Re: [PATCH 3/3] m68k: switch to MEMBLOCK + NO_BOOTMEM

From: Greg Ungerer
Date: Tue Jul 03 2018 - 22:03:05 EST

Hi Mike,

On 04/07/18 11:39, Greg Ungerer wrote:
On 03/07/18 20:29, Mike Rapoport wrote:
In m68k the physical memory is described by [memory_start, memory_end] for
!MMU variant and by m68k_memory array of memory ranges for the MMU version.
This information is directly used to register the physical memory with
memblock.

The reserve_bootmem() calls are replaced with memblock_reserve() and the
bootmap bitmap allocation is simply dropped.

Since the MMU variant creates early mappings only for the small part of the
memory we force bottom-up allocations in memblock because otherwise we will
attempt to access memory that not yet mapped

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>

This builds cleanly for me with a m5475_defconfig, but it fails
to boot on real hardware. No console, no nothing on startup.
I haven't debugged any further yet.

The M5475 is a ColdFire with MMU enabled target.

With some early serial debug trace I see:

Linux version 4.18.0-rc3-00003-g109f5e551b18-dirty (gerg@goober) (gcc version 5.4.0 (GCC)) #5 Wed Jul 4 12:00:03 AEST 2018
On node 0 totalpages: 4096
DMA zone: 18 pages used for memmap
DMA zone: 0 pages reserved
DMA zone: 4096 pages, LIFO batch:0
pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
pcpu-alloc: [0] 0
Built 1 zonelists, mobility grouping off. Total pages: 4078
Kernel command line: root=/dev/mtdblock0
Dentry cache hash table entries: 4096 (order: 1, 16384 bytes)
Inode-cache hash table entries: 2048 (order: 0, 8192 bytes)
Sorting __ex_table...
Memory: 3032K/32768K available (1489K kernel code, 96K rwdata, 240K rodata, 56K init, 77K bss, 29736K reserved, 0K cma-reserved)
SLUB: HWalign=16, Order=0-3, MinObjects=0, CPUs=1, Nodes=8
NR_IRQS: 256
clocksource: slt: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 14370379300 ns
Calibrating delay loop... 264.19 BogoMIPS (lpj=1320960)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 2048 (order: 0, 8192 bytes)
Mountpoint-cache hash table entries: 2048 (order: 0, 8192 bytes)
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
ColdFire: PCI bus initialization...
Coldfire: PCI IO/config window mapped to 0xe0000000
PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io 0x0000-0xffff]
pci_bus 0000:00: root bus resource [mem 0x00000000-0xffffffff]
pci_bus 0000:00: root bus resource [bus 00-ff]
pci 0000:00:14.0: [8086:1229] type 00 class 0x020000
pci 0000:00:14.0: reg 0x10: [mem 0x00000000-0x00000fff]
pci 0000:00:14.0: reg 0x14: [io 0x0000-0x003f]
pci 0000:00:14.0: reg 0x18: [mem 0x00000000-0x000fffff]
pci 0000:00:14.0: reg 0x30: [mem 0x00000000-0x000fffff pref]
pci 0000:00:14.0: supports D1 D2
pci 0000:00:14.0: PME# supported from D0 D1 D2 D3hot
pci 0000:00:14.0: BAR 2: assigned [mem 0xf0000000-0xf00fffff]
pci 0000:00:14.0: BAR 6: assigned [mem 0xf0100000-0xf01fffff pref]
pci 0000:00:14.0: BAR 0: assigned [mem 0xf0200000-0xf0200fff]
pci 0000:00:14.0: BAR 1: assigned [io 0x0400-0x043f]
vgaarb: loaded
clocksource: Switched to clocksource slt
PCI: CLS 32 bytes, default 16
workingset: timestamp_bits=27 max_order=9 bucket_order=0
kobject_add_internal failed for slab (error: -12 parent: kernel)
Cannot register slab subsystem.
romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
io scheduler noop registered (default)
io scheduler mq-deadline registered
io scheduler kyber registered
kobject_add_internal failed for ptyp0 (error: -12 parent: tty)
Kernel panic - not syncing: Couldn't register pty driver
CPU: 0 PID: 1 Comm: swapper Not tainted 4.18.0-rc3-00003-g109f5e551b18-dirty #5
Stack from 00283ee4:
00283ee4 001bc27a 000287ea 0019075c 00000019 001f5390 0018ba36 002c6a00
002c6a80 0014ab82 00148816 001f2c2a 001b948c 00000000 001f2ad0 001f6ce8
0002118e 00283f8c 000211b4 00000006 00000019 001f5390 0018ba36 00000007
00000000 001f53cc 00305fb0 0002118e 0003df6a 00000000 00000006 00000006
00305fb0 00305fb5 001ea7f6 001ba406 00305fb0 001d1c58 00000019 00000006
00000006 00000000 0003df6a 001ea804 001f2ad0 00000000 001e5964 00282001
Call Trace:
[<000287ea>] 0x000287ea
[<0019075c>] 0x0019075c
[<0018ba36>] 0x0018ba36
[<0014ab82>] 0x0014ab82
[<00148816>] 0x00148816

