Introduce helper function dmar_walk_resources to walk resource entries
in DMAR table and ACPI buffer object returned by ACPI _DSM method
for IOMMU hot-plug.

Signed-off-by: Jiang Liu <jiang....@linux.intel.com>
---
 drivers/iommu/dmar.c        |  208 +++++++++++++++++++++++--------------------
 drivers/iommu/intel-iommu.c |    4 +-
 include/linux/dmar.h        |   19 ++--
 3 files changed, 122 insertions(+), 109 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 4306885f48b1..4fdf238a2a28 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -44,6 +44,14 @@
 
 #include "irq_remapping.h"
 
+typedef int (*dmar_res_handler_t)(struct acpi_dmar_header *, void *);
+struct dmar_res_callback {
+       dmar_res_handler_t      cb[ACPI_DMAR_TYPE_RESERVED];
+       void                    *arg[ACPI_DMAR_TYPE_RESERVED];
+       bool                    ignore_unhandled;
+       bool                    print_entry;
+};
+
 /*
  * Assumptions:
  * 1) The hotplug framework guarentees that DMAR unit will be hot-added
@@ -333,7 +341,7 @@ static struct notifier_block dmar_pci_bus_nb = {
  * present in the platform
  */
 static int __init
-dmar_parse_one_drhd(struct acpi_dmar_header *header)
+dmar_parse_one_drhd(struct acpi_dmar_header *header, void *arg)
 {
        struct acpi_dmar_hardware_unit *drhd;
        struct dmar_drhd_unit *dmaru;
@@ -364,6 +372,10 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header)
                return ret;
        }
        dmar_register_drhd_unit(dmaru);
+
+       if (arg)
+               (*(int *)arg)++;
+
        return 0;
 }
 
@@ -376,7 +388,8 @@ static void dmar_free_drhd(struct dmar_drhd_unit *dmaru)
        kfree(dmaru);
 }
 
-static int __init dmar_parse_one_andd(struct acpi_dmar_header *header)
+static int __init dmar_parse_one_andd(struct acpi_dmar_header *header,
+                                     void *arg)
 {
        struct acpi_dmar_andd *andd = (void *)header;
 
@@ -398,7 +411,7 @@ static int __init dmar_parse_one_andd(struct 
acpi_dmar_header *header)
 
 #ifdef CONFIG_ACPI_NUMA
 static int __init
-dmar_parse_one_rhsa(struct acpi_dmar_header *header)
+dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
 {
        struct acpi_dmar_rhsa *rhsa;
        struct dmar_drhd_unit *drhd;
@@ -425,6 +438,8 @@ dmar_parse_one_rhsa(struct acpi_dmar_header *header)
 
        return 0;
 }
+#else
+#define        dmar_parse_one_rhsa             dmar_res_noop
 #endif
 
 static void __init
@@ -486,6 +501,52 @@ static int __init dmar_table_detect(void)
        return (ACPI_SUCCESS(status) ? 1 : 0);
 }
 
+static int dmar_walk_resources(struct acpi_dmar_header *start, size_t len,
+                              struct dmar_res_callback *cb)
+{
+       int ret = 0;
+       struct acpi_dmar_header *iter, *next;
+       struct acpi_dmar_header *end = ((void *)start) + len;
+
+       for (iter = start; iter < end && ret == 0; iter = next) {
+               next = (void *)iter + iter->length;
+               if (iter->length == 0) {
+                       /* Avoid looping forever on bad ACPI tables */
+                       pr_debug(FW_BUG "Invalid 0-length structure\n");
+                       break;
+               } else if (next > end) {
+                       /* Avoid passing table end */
+                       pr_warn(FW_BUG "record passes table end\n");
+                       ret = -EINVAL;
+                       break;
+               }
+
+               if (cb->print_entry)
+                       dmar_table_print_dmar_entry(iter);
+
+               if (iter->type >= ACPI_DMAR_TYPE_RESERVED) {
+                       /* continue for forward compatibility */
+                       pr_debug("Unknown DMAR structure type %d\n",
+                                iter->type);
+               } else if (cb->cb[iter->type]) {
+                       ret = cb->cb[iter->type](iter, cb->arg[iter->type]);
+               } else if (!cb->ignore_unhandled) {
+                       pr_warn("No handler for DMAR structure type %d\n",
+                               iter->type);
+                       ret = -EINVAL;
+               }
+       }
+
+       return ret;
+}
+
+static inline int dmar_walk_dmar_table(struct acpi_table_dmar *dmar,
+                                      struct dmar_res_callback *cb)
+{
+       return dmar_walk_resources((struct acpi_dmar_header *)(dmar + 1),
+                                  dmar->header.length - sizeof(*dmar), cb);
+}
+
 /**
  * parse_dmar_table - parses the DMA reporting table
  */
@@ -493,9 +554,18 @@ static int __init
 parse_dmar_table(void)
 {
        struct acpi_table_dmar *dmar;
-       struct acpi_dmar_header *entry_header;
        int ret = 0;
        int drhd_count = 0;
+       struct dmar_res_callback cb = {
+               .print_entry = true,
+               .ignore_unhandled = true,
+               .arg[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &drhd_count,
+               .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_parse_one_drhd,
+               .cb[ACPI_DMAR_TYPE_RESERVED_MEMORY] = &dmar_parse_one_rmrr,
+               .cb[ACPI_DMAR_TYPE_ATSR] = &dmar_parse_one_atsr,
+               .cb[ACPI_DMAR_HARDWARE_AFFINITY] = &dmar_parse_one_rhsa,
+               .cb[ACPI_DMAR_TYPE_ANDD] = &dmar_parse_one_andd,
+       };
 
