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From: Mike Rapoport <rppt@kernel.org>
To: Rob Herring <robh@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Russell King <linux@armlinux.org.uk>,
	Nicolas Pitre <nico@fluxnic.net>,
	Ard Biesheuvel <ardb@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Nick Kossifidis <mick@ics.forth.gr>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Frank Rowand <frowand.list@gmail.com>,
	Dave Young <dyoung@redhat.com>, Baoquan He <bhe@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-riscv@lists.infradead.org, kexec@lists.infradead.org,
	linux-mm@kvack.org, linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 02/10] memblock: Add variables for usable memory limitation
Date: Sun, 18 Jul 2021 12:31:21 +0300	[thread overview]
Message-ID: <YPP06QG7hfypZgYg@kernel.org> (raw)
In-Reply-To: <20210714135101.GB2441138@robh.at.kernel.org>

Hi,

On Wed, Jul 14, 2021 at 07:51:01AM -0600, Rob Herring wrote:
> On Wed, Jul 14, 2021 at 02:50:12PM +0200, Geert Uytterhoeven wrote:
> > Add two global variables (cap_mem_addr and cap_mem_size) for storing a
> > base address and size, describing a limited region in which memory may
> > be considered available for use by the kernel.  If enabled, memory
> > outside of this range is not available for use.
> > 
> > These variables can by filled by firmware-specific code, and used in
> > calls to memblock_cap_memory_range() by architecture-specific code.
> > An example user is the parser of the "linux,usable-memory-range"
> > property in the DT "/chosen" node.
> > 
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > ---
> > This is similar to how the initial ramdisk (phys_initrd_{start,size})
> > and ELF core headers (elfcorehdr_{addr,size})) are handled.
> > 
> > Does there exist a suitable place in the common memblock code to call
> > "memblock_cap_memory_range(cap_mem_addr, cap_mem_size)", or does this
> > have to be done in architecture-specific code?
> 
> Can't you just call it from early_init_dt_scan_usablemem? If the 
> property is present, you want to call it. If the property is not 
> present, nothing happens.

For memblock_cap_memory_range() to work properly it should be called after
memory is detected and added to memblock with memblock_add[_node]()

I'm not huge fan of adding more globals to memblock so if such ordering can
be implemented on the DT side it would be great.

I don't see a way to actually enforce this ordering, so maybe we'd want to
add warning in memblock_cap_memory_range() if memblock.memory is empty.
 
> Rob

-- 
Sincerely yours,
Mike.

WARNING: multiple messages have this Message-ID
From: Mike Rapoport <rppt@kernel.org>
To: Rob Herring <robh@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Russell King <linux@armlinux.org.uk>,
	Nicolas Pitre <nico@fluxnic.net>,
	Ard Biesheuvel <ardb@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Nick Kossifidis <mick@ics.forth.gr>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Frank Rowand <frowand.list@gmail.com>,
	Dave Young <dyoung@redhat.com>, Baoquan He <bhe@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-riscv@lists.infradead.org, kexec@lists.infradead.org,
	linux-mm@kvack.org, linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 02/10] memblock: Add variables for usable memory limitation
Date: Sun, 18 Jul 2021 12:31:21 +0300	[thread overview]
Message-ID: <YPP06QG7hfypZgYg@kernel.org> (raw)
In-Reply-To: <20210714135101.GB2441138@robh.at.kernel.org>

