From: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>

Add logic to decode AMD IOMMU event flag based on information from AMD IOMMU 
specification.
This should simplify debugging IOMMU errors.  Also, dump DTE information in 
additional cases.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
Changelog:
V2:
        * Fix printing format to reduce noise
        * Use string table instead of switch/case
        * Use pr_cont instead of printk

 drivers/iommu/amd_iommu.c |  170 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 136 insertions(+), 34 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index b287ca3..3362678 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -601,6 +601,93 @@ static void amd_iommu_stats_init(void)
  *
  ****************************************************************************/
 
+struct _event_log_flags {
+       u32     gn:1, /* 16 */
+               nx:1, /* 17 */
+               us:1, /* 18 */
+                i:1, /* 19 */
+               pr:1, /* 20 */
+               rw:1, /* 21 */
+               pe:1, /* 22 */
+               rz:1, /* 23 */
+               tr:1, /* 24 */
+               type:3, /* [27:25] */
+               _reserved_:20; /* Reserved */
+};
+
+static const char * const _type_field_encodings[] = {
+       /* 00 */"Reserved",
+       /* 01 */"Master Abort",
+       /* 10 */"Target Abort",
+       /* 11 */"Data Error",
+};
+
+static const char * const _invalid_transaction_desc[] = {
+       /* 000 */"Read request or non-posted write in the interrupt "
+                "addres range",
+       /* 001 */"Pretranslated transaction received from an I/O device "
+                "that has I=0 or V=0 in DTE",
+       /* 010 */"Port I/O space transaction received from an I/O device "
+                "that has IoCtl=00b in DTE",
+       /* 011 */"Posted write to invalid address range",
+       /* 100 */"Invalid read request or non-posted write",
+       /* 101 */"Posted write to the interrupt/EOI range from an I/O "
+                "device that has IntCtl=00b in DTE",
+       /* 110 */"Posted write to a reserved interrupt address range",
+       /* 111 */"Invalid transaction to the system management address range",
+};
+
+static const char * const _invalid_translation_desc[] = {
+       /* 000 */"Translation request received from an I/O device that has "
+                "I=0, or has V=0, or has V=1 and TV=0 in DTE",
+       /* 001 */"Translation request in invalid address range",
+       /* 010 */"Invalid translation request",
+       /* 011 */"Reserved",
+       /* 100 */"Reserved",
+       /* 101 */"Reserved",
+       /* 110 */"Reserved",
+       /* 111 */"Reserved",
+};
+
+static void dump_flags(int flags, int ev_type)
+{
+       struct _event_log_flags *p = (struct _event_log_flags *) &flags;
+       u32 err_type = p->type;
+
+       pr_err("AMD-Vi: Flags details: %s, NX:%u, %s, %s, %s, %s, %s, %s, %s\n",
+               (p->gn ? "Use guest address" : "Use nested address"),
+               (p->nx),
+               (p->us ? "User privileges" : "Supervisor privileges"),
+               (p->i ? "Interrupt request" : "memory request"),
+               (p->pr ? "Page present or Interrupt remapped" :
+                       "Page not present or Interrupt blocked"),
+               (p->rw ? "Write transaction" : "Read transaction"),
+               (p->pe ? "Does not have permission" : "Has permission"),
+               (p->rz ? "Reserv bit not zero" : "Illegal level encoding"),
+               (p->tr ? "Translation request" : "Transaction request"));
+
+       pr_err("AMD-Vi: Type of error: (0x%x) ", err_type);
+       if ((ev_type == EVENT_TYPE_DEV_TAB_ERR)  ||
+           (ev_type == EVENT_TYPE_PAGE_TAB_ERR) ||
+           (ev_type == EVENT_TYPE_CMD_HARD_ERR)) {
+               if (err_type < ARRAY_SIZE(_type_field_encodings)) {
+                       pr_cont("%s\n",
+                               _type_field_encodings[err_type]);
+               }
+       } else if (ev_type == EVENT_TYPE_INV_DEV_REQ) {
+               if (p->tr == 0) {
+                       if (err_type < ARRAY_SIZE(_invalid_translation_desc))
+                               pr_cont("%s\n",
+                                       _invalid_translation_desc[err_type]);
+               } else {
+                       if (err_type < ARRAY_SIZE(_invalid_transaction_desc))
+                               pr_cont("%s\n",
+                                       _invalid_transaction_desc[err_type]);
+               }
+       }
+       pr_err("AMD-Vi: (Note: Please refer to AMD IOMMU specification for 
details.)\n");
+}
+
 static void dump_dte_entry(u16 devid)
 {
        int i;
@@ -619,81 +706,95 @@ static void dump_command(unsigned long phys_addr)
                pr_err("AMD-Vi: CMD[%d]: %08x\n", i, cmd->data[i]);
 }
 
