[Xen-devel] [PATCH] arm/acpi: hide watchdog timer in GTDT table for dom0

[Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>]

Either we have to hide the watchdog timer section in GTDT or emulate
watchdog timer block for dom0. Otherwise, system gets panic when
dom0 accesses its MMIO registers. The current XEN doesn't support
virtualization of watchdog timer, so hide the watchdog timer section
for dom0.

Signed-off-by: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
---
 xen/arch/arm/domain_build.c | 41 +++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/acpi.h  |  1 +
 2 files changed, 42 insertions(+)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index e8a400c..611c803 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1668,6 +1668,8 @@ static int acpi_create_xsdt(struct domain *d, struct 
membank tbl_add[])
                            ACPI_SIG_FADT, tbl_add[TBL_FADT].start);
     acpi_xsdt_modify_entry(xsdt->table_offset_entry, entry_count,
                            ACPI_SIG_MADT, tbl_add[TBL_MADT].start);
+    acpi_xsdt_modify_entry(xsdt->table_offset_entry, entry_count,
+                           ACPI_SIG_GTDT, tbl_add[TBL_GTDT].start);
     xsdt->table_offset_entry[entry_count] = tbl_add[TBL_STAO].start;
 
     xsdt->header.length = table_size;
@@ -1718,6 +1720,41 @@ static int acpi_create_stao(struct domain *d, struct 
membank tbl_add[])
     return 0;
 }
 
+static int acpi_create_gtdt(struct domain *d, struct membank tbl_add[])
+{
+    struct acpi_table_header *table = NULL;
+    struct acpi_table_gtdt *gtdt = NULL;
+    u32 table_size = sizeof(struct acpi_table_gtdt);
+    u32 offset = acpi_get_table_offset(tbl_add, TBL_GTDT);
+    acpi_status status;
+    u8 *base_ptr, checksum;
+
+    status = acpi_get_table(ACPI_SIG_GTDT, 0, &table);
+
+    if ( ACPI_FAILURE(status) )
+    {
+        const char *msg = acpi_format_exception(status);
+
+        printk("Failed to get GTDT table, %s\n", msg);
+        return -EINVAL;
+    }
+
+    base_ptr = d->arch.efi_acpi_table + offset;
+    ACPI_MEMCPY(base_ptr, table, sizeof(struct acpi_table_gtdt));
+
+    gtdt = (struct acpi_table_gtdt *)base_ptr;
+    gtdt->header.length = table_size;
+    gtdt->platform_timer_count = 0;
+    gtdt->platform_timer_offset = table_size;
+    checksum = acpi_tb_checksum(ACPI_CAST_PTR(u8, gtdt), table_size);
+    gtdt->header.checksum -= checksum;
+
+    tbl_add[TBL_GTDT].start = d->arch.efi_acpi_gpa + offset;
+    tbl_add[TBL_GTDT].size = table_size;
+
+    return 0;
+}
+
 static int acpi_create_madt(struct domain *d, struct membank tbl_add[])
 {
     struct acpi_table_header *table = NULL;
@@ -1909,6 +1946,10 @@ static int prepare_acpi(struct domain *d, struct 
kernel_info *kinfo)
     if ( rc != 0 )
         return rc;
 
+    rc = acpi_create_gtdt(d, tbl_add);
+    if ( rc != 0 )
+        return rc;
+
     rc = acpi_create_xsdt(d, tbl_add);
     if ( rc != 0 )
         return rc;
diff --git a/xen/include/asm-arm/acpi.h b/xen/include/asm-arm/acpi.h
index 9f954d3..214511c 100644
--- a/xen/include/asm-arm/acpi.h
+++ b/xen/include/asm-arm/acpi.h
@@ -36,6 +36,7 @@ typedef enum {
     TBL_FADT,
     TBL_MADT,
     TBL_STAO,
+    TBL_GTDT,
     TBL_XSDT,
     TBL_RSDP,
     TBL_EFIT,
-- 
Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm Technologies, 
Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux 
Foundation Collaborative Project.


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