[<001f2c2a>] 0x001f2c2a
[<001f2ad0>] 0x001f2ad0
[<0002118e>] 0x0002118e
[<000211b4>] 0x000211b4
[<0018ba36>] 0x0018ba36

[<0002118e>] 0x0002118e
[<0003df6a>] 0x0003df6a
[<001ea7f6>] 0x001ea7f6
[<0003df6a>] 0x0003df6a
[<001ea804>] 0x001ea804

[<001f2ad0>] 0x001f2ad0
[<00190bae>] 0x00190bae
[<00190bb6>] 0x00190bb6
[<00190bae>] 0x00190bae
[<00021aac>] 0x00021aac

---[ end Kernel panic - not syncing: Couldn't register pty driver ]---
random: fast init done

Regards
Greg



---
 arch/m68k/Kconfig | 3 +++
 arch/m68k/kernel/setup_mm.c | 14 ++++----------
 arch/m68k/kernel/setup_no.c | 20 ++++----------------
 arch/m68k/mm/init.c | 1 -
 arch/m68k/mm/mcfmmu.c | 11 +++++++----
 arch/m68k/mm/motorola.c | 35 +++++++++++------------------------
 arch/m68k/sun3/config.c | 4 ----
 7 files changed, 29 insertions(+), 59 deletions(-)