Hi,

On Wed, Jul 14, 2021 at 07:51:01AM -0600, Rob Herring wrote:
> On Wed, Jul 14, 2021 at 02:50:12PM +0200, Geert Uytterhoeven wrote:
> > Add two global variables (cap_mem_addr and cap_mem_size) for storing a
> > base address and size, describing a limited region in which memory may
> > be considered available for use by the kernel.  If enabled, memory
> > outside of this range is not available for use.
> > 
> > These variables can by filled by firmware-specific code, and used in
> > calls to memblock_cap_memory_range() by architecture-specific code.
> > An example user is the parser of the "linux,usable-memory-range"
> > property in the DT "/chosen" node.
> > 
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > ---
> > This is similar to how the initial ramdisk (phys_initrd_{start,size})
> > and ELF core headers (elfcorehdr_{addr,size})) are handled.
> > 
> > Does there exist a suitable place in the common memblock code to call
> > "memblock_cap_memory_range(cap_mem_addr, cap_mem_size)", or does this
> > have to be done in architecture-specific code?
> 
> Can't you just call it from early_init_dt_scan_usablemem? If the 
> property is present, you want to call it. If the property is not 
> present, nothing happens.

For memblock_cap_memory_range() to work properly it should be called after
memory is detected and added to memblock with memblock_add[_node]()

I'm not huge fan of adding more globals to memblock so if such ordering can
be implemented on the DT side it would be great.

I don't see a way to actually enforce this ordering, so maybe we'd want to
add warning in memblock_cap_memory_range() if memblock.memory is empty.
 
> Rob

-- 
Sincerely yours,
Mike.

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

WARNING: multiple messages have this Message-ID
From: Mike Rapoport <rppt@kernel.org>
To: Rob Herring <robh@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Russell King <linux@armlinux.org.uk>,
	Nicolas Pitre <nico@fluxnic.net>,
	Ard Biesheuvel <ardb@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Nick Kossifidis <mick@ics.forth.gr>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Frank Rowand <frowand.list@gmail.com>,
	Dave Young <dyoung@redhat.com>, Baoquan He <bhe@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-riscv@lists.infradead.org, kexec@lists.infradead.org,
	linux-mm@kvack.org, linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 02/10] memblock: Add variables for usable memory limitation
Date: Sun, 18 Jul 2021 12:31:21 +0300	[thread overview]
Message-ID: <YPP06QG7hfypZgYg@kernel.org> (raw)
In-Reply-To: <20210714135101.GB2441138@robh.at.kernel.org>

Hi,

On Wed, Jul 14, 2021 at 07:51:01AM -0600, Rob Herring wrote:
> On Wed, Jul 14, 2021 at 02:50:12PM +0200, Geert Uytterhoeven wrote:
> > Add two global variables (cap_mem_addr and cap_mem_size) for storing a
> > base address and size, describing a limited region in which memory may
> > be considered available for use by the kernel.  If enabled, memory
> > outside of this range is not available for use.
> > 
> > These variables can by filled by firmware-specific code, and used in
> > calls to memblock_cap_memory_range() by architecture-specific code.
> > An example user is the parser of the "linux,usable-memory-range"
> > property in the DT "/chosen" node.
> > 
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > ---
> > This is similar to how the initial ramdisk (phys_initrd_{start,size})
> > and ELF core headers (elfcorehdr_{addr,size})) are handled.
> > 
> > Does there exist a suitable place in the common memblock code to call
> > "memblock_cap_memory_range(cap_mem_addr, cap_mem_size)", or does this
> > have to be done in architecture-specific code?
> 
> Can't you just call it from early_init_dt_scan_usablemem? If the 
> property is present, you want to call it. If the property is not 
> present, nothing happens.

For memblock_cap_memory_range() to work properly it should be called after
memory is detected and added to memblock with memblock_add[_node]()

I'm not huge fan of adding more globals to memblock so if such ordering can
be implemented on the DT side it would be great.

I don't see a way to actually enforce this ordering, so maybe we'd want to
add warning in memblock_cap_memory_range() if memblock.memory is empty.
 
