mips: switch to NO_BOOTMEM

MIPS already has memblock support and all the memory is already registered
with it.

This patch replaces bootmem memory reservations with memblock ones and
removes the bootmem initialization.

Since memblock allocates memory in top-down mode, we ensure that memblock
limit is max_low_pfn to prevent allocations from the high memory.

To have the exceptions base in the lower 512M of the physical memory, its
allocation in arch/mips/kernel/traps.c::traps_init() is using bottom-up
mode.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20560/
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org

2 files changed, 26 insertions, 76 deletions

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 32fc11d72ad3..2fde53ebb3af 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -333,7 +333,7 @@ static void __init finalize_initrd(void)
 
         maybe_bswap_initrd();
 
-        reserve_bootmem(__pa(initrd_start), size, BOOTMEM_DEFAULT);
+        memblock_reserve(__pa(initrd_start), size);
         initrd_below_start_ok = 1;
 
         pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
@@ -370,20 +370,10 @@ static void __init bootmem_init(void)
 
 #else  /* !CONFIG_SGI_IP27 */
 
-static unsigned long __init bootmap_bytes(unsigned long pages)
-{
-        unsigned long bytes = DIV_ROUND_UP(pages, 8);
-
-        return ALIGN(bytes, sizeof(long));
-}
-
 static void __init bootmem_init(void)
 {
         unsigned long reserved_end;
-        unsigned long mapstart = ~0UL;
-        unsigned long bootmap_size;
         phys_addr_t ramstart = PHYS_ADDR_MAX;
-        bool bootmap_valid = false;
         int i;
 
         /*
@@ -395,6 +385,8 @@ static void __init bootmem_init(void)
         init_initrd();
         reserved_end = (unsigned long) PFN_UP(__pa_symbol(&_end));
 
+        memblock_reserve(PHYS_OFFSET, reserved_end << PAGE_SHIFT);
+
         /*
          * max_low_pfn is not a number of pages. The number of pages
          * of the system is given by 'max_low_pfn - min_low_pfn'.
@@ -442,9 +434,6 @@ static void __init bootmem_init(void)
                 if (initrd_end && end <= (unsigned long)PFN_UP(__pa(initrd_end)))
                         continue;
 #endif
-                if (start >= mapstart)
-                        continue;
-                mapstart = max(reserved_end, start);
         }
 
         if (min_low_pfn >= max_low_pfn)
@@ -456,9 +445,11 @@ static void __init bootmem_init(void)
         /*
          * Reserve any memory between the start of RAM and PHYS_OFFSET
          */
-        if (ramstart > PHYS_OFFSET)
+        if (ramstart > PHYS_OFFSET) {
                 add_memory_region(PHYS_OFFSET, ramstart - PHYS_OFFSET,
                                   BOOT_MEM_RESERVED);
+                memblock_reserve(PHYS_OFFSET, ramstart - PHYS_OFFSET);
+        }
 
         if (min_low_pfn > ARCH_PFN_OFFSET) {
                 pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
@@ -483,52 +474,6 @@ static void __init bootmem_init(void)
                 max_low_pfn = PFN_DOWN(HIGHMEM_START);
         }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-        /*
-         * mapstart should be after initrd_end
-         */
-        if (initrd_end)
-                mapstart = max(mapstart, (unsigned long)PFN_UP(__pa(initrd_end)));
-#endif
-
-        /*
-         * check that mapstart doesn't overlap with any of
-         * memory regions that have been reserved through eg. DTB
-         */
-        bootmap_size = bootmap_bytes(max_low_pfn - min_low_pfn);
-
-        bootmap_valid = memory_region_available(PFN_PHYS(mapstart),
-                                                bootmap_size);
-        for (i = 0; i < boot_mem_map.nr_map && !bootmap_valid; i++) {
-                unsigned long mapstart_addr;
-
-                switch (boot_mem_map.map[i].type) {
-                case BOOT_MEM_RESERVED:
-                        mapstart_addr = PFN_ALIGN(boot_mem_map.map[i].addr +
-                                                boot_mem_map.map[i].size);
-                        if (PHYS_PFN(mapstart_addr) < mapstart)
-                                break;
-
-                        bootmap_valid = memory_region_available(mapstart_addr,
-                                                                bootmap_size);
-                        if (bootmap_valid)
-                                mapstart = PHYS_PFN(mapstart_addr);
-                        break;
-                default:
-                        break;
-                }
-        }
-
-        if (!bootmap_valid)
-                panic("No memory area to place a bootmap bitmap");
-
-        /*
-         * Initialize the boot-time allocator with low memory only.
-         */
-        if (bootmap_size != init_bootmem_node(NODE_DATA(0), mapstart,
-                                         min_low_pfn, max_low_pfn))
-                panic("Unexpected memory size required for bootmap");
-
         for (i = 0; i < boot_mem_map.nr_map; i++) {
                 unsigned long start, end;
 