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 785612b..bd7f38a 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -24,6 +24,9 @@ config M68K
ÂÂÂÂÂ select MODULES_USE_ELF_RELA
ÂÂÂÂÂ select OLD_SIGSUSPEND3
ÂÂÂÂÂ select OLD_SIGACTION
+ÂÂÂ select HAVE_MEMBLOCK
+ÂÂÂ select ARCH_DISCARD_MEMBLOCK
+ÂÂÂ select NO_BOOTMEM
 config CPU_BIG_ENDIAN
ÂÂÂÂÂ def_bool y
diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
index f35e3eb..6512955 100644
--- a/arch/m68k/kernel/setup_mm.c
+++ b/arch/m68k/kernel/setup_mm.c
@@ -21,6 +21,7 @@
 #include <linux/string.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/module.h>
@@ -165,6 +166,8 @@ static void __init m68k_parse_bootinfo(const struct bi_record *record)
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ be32_to_cpu(m->addr);
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ m68k_memory[m68k_num_memory].size =
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ be32_to_cpu(m->size);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ memblock_add(m68k_memory[m68k_num_memory].addr,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ m68k_memory[m68k_num_memory].size);
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ m68k_num_memory++;
ÂÂÂÂÂÂÂÂÂÂÂÂÂ } else
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pr_warn("%s: too many memory chunks\n",
@@ -224,10 +227,6 @@ static void __init m68k_parse_bootinfo(const struct bi_record *record)
 void __init setup_arch(char **cmdline_p)
 {
-#ifndef CONFIG_SUN3
-ÂÂÂ int i;
-#endif
-
ÂÂÂÂÂ /* The bootinfo is located right after the kernel */
ÂÂÂÂÂ if (!CPU_IS_COLDFIRE)
ÂÂÂÂÂÂÂÂÂ m68k_parse_bootinfo((const struct bi_record *)_end);
@@ -356,14 +355,9 @@ void __init setup_arch(char **cmdline_p)
 #endif
 #ifndef CONFIG_SUN3
-ÂÂÂ for (i = 1; i < m68k_num_memory; i++)
-ÂÂÂÂÂÂÂ free_bootmem_node(NODE_DATA(i), m68k_memory[i].addr,
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ m68k_memory[i].size);
 #ifdef CONFIG_BLK_DEV_INITRD
ÂÂÂÂÂ if (m68k_ramdisk.size) {
-ÂÂÂÂÂÂÂ reserve_bootmem_node(__virt_to_node(phys_to_virt(m68k_ramdisk.addr)),
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ m68k_ramdisk.addr, m68k_ramdisk.size,
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ BOOTMEM_DEFAULT);
+ÂÂÂÂÂÂÂ memblock_reserve(m68k_ramdisk.addr, m68k_ramdisk.size);
ÂÂÂÂÂÂÂÂÂ initrd_start = (unsigned long)phys_to_virt(m68k_ramdisk.addr);
ÂÂÂÂÂÂÂÂÂ initrd_end = initrd_start + m68k_ramdisk.size;
ÂÂÂÂÂÂÂÂÂ pr_info("initrd: %08lx - %08lx\n", initrd_start, initrd_end);
diff --git a/arch/m68k/kernel/setup_no.c b/arch/m68k/kernel/setup_no.c
index a98af10..3e8d87a 100644
--- a/arch/m68k/kernel/setup_no.c
+++ b/arch/m68k/kernel/setup_no.c
@@ -28,6 +28,7 @@
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/seq_file.h>
 #include <linux/init.h>
 #include <linux/initrd.h>
@@ -86,8 +87,6 @@ void (*mach_power_off)(void);
 void __init setup_arch(char **cmdline_p)
 {
-ÂÂÂ int bootmap_size;
-
ÂÂÂÂÂ memory_start = PAGE_ALIGN(_ramstart);
ÂÂÂÂÂ memory_end = _ramend;
@@ -142,6 +141,8 @@ void __init setup_arch(char **cmdline_p)
ÂÂÂÂÂ pr_debug("MEMORY -> ROMFS=0x%p-0x%06lx MEM=0x%06lx-0x%06lx\n ",
ÂÂÂÂÂÂÂÂÂÂ __bss_stop, memory_start, memory_start, memory_end);
+ÂÂÂ memblock_add(memory_start, memory_end - memory_start);
+
ÂÂÂÂÂ /* Keep a copy of command line */
ÂÂÂÂÂ *cmdline_p = &command_line[0];
ÂÂÂÂÂ memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
@@ -158,23 +159,10 @@ void __init setup_arch(char **cmdline_p)
ÂÂÂÂÂ min_low_pfn = PFN_DOWN(memory_start);
ÂÂÂÂÂ max_pfn = max_low_pfn = PFN_DOWN(memory_end);
-ÂÂÂ bootmap_size = init_bootmem_node(
-ÂÂÂÂÂÂÂÂÂÂÂ NODE_DATA(0),
-ÂÂÂÂÂÂÂÂÂÂÂ min_low_pfn,ÂÂÂÂÂÂÂ /* map goes here */
-ÂÂÂÂÂÂÂÂÂÂÂ PFN_DOWN(PAGE_OFFSET),
-ÂÂÂÂÂÂÂÂÂÂÂ max_pfn);
-ÂÂÂ /*
-ÂÂÂÂ * Free the usable memory, we have to make sure we do not free
-ÂÂÂÂ * the bootmem bitmap so we then reserve it after freeing it :-)
-ÂÂÂÂ */
-ÂÂÂ free_bootmem(memory_start, memory_end - memory_start);
-ÂÂÂ reserve_bootmem(memory_start, bootmap_size, BOOTMEM_DEFAULT);
-
 #if defined(CONFIG_UBOOT) && defined(CONFIG_BLK_DEV_INITRD)
ÂÂÂÂÂ if ((initrd_start > 0) && (initrd_start < initrd_end) &&
ÂÂÂÂÂÂÂÂÂÂÂÂÂ (initrd_end < memory_end))
-ÂÂÂÂÂÂÂ reserve_bootmem(initrd_start, initrd_end - initrd_start,
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ BOOTMEM_DEFAULT);
+ÂÂÂÂÂÂÂ memblock_reserve(initrd_start, initrd_end - initrd_start);