> Rob

-- 
Sincerely yours,
Mike.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2021-07-18  9:31 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-14 12:50 [PATCH v4 00/10] Add generic support for kdump DT properties Geert Uytterhoeven
2021-07-14 12:50 ` Geert Uytterhoeven
2021-07-14 12:50 ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 01/10] crash_dump: Make elfcorehdr_{addr,size} always visible Geert Uytterhoeven
2021-07-14 12:50   ` [PATCH v4 01/10] crash_dump: Make elfcorehdr_{addr, size} " Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 13:46   ` [PATCH v4 01/10] crash_dump: Make elfcorehdr_{addr,size} " Rob Herring
2021-07-14 13:46     ` Rob Herring
2021-07-14 13:46     ` Rob Herring
2021-07-14 12:50 ` [PATCH v4 02/10] memblock: Add variables for usable memory limitation Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 13:51   ` Rob Herring
2021-07-14 13:51     ` Rob Herring
2021-07-14 13:51     ` Rob Herring
2021-07-18  9:31     ` Mike Rapoport [this message]
2021-07-18  9:31       ` Mike Rapoport
2021-07-18  9:31       ` Mike Rapoport
2021-07-19  6:59       ` Geert Uytterhoeven
2021-07-19  6:59         ` Geert Uytterhoeven
2021-07-19  6:59         ` Geert Uytterhoeven
2021-07-19  6:59         ` Geert Uytterhoeven
2021-07-20  5:41         ` Mike Rapoport
2021-07-20  5:41           ` Mike Rapoport
2021-07-20  5:41           ` Mike Rapoport
2021-07-20  5:41           ` Mike Rapoport
2021-07-20  7:23           ` Geert Uytterhoeven
2021-07-20  7:23             ` Geert Uytterhoeven
2021-07-20  7:23             ` Geert Uytterhoeven
2021-07-20  7:23             ` Geert Uytterhoeven
2021-08-11  8:11     ` Geert Uytterhoeven
2021-08-11  8:11       ` Geert Uytterhoeven
2021-08-11  8:11       ` Geert Uytterhoeven
2021-08-11  8:11       ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 03/10] of: fdt: Add generic support for parsing elf core headers property Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 04/10] of: fdt: Add generic support for parsing usable memory range property Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 05/10] of: fdt: Use IS_ENABLED(CONFIG_BLK_DEV_INITRD) instead of #ifdef Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 06/10] riscv: Remove non-standard linux,elfcorehdr handling Geert Uytterhoeven
2021-07-14 12:50   ` [PATCH v4 06/10] riscv: Remove non-standard linux, elfcorehdr handling Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-20 15:43   ` [PATCH v4 06/10] riscv: Remove non-standard linux,elfcorehdr handling Palmer Dabbelt
2021-07-20 15:43     ` [PATCH v4 06/10] riscv: Remove non-standard linux, elfcorehdr handling Palmer Dabbelt
2021-07-20 15:43     ` Palmer Dabbelt
2021-07-23 15:17     ` [PATCH v4 06/10] riscv: Remove non-standard linux,elfcorehdr handling Geert Uytterhoeven
2021-07-23 15:17       ` [PATCH v4 06/10] riscv: Remove non-standard linux, elfcorehdr handling Geert Uytterhoeven
2021-07-23 15:17       ` [PATCH v4 06/10] riscv: Remove non-standard linux,elfcorehdr handling Geert Uytterhoeven
2021-07-23 15:17       ` [PATCH v4 06/10] riscv: Remove non-standard linux, elfcorehdr handling Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 07/10] arm64: kdump: Remove custom linux,elfcorehdr parsing Geert Uytterhoeven
2021-07-14 12:50   ` [PATCH v4 07/10] arm64: kdump: Remove custom linux, elfcorehdr parsing Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 08/10] arm64: kdump: Remove custom linux,usable-memory-range parsing Geert Uytterhoeven
2021-07-14 12:50   ` [PATCH v4 08/10] arm64: kdump: Remove custom linux, usable-memory-range parsing Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 09/10] arm64: kdump: Use IS_ENABLED(CONFIG_CRASH_DUMP) instead of #ifdef Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50 ` [PATCH v4 10/10] ARM: Parse kdump DT properties Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 12:50   ` Geert Uytterhoeven
2021-07-14 14:53   ` Rob Herring
2021-07-14 14:53     ` Rob Herring
2021-07-14 14:53     ` Rob Herring

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