Subject: [RFC PATCH] Avoid all Linux /dev/mem accesses when -c is specified
From: Roy Franz <roy.franz@linaro.org>
Date: 05/15/2015 12:50 PM
To: linaro-uefi@lists.linaro.org, linaro-acpi@lists.linaro.org, graeme.gregory@linaro.org, al.stone@linaro.org
CC: Roy Franz <roy.franz@linaro.org>

Don't try to read the RSDP structure or RSDT/XSDT tables
from memory with the -c option.  These are now provided
as files in /sysfs, and this allows acpidump to function
when /dev/mem is not available, which will be the case
for Aarch64 servers.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
---
 source/os_specific/service_layers/oslinuxtbl.c | 87 +++++++++++++-------------
 1 file changed, 43 insertions(+), 44 deletions(-)

Index: acpica-unix/source/os_specific/service_layers/oslinuxtbl.c
===================================================================
--- acpica-unix.orig/source/os_specific/service_layers/oslinuxtbl.c
+++ acpica-unix/source/os_specific/service_layers/oslinuxtbl.c
@@ -686,70 +686,69 @@ OslTableInitialize (
         return (AE_OK);
     }
 
+    if (!Gbl_DumpCustomizedTables)
+    {
     /* Get RSDP from memory */
 
-    Status = OslLoadRsdp ();
-    if (ACPI_FAILURE (Status))
-    {
-        return (Status);
-    }
+        Status = OslLoadRsdp ();
+        if (ACPI_FAILURE (Status))
+        {
+            return (Status);
+        }
 
-    /* Get XSDT from memory */
+        /* Get XSDT from memory */
 
-    if (Gbl_Rsdp.Revision && !Gbl_DoNotDumpXsdt)
-    {
-        if (Gbl_Xsdt)
+        if (Gbl_Rsdp.Revision && !Gbl_DoNotDumpXsdt)
         {
-            free (Gbl_Xsdt);
-            Gbl_Xsdt = NULL;
+            if (Gbl_Xsdt)
+            {
+                free (Gbl_Xsdt);
+                Gbl_Xsdt = NULL;
+            }
+
+            Gbl_Revision = 2;
+            Status = OslGetBiosTable (ACPI_SIG_XSDT, 0,
+                ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Xsdt), &Address);
+            if (ACPI_FAILURE (Status))
+            {
+                return (Status);
+            }
         }
 
-        Gbl_Revision = 2;
-        Status = OslGetBiosTable (ACPI_SIG_XSDT, 0,
-            ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Xsdt), &Address);
-        if (ACPI_FAILURE (Status))
+        /* Get RSDT from memory */
+
+        if (Gbl_Rsdp.RsdtPhysicalAddress)
         {
-            return (Status);
+            if (Gbl_Rsdt)
+            {
+                free (Gbl_Rsdt);
+                Gbl_Rsdt = NULL;
+            }
+
+            Status = OslGetBiosTable (ACPI_SIG_RSDT, 0,
+                ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Rsdt), &Address);
+            if (ACPI_FAILURE (Status))
+            {
+                return (Status);
+            }
         }
-    }
 
-    /* Get RSDT from memory */
+        /* Get FADT from memory */
 
-    if (Gbl_Rsdp.RsdtPhysicalAddress)
-    {
-        if (Gbl_Rsdt)
+        if (Gbl_Fadt)
         {
-            free (Gbl_Rsdt);
-            Gbl_Rsdt = NULL;
+            free (Gbl_Fadt);
+            Gbl_Fadt = NULL;
         }
 
-        Status = OslGetBiosTable (ACPI_SIG_RSDT, 0,
-            ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Rsdt), &Address);
+        Status = OslGetBiosTable (ACPI_SIG_FADT, 0,
+            ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Fadt), &Gbl_FadtAddress);
         if (ACPI_FAILURE (Status))
         {
             return (Status);
         }
-    }
-
-    /* Get FADT from memory */
-
-    if (Gbl_Fadt)
-    {
-        free (Gbl_Fadt);
-        Gbl_Fadt = NULL;
-    }
 
-    Status = OslGetBiosTable (ACPI_SIG_FADT, 0,
-        ACPI_CAST_PTR (ACPI_TABLE_HEADER *, &Gbl_Fadt), &Gbl_FadtAddress);
-    if (ACPI_FAILURE (Status))
-    {
-        return (Status);
-    }
-
-    if (!Gbl_DumpCustomizedTables)
-    {
         /* Add mandatory tables to global table list first */
-
         Status = OslAddTableToList (ACPI_RSDP_NAME, 0);
         if (ACPI_FAILURE (Status))
         {