On Thu, Mar 21, 2019 at 06:33:08PM +0800, Lianbo Jiang wrote:
> When doing kexec_file_load, the first kernel needs to pass the e820
Please end function names with parentheses.
> reserved ranges to the second kernel.
... because... ?
> But kernel can not exactly match the e820 reserved ranges
^
the
> when walking through the iomem resources with the descriptor
> 'IORES_DESC_NONE', because several e820 types( e.g.
> E820_TYPE_RESERVED_KERN/E820_TYPE_RAM/E820_TYPE_UNUSABLE/E820
> _TYPE_RESERVED) are converted to the descriptor 'IORES_DESC_NONE'.
> It may pass these four types to the kdump kernel, that is not desired result.
Rewrite that sentence.
> So, this patch adds a new I/O resource descriptor 'IORES_DESC_RESERVED'
Avoid having "This patch" or "This commit" in the commit message. It is
tautologically useless.
Also, do
$ git grep 'This patch' Documentation/process
for more details.
> for the iomem resources search interfaces. It is helpful to exactly
> match the reserved resource ranges when walking through iomem resources.
>
> In addition, since the new descriptor 'IORES_DESC_RESERVED' is introduced,
> these code originally related to the descriptor 'IORES_DESC_NONE' need to
"the code"
> be updated.
> Otherwise, it will be easily confused and also cause some errors.
What errors?
> Because the 'E820_TYPE_RESERVED' type is converted to the new
> descriptor 'IORES_DESC_RESERVED' instead of 'IORES_DESC_NONE', it has been
> changed.
That sentence I cannot parse.
> Suggested-by: Borislav Petkov <bp@xxxxxxx>
> Signed-off-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
> ---
> arch/x86/kernel/e820.c | 2 +-
> include/linux/ioport.h | 1 +
> kernel/resource.c | 6 +++---
> 3 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
> index 2879e234e193..16fcde196243 100644
> --- a/arch/x86/kernel/e820.c
> +++ b/arch/x86/kernel/e820.c
> @@ -1050,10 +1050,10 @@ static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
> case E820_TYPE_NVS: return IORES_DESC_ACPI_NV_STORAGE;
> case E820_TYPE_PMEM: return IORES_DESC_PERSISTENT_MEMORY;
> case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
> + case E820_TYPE_RESERVED: return IORES_DESC_RESERVED;
> case E820_TYPE_RESERVED_KERN: /* Fall-through: */
> case E820_TYPE_RAM: /* Fall-through: */
> case E820_TYPE_UNUSABLE: /* Fall-through: */
> - case E820_TYPE_RESERVED: /* Fall-through: */
> default: return IORES_DESC_NONE;
> }
> }
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index da0ebaec25f0..6ed59de48bd5 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -133,6 +133,7 @@ enum {
> IORES_DESC_PERSISTENT_MEMORY_LEGACY = 5,
> IORES_DESC_DEVICE_PRIVATE_MEMORY = 6,
> IORES_DESC_DEVICE_PUBLIC_MEMORY = 7,
> + IORES_DESC_RESERVED = 8,
> };
>
> /* helpers to define resources */
IORES_DESC_RESERVED is supposed to represent E820_TYPE_RESERVED. And if
that is the case, then all three hunks below look wrong to me. If you
want to pass E820_TYPE_RESERVED ranges, then do that explicitly.
> diff --git a/kernel/resource.c b/kernel/resource.c
> index e81b17b53fa5..ee7348761858 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -990,7 +990,7 @@ __reserve_region_with_split(struct resource *root, resource_size_t start,
> res->start = start;
> res->end = end;
> res->flags = type | IORESOURCE_BUSY;
> - res->desc = IORES_DESC_NONE;
> + res->desc = IORES_DESC_RESERVED;
>
> while (1) {
>
> @@ -1025,7 +1025,7 @@ __reserve_region_with_split(struct resource *root, resource_size_t start,
> next_res->start = conflict->end + 1;
> next_res->end = end;
> next_res->flags = type | IORESOURCE_BUSY;
> - next_res->desc = IORES_DESC_NONE;
> + next_res->desc = IORES_DESC_RESERVED;
> }
> } else {
> res->start = conflict->end + 1;
> @@ -1488,7 +1488,7 @@ static int __init reserve_setup(char *str)
> res->start = io_start;
> res->end = io_start + io_num - 1;
> res->flags |= IORESOURCE_BUSY;
> - res->desc = IORES_DESC_NONE;
> + res->desc = IORES_DESC_RESERVED;
> res->child = NULL;
> if (request_resource(parent, res) == 0)
> reserved = x+1;
> --
> 2.17.1
>
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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