x86, dmar: move page fault handling code to dmar.c

Impact: code movement

Move page fault handling code to dmar.c
This will be shared both by DMA-remapping and Intr-remapping code.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 191 insertions, 0 deletions

diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 5f333403c2ea..75d34bf2db50 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -31,6 +31,8 @@
 #include <linux/iova.h>
 #include <linux/intel-iommu.h>
 #include <linux/timer.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
 
 #undef PREFIX
 #define PREFIX "DMAR:"
@@ -812,3 +814,192 @@ int dmar_enable_qi(struct intel_iommu *iommu)
 
         return 0;
 }
+
+/* iommu interrupt handling. Most stuff are MSI-like. */
+
+static const char *fault_reason_strings[] =
+{
+        "Software",
+        "Present bit in root entry is clear",
+        "Present bit in context entry is clear",
+        "Invalid context entry",
+        "Access beyond MGAW",
+        "PTE Write access is not set",
+        "PTE Read access is not set",
+        "Next page table ptr is invalid",
+        "Root table address invalid",
+        "Context table ptr is invalid",
+        "non-zero reserved fields in RTP",
+        "non-zero reserved fields in CTP",
+        "non-zero reserved fields in PTE",
+};
+#define MAX_FAULT_REASON_IDX    (ARRAY_SIZE(fault_reason_strings) - 1)
+
+const char *dmar_get_fault_reason(u8 fault_reason)
+{
+        if (fault_reason > MAX_FAULT_REASON_IDX)
+                return "Unknown";
+        else
+                return fault_reason_strings[fault_reason];
+}
+
+void dmar_msi_unmask(unsigned int irq)
+{
+        struct intel_iommu *iommu = get_irq_data(irq);
+        unsigned long flag;
+
+        /* unmask it */
+        spin_lock_irqsave(&iommu->register_lock, flag);
+        writel(0, iommu->reg + DMAR_FECTL_REG);
+        /* Read a reg to force flush the post write */
+        readl(iommu->reg + DMAR_FECTL_REG);
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+void dmar_msi_mask(unsigned int irq)
+{
+        unsigned long flag;
+        struct intel_iommu *iommu = get_irq_data(irq);
+
+        /* mask it */
+        spin_lock_irqsave(&iommu->register_lock, flag);
+        writel(DMA_FECTL_IM, iommu->reg + DMAR_FECTL_REG);
+        /* Read a reg to force flush the post write */
+        readl(iommu->reg + DMAR_FECTL_REG);
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+void dmar_msi_write(int irq, struct msi_msg *msg)
+{
+        struct intel_iommu *iommu = get_irq_data(irq);
+        unsigned long flag;
+
+        spin_lock_irqsave(&iommu->register_lock, flag);
+        writel(msg->data, iommu->reg + DMAR_FEDATA_REG);
+        writel(msg->address_lo, iommu->reg + DMAR_FEADDR_REG);
+        writel(msg->address_hi, iommu->reg + DMAR_FEUADDR_REG);
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+void dmar_msi_read(int irq, struct msi_msg *msg)
+{
+        struct intel_iommu *iommu = get_irq_data(irq);
+        unsigned long flag;
+
+        spin_lock_irqsave(&iommu->register_lock, flag);
+        msg->data = readl(iommu->reg + DMAR_FEDATA_REG);
+        msg->address_lo = readl(iommu->reg + DMAR_FEADDR_REG);
+        msg->address_hi = readl(iommu->reg + DMAR_FEUADDR_REG);
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
+                u8 fault_reason, u16 source_id, unsigned long long addr)
+{
+        const char *reason;
+
+        reason = dmar_get_fault_reason(fault_reason);
+
+        printk(KERN_ERR
+                "DMAR:[%s] Request device [%02x:%02x.%d] "
+                "fault addr %llx \n"
+                "DMAR:[fault reason %02d] %s\n",
+                (type ? "DMA Read" : "DMA Write"),
+                (source_id >> 8), PCI_SLOT(source_id & 0xFF),
+                PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
+        return 0;
+}
+
+#define PRIMARY_FAULT_REG_LEN (16)
+static irqreturn_t dmar_fault(int irq, void *dev_id)
+{
+        struct intel_iommu *iommu = dev_id;
+        int reg, fault_index;
+        u32 fault_status;
+        unsigned long flag;
+
+        spin_lock_irqsave(&iommu->register_lock, flag);
+        fault_status = readl(iommu->reg + DMAR_FSTS_REG);
+
+        /* TBD: ignore advanced fault log currently */
+        if (!(fault_status & DMA_FSTS_PPF))
+                goto clear_overflow;
+
+        fault_index = dma_fsts_fault_record_index(fault_status);
+        reg = cap_fault_reg_offset(iommu->cap);
+        while (1) {
+                u8 fault_reason;
+                u16 source_id;
+                u64 guest_addr;
+                int type;
+                u32 data;
+
+                /* highest 32 bits */
+                data = readl(iommu->reg + reg +
+                                fault_index * PRIMARY_FAULT_REG_LEN + 12);
+                if (!(data & DMA_FRCD_F))
+                        break;
+
+                fault_reason = dma_frcd_fault_reason(data);
+                type = dma_frcd_type(data);
+
+                data = readl(iommu->reg + reg +
+                                fault_index * PRIMARY_FAULT_REG_LEN + 8);
+                source_id = dma_frcd_source_id(data);
+
+                guest_addr = dmar_readq(iommu->reg + reg +
+                                fault_index * PRIMARY_FAULT_REG_LEN);
+                guest_addr = dma_frcd_page_addr(guest_addr);
+                /* clear the fault */
+                writel(DMA_FRCD_F, iommu->reg + reg +
+                        fault_index * PRIMARY_FAULT_REG_LEN + 12);
+
+                spin_unlock_irqrestore(&iommu->register_lock, flag);
+
+                dmar_fault_do_one(iommu, type, fault_reason,
+                                source_id, guest_addr);
+
+                fault_index++;
+                if (fault_index > cap_num_fault_regs(iommu->cap))
+                        fault_index = 0;
+                spin_lock_irqsave(&iommu->register_lock, flag);
+        }
+clear_overflow:
+        /* clear primary fault overflow */
+        fault_status = readl(iommu->reg + DMAR_FSTS_REG);
+        if (fault_status & DMA_FSTS_PFO)
+                writel(DMA_FSTS_PFO, iommu->reg + DMAR_FSTS_REG);
+
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+        return IRQ_HANDLED;
+}
+
+int dmar_set_interrupt(struct intel_iommu *iommu)
+{
+        int irq, ret;
+
+        irq = create_irq();
+        if (!irq) {
+                printk(KERN_ERR "IOMMU: no free vectors\n");
+                return -EINVAL;
+        }
+
+        set_irq_data(irq, iommu);
+        iommu->irq = irq;
+
+        ret = arch_setup_dmar_msi(irq);
+        if (ret) {
+                set_irq_data(irq, NULL);
+                iommu->irq = 0;
+                destroy_irq(irq);
+                return 0;
+        }
+
+        /* Force fault register is cleared */
+        dmar_fault(irq, iommu);
+
+        ret = request_irq(irq, dmar_fault, 0, iommu->name, iommu);
+        if (ret)
+                printk(KERN_ERR "IOMMU: can't request irq\n");
+        return ret;
+}