From: Yinghai Lu Subject: dmar: fix using early fixmap mapping for DMAR table parsing References: fate #303948 and fate #303984 Patch-Mainline: queued for .28 Commit-ID: f12c73e7fa7ebf9ad6defee2c4fb2664e743e970 Signed-off-by: Thomas Renninger Very early detection of the DMAR tables will setup fixmap mapping. For parsing these tables later (while enabling dma and/or interrupt remapping), early fixmap mapping shouldn't be used. Fix it by calling table detection routines again, which will call generic apci_get_table() for setting up the correct mapping. Signed-off-by: Yinghai Lu Signed-off-by: Suresh Siddha Signed-off-by: Ingo Molnar --- drivers/pci/dmar.c | 49 ++++++++++++++++++++++++++++--------------------- include/linux/dmar.h | 1 - 2 files changed, 28 insertions(+), 22 deletions(-) Index: linux-2.6.26/drivers/pci/dmar.c =================================================================== --- linux-2.6.26.orig/drivers/pci/dmar.c +++ linux-2.6.26/drivers/pci/dmar.c @@ -289,6 +289,24 @@ dmar_table_print_dmar_entry(struct acpi_ } } +/** + * dmar_table_detect - checks to see if the platform supports DMAR devices + */ +static int __init dmar_table_detect(void) +{ + acpi_status status = AE_OK; + + /* if we could find DMAR table, then there are DMAR devices */ + status = acpi_get_table(ACPI_SIG_DMAR, 0, + (struct acpi_table_header **)&dmar_tbl); + + if (ACPI_SUCCESS(status) && !dmar_tbl) { + printk (KERN_WARNING PREFIX "Unable to map DMAR\n"); + status = AE_NOT_FOUND; + } + + return (ACPI_SUCCESS(status) ? 1 : 0); +} /** * parse_dmar_table - parses the DMA reporting table @@ -300,6 +318,12 @@ parse_dmar_table(void) struct acpi_dmar_header *entry_header; int ret = 0; + /* + * Do it again, earlier dmar_tbl mapping could be mapped with + * fixed map. + */ + dmar_table_detect(); + dmar = (struct acpi_table_dmar *)dmar_tbl; if (!dmar) return -ENODEV; @@ -432,30 +456,11 @@ int __init dmar_table_init(void) return 0; } -/** - * early_dmar_detect - checks to see if the platform supports DMAR devices - */ -int __init early_dmar_detect(void) -{ - acpi_status status = AE_OK; - - /* if we could find DMAR table, then there are DMAR devices */ - status = acpi_get_table(ACPI_SIG_DMAR, 0, - (struct acpi_table_header **)&dmar_tbl); - - if (ACPI_SUCCESS(status) && !dmar_tbl) { - printk (KERN_WARNING PREFIX "Unable to map DMAR\n"); - status = AE_NOT_FOUND; - } - - return (ACPI_SUCCESS(status) ? 1 : 0); -} - void __init detect_intel_iommu(void) { int ret; - ret = early_dmar_detect(); + ret = dmar_table_detect(); #ifdef CONFIG_DMAR { @@ -481,14 +486,16 @@ void __init detect_intel_iommu(void) " x2apic support\n"); dmar_disabled = 1; - return; + goto end; } if (ret && !no_iommu && !iommu_detected && !swiotlb && !dmar_disabled) iommu_detected = 1; } +end: #endif + dmar_tbl = NULL; } Index: linux-2.6.26/include/linux/dmar.h =================================================================== --- linux-2.6.26.orig/include/linux/dmar.h +++ linux-2.6.26/include/linux/dmar.h @@ -45,7 +45,6 @@ extern struct list_head dmar_drhd_units; list_for_each_entry(drhd, &dmar_drhd_units, list) extern int dmar_table_init(void); -extern int early_dmar_detect(void); extern int dmar_dev_scope_init(void); /* Intel IOMMU detection */