From cf2758159ea011a5e75e260256300313789073b4 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 20 Mar 2012 18:25:00 -0400 Subject: [PATCH 1/3] x86: add io_apic_ops 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. [ Impact: indirect IO APIC access via io_apic_ops ] Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Konrad Rzeszutek Wilk Acked-by: Suresh Siddha --- arch/x86/include/asm/io_apic.h | 9 +++++++ arch/x86/kernel/apic/io_apic.c | 50 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 56 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h index 690d1cc..190d8c2 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 6d10a66..0c3527b 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -67,6 +67,25 @@ #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 +313,24 @@ 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]; @@ -314,14 +351,15 @@ 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); @@ -334,7 +372,8 @@ 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); @@ -3873,6 +3912,11 @@ 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; -- 1.7.7.5