From: Jan Beulich <jbeulich@suse.com>
Date: Wed, 4 Jun 2014 15:20:38 +0000 (+0200)
Subject: ACPI/ERST: fix table mapping
X-Git-Tag: 4.2.5-rc1~1
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=68dc110d63d24df71a0278812c2a4d99d3206faf;p=xen.git

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@suse.com>
master commit: fca69b1fc606ece62430076ca4a157e4bed749a8
master date: 2014-05-26 12:25:01 +0200
---

diff --git a/xen/drivers/acpi/apei/erst.c b/xen/drivers/acpi/apei/erst.c
index 71db9fa5a4..8af12639fa 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 0a7aafa830..30c334f1ad 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