[PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

Subsystems: linux for powerpc (32-bit and 64-bit), the rest

STALE1996d LANDED: 1 (0M)

1 review trailer; landed in mainline as 886db32398ab on 2021-03-11.

7 messages, 5 authors, 2021-03-11 · open the first message on its own page

[PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

From: Thiago Jung Bauermann <hidden>
Date: 2021-02-20 00:53:58

Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump
kernel") fixed how elf64_load() estimates the FDT size needed by the
crashdump kernel.

At the same time, commit 130b2d59cec0 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic
function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That
change made the code overestimate it a bit by counting twice the space
required for the kernel command line and /chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.

Signed-off-by: Thiago Jung Bauermann <redacted>
Reviewed-by: Lakshmi Ramasubramanian <redacted>
---
 arch/powerpc/include/asm/kexec.h  |  2 +-
 arch/powerpc/kexec/elf_64.c       |  2 +-
 arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------
 3 files changed, 10 insertions(+), 20 deletions(-)

Applies on top of next-20210219.

Changes since v1:

- Adjusted comment describing kexec_extra_fdt_size_ppc64() as suggested
  by Lakshmi.
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index baab158e215c..5a11cc8d2350 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -128,7 +128,7 @@ int load_crashdump_segments_ppc64(struct kimage *image,
 int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
 			  const void *fdt, unsigned long kernel_load_addr,
 			  unsigned long fdt_load_addr);
-unsigned int kexec_fdt_totalsize_ppc64(struct kimage *image);
+unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image);
 int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
 			unsigned long initrd_load_addr,
 			unsigned long initrd_len, const char *cmdline);
diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index 0492ca6003f3..5a569bb51349 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -104,7 +104,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 
 	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
 					   initrd_len, cmdline,
-					   kexec_fdt_totalsize_ppc64(image));
+					   kexec_extra_fdt_size_ppc64(image));
 	if (!fdt) {
 		pr_err("Error setting up the new device tree.\n");
 		ret = -EINVAL;
diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
index 3609de30a170..297f73795a1f 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -927,37 +927,27 @@ int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
 }
 
 /**
- * kexec_fdt_totalsize_ppc64 - Return the estimated size needed to setup FDT
- *                             for kexec/kdump kernel.
- * @image:                     kexec image being loaded.
+ * kexec_extra_fdt_size_ppc64 - Return the estimated additional size needed to
+ *                              setup FDT for kexec/kdump kernel.
+ * @image:                      kexec image being loaded.
  *
- * Returns the estimated size needed for kexec/kdump kernel FDT.
+ * Returns the estimated extra size needed for kexec/kdump kernel FDT.
  */
-unsigned int kexec_fdt_totalsize_ppc64(struct kimage *image)
+unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image)
 {
-	unsigned int fdt_size;
 	u64 usm_entries;
 
-	/*
-	 * The below estimate more than accounts for a typical kexec case where
-	 * the additional space is to accommodate things like kexec cmdline,
-	 * chosen node with properties for initrd start & end addresses and
-	 * a property to indicate kexec boot..
-	 */
-	fdt_size = fdt_totalsize(initial_boot_params) + (2 * COMMAND_LINE_SIZE);
 	if (image->type != KEXEC_TYPE_CRASH)
-		return fdt_size;
+		return 0;
 
 	/*
-	 * For kdump kernel, also account for linux,usable-memory and
+	 * For kdump kernel, account for linux,usable-memory and
 	 * linux,drconf-usable-memory properties. Get an approximate on the
 	 * number of usable memory entries and use for FDT size estimation.
 	 */
 	usm_entries = ((memblock_end_of_DRAM() / drmem_lmb_size()) +
 		       (2 * (resource_size(&crashk_res) / drmem_lmb_size())));
-	fdt_size += (unsigned int)(usm_entries * sizeof(u64));
-
-	return fdt_size;
+	return (unsigned int)(usm_entries * sizeof(u64));
 }
 
 /**

Re: [PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

From: Hari Bathini <hbathini@linux.ibm.com>
Date: 2021-02-20 17:14:28


On 20/02/21 6:22 am, Thiago Jung Bauermann wrote:
Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump
kernel") fixed how elf64_load() estimates the FDT size needed by the
crashdump kernel.

At the same time, commit 130b2d59cec0 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic
function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That
change made the code overestimate it a bit by counting twice the space
required for the kernel command line and /chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.
Thanks for fixing this, Thiago.

Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
quoted hunk
Signed-off-by: Thiago Jung Bauermann <redacted>
Reviewed-by: Lakshmi Ramasubramanian <redacted>
---
  arch/powerpc/include/asm/kexec.h  |  2 +-
  arch/powerpc/kexec/elf_64.c       |  2 +-
  arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------
  3 files changed, 10 insertions(+), 20 deletions(-)

Applies on top of next-20210219.

