memblock: Introduce default allocation limit and use it to replace explicit ones
This introduce memblock.current_limit which is used to limit allocations
from memblock_alloc() or memblock_alloc_base(..., MEMBLOCK_ALLOC_ACCESSIBLE).
The old MEMBLOCK_ALLOC_ANYWHERE changes value from 0 to ~(u64)0 and can still
be used with memblock_alloc_base() to allocate really anywhere.
It is -no-longer- cropped to MEMBLOCK_REAL_LIMIT which disappears.
Note to archs: I'm leaving the default limit to MEMBLOCK_ALLOC_ANYWHERE. I
strongly recommend that you ensure that you set an appropriate limit
during boot in order to guarantee that an memblock_alloc() at any time
results in something that is accessible with a simple __va().
The reason is that a subsequent patch will introduce the ability for
the array to resize itself by reallocating itself. The MEMBLOCK core will
honor the current limit when performing those allocations.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index fed9bf6..3aec0b9 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -98,7 +98,7 @@
if ((memory_limit && (start + size) > memory_limit) ||
overlaps_crashkernel(start, size)) {
- p = __va(memblock_alloc_base(size, PAGE_SIZE, memblock.rmo_size));
+ p = __va(memblock_alloc(size, PAGE_SIZE));
memcpy(p, initial_boot_params, size);
initial_boot_params = (struct boot_param_header *)p;
DBG("Moved device tree to 0x%p\n", p);
@@ -655,6 +655,21 @@
static inline void __init phyp_dump_reserve_mem(void) {}
#endif /* CONFIG_PHYP_DUMP && CONFIG_PPC_RTAS */
+static void set_boot_memory_limit(void)
+{
+#ifdef CONFIG_PPC32
+ /* 601 can only access 16MB at the moment */
+ if (PVR_VER(mfspr(SPRN_PVR)) == 1)
+ memblock_set_current_limit(0x01000000);
+ /* 8xx can only access 8MB at the moment */
+ else if (PVR_VER(mfspr(SPRN_PVR)) == 0x50)
+ memblock_set_current_limit(0x00800000);
+ else
+ memblock_set_current_limit(0x10000000);
+#else
+ memblock_set_current_limit(memblock.rmo_size);
+#endif
+}
void __init early_init_devtree(void *params)
{
@@ -683,6 +698,7 @@
/* Scan memory nodes and rebuild MEMBLOCKs */
memblock_init();
+
of_scan_flat_dt(early_init_dt_scan_root, NULL);
of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
@@ -718,6 +734,8 @@
DBG("Phys. mem: %llx\n", memblock_phys_mem_size());
+ set_boot_memory_limit();
+
/* We may need to relocate the flat tree, do it now.
* FIXME .. and the initrd too? */
move_device_tree();
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index a10ffc8..b7eb1de 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -246,7 +246,7 @@
unsigned int i;
/* interrupt stacks must be in lowmem, we get that for free on ppc32
- * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
+ * as the memblock is limited to lowmem by default */
for_each_possible_cpu(i) {
softirq_ctx[i] = (struct thread_info *)
__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));