[PATCH] openrisc: Reserve memblock for initrd

[PATCH] openrisc: Reserve memblock for initrd

[Stafford Horne]

Recently OpenRISC added support for external initrd images, but I found
some instability when using larger buildroot initrd images. It turned
out that I forgot to reserve the memblock space for the initrd image.

This patch fixes the instability issue by reserving memblock space.

Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
Signed-off-by: Stafford Horne <shorne@gmail.com>
---
 arch/openrisc/kernel/setup.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
index b18e775f8be3..2c8aa53cc7ba 100644
--- a/arch/openrisc/kernel/setup.c
+++ b/arch/openrisc/kernel/setup.c
@@ -80,6 +80,15 @@ static void __init setup_memory(void)
 	 */
 	memblock_reserve(__pa(_stext), _end - _stext);
 
+#ifdef CONFIG_BLK_DEV_INITRD
+	/* Then reserve the initrd, if any */
+	if (initrd_start && (initrd_end > initrd_start)) {
+		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
+			ALIGN(initrd_end, PAGE_SIZE) -
+			ALIGN_DOWN(initrd_start, PAGE_SIZE));
+	}
+#endif /* CONFIG_BLK_DEV_INITRD */
+
 	early_init_fdt_reserve_self();
 	early_init_fdt_scan_reserved_mem();
 
-- 
2.26.2

[OpenRISC] [PATCH] openrisc: Reserve memblock for initrd

[Stafford Horne]

Recently OpenRISC added support for external initrd images, but I found
some instability when using larger buildroot initrd images. It turned
out that I forgot to reserve the memblock space for the initrd image.

This patch fixes the instability issue by reserving memblock space.

Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
Signed-off-by: Stafford Horne <shorne@gmail.com>
---
 arch/openrisc/kernel/setup.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
index b18e775f8be3..2c8aa53cc7ba 100644
--- a/arch/openrisc/kernel/setup.c
+++ b/arch/openrisc/kernel/setup.c
@@ -80,6 +80,15 @@ static void __init setup_memory(void)
 	 */
 	memblock_reserve(__pa(_stext), _end - _stext);
 
+#ifdef CONFIG_BLK_DEV_INITRD
+	/* Then reserve the initrd, if any */
+	if (initrd_start && (initrd_end > initrd_start)) {
+		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
+			ALIGN(initrd_end, PAGE_SIZE) -
+			ALIGN_DOWN(initrd_start, PAGE_SIZE));
+	}
+#endif /* CONFIG_BLK_DEV_INITRD */
+
 	early_init_fdt_reserve_self();
 	early_init_fdt_scan_reserved_mem();
 
-- 
2.26.2

Re: [PATCH] openrisc: Reserve memblock for initrd

[Mike Rapoport]

On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> Recently OpenRISC added support for external initrd images, but I found
> some instability when using larger buildroot initrd images. It turned
> out that I forgot to reserve the memblock space for the initrd image.
> 
> This patch fixes the instability issue by reserving memblock space.
> 
> Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> Signed-off-by: Stafford Horne <shorne@gmail.com>
> ---
>  arch/openrisc/kernel/setup.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> index b18e775f8be3..2c8aa53cc7ba 100644
> --- a/arch/openrisc/kernel/setup.c
> +++ b/arch/openrisc/kernel/setup.c
> @@ -80,6 +80,15 @@ static void __init setup_memory(void)
>  	 */
>  	memblock_reserve(__pa(_stext), _end - _stext);
>  
> +#ifdef CONFIG_BLK_DEV_INITRD
> +	/* Then reserve the initrd, if any */
> +	if (initrd_start && (initrd_end > initrd_start)) {
> +		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> +			ALIGN(initrd_end, PAGE_SIZE) -
> +			ALIGN_DOWN(initrd_start, PAGE_SIZE));
> +	}

The core mm takes care of reserving the entrire pages for the memory
reserved with memblock, so it is not necessary to do it here.

> +#endif /* CONFIG_BLK_DEV_INITRD */
> +
>  	early_init_fdt_reserve_self();
>  	early_init_fdt_scan_reserved_mem();
>  
> -- 
> 2.26.2
> 

-- 
Sincerely yours,
Mike.

