x64, x2apic/intr-remap: Interrupt remapping infrastructure

Interrupt remapping (part of Intel Virtualization Tech for directed I/O)
infrastructure.

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>

1 files changed, 137 insertions, 0 deletions

diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
index a80b87921c68..3d10cdc90314 100644
--- a/drivers/pci/intr_remapping.c
+++ b/drivers/pci/intr_remapping.c
@@ -1,10 +1,147 @@
 #include <linux/dmar.h>
+#include <linux/spinlock.h>
+#include <linux/jiffies.h>
+#include <linux/pci.h>
 #include <asm/io_apic.h>
 #include "intel-iommu.h"
 #include "intr_remapping.h"
 
 static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
 static int ir_ioapic_num;
+int intr_remapping_enabled;
+
+static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
+{
+        u64 addr;
+        u32 cmd, sts;
+        unsigned long flags;
+
+        addr = virt_to_phys((void *)iommu->ir_table->base);
+
+        spin_lock_irqsave(&iommu->register_lock, flags);
+
+        dmar_writeq(iommu->reg + DMAR_IRTA_REG,
+                    (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
+
+        /* Set interrupt-remapping table pointer */
+        cmd = iommu->gcmd | DMA_GCMD_SIRTP;
+        writel(cmd, iommu->reg + DMAR_GCMD_REG);
+
+        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+                      readl, (sts & DMA_GSTS_IRTPS), sts);
+        spin_unlock_irqrestore(&iommu->register_lock, flags);
+
+        /*
+         * global invalidation of interrupt entry cache before enabling
+         * interrupt-remapping.
+         */
+        qi_global_iec(iommu);
+
+        spin_lock_irqsave(&iommu->register_lock, flags);
+
+        /* Enable interrupt-remapping */
+        cmd = iommu->gcmd | DMA_GCMD_IRE;
+        iommu->gcmd |= DMA_GCMD_IRE;
+        writel(cmd, iommu->reg + DMAR_GCMD_REG);
+
+        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+                      readl, (sts & DMA_GSTS_IRES), sts);
+
+        spin_unlock_irqrestore(&iommu->register_lock, flags);
+}
+
+
+static int setup_intr_remapping(struct intel_iommu *iommu, int mode)
+{
+        struct ir_table *ir_table;
+        struct page *pages;
+
+        ir_table = iommu->ir_table = kzalloc(sizeof(struct ir_table),
+                                             GFP_KERNEL);
+
+        if (!iommu->ir_table)
+                return -ENOMEM;
+
+        pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, INTR_REMAP_PAGE_ORDER);
+
+        if (!pages) {
+                printk(KERN_ERR "failed to allocate pages of order %d\n",
+                       INTR_REMAP_PAGE_ORDER);
+                kfree(iommu->ir_table);
+                return -ENOMEM;
+        }
+
+        ir_table->base = page_address(pages);
+
+        iommu_set_intr_remapping(iommu, mode);
+        return 0;
+}
+
+int __init enable_intr_remapping(int eim)
+{
+        struct dmar_drhd_unit *drhd;
+        int setup = 0;
+
+        /*
+         * check for the Interrupt-remapping support
+         */
+        for_each_drhd_unit(drhd) {
+                struct intel_iommu *iommu = drhd->iommu;
+
+                if (!ecap_ir_support(iommu->ecap))
+                        continue;
+
+                if (eim && !ecap_eim_support(iommu->ecap)) {
+                        printk(KERN_INFO "DRHD %Lx: EIM not supported by DRHD, "
+                               " ecap %Lx\n", drhd->reg_base_addr, iommu->ecap);
+                        return -1;
+                }
+        }
+
+        /*
+         * Enable queued invalidation for all the DRHD's.
+         */
+        for_each_drhd_unit(drhd) {
+                int ret;
+                struct intel_iommu *iommu = drhd->iommu;
+                ret = dmar_enable_qi(iommu);
+
+                if (ret) {
+                        printk(KERN_ERR "DRHD %Lx: failed to enable queued, "
+                               " invalidation, ecap %Lx, ret %d\n",
+                               drhd->reg_base_addr, iommu->ecap, ret);
+                        return -1;
+                }
+        }
+
+        /*
+         * Setup Interrupt-remapping for all the DRHD's now.
+         */
+        for_each_drhd_unit(drhd) {
+                struct intel_iommu *iommu = drhd->iommu;
+
+                if (!ecap_ir_support(iommu->ecap))
+                        continue;
+
+                if (setup_intr_remapping(iommu, eim))
+                        goto error;
+
+                setup = 1;
+        }
+
+        if (!setup)
+                goto error;
+
+        intr_remapping_enabled = 1;
+
+        return 0;
+
+error:
+        /*
+         * handle error condition gracefully here!
+         */
+        return -1;
+}
 
 static int ir_parse_ioapic_scope(struct acpi_dmar_header *header,
                                  struct intel_iommu *iommu)