x64, x2apic/intr-remap: routines managing Interrupt remapping table entries.

Routines handling the management of interrupt remapping table entries.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 247 insertions, 0 deletions

diff --git a/drivers/pci/intel-iommu.h b/drivers/pci/intel-iommu.h
index a81a74e2bd9e..2142c01e0143 100644
--- a/drivers/pci/intel-iommu.h
+++ b/drivers/pci/intel-iommu.h
@@ -123,6 +123,7 @@ static inline void dmar_writeq(void __iomem *addr, u64 val)
 #define ecap_qis(e)             ((e) & 0x2)
 #define ecap_eim_support(e)     ((e >> 4) & 0x1)
 #define ecap_ir_support(e)      ((e >> 3) & 0x1)
+#define ecap_max_handle_mask(e) ((e >> 20) & 0xf)
 
 
 /* IOTLB_REG */
@@ -255,6 +256,8 @@ struct q_inval {
 #define INTR_REMAP_PAGE_ORDER   8
 #define INTR_REMAP_TABLE_REG_SIZE       0xf
 
+#define INTR_REMAP_TABLE_ENTRIES        65536
+
 struct ir_table {
         struct irte *base;
 };
@@ -300,4 +303,5 @@ extern void free_iommu(struct intel_iommu *iommu);
 extern int dmar_enable_qi(struct intel_iommu *iommu);
 extern void qi_global_iec(struct intel_iommu *iommu);
 
+extern void qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu);
 #endif
diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index 3d10cdc90314..bddb4b19b6c7 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -2,6 +2,7 @@
 #include <linux/spinlock.h>
 #include <linux/jiffies.h>
 #include <linux/pci.h>
+#include <linux/irq.h>
 #include <asm/io_apic.h>
 #include "intel-iommu.h"
 #include "intr_remapping.h"
@@ -10,6 +11,248 @@ static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
 static int ir_ioapic_num;
 int intr_remapping_enabled;
 