@@ -577,9 +522,9 @@ static void __init bootmem_init(void)
                 default:
                         /* Not usable memory */
                         if (start > min_low_pfn && end < max_low_pfn)
-                                reserve_bootmem(boot_mem_map.map[i].addr,
-                                                boot_mem_map.map[i].size,
-                                                BOOTMEM_DEFAULT);
+                                memblock_reserve(boot_mem_map.map[i].addr,
+                                                boot_mem_map.map[i].size);
+
                         continue;
                 }
 
@@ -602,15 +547,9 @@ static void __init bootmem_init(void)
                 size = end - start;
 
                 /* Register lowmem ranges */
-                free_bootmem(PFN_PHYS(start), size << PAGE_SHIFT);
                 memory_present(0, start, end);
         }
 
-        /*
-         * Reserve the bootmap memory.
-         */
-        reserve_bootmem(PFN_PHYS(mapstart), bootmap_size, BOOTMEM_DEFAULT);
-
 #ifdef CONFIG_RELOCATABLE
         /*
          * The kernel reserves all memory below its _end symbol as bootmem,
@@ -907,21 +846,29 @@ static void __init arch_mem_init(char **cmdline_p)
         early_init_fdt_scan_reserved_mem();
 
         bootmem_init();
+
+        /*
+         * Prevent memblock from allocating high memory.
+         * This cannot be done before max_low_pfn is detected, so up
+         * to this point is possible to only reserve physical memory
+         * with memblock_reserve; memblock_virt_alloc* can be used
+         * only after this point
+         */
+        memblock_set_current_limit(PFN_PHYS(max_low_pfn));
+
 #ifdef CONFIG_PROC_VMCORE
         if (setup_elfcorehdr && setup_elfcorehdr_size) {
                 printk(KERN_INFO "kdump reserved memory at %lx-%lx\n",
                        setup_elfcorehdr, setup_elfcorehdr_size);
-                reserve_bootmem(setup_elfcorehdr, setup_elfcorehdr_size,
-                                BOOTMEM_DEFAULT);
+                memblock_reserve(setup_elfcorehdr, setup_elfcorehdr_size);
         }
 #endif
 
         mips_parse_crashkernel();
 #ifdef CONFIG_KEXEC
         if (crashk_res.start != crashk_res.end)
-                reserve_bootmem(crashk_res.start,
-                                crashk_res.end - crashk_res.start + 1,
-                                BOOTMEM_DEFAULT);
+                memblock_reserve(crashk_res.start,
+                                 crashk_res.end - crashk_res.start + 1);
 #endif
         device_tree_init();
         sparse_init();
@@ -931,7 +878,7 @@ static void __init arch_mem_init(char **cmdline_p)
         /* Tell bootmem about cma reserved memblock section */
         for_each_memblock(reserved, reg)
                 if (reg->size != 0)
-                        reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
+                        memblock_reserve(reg->base, reg->size);
 
         reserve_bootmem_region(__pa_symbol(&__nosave_begin),
                         __pa_symbol(&__nosave_end)); /* Reserve for hibernation */
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 576aeef89423..5feef28deac8 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -29,6 +29,7 @@
 #include <linux/spinlock.h>
 #include <linux/kallsyms.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/interrupt.h>
 #include <linux/ptrace.h>
 #include <linux/kgdb.h>
@@ -2260,8 +2261,10 @@ void __init trap_init(void)
                 unsigned long size = 0x200 + VECTORSPACING*64;
                 phys_addr_t ebase_pa;
 
+                memblock_set_bottom_up(true);
                 ebase = (unsigned long)
                         __alloc_bootmem(size, 1 << fls(size), 0);
+                memblock_set_bottom_up(false);
 
                 /*
                  * Try to ensure ebase resides in KSeg0 if possible.