[OpenRISC] [PATCH] openrisc: Reserve memblock for initrd

[Mike Rapoport]

On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> Recently OpenRISC added support for external initrd images, but I found
> some instability when using larger buildroot initrd images. It turned
> out that I forgot to reserve the memblock space for the initrd image.
> 
> This patch fixes the instability issue by reserving memblock space.
> 
> Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> Signed-off-by: Stafford Horne <shorne@gmail.com>
> ---
>  arch/openrisc/kernel/setup.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> index b18e775f8be3..2c8aa53cc7ba 100644
> --- a/arch/openrisc/kernel/setup.c
> +++ b/arch/openrisc/kernel/setup.c
> @@ -80,6 +80,15 @@ static void __init setup_memory(void)
>  	 */
>  	memblock_reserve(__pa(_stext), _end - _stext);
>  
> +#ifdef CONFIG_BLK_DEV_INITRD
> +	/* Then reserve the initrd, if any */
> +	if (initrd_start && (initrd_end > initrd_start)) {
> +		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> +			ALIGN(initrd_end, PAGE_SIZE) -
> +			ALIGN_DOWN(initrd_start, PAGE_SIZE));
> +	}

The core mm takes care of reserving the entrire pages for the memory
reserved with memblock, so it is not necessary to do it here.

> +#endif /* CONFIG_BLK_DEV_INITRD */
> +
>  	early_init_fdt_reserve_self();
>  	early_init_fdt_scan_reserved_mem();
>  
> -- 
> 2.26.2
> 

-- 
Sincerely yours,
Mike.

Re: [PATCH] openrisc: Reserve memblock for initrd

[Stafford Horne]

On Tue, Sep 01, 2020 at 08:59:24AM +0300, Mike Rapoport wrote:
> On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> > Recently OpenRISC added support for external initrd images, but I found
> > some instability when using larger buildroot initrd images. It turned
> > out that I forgot to reserve the memblock space for the initrd image.
> > 
> > This patch fixes the instability issue by reserving memblock space.
> > 
> > Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> > Signed-off-by: Stafford Horne <shorne@gmail.com>
> > ---
> >  arch/openrisc/kernel/setup.c | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> > index b18e775f8be3..2c8aa53cc7ba 100644
> > --- a/arch/openrisc/kernel/setup.c
> > +++ b/arch/openrisc/kernel/setup.c
> > @@ -80,6 +80,15 @@ static void __init setup_memory(void)
> >  	 */
> >  	memblock_reserve(__pa(_stext), _end - _stext);
> >  
> > +#ifdef CONFIG_BLK_DEV_INITRD
> > +	/* Then reserve the initrd, if any */
> > +	if (initrd_start && (initrd_end > initrd_start)) {
> > +		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> > +			ALIGN(initrd_end, PAGE_SIZE) -
> > +			ALIGN_DOWN(initrd_start, PAGE_SIZE));
> > +	}
> 
> The core mm takes care of reserving the entrire pages for the memory
> reserved with memblock, so it is not necessary to do it here.

Thanks for the pointer

I guess what you mean is it is not required to do the page alignment.  I used
other architectures as an example and most do the alignment, I think for most
architectures this can be pulled out to generic code.

-Stafford

> > +#endif /* CONFIG_BLK_DEV_INITRD */
> > +
> >  	early_init_fdt_reserve_self();
> >  	early_init_fdt_scan_reserved_mem();
> >  
> > -- 
> > 2.26.2
> > 
> 
> -- 
> Sincerely yours,
> Mike.

[OpenRISC] [PATCH] openrisc: Reserve memblock for initrd

[Stafford Horne]

On Tue, Sep 01, 2020 at 08:59:24AM +0300, Mike Rapoport wrote:
> On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> > Recently OpenRISC added support for external initrd images, but I found
> > some instability when using larger buildroot initrd images. It turned
> > out that I forgot to reserve the memblock space for the initrd image.
> > 
> > This patch fixes the instability issue by reserving memblock space.
> > 
> > Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> > Signed-off-by: Stafford Horne <shorne@gmail.com>
> > ---
> >  arch/openrisc/kernel/setup.c | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> > index b18e775f8be3..2c8aa53cc7ba 100644
> > --- a/arch/openrisc/kernel/setup.c
> > +++ b/arch/openrisc/kernel/setup.c
> > @@ -80,6 +80,15 @@ static void __init setup_memory(void)
> >  	 */
> >  	memblock_reserve(__pa(_stext), _end - _stext);
> >  
> > +#ifdef CONFIG_BLK_DEV_INITRD
> > +	/* Then reserve the initrd, if any */
> > +	if (initrd_start && (initrd_end > initrd_start)) {
> > +		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> > +			ALIGN(initrd_end, PAGE_SIZE) -
> > +			ALIGN_DOWN(initrd_start, PAGE_SIZE));
> > +	}
> 
> The core mm takes care of reserving the entrire pages for the memory
> reserved with memblock, so it is not necessary to do it here.

