Commit 93758238 authored by Weidong Han's avatar Weidong Han Committed by Ingo Molnar
Browse files

x86, intr-remap: enable interrupt remapping early 



Currently, when x2apic is not enabled, interrupt remapping
will be enabled in init_dmars(), where it is too late to remap
ioapic interrupts, that is, ioapic interrupts are really in
compatibility mode, not remappable mode.

This patch always enables interrupt remapping before ioapic
setup, it guarantees all interrupts will be remapped when
interrupt remapping is enabled. Thus it doesn't need to set
the compatibility interrupt bit.

[ Impact: refactor intr-remap init sequence, enable fuller remap mode ]

Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarWeidong Han <weidong.han@intel.com>
Acked-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: allen.m.kay@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1239957736-6161-4-git-send-email-weidong.han@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 5d0ae2db

arch/x86/include/asm/apic.h

+3 −4
Original line number Diff line number Diff line
@@ -169,7 +169,6 @@ static inline u64 native_x2apic_icr_read(void) 
extern int x2apic, x2apic_phys;

extern void check_x2apic(void);

extern void enable_x2apic(void);

extern void enable_IR_x2apic(void);

extern void x2apic_icr_write(u32 low, u32 id);

static inline int x2apic_enabled(void)

{
@@ -190,18 +189,18 @@ static inline void check_x2apic(void) 
static inline void enable_x2apic(void)

{

}

static inline void enable_IR_x2apic(void)

{

}

static inline int x2apic_enabled(void)

{

	return 0;

}



#define	x2apic	0

#define	x2apic_preenabled 0



#endif



extern void enable_IR_x2apic(void);



extern int get_physical_broadcast(void);



extern void apic_disable(void);

arch/x86/kernel/apic/apic.c

+36 −40
Original line number Diff line number Diff line
@@ -141,6 +141,8 @@ static int x2apic_preenabled; 
static int disable_x2apic;

static __init int setup_nox2apic(char *str)

{

	if (x2apic_enabled())

		panic("Bios already enabled x2apic, can't enforce nox2apic");

	disable_x2apic = 1;

	setup_clear_cpu_cap(X86_FEATURE_X2APIC);

	return 0;
@@ -1345,6 +1347,7 @@ void enable_x2apic(void) 
		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);

	}

}

#endif /* CONFIG_X86_X2APIC */



void __init enable_IR_x2apic(void)

{
@@ -1353,32 +1356,21 @@ void __init enable_IR_x2apic(void) 
	unsigned long flags;

	struct IO_APIC_route_entry **ioapic_entries = NULL;



	if (!cpu_has_x2apic)

		return;



	if (!x2apic_preenabled && disable_x2apic) {

		pr_info("Skipped enabling x2apic and Interrupt-remapping "

			"because of nox2apic\n");

		return;

	ret = dmar_table_init();

	if (ret) {

		pr_debug("dmar_table_init() failed with %d:\n", ret);

		goto ir_failed;

	}



	if (x2apic_preenabled && disable_x2apic)

		panic("Bios already enabled x2apic, can't enforce nox2apic");



	if (!x2apic_preenabled && skip_ioapic_setup) {

		pr_info("Skipped enabling x2apic and Interrupt-remapping "

			"because of skipping io-apic setup\n");

		return;

	if (!intr_remapping_supported()) {

		pr_debug("intr-remapping not supported\n");

		goto ir_failed;

	}



	ret = dmar_table_init();

	if (ret) {

		pr_info("dmar_table_init() failed with %d:\n", ret);



		if (x2apic_preenabled)

			panic("x2apic enabled by bios. But IR enabling failed");

		else

			pr_info("Not enabling x2apic,Intr-remapping\n");

	if (!x2apic_preenabled && skip_ioapic_setup) {

		pr_info("Skipped enabling intr-remap because of skipping "

			"io-apic setup\n");

		return;

	}
@@ -1398,20 +1390,25 @@ void __init enable_IR_x2apic(void) 
	mask_IO_APIC_setup(ioapic_entries);

	mask_8259A();