        /*
         * Do it again, earlier dmar_tbl mapping could be mapped with
@@ -520,50 +590,10 @@ parse_dmar_table(void)
 
        pr_info("Host address width %d\n", dmar->width + 1);
 
-       entry_header = (struct acpi_dmar_header *)(dmar + 1);
-       while (((unsigned long)entry_header) <
-                       (((unsigned long)dmar) + dmar_tbl->length)) {
-               /* Avoid looping forever on bad ACPI tables */
-               if (entry_header->length == 0) {
-                       pr_warn("Invalid 0-length structure\n");
-                       ret = -EINVAL;
-                       break;
-               }
-
-               dmar_table_print_dmar_entry(entry_header);
-
-               switch (entry_header->type) {
-               case ACPI_DMAR_TYPE_HARDWARE_UNIT:
-                       drhd_count++;
-                       ret = dmar_parse_one_drhd(entry_header);
-                       break;
-               case ACPI_DMAR_TYPE_RESERVED_MEMORY:
-                       ret = dmar_parse_one_rmrr(entry_header);
-                       break;
-               case ACPI_DMAR_TYPE_ATSR:
-                       ret = dmar_parse_one_atsr(entry_header);
-                       break;
-               case ACPI_DMAR_HARDWARE_AFFINITY:
-#ifdef CONFIG_ACPI_NUMA
-                       ret = dmar_parse_one_rhsa(entry_header);
-#endif
-                       break;
-               case ACPI_DMAR_TYPE_ANDD:
-                       ret = dmar_parse_one_andd(entry_header);
-                       break;
-               default:
-                       pr_warn("Unknown DMAR structure type %d\n",
-                               entry_header->type);
-                       ret = 0; /* for forward compatibility */
-                       break;
-               }
-               if (ret)
-                       break;
-
-               entry_header = ((void *)entry_header + entry_header->length);
-       }
-       if (drhd_count == 0)
+       ret = dmar_walk_dmar_table(dmar, &cb);
+       if (ret == 0 && drhd_count == 0)
                pr_warn(FW_BUG "No DRHD structure found in DMAR table\n");
+
        return ret;
 }
 
@@ -762,76 +792,60 @@ static void warn_invalid_dmar(u64 addr, const char 
*message)
                dmi_get_system_info(DMI_PRODUCT_VERSION));
 }
 
-static int __init check_zero_address(void)
+static int __ref
+dmar_validate_one_drhd(struct acpi_dmar_header *entry, void *arg)
 {
-       struct acpi_table_dmar *dmar;
-       struct acpi_dmar_header *entry_header;
        struct acpi_dmar_hardware_unit *drhd;
+       void __iomem *addr;
+       u64 cap, ecap;
 
-       dmar = (struct acpi_table_dmar *)dmar_tbl;
-       entry_header = (struct acpi_dmar_header *)(dmar + 1);
-
-       while (((unsigned long)entry_header) <
-                       (((unsigned long)dmar) + dmar_tbl->length)) {
-               /* Avoid looping forever on bad ACPI tables */
-               if (entry_header->length == 0) {
-                       pr_warn("Invalid 0-length structure\n");
-                       return 0;
-               }
-
-               if (entry_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT) {
-                       void __iomem *addr;
-                       u64 cap, ecap;
-
-                       drhd = (void *)entry_header;
-                       if (!drhd->address) {
-                               warn_invalid_dmar(0, "");
-                               goto failed;
-                       }
+       drhd = (void *)entry;
+       if (!drhd->address) {
+               warn_invalid_dmar(0, "");
+               return -EINVAL;
+       }
 