Thanks for the pointer

I guess what you mean is it is not required to do the page alignment.  I used
other architectures as an example and most do the alignment, I think for most
architectures this can be pulled out to generic code.

-Stafford

> > +#endif /* CONFIG_BLK_DEV_INITRD */
> > +
> >  	early_init_fdt_reserve_self();
> >  	early_init_fdt_scan_reserved_mem();
> >  
> > -- 
> > 2.26.2
> > 
> 
> -- 
> Sincerely yours,
> Mike.

Re: [PATCH] openrisc: Reserve memblock for initrd

[Mike Rapoport]

On Tue, Sep 01, 2020 at 07:20:44PM +0900, Stafford Horne wrote:
> On Tue, Sep 01, 2020 at 08:59:24AM +0300, Mike Rapoport wrote:
> > On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> > > Recently OpenRISC added support for external initrd images, but I found
> > > some instability when using larger buildroot initrd images. It turned
> > > out that I forgot to reserve the memblock space for the initrd image.
> > > 
> > > This patch fixes the instability issue by reserving memblock space.
> > > 
> > > Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> > > Signed-off-by: Stafford Horne <shorne@gmail.com>
> > > ---
> > >  arch/openrisc/kernel/setup.c | 9 +++++++++
> > >  1 file changed, 9 insertions(+)
> > > 
> > > diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> > > index b18e775f8be3..2c8aa53cc7ba 100644
> > > --- a/arch/openrisc/kernel/setup.c
> > > +++ b/arch/openrisc/kernel/setup.c
> > > @@ -80,6 +80,15 @@ static void __init setup_memory(void)
> > >  	 */
> > >  	memblock_reserve(__pa(_stext), _end - _stext);
> > >  
> > > +#ifdef CONFIG_BLK_DEV_INITRD
> > > +	/* Then reserve the initrd, if any */
> > > +	if (initrd_start && (initrd_end > initrd_start)) {
> > > + 	memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> > > +		ALIGN(initrd_end, PAGE_SIZE) -
> > > +		ALIGN_DOWN(initrd_start, PAGE_SIZE));
> > > +	}
> > 
> > The core mm takes care of reserving the entrire pages for the memory
> > reserved with memblock, so it is not necessary to do it here.
> 
> Thanks for the pointer
> 
> I guess what you mean is it is not required to do the page alignment.

Right. 

> I used other architectures as an example and most do the alignment, I
> think for most architectures this can be pulled out to generic code.

You are more than welcome :)
We already have a generic free_initrd_mem(), maybe it's time to have a
generic reserve_initrd_mem().

I'm ok with openrisc doing the alignment, but I think using local
variables would make the core more readable, e.g

	if (initd_start && (initrd_end)) {
		unsigned long aligned_start = ALIGN_DOWN(initrd_start, PAGE_SIZE);
		unsigned long aligned_end = ALIGN(end, PAGE_SIZE);

		memblock_reserve(aligned_start, aligned_end);
	}

What do you say?

> -Stafford
> 
> > > +#endif /* CONFIG_BLK_DEV_INITRD */
> > > +
> > >  	early_init_fdt_reserve_self();
> > >  	early_init_fdt_scan_reserved_mem();
> > >  
> > > -- 
> > > 2.26.2
> > > 
> > 
> > -- 
> > Sincerely yours,
> > Mike.

-- 
Sincerely yours,
Mike.

[OpenRISC] [PATCH] openrisc: Reserve memblock for initrd

[Mike Rapoport]

