[Xen-changelog] [xen stable-4.2] ACPI/ERST: fix table mapping

[patchbot@xxxxxxx]

commit 68dc110d63d24df71a0278812c2a4d99d3206faf
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Jun 4 17:20:38 2014 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Jun 4 17:20:38 2014 +0200

    ACPI/ERST: fix table mapping
    
    acpi_get_table(), when executed before reaching SYS_STATE_active, will
    return a mapping valid only until the next invocation of that funciton.
    Consequently storing the returned pointer for later use is incorrect.
    Copy the logic used in VT-d's DMAR handling.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: fca69b1fc606ece62430076ca4a157e4bed749a8
    master date: 2014-05-26 12:25:01 +0200
---
 xen/drivers/acpi/apei/erst.c |   28 +++++++++++++++++++++++++---
 xen/include/asm-x86/fixmap.h |    2 ++
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/xen/drivers/acpi/apei/erst.c b/xen/drivers/acpi/apei/erst.c
index 71db9fa..8af1263 100644
--- a/xen/drivers/acpi/apei/erst.c
+++ b/xen/drivers/acpi/apei/erst.c
@@ -32,6 +32,7 @@
 #include <xen/string.h>
 #include <xen/types.h>
 #include <xen/spinlock.h>
+#include <xen/mm.h>
 #include <xen/cper.h>
 #include <asm/fixmap.h>
 #include <asm/io.h>
@@ -791,21 +792,42 @@ int __init erst_init(void)
 {
        int rc = 0;
        acpi_status status;
+       acpi_physical_address erst_addr;
+       acpi_native_uint erst_len;
        struct apei_exec_context ctx;
 
        if (acpi_disabled)
                return -ENODEV;
 
-       status = acpi_get_table(ACPI_SIG_ERST, 0,
-                               (struct acpi_table_header **)&erst_tab);
+       status = acpi_get_table_phys(ACPI_SIG_ERST, 0, &erst_addr, &erst_len);
        if (status == AE_NOT_FOUND) {
                printk(KERN_INFO "ERST table was not found\n");
                return -ENODEV;
-       } else if (ACPI_FAILURE(status)) {
+       }
+       if (ACPI_FAILURE(status)) {
                const char *msg = acpi_format_exception(status);
                printk(KERN_WARNING "Failed to get ERST table: %s\n", msg);
                return -EINVAL;
        }
+#ifdef CONFIG_X86_32
+       if (erst_addr + erst_len > (DIRECTMAP_MBYTES << 20)) {
+               unsigned long offset = erst_addr & (PAGE_SIZE - 1);
+               unsigned long mapped_size = PAGE_SIZE - offset;
+
+               set_fixmap(FIX_ERST_LO, erst_addr);
+               if (mapped_size < erst_len)
+                       set_fixmap(FIX_ERST_HI, erst_addr + PAGE_SIZE);
+               erst_tab = (void *)fix_to_virt(FIX_ERST_LO) + offset;
+       } else
+#endif
+       {
+               map_pages_to_xen((unsigned long)__va(erst_addr),
+                                PFN_DOWN(erst_addr),
+                                PFN_UP(erst_addr + erst_len)
+                                - PFN_DOWN(erst_addr),
+                                PAGE_HYPERVISOR);
+               erst_tab = __va(erst_addr);
+       }
 
        rc = erst_check_table(erst_tab);
        if (rc) {
diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h
index 0a7aafa..30c334f 100644
--- a/xen/include/asm-x86/fixmap.h
+++ b/xen/include/asm-x86/fixmap.h
@@ -39,6 +39,8 @@ enum fixed_addresses {
 #define FIX_VGC_BEGIN FIX_PAE_HIGHMEM_END
     FIX_DMAR_ZAP_HI,
     FIX_DMAR_ZAP_LO,
+    FIX_ERST_HI,
+    FIX_ERST_LO,
 #else
     FIX_VGC_END,
     FIX_VGC_BEGIN = FIX_VGC_END
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.2

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