#ifdef CONFIG_X86_X2APIC

	if (cpu_has_x2apic)

		ret = enable_intr_remapping(EIM_32BIT_APIC_ID);



	if (ret && x2apic_preenabled) {

		local_irq_restore(flags);

		panic("x2apic enabled by bios. But IR enabling failed");

	}

	else

#endif

		ret = enable_intr_remapping(EIM_8BIT_APIC_ID);



	if (ret)

		goto end_restore;



	if (!x2apic) {

	pr_info("Enabled Interrupt-remapping\n");



#ifdef CONFIG_X86_X2APIC

	if (cpu_has_x2apic && !x2apic) {

		x2apic = 1;

		enable_x2apic();

		pr_info("Enabled x2apic\n");

	}

#endif



end_restore:

	if (ret)
@@ -1426,30 +1423,29 @@ end_restore: 
	local_irq_restore(flags);



end:

	if (!ret) {

		if (!x2apic_preenabled)

			pr_info("Enabled x2apic and interrupt-remapping\n");

		else

			pr_info("Enabled Interrupt-remapping\n");

	} else

		pr_err("Failed to enable Interrupt-remapping and x2apic\n");

	if (ioapic_entries)

		free_ioapic_entries(ioapic_entries);



	if (!ret)

		return;



ir_failed:

	if (x2apic_preenabled)

		panic("x2apic enabled by bios. But IR enabling failed");

	else if (cpu_has_x2apic)

		pr_info("Not enabling x2apic,Intr-remapping\n");

#else

	if (!cpu_has_x2apic)

		return;



	if (x2apic_preenabled)

		panic("x2apic enabled prior OS handover,"

		      " enable CONFIG_INTR_REMAP");



	pr_info("Enable CONFIG_INTR_REMAP for enabling intr-remapping "

		" and x2apic\n");

		      " enable CONFIG_X86_X2APIC, CONFIG_INTR_REMAP");

#endif



	return;

}

#endif /* CONFIG_X86_X2APIC */





#ifdef CONFIG_X86_64

/*

drivers/pci/intel-iommu.c

+0 −9
Original line number Diff line number Diff line
@@ -1968,15 +1968,6 @@ static int __init init_dmars(void) 
		}

	}



#ifdef CONFIG_INTR_REMAP

	if (!intr_remapping_enabled) {

		ret = enable_intr_remapping(0);

		if (ret)

			printk(KERN_ERR

			       "IOMMU: enable interrupt remapping failed\n");

	}

#endif



	/*

	 * For each rmrr

	 *   for each dev attached to rmrr

drivers/pci/intr_remapping.c

+14 −14
Original line number Diff line number Diff line
@@ -423,20 +423,6 @@ static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode) 
		      readl, (sts & DMA_GSTS_IRTPS), sts);

	spin_unlock_irqrestore(&iommu->register_lock, flags);



	if (mode == 0) {

		spin_lock_irqsave(&iommu->register_lock, flags);



		/* enable comaptiblity format interrupt pass through */

		cmd = iommu->gcmd | DMA_GCMD_CFI;

		iommu->gcmd |= DMA_GCMD_CFI;

		writel(cmd, iommu->reg + DMAR_GCMD_REG);



		IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,

			      readl, (sts & DMA_GSTS_CFIS), sts);



		spin_unlock_irqrestore(&iommu->register_lock, flags);

	}



	/*

	 * global invalidation of interrupt entry cache before enabling

	 * interrupt-remapping.
@@ -516,6 +502,20 @@ end: 
	spin_unlock_irqrestore(&iommu->register_lock, flags);

}



int __init intr_remapping_supported(void)

{

	struct dmar_drhd_unit *drhd;



	for_each_drhd_unit(drhd) {

		struct intel_iommu *iommu = drhd->iommu;



		if (!ecap_ir_support(iommu->ecap))

			return 0;

	}



	return 1;

}



int __init enable_intr_remapping(int eim)

{

	struct dmar_drhd_unit *drhd;

include/linux/dmar.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ struct irte { 
};

#ifdef CONFIG_INTR_REMAP

extern int intr_remapping_enabled;

extern int intr_remapping_supported(void);

extern int enable_intr_remapping(int);

extern void disable_intr_remapping(void);

extern int reenable_intr_remapping(int);

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