[PATCH 3/6] nvdimm acpi: introduce patched dsm memory

[Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>]

The dsm memory is used to save the input parameters and store
the dsm result which is filled by QEMU.

The address of dsm memory is decided by bios and patched into
int64 object returned by "MEMA" method

Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
---
 hw/acpi/aml-build.c         | 12 ++++++++++++
 hw/acpi/nvdimm.c            | 24 ++++++++++++++++++++++--
 include/hw/acpi/aml-build.h |  1 +
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index 78e1290..83eadb3 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -394,6 +394,18 @@ Aml *aml_int(const uint64_t val)
 }
 
 /*
+ * ACPI 1.0b: 16.2.3 Data Objects Encoding:
+ * encode: QWordConst
+ */
+Aml *aml_int64(const uint64_t val)
+{
+    Aml *var = aml_alloc();
+    build_append_byte(var->buf, 0x0E); /* QWordPrefix */
+    build_append_int_noprefix(var->buf, val, 8);
+    return var;
+}
+
+/*
  * helper to construct NameString, which returns Aml object
  * for using with aml_append or other aml_* terms
  */
diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c
index bc7cd8f..a72104c 100644
--- a/hw/acpi/nvdimm.c
+++ b/hw/acpi/nvdimm.c
@@ -28,6 +28,7 @@
 
 #include "hw/acpi/acpi.h"
 #include "hw/acpi/aml-build.h"
+#include "hw/acpi/bios-linker-loader.h"
 #include "hw/nvram/fw_cfg.h"
 #include "hw/mem/nvdimm.h"
 
@@ -402,7 +403,8 @@ void nvdimm_init_acpi_state(AcpiNVDIMMState *state, MemoryRegion *io,
                     state->dsm_mem->len);
 }
 
-#define NVDIMM_COMMON_DSM      "NCAL"
+#define NVDIMM_GET_DSM_MEM      "MEMA"
+#define NVDIMM_COMMON_DSM       "NCAL"
 
 static void nvdimm_build_common_dsm(Aml *dev)
 {
@@ -468,7 +470,8 @@ static void nvdimm_build_ssdt(GSList *device_list, GArray *table_offsets,
                               GArray *table_data, GArray *linker,
                               uint8_t revision)
 {
-    Aml *ssdt, *sb_scope, *dev;
+    Aml *ssdt, *sb_scope, *dev, *method;
+    int offset;
 
     acpi_add_table(table_offsets, table_data);
 
@@ -499,9 +502,26 @@ static void nvdimm_build_ssdt(GSList *device_list, GArray *table_offsets,
 
     aml_append(sb_scope, dev);
 
+    /*
+     * leave it at the end of ssdt so that we can conveniently get the
+     * offset of int64 object returned by the function which will be
+     * patched with the real address of the dsm memory by BIOS.
+     */
+    method = aml_method(NVDIMM_GET_DSM_MEM, 0, AML_NOTSERIALIZED);
+    aml_append(method, aml_return(aml_int64(0x0)));
+    aml_append(sb_scope, method);
     aml_append(ssdt, sb_scope);
     /* copy AML table into ACPI tables blob and patch header there */
     g_array_append_vals(table_data, ssdt->buf->data, ssdt->buf->len);
+
+    offset = table_data->len - 8;
+
+    bios_linker_loader_alloc(linker, NVDIMM_DSM_MEM_FILE, TARGET_PAGE_SIZE,
+                             false /* high memory */);
+    bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
+                                   NVDIMM_DSM_MEM_FILE, table_data,
+                                   table_data->data + offset,
+                                   sizeof(uint64_t));
     build_header(linker, table_data,
         (void *)(table_data->data + table_data->len - ssdt->buf->len),
         "SSDT", ssdt->buf->len, revision, "NVDIMM");
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index ef44d02..b4726a4 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -246,6 +246,7 @@ Aml *aml_name(const char *name_format, ...) GCC_FMT_ATTR(1, 2);
 Aml *aml_name_decl(const char *name, Aml *val);
 Aml *aml_return(Aml *val);
 Aml *aml_int(const uint64_t val);
+Aml *aml_int64(const uint64_t val);
 Aml *aml_arg(int pos);
 Aml *aml_to_integer(Aml *arg);
 Aml *aml_to_hexstring(Aml *src, Aml *dst);
-- 
1.8.3.1

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