在 2022/5/11 下午8:37, Xianting Tian 写道:
>
> 在 2022/5/11 下午8:27, David Hildenbrand 写道:
>> On 11.05.22 13:24, Xianting Tian wrote:
>>> Commit 00ab027a3b82 ("RISC-V: Add kernel image sections to the
>>> resource tree")
>>> added IORESOURCE_BUSY flag for no-map reserved memory, this casued
>>> devm_ioremap_resource() failed for the no-map reserved memory in
>>> subsequent
>>> operations of related driver, so remove the IORESOURCE_BUSY flag.
>>>
>>> The code to reproduce the issue,
>>> dts:
>>> mem0: memory@a0000000 {
>>> reg = <0x0 0xa0000000 0 0x1000000>;
>>> no-map;
>>> };
>>>
>>> &test {
>>> status = "okay";
>>> memory-region = <&mem0>;
>>> };
>>>
>>> code:
>>> np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
>>> ret = of_address_to_resource(np, 0, &r);
>>> base = devm_ioremap_resource(&pdev->dev, &r);
>>> // base = -EBUSY
>>>
>>> Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the
>>> resource tree")
>>> Reported-by: Huaming Jiang <[email protected]>
>>> Reviewed-by: Guo Ren <[email protected]>
>>> CC: Nick Kossifidis <[email protected]>
>>> Signed-off-by: Xianting Tian <[email protected]>
>>> ---
>>> arch/riscv/kernel/setup.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
>>> index 834eb652a7b9..71f2966b1474 100644
>>> --- a/arch/riscv/kernel/setup.c
>>> +++ b/arch/riscv/kernel/setup.c
>>> @@ -214,7 +214,7 @@ static void __init init_resources(void)
>>> if (unlikely(memblock_is_nomap(region))) {
>>> res->name = "Reserved";
>>> - res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
>>> + res->flags = IORESOURCE_MEM;
>>> } else {
>>> res->name = "System RAM";
>>> res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
>> I assume the "Reserved" part is essentially unused by the kernel
>> correct?
>
> I think we may use it, actually we found the issue in our product
> after merged kdump functionality.
>
> Actually, the code didn't add IORESOURCE_BUSY for no-map reserved
> memory before 00ab027a3b82 merged, so it is a typo for commit
> 00ab027a3b82 to add IORESOURCE_BUSY?
This is arm64 code, which doesn't add IORESOURCE_BUSY for no-map
reserved memory,
arch/arm64/kernel/setup.c
for_each_mem_region(region) {
res = &standard_resources[i++];
if (memblock_is_nomap(region)) {
res->name = "reserved";
res->flags = IORESOURCE_MEM;
res->start =
__pfn_to_phys(memblock_region_reserved_base_pfn(region));
res->end =
__pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
>
>>