2009-04-08 10:46:20

by Weidong Han

[permalink] [raw]
Subject: [PATCH 1/2] intel-iommu: enable interrupt remapping early

Interrupt remapping is decoupled from x2apic. When x2apic is not
enabled, interrupt remapping will be enabled in init_dmars where is
late to remap io-apic interrupts, i.e. most of interrupts are in
compatibility mode, not remappable mode.

This patch early enables interrupt remapping before io-apic and x2apic
setup, then there are no compatibility interrupts when interrup remapping
is enabled. Thus it needn't to set compatibility interrupt bit.


Signed-off-by: Weidong Han <[email protected]>
---
arch/x86/include/asm/apic.h | 9 +++
arch/x86/kernel/apic/apic.c | 157 ++++++++++++++++++++++--------------------
arch/x86/kernel/smpboot.c | 7 ++
drivers/pci/intel-iommu.c | 9 ---
drivers/pci/intr_remapping.c | 14 ----
5 files changed, 99 insertions(+), 97 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 42f2f83..e60c6fa 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -202,6 +202,15 @@ static inline int x2apic_enabled(void)

#endif

+#ifdef CONFIG_INTR_REMAP
+extern void early_enable_intr_remapping(void);
+#else
+static inline void early_enable_intr_remapping(void)
+{
+ return;
+}
+#endif
+
extern int get_physical_broadcast(void);

#ifdef CONFIG_X86_X2APIC
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 098ec84..30c857c 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1276,6 +1276,71 @@ void __cpuinit end_local_APIC_setup(void)
apic_pm_activate();
}

+#ifdef CONFIG_INTR_REMAP
+void __init early_enable_intr_remapping(void)
+{
+ int ret;
+ unsigned long flags;
+ int eim;
+ int preenabled = 0;
+ struct IO_APIC_route_entry **ioapic_entries = NULL;
+
+ ret = dmar_table_init();
+ if (ret) {
+ pr_info("dmar_table_init() failed with %d:\n", ret);
+ return;
+ }
+
+ ioapic_entries = alloc_ioapic_entries();
+ if (!ioapic_entries) {
+ pr_info("Allocate ioapic_entries failed: %d\n", ret);
+ return;
+ }
+
+ ret = save_IO_APIC_setup(ioapic_entries);
+ if (ret) {
+ pr_info("Saving IO-APIC state failed: %d\n", ret);
+ goto end;
+ }
+
+ local_irq_save(flags);
+ mask_IO_APIC_setup(ioapic_entries);
+ mask_8259A();
+
+#ifdef CONFIG_X86_X2APIC
+ if (cpu_has_x2apic && !disable_x2apic && !skip_ioapic_setup)
+ eim = EIM_32BIT_APIC_ID;
+ else
+ eim = EIM_8BIT_APIC_ID;
+ ret = enable_intr_remapping(eim);
+ preenabled = x2apic_preenabled;
+#else
+ eim = EIM_8BIT_APIC_ID;
+ ret = enable_intr_remapping(eim);
+#endif
+ if (ret)
+ /*
+ * IR enabling failed
+ */
+ restore_IO_APIC_setup(ioapic_entries);
+ else
+ reinit_intr_remapped_IO_APIC(preenabled, ioapic_entries);
+
+ unmask_8259A();
+ local_irq_restore(flags);
+end:
+ if (!ret)
+ pr_info("Enabled Interrupt-remapping\n");
+ else
+ pr_err("Failed to enable Interrupt-remapping\n");
+
+ if (ioapic_entries)
+ free_ioapic_entries(ioapic_entries);
+
+ return;
+}
+#endif
+
#ifdef CONFIG_X86_X2APIC
void check_x2apic(void)
{
@@ -1301,17 +1366,13 @@ void enable_x2apic(void)

void __init enable_IR_x2apic(void)
{
-#ifdef CONFIG_INTR_REMAP
- int ret;
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");
+ pr_info("Skipped enabling x2apic because of nox2apic\n");
return;
}

@@ -1319,87 +1380,28 @@ void __init enable_IR_x2apic(void)
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");
+ pr_info("Skipped enabling x2apic because of "
+ "skipping io-apic setup\n");
return;
}

- ret = dmar_table_init();
- if (ret) {
- pr_info("dmar_table_init() failed with %d:\n", ret);
+ if (!intr_remapping_enabled && x2apic_preenabled)
+ panic("x2apic enabled by bios. But interrup-remapping "
+ "is not enabled successfully");

- if (x2apic_preenabled)
- panic("x2apic enabled by bios. But IR enabling failed");
- else
- pr_info("Not enabling x2apic,Intr-remapping\n");
+ if (!intr_remapping_enabled) {
+ pr_err("Enable CONFIG_INTR_REMAP and CONFIG_X86_X2APIC for "
+ "enabling interrupt-remapping and x2apic\n");
return;
}

- ioapic_entries = alloc_ioapic_entries();
- if (!ioapic_entries) {
- pr_info("Allocate ioapic_entries failed: %d\n", ret);
- goto end;
- }
-
- ret = save_IO_APIC_setup(ioapic_entries);
- if (ret) {
- pr_info("Saving IO-APIC state failed: %d\n", ret);
- goto end;
- }
-
- local_irq_save(flags);
- mask_IO_APIC_setup(ioapic_entries);
- mask_8259A();
-
- 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");
- }
-
- if (ret)
- goto end_restore;
-
if (!x2apic) {
+ local_irq_save(flags);
x2apic = 1;
enable_x2apic();
+ local_irq_restore(flags);
}

-end_restore:
- if (ret)
- /*
- * IR enabling failed
- */
- restore_IO_APIC_setup(ioapic_entries);
- else
- reinit_intr_remapped_IO_APIC(x2apic_preenabled, ioapic_entries);
-
- unmask_8259A();
- 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);
-#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");
-#endif
-
return;
}
#endif /* CONFIG_X86_X2APIC */
@@ -1595,6 +1597,13 @@ int __init APIC_init_uniprocessor(void)
}
#endif

+ /*
+ * Enable interrupt remapping before enable apic and x2apic,
+ * then all interrupts will be set to remappable format during
+ * interrupt setup
+ */
+ early_enable_intr_remapping();
+
enable_IR_x2apic();
#ifdef CONFIG_X86_64
default_setup_apic_routing();
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 58d24ef..b3c83b6 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1062,6 +1062,13 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
}
set_cpu_sibling_map(0);

+ /*
+ * Enable interrupt remapping before enable apic and x2apic,
+ * then all interrupts will be set to remappable format during
+ * interrupt setup
+ */
+ early_enable_intr_remapping();
+
enable_IR_x2apic();
#ifdef CONFIG_X86_64
default_setup_apic_routing();
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index dcda521..eaa1c99 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -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
diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index f5e0ea7..4af5fb4 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -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.
--
1.6.0.4