 #endif /* if defined(CONFIG_BLK_DEV_INITRD) */
ÂÂÂÂÂ /*
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index 8827b7f..38e2b27 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c
@@ -71,7 +71,6 @@ void __init m68k_setup_node(int node)
ÂÂÂÂÂÂÂÂÂ pg_data_table[i] = pg_data_map + node;
ÂÂÂÂÂ }
 #endif
-ÂÂÂ pg_data_map[node].bdata = bootmem_node_data + node;
ÂÂÂÂÂ node_set_online(node);
 }
diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c
index 2925d79..e9e60e1 100644
--- a/arch/m68k/mm/mcfmmu.c
+++ b/arch/m68k/mm/mcfmmu.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/string.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <asm/setup.h>
 #include <asm/page.h>
@@ -160,6 +161,8 @@ void __init cf_bootmem_alloc(void)
ÂÂÂÂÂ m68k_memory[0].addr = _rambase;
ÂÂÂÂÂ m68k_memory[0].size = _ramend - _rambase;
+ÂÂÂ memblock_add(m68k_memory[0].addr, m68k_memory[0].size);
+
ÂÂÂÂÂ /* compute total pages in system */
ÂÂÂÂÂ num_pages = PFN_DOWN(_ramend - _rambase);
@@ -170,14 +173,14 @@ void __init cf_bootmem_alloc(void)
ÂÂÂÂÂ max_pfn = max_low_pfn = PFN_DOWN(_ramend);
ÂÂÂÂÂ high_memory = (void *)_ramend;
+ÂÂÂ /* Reserve kernel text/data/bss */
+ÂÂÂ memblock_reserve(memstart, _ramend - memstart);
+
ÂÂÂÂÂ m68k_virt_to_node_shift = fls(_ramend - 1) - 6;
ÂÂÂÂÂ module_fixup(NULL, __start_fixup, __stop_fixup);
-ÂÂÂ /* setup bootmem data */
+ÂÂÂ /* setup node data */
ÂÂÂÂÂ m68k_setup_node(0);
-ÂÂÂ memstart += init_bootmem_node(NODE_DATA(0), start_pfn,
-ÂÂÂÂÂÂÂ min_low_pfn, max_low_pfn);
-ÂÂÂ free_bootmem_node(NODE_DATA(0), memstart, _ramend - memstart);
 }
 /*
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index e490ecc..4e17ecb 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -19,6 +19,7 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/gfp.h>
 #include <asm/setup.h>
@@ -208,7 +209,7 @@ void __init paging_init(void)
 {
ÂÂÂÂÂ unsigned long zones_size[MAX_NR_ZONES] = { 0, };
ÂÂÂÂÂ unsigned long min_addr, max_addr;
-ÂÂÂ unsigned long addr, size, end;
+ÂÂÂ unsigned long addr;
ÂÂÂÂÂ int i;
 #ifdef DEBUG
@@ -253,34 +254,20 @@ void __init paging_init(void)
ÂÂÂÂÂ min_low_pfn = availmem >> PAGE_SHIFT;
ÂÂÂÂÂ max_pfn = max_low_pfn = max_addr >> PAGE_SHIFT;
-ÂÂÂ for (i = 0; i < m68k_num_memory; i++) {
-ÂÂÂÂÂÂÂ addr = m68k_memory[i].addr;
-ÂÂÂÂÂÂÂ end = addr + m68k_memory[i].size;
-ÂÂÂÂÂÂÂ m68k_setup_node(i);
-ÂÂÂÂÂÂÂ availmem = PAGE_ALIGN(availmem);
-ÂÂÂÂÂÂÂ availmem += init_bootmem_node(NODE_DATA(i),
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ availmem >> PAGE_SHIFT,
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ addr >> PAGE_SHIFT,
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ end >> PAGE_SHIFT);
-ÂÂÂ }
+ÂÂÂ /* Reserve kernel text/data/bss and the memory allocated in head.S */
+ÂÂÂ memblock_reserve(m68k_memory[0].addr, availmem - m68k_memory[0].addr);
ÂÂÂÂÂ /*
ÂÂÂÂÂÂ * Map the physical memory available into the kernel virtual
-ÂÂÂÂ * address space. First initialize the bootmem allocator with
-ÂÂÂÂ * the memory we already mapped, so map_node() has something
-ÂÂÂÂ * to allocate.
+ÂÂÂÂ * address space. Make sure memblock will not try to allocate
+ÂÂÂÂ * pages beyond the memory we already mapped in head.S
ÂÂÂÂÂÂ */
-ÂÂÂ addr = m68k_memory[0].addr;
-ÂÂÂ size = m68k_memory[0].size;
-ÂÂÂ free_bootmem_node(NODE_DATA(0), availmem,
-ÂÂÂÂÂÂÂÂÂÂÂÂÂ min(m68k_init_mapped_size, size) - (availmem - addr));
-ÂÂÂ map_node(0);
-ÂÂÂ if (size > m68k_init_mapped_size)
-ÂÂÂÂÂÂÂ free_bootmem_node(NODE_DATA(0), addr + m68k_init_mapped_size,
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ size - m68k_init_mapped_size);
-
-ÂÂÂ for (i = 1; i < m68k_num_memory; i++)
+ÂÂÂ memblock_set_bottom_up(true);
+
+ÂÂÂ for (i = 0; i < m68k_num_memory; i++) {
+ÂÂÂÂÂÂÂ m68k_setup_node(i);
ÂÂÂÂÂÂÂÂÂ map_node(i);
+ÂÂÂ }
ÂÂÂÂÂ flush_tlb_all();
diff --git a/arch/m68k/sun3/config.c b/arch/m68k/sun3/config.c
index 1d28d38..79a2bb8 100644
--- a/arch/m68k/sun3/config.c
+++ b/arch/m68k/sun3/config.c
@@ -123,10 +123,6 @@ static void __init sun3_bootmem_alloc(unsigned long memory_start,
ÂÂÂÂÂ availmem = memory_start;
ÂÂÂÂÂ m68k_setup_node(0);
-ÂÂÂ availmem += init_bootmem(start_page, num_pages);
-ÂÂÂ availmem = (availmem + (PAGE_SIZE-1)) & PAGE_MASK;
-
-ÂÂÂ free_bootmem(__pa(availmem), memory_end - (availmem));
 }

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