+static struct {
+        struct intel_iommu *iommu;
+        u16 irte_index;
+        u16 sub_handle;
+        u8  irte_mask;
+} irq_2_iommu[NR_IRQS];
+
+static DEFINE_SPINLOCK(irq_2_ir_lock);
+
+int irq_remapped(int irq)
+{
+        if (irq > NR_IRQS)
+                return 0;
+
+        if (!irq_2_iommu[irq].iommu)
+                return 0;
+
+        return 1;
+}
+
+int get_irte(int irq, struct irte *entry)
+{
+        int index;
+
+        if (!entry || irq > NR_IRQS)
+                return -1;
+
+        spin_lock(&irq_2_ir_lock);
+        if (!irq_2_iommu[irq].iommu) {
+                spin_unlock(&irq_2_ir_lock);
+                return -1;
+        }
+
+        index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
+        *entry = *(irq_2_iommu[irq].iommu->ir_table->base + index);
+
+        spin_unlock(&irq_2_ir_lock);
+        return 0;
+}
+
+int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
+{
+        struct ir_table *table = iommu->ir_table;
+        u16 index, start_index;
+        unsigned int mask = 0;
+        int i;
+
+        if (!count)
+                return -1;
+
+        /*
+         * start the IRTE search from index 0.
+         */
+        index = start_index = 0;
+
+        if (count > 1) {
+                count = __roundup_pow_of_two(count);
+                mask = ilog2(count);
+        }
+
+        if (mask > ecap_max_handle_mask(iommu->ecap)) {
+                printk(KERN_ERR
+                       "Requested mask %x exceeds the max invalidation handle"
+                       " mask value %Lx\n", mask,
+                       ecap_max_handle_mask(iommu->ecap));
+                return -1;
+        }
+
+        spin_lock(&irq_2_ir_lock);
+        do {
+                for (i = index; i < index + count; i++)
+                        if  (table->base[i].present)
+                                break;
+                /* empty index found */
+                if (i == index + count)
+                        break;
+
+                index = (index + count) % INTR_REMAP_TABLE_ENTRIES;
+
+                if (index == start_index) {
+                        spin_unlock(&irq_2_ir_lock);
+                        printk(KERN_ERR "can't allocate an IRTE\n");
+                        return -1;
+                }
+        } while (1);
+
+        for (i = index; i < index + count; i++)
+                table->base[i].present = 1;
+
+        irq_2_iommu[irq].iommu = iommu;
+        irq_2_iommu[irq].irte_index =  index;
+        irq_2_iommu[irq].sub_handle = 0;
+        irq_2_iommu[irq].irte_mask = mask;
+
+        spin_unlock(&irq_2_ir_lock);
+
+        return index;
+}
+
+static void qi_flush_iec(struct intel_iommu *iommu, int index, int mask)
+{
+        struct qi_desc desc;
+
+        desc.low = QI_IEC_IIDEX(index) | QI_IEC_TYPE | QI_IEC_IM(mask)
+                   | QI_IEC_SELECTIVE;
+        desc.high = 0;
+
+        qi_submit_sync(&desc, iommu);
+}
+
+int map_irq_to_irte_handle(int irq, u16 *sub_handle)
+{
+        int index;
+
+        spin_lock(&irq_2_ir_lock);
+        if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
+                spin_unlock(&irq_2_ir_lock);
+                return -1;
+        }
+
+        *sub_handle = irq_2_iommu[irq].sub_handle;
+        index = irq_2_iommu[irq].irte_index;
+        spin_unlock(&irq_2_ir_lock);
+        return index;
+}
+
+int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
+{
+        spin_lock(&irq_2_ir_lock);
+        if (irq >= NR_IRQS || irq_2_iommu[irq].iommu) {
+                spin_unlock(&irq_2_ir_lock);
+                return -1;
+        }
+
+        irq_2_iommu[irq].iommu = iommu;
+        irq_2_iommu[irq].irte_index = index;
+        irq_2_iommu[irq].sub_handle = subhandle;
+        irq_2_iommu[irq].irte_mask = 0;
+
+        spin_unlock(&irq_2_ir_lock);
+
+        return 0;
+}
+
+int clear_irte_irq(int irq, struct intel_iommu *iommu, u16 index)
+{
+        spin_lock(&irq_2_ir_lock);
+        if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
+                spin_unlock(&irq_2_ir_lock);
+                return -1;
+        }
+
+        irq_2_iommu[irq].iommu = NULL;
+        irq_2_iommu[irq].irte_index = 0;
+        irq_2_iommu[irq].sub_handle = 0;
+        irq_2_iommu[irq].irte_mask = 0;
+
+        spin_unlock(&irq_2_ir_lock);
+
+        return 0;
+}
+
+int modify_irte(int irq, struct irte *irte_modified)
+{
+        int index;
+        struct irte *irte;
+        struct intel_iommu *iommu;
+
+        spin_lock(&irq_2_ir_lock);
+        if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
+                spin_unlock(&irq_2_ir_lock);
+                return -1;
+        }
+
+        iommu = irq_2_iommu[irq].iommu;
+
+        index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
+        irte = &iommu->ir_table->base[index];
+
+        set_64bit((unsigned long *)irte, irte_modified->low | (1 << 1));
+        __iommu_flush_cache(iommu, irte, sizeof(*irte));
+
+        qi_flush_iec(iommu, index, 0);
+
+        spin_unlock(&irq_2_ir_lock);
+        return 0;
+}
+
+int flush_irte(int irq)
+{
+        int index;
+        struct intel_iommu *iommu;
+
+        spin_lock(&irq_2_ir_lock);
+        if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
+                spin_unlock(&irq_2_ir_lock);
+                return -1;
+        }
+
+        iommu = irq_2_iommu[irq].iommu;
+
+        index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
+
+        qi_flush_iec(iommu, index, irq_2_iommu[irq].irte_mask);
+        spin_unlock(&irq_2_ir_lock);
+
+        return 0;
+}
+
+int free_irte(int irq)
+{
+        int index, i;
+        struct irte *irte;
+        struct intel_iommu *iommu;
+
+        spin_lock(&irq_2_ir_lock);
+        if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
+                spin_unlock(&irq_2_ir_lock);
+                return -1;
+        }
+
+        iommu = irq_2_iommu[irq].iommu;
+
+        index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
+        irte = &iommu->ir_table->base[index];
+
+        if (!irq_2_iommu[irq].sub_handle) {
+                for (i = 0; i < (1 << irq_2_iommu[irq].irte_mask); i++)
+                        set_64bit((unsigned long *)irte, 0);
+                qi_flush_iec(iommu, index, irq_2_iommu[irq].irte_mask);
+        }
+
+        irq_2_iommu[irq].iommu = NULL;
+        irq_2_iommu[irq].irte_index = 0;
+        irq_2_iommu[irq].sub_handle = 0;
+        irq_2_iommu[irq].irte_mask = 0;
+
+        spin_unlock(&irq_2_ir_lock);
+
+        return 0;
+}
+
 static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
 {
         u64 addr;