James,
On Thu, Feb 1, 2018 at 1:12 PM, Mathieu Malaterre <malat@xxxxxxxxxx> wrote:
> 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
Could you please review the patch v3 ?
Thanks,