On Tue, Sep 01, 2020 at 07:20:44PM +0900, Stafford Horne wrote:
> On Tue, Sep 01, 2020 at 08:59:24AM +0300, Mike Rapoport wrote:
> > On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> > > Recently OpenRISC added support for external initrd images, but I found
> > > some instability when using larger buildroot initrd images. It turned
> > > out that I forgot to reserve the memblock space for the initrd image.
> > > 
> > > This patch fixes the instability issue by reserving memblock space.
> > > 
> > > Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> > > Signed-off-by: Stafford Horne <shorne@gmail.com>
> > > ---
> > >  arch/openrisc/kernel/setup.c | 9 +++++++++
> > >  1 file changed, 9 insertions(+)
> > > 
> > > diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> > > index b18e775f8be3..2c8aa53cc7ba 100644
> > > --- a/arch/openrisc/kernel/setup.c
> > > +++ b/arch/openrisc/kernel/setup.c
> > > @@ -80,6 +80,15 @@ static void __init setup_memory(void)
> > >  	 */
> > >  	memblock_reserve(__pa(_stext), _end - _stext);
> > >  
> > > +#ifdef CONFIG_BLK_DEV_INITRD
> > > +	/* Then reserve the initrd, if any */
> > > +	if (initrd_start && (initrd_end > initrd_start)) {
> > > + 	memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> > > +		ALIGN(initrd_end, PAGE_SIZE) -
> > > +		ALIGN_DOWN(initrd_start, PAGE_SIZE));
> > > +	}
> > 
> > The core mm takes care of reserving the entrire pages for the memory
> > reserved with memblock, so it is not necessary to do it here.
> 
> Thanks for the pointer
> 
> I guess what you mean is it is not required to do the page alignment.

Right. 

> I used other architectures as an example and most do the alignment, I
> think for most architectures this can be pulled out to generic code.

You are more than welcome :)
We already have a generic free_initrd_mem(), maybe it's time to have a
generic reserve_initrd_mem().

I'm ok with openrisc doing the alignment, but I think using local
variables would make the core more readable, e.g

	if (initd_start && (initrd_end)) {
		unsigned long aligned_start = ALIGN_DOWN(initrd_start, PAGE_SIZE);
		unsigned long aligned_end = ALIGN(end, PAGE_SIZE);

		memblock_reserve(aligned_start, aligned_end);
	}

What do you say?

> -Stafford
> 
> > > +#endif /* CONFIG_BLK_DEV_INITRD */
> > > +
> > >  	early_init_fdt_reserve_self();
> > >  	early_init_fdt_scan_reserved_mem();
> > >  
> > > -- 
> > > 2.26.2
> > > 
> > 
> > -- 
> > Sincerely yours,
> > Mike.

-- 
Sincerely yours,
Mike.

Re: [PATCH] openrisc: Reserve memblock for initrd

[Stafford Horne]

On Tue, Sep 01, 2020 at 03:11:30PM +0300, Mike Rapoport wrote:
> On Tue, Sep 01, 2020 at 07:20:44PM +0900, Stafford Horne wrote:
> > On Tue, Sep 01, 2020 at 08:59:24AM +0300, Mike Rapoport wrote:
> > > On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> > > > Recently OpenRISC added support for external initrd images, but I found
> > > > some instability when using larger buildroot initrd images. It turned
> > > > out that I forgot to reserve the memblock space for the initrd image.
> > > > 
> > > > This patch fixes the instability issue by reserving memblock space.
> > > > 
> > > > Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> > > > Signed-off-by: Stafford Horne <shorne@gmail.com>
> > > > ---
> > > >  arch/openrisc/kernel/setup.c | 9 +++++++++
> > > >  1 file changed, 9 insertions(+)
> > > > 
> > > > diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> > > > index b18e775f8be3..2c8aa53cc7ba 100644
> > > > --- a/arch/openrisc/kernel/setup.c
> > > > +++ b/arch/openrisc/kernel/setup.c
> > > > @@ -80,6 +80,15 @@ static void __init setup_memory(void)
> > > >  	 */
> > > >  	memblock_reserve(__pa(_stext), _end - _stext);
> > > >  
> > > > +#ifdef CONFIG_BLK_DEV_INITRD
> > > > +	/* Then reserve the initrd, if any */
> > > > +	if (initrd_start && (initrd_end > initrd_start)) {
> > > > + 	memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> > > > +		ALIGN(initrd_end, PAGE_SIZE) -
> > > > +		ALIGN_DOWN(initrd_start, PAGE_SIZE));
> > > > +	}
> > > 
> > > The core mm takes care of reserving the entrire pages for the memory
> > > reserved with memblock, so it is not necessary to do it here.
> > 
> > Thanks for the pointer
> > 
> > I guess what you mean is it is not required to do the page alignment.
> 
> Right. 
> 
> > I used other architectures as an example and most do the alignment, I
> > think for most architectures this can be pulled out to generic code.
> 
> You are more than welcome :)
> We already have a generic free_initrd_mem(), maybe it's time to have a
> generic reserve_initrd_mem().
> 
> I'm ok with openrisc doing the alignment, but I think using local
> variables would make the core more readable, e.g
> 
> 	if (initd_start && (initrd_end)) {
> 		unsigned long aligned_start = ALIGN_DOWN(initrd_start, PAGE_SIZE);
> 		unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
> 
> 		memblock_reserve(aligned_start, aligned_end);
> 	}
> 
> What do you say?