-                       addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
-                       if (!addr ) {
-                               printk("IOMMU: can't validate: %llx\n", 
drhd->address);
-                               goto failed;
-                       }
-                       cap = dmar_readq(addr + DMAR_CAP_REG);
-                       ecap = dmar_readq(addr + DMAR_ECAP_REG);
-                       early_iounmap(addr, VTD_PAGE_SIZE);
-                       if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
-                               warn_invalid_dmar(drhd->address,
-                                                 " returns all ones");
-                               goto failed;
-                       }
-               }
+       addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
+       if (!addr) {
+               pr_warn("IOMMU: can't validate: %llx\n", drhd->address);
+               return -EINVAL;
+       }
+       cap = dmar_readq(addr + DMAR_CAP_REG);
+       ecap = dmar_readq(addr + DMAR_ECAP_REG);
+       early_iounmap(addr, VTD_PAGE_SIZE);
 
-               entry_header = ((void *)entry_header + entry_header->length);
+       if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
+               warn_invalid_dmar(drhd->address, " returns all ones");
+               return -EINVAL;
        }
-       return 1;
 
-failed:
        return 0;
 }
 
 int __init detect_intel_iommu(void)
 {
        int ret;
+       struct dmar_res_callback validate_drhd_cb = {
+               .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_validate_one_drhd,
+               .ignore_unhandled = true,
+       };
 
        down_write(&dmar_global_lock);
        ret = dmar_table_detect();
        if (ret)
-               ret = check_zero_address();
-       {
-               if (ret && !no_iommu && !iommu_detected && !dmar_disabled) {
-                       iommu_detected = 1;
-                       /* Make sure ACS will be enabled */
-                       pci_request_acs();
-               }
+               ret = !dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
+                                           &validate_drhd_cb);
+       if (ret && !no_iommu && !iommu_detected && !dmar_disabled) {
+               iommu_detected = 1;
+               /* Make sure ACS will be enabled */
+               pci_request_acs();
+       }
 
 #ifdef CONFIG_X86
-               if (ret)
-                       x86_init.iommu.iommu_init = intel_iommu_init;
+       if (ret)
+               x86_init.iommu.iommu_init = intel_iommu_init;
 #endif
-       }
+
        early_acpi_os_unmap_memory((void __iomem *)dmar_tbl, dmar_tbl_size);
        dmar_tbl = NULL;
        up_write(&dmar_global_lock);
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 58cc2b75d7ae..d0c37d59e6be 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3658,7 +3658,7 @@ static inline void init_iommu_pm_ops(void) {}
 #endif /* CONFIG_PM */
 
 
-int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header)
+int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
 {
        struct acpi_dmar_reserved_memory *rmrr;
        struct dmar_rmrr_unit *rmrru;
@@ -3684,7 +3684,7 @@ int __init dmar_parse_one_rmrr(struct acpi_dmar_header 
*header)
        return 0;
 }
 
-int __init dmar_parse_one_atsr(struct acpi_dmar_header *hdr)
+int __init dmar_parse_one_atsr(struct acpi_dmar_header *hdr, void *arg)
 {
        struct acpi_dmar_atsr *atsr;
        struct dmar_atsr_unit *atsru;
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 1deece46a0ca..fac8ca34f9a8 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -115,22 +115,21 @@ extern int dmar_remove_dev_scope(struct 
dmar_pci_notify_info *info,
 extern int detect_intel_iommu(void);
 extern int enable_drhd_fault_handling(void);
 
+static inline int dmar_res_noop(struct acpi_dmar_header *hdr, void *arg)
+{
+       return 0;
+}
+
 #ifdef CONFIG_INTEL_IOMMU
 extern int iommu_detected, no_iommu;
 extern int intel_iommu_init(void);
-extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header);
-extern int dmar_parse_one_atsr(struct acpi_dmar_header *header);
+extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg);
+extern int dmar_parse_one_atsr(struct acpi_dmar_header *header, void *arg);
 extern int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info);
 #else /* !CONFIG_INTEL_IOMMU: */
 static inline int intel_iommu_init(void) { return -ENODEV; }
-static inline int dmar_parse_one_rmrr(struct acpi_dmar_header *header)
-{
-       return 0;
-}
-static inline int dmar_parse_one_atsr(struct acpi_dmar_header *header)
-{
-       return 0;
-}
+#define        dmar_parse_one_rmrr             dmar_res_noop
+#define        dmar_parse_one_atsr             dmar_res_noop
 static inline int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info 
*info)
 {
        return 0;
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to