-static void iommu_print_event(struct amd_iommu *iommu, void *__evt)
+void amd_iommu_print_event(int type, int devid, int domid,
+                             int flags, u64 address)
 {
-       int type, devid, domid, flags;
-       volatile u32 *event = __evt;
-       int count = 0;
-       u64 address;
-
-retry:
-       type    = (event[1] >> EVENT_TYPE_SHIFT)  & EVENT_TYPE_MASK;
-       devid   = (event[0] >> EVENT_DEVID_SHIFT) & EVENT_DEVID_MASK;
-       domid   = (event[1] >> EVENT_DOMID_SHIFT) & EVENT_DOMID_MASK;
-       flags   = (event[1] >> EVENT_FLAGS_SHIFT) & EVENT_FLAGS_MASK;
-       address = (u64)(((u64)event[3]) << 32) | event[2];
-
-       if (type == 0) {
-               /* Did we hit the erratum? */
-               if (++count == LOOP_TIMEOUT) {
-                       pr_err("AMD-Vi: No event written to event log\n");
-                       return;
-               }
-               udelay(1);
-               goto retry;
-       }
-
-       printk(KERN_ERR "AMD-Vi: Event logged [");
+       pr_err("AMD-Vi: Event logged [");
 
        switch (type) {
        case EVENT_TYPE_ILL_DEV:
-               printk("ILLEGAL_DEV_TABLE_ENTRY device=%02x:%02x.%x "
+               pr_cont("ILLEGAL_DEV_TABLE_ENTRY device=%02x:%02x.%x "
                       "address=0x%016llx flags=0x%04x]\n",
                       PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
                       address, flags);
+               dump_flags(flags, type);
                dump_dte_entry(devid);
                break;
        case EVENT_TYPE_IO_FAULT:
-               printk("IO_PAGE_FAULT device=%02x:%02x.%x "
+               pr_cont("IO_PAGE_FAULT device=%02x:%02x.%x "
                       "domain=0x%04x address=0x%016llx flags=0x%04x]\n",
                       PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
                       domid, address, flags);
+               dump_flags(flags, type);
+               dump_dte_entry(devid);
                break;
        case EVENT_TYPE_DEV_TAB_ERR:
-               printk("DEV_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
+               pr_cont("DEV_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
                       "address=0x%016llx flags=0x%04x]\n",
                       PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
                       address, flags);
+               dump_flags(flags, type);
                break;
        case EVENT_TYPE_PAGE_TAB_ERR:
-               printk("PAGE_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
+               pr_cont("PAGE_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
                       "domain=0x%04x address=0x%016llx flags=0x%04x]\n",
                       PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
                       domid, address, flags);
+               dump_flags(flags, type);
                break;
        case EVENT_TYPE_ILL_CMD:
-               printk("ILLEGAL_COMMAND_ERROR address=0x%016llx]\n", address);
+               pr_cont("ILLEGAL_COMMAND_ERROR address=0x%016llx]\n", address);
                dump_command(address);
                break;
        case EVENT_TYPE_CMD_HARD_ERR:
-               printk("COMMAND_HARDWARE_ERROR address=0x%016llx "
+               pr_cont("COMMAND_HARDWARE_ERROR address=0x%016llx "
                       "flags=0x%04x]\n", address, flags);
+               dump_flags(flags, type);
                break;
        case EVENT_TYPE_IOTLB_INV_TO:
-               printk("IOTLB_INV_TIMEOUT device=%02x:%02x.%x "
+               pr_cont("IOTLB_INV_TIMEOUT device=%02x:%02x.%x "
                       "address=0x%016llx]\n",
                       PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
                       address);
                break;
        case EVENT_TYPE_INV_DEV_REQ:
-               printk("INVALID_DEVICE_REQUEST device=%02x:%02x.%x "
+               pr_cont("INVALID_DEVICE_REQUEST device=%02x:%02x.%x "
                       "address=0x%016llx flags=0x%04x]\n",
                       PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
                       address, flags);
+               dump_flags(flags, type);
+               dump_dte_entry(devid);
                break;
        default:
-               printk(KERN_ERR "UNKNOWN type=0x%02x]\n", type);
+               pr_cont("UNKNOWN type=0x%02x]\n", type);
        }
+}
+
+static void iommu_handle_event(struct amd_iommu *iommu, void *__evt)
+{
+       int type, devid, domid, flags;
+       u32 *event = __evt;
+       int count = 0;
+       u64 address;
+
+retry:
+       type    = (event[1] >> EVENT_TYPE_SHIFT)  & EVENT_TYPE_MASK;
+       devid   = (event[0] >> EVENT_DEVID_SHIFT) & EVENT_DEVID_MASK;
+       domid   = (event[1] >> EVENT_DOMID_SHIFT) & EVENT_DOMID_MASK;
+       flags   = (event[1] >> EVENT_FLAGS_SHIFT) & EVENT_FLAGS_MASK;
+       address = (u64)(((u64)event[3]) << 32) | event[2];
+
+       if (type == 0) {
+               /* Did we hit the erratum? */
+               if (++count == LOOP_TIMEOUT) {
+                       pr_err("AMD-Vi: No event written to event log\n");
+                       return;
+               }
+               udelay(1);
+               goto retry;
+       }
+
+       amd_iommu_print_event(type, devid, domid, flags, address);
 
        memset(__evt, 0, 4 * sizeof(u32));
 }
@@ -709,7 +810,7 @@ static void iommu_poll_events(struct amd_iommu *iommu)
        tail = readl(iommu->mmio_base + MMIO_EVT_TAIL_OFFSET);
 
        while (head != tail) {
-               iommu_print_event(iommu, iommu->evt_buf + head);
+               iommu_handle_event(iommu, iommu->evt_buf + head);
                head = (head + EVENT_ENTRY_SIZE) % iommu->evt_buf_size;
        }
 
@@ -3268,6 +3369,7 @@ static int __init alloc_passthrough_domain(void)
 
        return 0;
 }
+
 static int amd_iommu_domain_init(struct iommu_domain *dom)
 {
        struct protection_domain *domain;
-- 
1.7.10.4


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