On Thu, Feb 1, 2018 at 12:37 PM, Marcin Nowakowski
<marcin.nowakowski@xxxxxxxx> wrote:
> Commit 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing") added a
> fix to ensure that the memory range between PHYS_OFFSET and low memory
> address specified by mem= cmdline argument is not later processed by
> free_all_bootmem. This change was incorrect for systems where the
> commandline specifies more than 1 mem argument, as it will cause all
> memory between PHYS_OFFSET and each of the memory offsets to be marked
> as reserved, which results in parts of the RAM marked as reserved
> (Creator CI20's u-boot has a default commandline argument 'mem=256M@0x0
> mem=768M@0x30000000').
>
> Change the behaviour to ensure that only the range between PHYS_OFFSET
> and the lowest start address of the memories is marked as protected.
>
> This change also ensures that the range is marked protected even if it's
> only defined through the devicetree and not only via commandline
> arguments.
>
> Reported-by: Mathieu Malaterre <mathieu.malaterre@xxxxxxxxx>
> Signed-off-by: Marcin Nowakowski <marcin.nowakowski@xxxxxxxx>
> Fixes: 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing")
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.11+
> ---
> v3: Update stable version, code cleanup as suggested by James Hogan
> v2: Use updated email adress, add tag for stable.
> ---
> arch/mips/kernel/setup.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 702c678de116..e4a1581ce822 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -375,6 +375,7 @@ static void __init bootmem_init(void)
> unsigned long reserved_end;
> unsigned long mapstart = ~0UL;
> unsigned long bootmap_size;
> + phys_addr_t ramstart = (phys_addr_t)ULLONG_MAX;
> bool bootmap_valid = false;
> int i;
>
> @@ -395,7 +396,8 @@ static void __init bootmem_init(void)
> max_low_pfn = 0;
>
> /*
> - * Find the highest page frame number we have available.
> + * Find the highest page frame number we have available
> + * and the lowest used RAM address
> */
> for (i = 0; i < boot_mem_map.nr_map; i++) {
> unsigned long start, end;
> @@ -407,6 +409,8 @@ static void __init bootmem_init(void)
> end = PFN_DOWN(boot_mem_map.map[i].addr
> + boot_mem_map.map[i].size);
>
> + ramstart = min(ramstart, boot_mem_map.map[i].addr);
> +
> #ifndef CONFIG_HIGHMEM
> /*
> * Skip highmem here so we get an accurate max_low_pfn if low
> @@ -436,6 +440,13 @@ static void __init bootmem_init(void)
> mapstart = max(reserved_end, start);
> }
>
> + /*
> + * Reserve any memory between the start of RAM and PHYS_OFFSET
> + */
> + if (ramstart > PHYS_OFFSET)
> + add_memory_region(PHYS_OFFSET, ramstart - PHYS_OFFSET,
> + BOOT_MEM_RESERVED);
> +
> if (min_low_pfn >= max_low_pfn)
> panic("Incorrect memory mapping !!!");
> if (min_low_pfn > ARCH_PFN_OFFSET) {
> @@ -664,9 +675,6 @@ static int __init early_parse_mem(char *p)
>
> add_memory_region(start, size, BOOT_MEM_RAM);
>
> - if (start && start > PHYS_OFFSET)
> - add_memory_region(PHYS_OFFSET, start - PHYS_OFFSET,
> - BOOT_MEM_RESERVED);
> return 0;
> }
> early_param("mem", early_parse_mem);
> --
> 2.14.1
>
Looks good to me:
$ cat /proc/cpuinfo
system type : JZ4780
machine : Creator CI20
processor : 0
cpu model : Ingenic JZRISC V4.15 FPU V0.0
BogoMIPS : 956.00
wait instruction : yes
microsecond timers : no
tlb_entries : 32
extra interrupt vector : yes
hardware watchpoint : yes, count: 1, address/irw mask: [0x0fff]
isa : mips1 mips2 mips32r1 mips32r2
ASEs implemented :
shadow register sets : 1
kscratch registers : 0
package : 0
core : 0
VCED exceptions : not available
VCEI exceptions : not available
$ uname -a
Linux ci20 4.15.0+ #323 PREEMPT Thu Feb 1 13:08:11 CET 2018 mips GNU/Linux
Tested-by: Mathieu Malaterre <malat@xxxxxxxxxx>
Thanks
