
+
io_apic = io_apic_base(entry->apic);
readl(&io_apic->data);
}
@@ -3894,6 +3933,11 @@ static struct resource * __init ioapic_setup_resources(int nr_ioapics)
void __init ioapic_and_gsi_init(void)
{
+ io_apic_ops.init();
+}
+
+static void __init __ioapic_init_mappings(void)
+{
unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
struct resource *ioapic_res;
int i;
--
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