Well, if the alignment is not needed I rather not do it.  That would make the
code as simple as:

        if (initrd_start && (initrd_end > initrd_start)) {
                memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
        }

Let me look what is involved in making a reserve_initrd_mem().

-Stafford

> > -Stafford
> > 
> > > > +#endif /* CONFIG_BLK_DEV_INITRD */
> > > > +
> > > >  	early_init_fdt_reserve_self();
> > > >  	early_init_fdt_scan_reserved_mem();
> > > >  
> > > > -- 
> > > > 2.26.2
> > > > 
> > > 
> > > -- 
> > > Sincerely yours,
> > > Mike.
> 
> -- 
> Sincerely yours,
> Mike.

[OpenRISC] [PATCH] openrisc: Reserve memblock for initrd

[Stafford Horne]

On Tue, Sep 01, 2020 at 03:11:30PM +0300, Mike Rapoport wrote:
> On Tue, Sep 01, 2020 at 07:20:44PM +0900, Stafford Horne wrote:
> > On Tue, Sep 01, 2020 at 08:59:24AM +0300, Mike Rapoport wrote:
> > > On Tue, Sep 01, 2020 at 06:21:01AM +0900, Stafford Horne wrote:
> > > > Recently OpenRISC added support for external initrd images, but I found
> > > > some instability when using larger buildroot initrd images. It turned
> > > > out that I forgot to reserve the memblock space for the initrd image.
> > > > 
> > > > This patch fixes the instability issue by reserving memblock space.
> > > > 
> > > > Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
> > > > Signed-off-by: Stafford Horne <shorne@gmail.com>
> > > > ---
> > > >  arch/openrisc/kernel/setup.c | 9 +++++++++
> > > >  1 file changed, 9 insertions(+)
> > > > 
> > > > diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
> > > > index b18e775f8be3..2c8aa53cc7ba 100644
> > > > --- a/arch/openrisc/kernel/setup.c
> > > > +++ b/arch/openrisc/kernel/setup.c
> > > > @@ -80,6 +80,15 @@ static void __init setup_memory(void)
> > > >  	 */
> > > >  	memblock_reserve(__pa(_stext), _end - _stext);
> > > >  
> > > > +#ifdef CONFIG_BLK_DEV_INITRD
> > > > +	/* Then reserve the initrd, if any */
> > > > +	if (initrd_start && (initrd_end > initrd_start)) {
> > > > + 	memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> > > > +		ALIGN(initrd_end, PAGE_SIZE) -
> > > > +		ALIGN_DOWN(initrd_start, PAGE_SIZE));
> > > > +	}
> > > 
> > > The core mm takes care of reserving the entrire pages for the memory
> > > reserved with memblock, so it is not necessary to do it here.
> > 
> > Thanks for the pointer
> > 
> > I guess what you mean is it is not required to do the page alignment.
> 
> Right. 
> 
> > I used other architectures as an example and most do the alignment, I
> > think for most architectures this can be pulled out to generic code.
> 
> You are more than welcome :)
> We already have a generic free_initrd_mem(), maybe it's time to have a
> generic reserve_initrd_mem().
> 
> I'm ok with openrisc doing the alignment, but I think using local
> variables would make the core more readable, e.g
> 
> 	if (initd_start && (initrd_end)) {
> 		unsigned long aligned_start = ALIGN_DOWN(initrd_start, PAGE_SIZE);
> 		unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
> 
> 		memblock_reserve(aligned_start, aligned_end);
> 	}
> 
> What do you say?

Well, if the alignment is not needed I rather not do it.  That would make the
code as simple as:

        if (initrd_start && (initrd_end > initrd_start)) {
                memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
        }

Let me look what is involved in making a reserve_initrd_mem().

-Stafford

> > -Stafford
> > 
> > > > +#endif /* CONFIG_BLK_DEV_INITRD */
> > > > +
> > > >  	early_init_fdt_reserve_self();
> > > >  	early_init_fdt_scan_reserved_mem();
> > > >  
> > > > -- 
> > > > 2.26.2
> > > > 
> > > 
> > > -- 
> > > Sincerely yours,
> > > Mike.
> 
> -- 
> Sincerely yours,
> Mike.