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authorChris Metcalf <cmetcalf@tilera.com>2013-08-06 14:29:59 -0400
committerChris Metcalf <cmetcalf@tilera.com>2013-08-12 14:46:43 -0400
commit77f8c740d1a4947afb7493e7aafdd977e6d7939c (patch)
tree67470387bec62f1a5475d194f4b6175dda079eb9
parentbda0f5bad812df076a28fa5e58d86dfe68415251 (diff)
downloadlinux-77f8c740d1a4947afb7493e7aafdd977e6d7939c.tar.bz2
tile: support "memmap" boot parameter
This change adds support for the "memmap" boot parameter similar to what x86 provides. The tile version supports "memmap=1G$5G", for example, as a way to reserve a 1 GB range starting at PA 5GB. The memory is reserved via bootmem during startup, and we create a suitable "struct resource" marked as "Reserved" so you can see the range reported by /proc/iomem. Up to 64 such regions can currently be reserved on the boot command line. We do not support the x86 options "memmap=nn@ss" (force some memory to be available at the given address) since it's pointless to try to have Linux use memory the Tilera hypervisor hasn't given it. We do not support "memmap=nn#ss" to add an ACPI range for later processing, since we don't support ACPI. We do not support "memmap=exactmap" since we don't support reading the e820 information from the BIOS like x86 does. I did add support for "memmap=nn" (and the synonym "mem=nn") which cap the highest PA value at "nn"; these are both just a synonym for the existing tile boot option "maxmem". Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
-rw-r--r--arch/tile/kernel/setup.c80
1 files changed, 76 insertions, 4 deletions
diff --git a/arch/tile/kernel/setup.c b/arch/tile/kernel/setup.c
index 676e155a0d63..b00e156118c3 100644
--- a/arch/tile/kernel/setup.c
+++ b/arch/tile/kernel/setup.c
@@ -154,6 +154,65 @@ static int __init setup_maxnodemem(char *str)
}
early_param("maxnodemem", setup_maxnodemem);
+struct memmap_entry {
+ u64 addr; /* start of memory segment */
+ u64 size; /* size of memory segment */
+};
+static struct memmap_entry memmap_map[64];
+static int memmap_nr;
+
+static void add_memmap_region(u64 addr, u64 size)
+{
+ if (memmap_nr >= ARRAY_SIZE(memmap_map)) {
+ pr_err("Ooops! Too many entries in the memory map!\n");
+ return;
+ }
+ memmap_map[memmap_nr].addr = addr;
+ memmap_map[memmap_nr].size = size;
+ memmap_nr++;
+}
+
+static int __init setup_memmap(char *p)
+{
+ char *oldp;
+ u64 start_at, mem_size;
+
+ if (!p)
+ return -EINVAL;
+
+ if (!strncmp(p, "exactmap", 8)) {
+ pr_err("\"memmap=exactmap\" not valid on tile\n");
+ return 0;
+ }
+
+ oldp = p;
+ mem_size = memparse(p, &p);
+ if (p == oldp)
+ return -EINVAL;
+
+ if (*p == '@') {
+ pr_err("\"memmap=nn@ss\" (force RAM) invalid on tile\n");
+ } else if (*p == '#') {
+ pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on tile\n");
+ } else if (*p == '$') {
+ start_at = memparse(p+1, &p);
+ add_memmap_region(start_at, mem_size);
+ } else {
+ if (mem_size == 0)
+ return -EINVAL;
+ maxmem_pfn = (mem_size >> HPAGE_SHIFT) <<
+ (HPAGE_SHIFT - PAGE_SHIFT);
+ }
+ return *p == '\0' ? 0 : -EINVAL;
+}
+early_param("memmap", setup_memmap);
+
+static int __init setup_mem(char *str)
+{
+ return setup_maxmem(str);
+}
+early_param("mem", setup_mem); /* compatibility with x86 */
+
static int __init setup_isolnodes(char *str)
{
char buf[MAX_NUMNODES * 5];
@@ -629,6 +688,12 @@ static void __init setup_bootmem_allocator(void)
for (i = 0; i < MAX_NUMNODES; ++i)
setup_bootmem_allocator_node(i);
+ /* Reserve any memory excluded by "memmap" arguments. */
+ for (i = 0; i < memmap_nr; ++i) {
+ struct memmap_entry *m = &memmap_map[i];
+ reserve_bootmem(m->addr, m->size, 0);
+ }
+
#ifdef CONFIG_KEXEC
if (crashk_res.start != crashk_res.end)
reserve_bootmem(crashk_res.start, resource_size(&crashk_res), 0);
@@ -1562,11 +1627,11 @@ insert_non_bus_resource(void)
#endif
static struct resource* __init
-insert_ram_resource(u64 start_pfn, u64 end_pfn)
+insert_ram_resource(u64 start_pfn, u64 end_pfn, bool reserved)
{
struct resource *res =
kzalloc(sizeof(struct resource), GFP_ATOMIC);
- res->name = "System RAM";
+ res->name = reserved ? "Reserved" : "System RAM";
res->start = start_pfn << PAGE_SHIFT;
res->end = (end_pfn << PAGE_SHIFT) - 1;
res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
@@ -1601,11 +1666,11 @@ static int __init request_standard_resources(void)
end_pfn > pci_reserve_start_pfn) {
if (end_pfn > pci_reserve_end_pfn)
insert_ram_resource(pci_reserve_end_pfn,
- end_pfn);
+ end_pfn, 0);
end_pfn = pci_reserve_start_pfn;
}
#endif
- insert_ram_resource(start_pfn, end_pfn);
+ insert_ram_resource(start_pfn, end_pfn, 0);
}
code_resource.start = __pa(_text - CODE_DELTA);
@@ -1616,6 +1681,13 @@ static int __init request_standard_resources(void)
insert_resource(&iomem_resource, &code_resource);
insert_resource(&iomem_resource, &data_resource);
+ /* Mark any "memmap" regions busy for the resource manager. */
+ for (i = 0; i < memmap_nr; ++i) {
+ struct memmap_entry *m = &memmap_map[i];
+ insert_ram_resource(PFN_DOWN(m->addr),
+ PFN_UP(m->addr + m->size - 1), 1);
+ }
+
#ifdef CONFIG_KEXEC
insert_resource(&iomem_resource, &crashk_res);
#endif