Hi Marcin,
Since it's been a week, could you confirm the patch is ok as-is or do
you think some comment(s) from James should be incorporated ?
On Tue, Jan 23, 2018 at 3:17 PM, James Hogan <jhogan@xxxxxxxxxx> wrote:
> On Thu, Dec 21, 2017 at 10:00:59PM +0100, Mathieu Malaterre wrote:
>> From: Marcin Nowakowski <marcin.nowakowski@xxxxxxxx>
>>
>> Change 73fbc1eba7ff added a fix to ensure that the memory range between
>
> Please refer to commits with e.g. commit 73fbc1eba7ff ("MIPS: fix
> mem=X@Y commandline processing").
>
>> 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
>
> I'm guessing that should technically be v4.11+
My fault, if this is the only change, I can re-submit.
>> ---
>> v2: Use updated email adress, add tag for stable.
>> arch/mips/kernel/setup.c | 19 ++++++++++++++++---
>> 1 file changed, 16 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
>> index 702c678de116..f19d61224c71 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 = ~0UL;
>
> Although practically it might not matter, technically phys_addr_t may be
> 64-bits (CONFIG_PHYS_ADDR_T_64BIT) even on a 32-bit kernels, in which
> case ~0UL may not be sufficiently large.
>
> Maybe that should be ~(phys_addr_t)0, or perhaps (phys_addr_t)ULLONG_MAX
> to match add_memory_region().
>
>> bool bootmap_valid = false;
>> int i;
>>
>> @@ -395,6 +396,21 @@ static void __init bootmem_init(void)
>> max_low_pfn = 0;
>>
>> /*
>> + * Reserve any memory between the start of RAM and PHYS_OFFSET
>> + */
>> + for (i = 0; i < boot_mem_map.nr_map; i++) {
>> + if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
>> + continue;
>> +
>> + ramstart = min(ramstart, boot_mem_map.map[i].addr);
>
> Is it worth incorporating this into the existing loop below ...
>
>> + }
>> +
>> + if (ramstart > PHYS_OFFSET)
>> + add_memory_region(PHYS_OFFSET, ramstart - PHYS_OFFSET,
>> + BOOT_MEM_RESERVED);
>
> ... and this then placed below that loop?
>
> Otherwise I can't find fault with this patch, though i'm not intimately
> familiar with bootmem.
>
> Cheers
> James
>
>> +
>> +
>> + /*
>> * Find the highest page frame number we have available.
>> */
>> for (i = 0; i < boot_mem_map.nr_map; i++) {
>> @@ -664,9 +680,6 @@ 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);
>> --
>> 2.11.0
>>