Static Allocation refers to system or sub-system(domains) for which memory
areas are pre-defined by configuration using physical address ranges.
Those pre-defined memory, -- Static Memory, as parts of RAM reserved in the
beginning, shall never go to heap allocator or boot allocator for any use.
Memory can be statically allocated to a domain using the property "xen,static-
mem" defined in the domain configuration. The number of cells for the address
and the size must be defined using respectively the properties
"#xen,static-mem-address-cells" and "#xen,static-mem-size-cells".
This patch introduces this new `xen,static-mem` feature, and also documents
and parses this new attribute at boot time.
This patch also introduces a new field "bool xen_domain" in "struct membank"
to tell the difference of one memory bank is reserved as the whole
hardware resource, or bind to one specific xen domain node, through
"xen,static-mem"
Signed-off-by: Penny Zheng <penny.zh...@arm.com>
---
v5 changes:
- check the node using the Xen domain binding whether contains the property
"xen,static-mem", not the property itself
- add "rc = ..." to get the error propagated
- introduce new field "bool xen_domain", then static memory shall be also stored
as reserved memory(bootinfo.reserved_mem), but being bind to one
specific Xen domain node.
- doc refinement
---
docs/misc/arm/device-tree/booting.txt | 33 ++++++++++++++++++++++++
xen/arch/arm/bootfdt.c | 36 +++++++++++++++++++++++++--
xen/include/asm-arm/setup.h | 1 +
3 files changed, 68 insertions(+), 2 deletions(-)
diff --git a/docs/misc/arm/device-tree/booting.txt
b/docs/misc/arm/device-tree/booting.txt
index 5243bc7fd3..95b20ddc3a 100644
--- a/docs/misc/arm/device-tree/booting.txt
+++ b/docs/misc/arm/device-tree/booting.txt
@@ -268,3 +268,36 @@ The DTB fragment is loaded at 0xc000000 in the example
above. It should
follow the convention explained in docs/misc/arm/passthrough.txt. The
DTB fragment will be added to the guest device tree, so that the guest
kernel will be able to discover the device.
+
+
+Static Allocation
+=============
+
+Static Allocation refers to system or sub-system(domains) for which memory
+areas are pre-defined by configuration using physical address ranges.
+
+Memory can be statically allocated to a domain using the property "xen,static-
+mem" defined in the domain configuration. The number of cells for the address
+and the size must be defined using respectively the properties
+"#xen,static-mem-address-cells" and "#xen,static-mem-size-cells".
+
+Below is an example on how to specify the static memory region in the
+device-tree:
+
+ / {
+ chosen {
+ domU1 {
+ compatible = "xen,domain";
+ #address-cells = <0x2>;
+ #size-cells = <0x2>;
+ cpus = <2>;
+ #xen,static-mem-address-cells = <0x1>;
+ #xen,static-mem-size-cells = <0x1>;
+ xen,static-mem = <0x30000000 0x20000000>;
+ ...
+ };
+ };
+ };
+
+This will reserve a 512MB region starting at the host physical address
+0x30000000 to be exclusively used by DomU1
diff --git a/xen/arch/arm/bootfdt.c b/xen/arch/arm/bootfdt.c
index 8c81be3379..00f34eec58 100644
--- a/xen/arch/arm/bootfdt.c
+++ b/xen/arch/arm/bootfdt.c
@@ -66,7 +66,7 @@ void __init device_tree_get_reg(const __be32 **cell, u32
address_cells,
static int __init device_tree_get_meminfo(const void *fdt, int node,
const char *prop_name,
u32 address_cells, u32 size_cells,
- void *data)
+ void *data, bool xen_domain)
{
const struct fdt_property *prop;
unsigned int i, banks;
@@ -90,6 +90,7 @@ static int __init device_tree_get_meminfo(const void *fdt,
int node,
continue;
mem->bank[mem->nr_banks].start = start;
mem->bank[mem->nr_banks].size = size;
+ mem->bank[mem->nr_banks].xen_domain = xen_domain;
mem->nr_banks++;
}
@@ -184,7 +185,8 @@ static int __init process_memory_node(const void *fdt, int
node,
return -EINVAL;
}
- return device_tree_get_meminfo(fdt, node, "reg", address_cells,
size_cells, data);
+ return device_tree_get_meminfo(fdt, node, "reg", address_cells, size_cells,
+ data, false);
}
static int __init process_reserved_memory_node(const void *fdt, int node,
@@ -338,6 +340,34 @@ static void __init process_chosen_node(const void *fdt,
int node,
add_boot_module(BOOTMOD_RAMDISK, start, end-start, false);
}
+static int __init process_domain_node(const void *fdt, int node,
+ const char *name,
+ u32 address_cells, u32 size_cells)
+{
+ const struct fdt_property *prop;
+
+ printk("Checking for \"xen,static-mem\" in domain node\n");
+
+ prop = fdt_get_property(fdt, node, "xen,static-mem", NULL);
+ if ( !prop )
+ /* No "xen,static-mem" present. */
+ return 0;
+
+ address_cells = device_tree_get_u32(fdt, node,
+ "#xen,static-mem-address-cells", 0);
+ size_cells = device_tree_get_u32(fdt, node,
+ "#xen,static-mem-size-cells", 0);
+ if ( address_cells < 1 || size_cells < 1 )
+ {
+ printk("fdt: node `%s': invalid #xen,static-mem-address-cells or
#xen,static-mem-size-cells",
+ name);
+ return -EINVAL;
+ }
+
+ return device_tree_get_meminfo(fdt, node, "xen,static-mem", address_cells,
+ size_cells, &bootinfo.reserved_mem, true);
+}
+
static int __init early_scan_node(const void *fdt,
int node, const char *name, int depth,
u32 address_cells, u32 size_cells,
@@ -356,6 +386,8 @@ static int __init early_scan_node(const void *fdt,
process_multiboot_node(fdt, node, name, address_cells, size_cells);
else if ( depth == 1 && device_tree_node_matches(fdt, node, "chosen") )
process_chosen_node(fdt, node, name, address_cells, size_cells);
+ else if ( depth == 2 && device_tree_node_compatible(fdt, node,
"xen,domain") )
+ rc = process_domain_node(fdt, node, name, address_cells, size_cells);
if ( rc < 0 )
printk("fdt: node `%s': parsing failed\n", name);
diff --git a/xen/include/asm-arm/setup.h b/xen/include/asm-arm/setup.h
index c4b6af6029..6c3c16294b 100644
--- a/xen/include/asm-arm/setup.h
+++ b/xen/include/asm-arm/setup.h
@@ -24,6 +24,7 @@ typedef enum {
struct membank {
paddr_t start;
paddr_t size;
+ bool xen_domain; /* whether memory bank is bind to Xen domain. */
};
struct meminfo {
--
2.25.1
