From 136d249ef7dbf0fefa292082cc40be1ea864cbd6 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 21 Mar 2012 22:58:08 -0400 Subject: [PATCH] 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 Signed-off-by: Konrad Rzeszutek Wilk Acked-by: Suresh Siddha Cc: jwboyer@redhat.com Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/1332385090-18056-2-git-send-email-konrad.wilk@oracle.com [ Made all the affected code easier on the eyes ] Signed-off-by: Ingo Molnar --- 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 690d1cc9a877..2c4943de5150 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 2c428c5d7ca3..e88300d8e80a 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -64,9 +64,28 @@ #include #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); } @@ -3893,6 +3932,11 @@ 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; -- 2.20.1