Commit e63075a3 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 27f574c2

arch/microblaze/include/asm/memblock.h

+0 −3
Original line number Diff line number Diff line
@@ -9,9 +9,6 @@ 
#ifndef _ASM_MICROBLAZE_MEMBLOCK_H

#define _ASM_MICROBLAZE_MEMBLOCK_H



/* MEMBLOCK limit is OFF */

#define MEMBLOCK_REAL_LIMIT	0xFFFFFFFF



#endif /* _ASM_MICROBLAZE_MEMBLOCK_H */

arch/powerpc/include/asm/memblock.h

+0 −7
Original line number Diff line number Diff line
@@ -5,11 +5,4 @@ 


#define MEMBLOCK_DBG(fmt...) udbg_printf(fmt)



#ifdef CONFIG_PPC32

extern phys_addr_t lowmem_end_addr;

#define MEMBLOCK_REAL_LIMIT	lowmem_end_addr

#else

#define MEMBLOCK_REAL_LIMIT	0

#endif



#endif /* _ASM_POWERPC_MEMBLOCK_H */

arch/powerpc/kernel/prom.c

+19 −1
Original line number Diff line number Diff line
@@ -98,7 +98,7 @@ static void __init move_device_tree(void) 


	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 void __init phyp_dump_reserve_mem(void) 
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 @@ void __init early_init_devtree(void *params) 


	/* 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 @@ void __init early_init_devtree(void *params) 


	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();

arch/powerpc/kernel/setup_32.c

+1 −1
Original line number Diff line number Diff line
@@ -246,7 +246,7 @@ static void __init irqstack_early_init(void) 
	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));

arch/powerpc/mm/40x_mmu.c

+3 −2
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include <linux/init.h>

#include <linux/delay.h>

#include <linux/highmem.h>

#include <linux/memblock.h>



#include <asm/pgalloc.h>

#include <asm/prom.h>
@@ -47,6 +48,7 @@ 
#include <asm/bootx.h>

#include <asm/machdep.h>

#include <asm/setup.h>



#include "mmu_decl.h"



extern int __map_without_ltlbs;
@@ -139,8 +141,7 @@ unsigned long __init mmu_mapin_ram(unsigned long top) 
	 * coverage with normal-sized pages (or other reasons) do not

	 * attempt to allocate outside the allowed range.

	 */



	__initial_memory_limit_addr = memstart_addr + mapped;

	memblock_set_current_limit(memstart_addr + mapped);



	return mapped;

}

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