Changes since v1:

- Adjusted comment describing kexec_extra_fdt_size_ppc64() as suggested
   by Lakshmi.
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index baab158e215c..5a11cc8d2350 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -128,7 +128,7 @@ int load_crashdump_segments_ppc64(struct kimage *image,
  int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
  			  const void *fdt, unsigned long kernel_load_addr,
  			  unsigned long fdt_load_addr);
-unsigned int kexec_fdt_totalsize_ppc64(struct kimage *image);
+unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image);
  int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
  			unsigned long initrd_load_addr,
  			unsigned long initrd_len, const char *cmdline);
diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index 0492ca6003f3..5a569bb51349 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -104,7 +104,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
  
  	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
  					   initrd_len, cmdline,
-					   kexec_fdt_totalsize_ppc64(image));
+					   kexec_extra_fdt_size_ppc64(image));
  	if (!fdt) {
  		pr_err("Error setting up the new device tree.\n");
  		ret = -EINVAL;
diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
index 3609de30a170..297f73795a1f 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -927,37 +927,27 @@ int setup_purgatory_ppc64(struct kimage *image, const void *slave_code,
  }
  
  /**
- * kexec_fdt_totalsize_ppc64 - Return the estimated size needed to setup FDT
- *                             for kexec/kdump kernel.
- * @image:                     kexec image being loaded.
+ * kexec_extra_fdt_size_ppc64 - Return the estimated additional size needed to
+ *                              setup FDT for kexec/kdump kernel.
+ * @image:                      kexec image being loaded.
   *
- * Returns the estimated size needed for kexec/kdump kernel FDT.
+ * Returns the estimated extra size needed for kexec/kdump kernel FDT.
   */
-unsigned int kexec_fdt_totalsize_ppc64(struct kimage *image)
+unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image)
  {
-	unsigned int fdt_size;
  	u64 usm_entries;
  
-	/*
-	 * The below estimate more than accounts for a typical kexec case where
-	 * the additional space is to accommodate things like kexec cmdline,
-	 * chosen node with properties for initrd start & end addresses and
-	 * a property to indicate kexec boot..
-	 */
-	fdt_size = fdt_totalsize(initial_boot_params) + (2 * COMMAND_LINE_SIZE);
  	if (image->type != KEXEC_TYPE_CRASH)
-		return fdt_size;
+		return 0;
  
  	/*
-	 * For kdump kernel, also account for linux,usable-memory and
+	 * For kdump kernel, account for linux,usable-memory and
  	 * linux,drconf-usable-memory properties. Get an approximate on the
  	 * number of usable memory entries and use for FDT size estimation.
  	 */
  	usm_entries = ((memblock_end_of_DRAM() / drmem_lmb_size()) +
  		       (2 * (resource_size(&crashk_res) / drmem_lmb_size())));
-	fdt_size += (unsigned int)(usm_entries * sizeof(u64));
-
-	return fdt_size;
+	return (unsigned int)(usm_entries * sizeof(u64));
  }
  
  /**

Re: [PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

From: Rob Herring <robh@kernel.org>
Date: 2021-03-10 02:09:10

On Fri, Feb 19, 2021 at 6:52 PM Thiago Jung Bauermann
[off-list ref] wrote:
Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump
kernel") fixed how elf64_load() estimates the FDT size needed by the
crashdump kernel.

At the same time, commit 130b2d59cec0 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic
function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That
change made the code overestimate it a bit by counting twice the space
required for the kernel command line and /chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.

Signed-off-by: Thiago Jung Bauermann <redacted>
Reviewed-by: Lakshmi Ramasubramanian <redacted>
---
 arch/powerpc/include/asm/kexec.h  |  2 +-
 arch/powerpc/kexec/elf_64.c       |  2 +-
 arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------
 3 files changed, 10 insertions(+), 20 deletions(-)
I ended up delaying the referenced series til 5.13, but have applied
it now. Can I get an ack from the powerpc maintainers on this one?
I'll fixup the commit log to make sense given the commit id's aren't
valid.

Rob

Re: [PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

From: Lakshmi Ramasubramanian <hidden>
Date: 2021-03-10 02:32:04

On 3/9/21 6:08 PM, Rob Herring wrote:

Hi Rob,
On Fri, Feb 19, 2021 at 6:52 PM Thiago Jung Bauermann
[off-list ref] wrote:
quoted
Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump
kernel") fixed how elf64_load() estimates the FDT size needed by the
crashdump kernel.

At the same time, commit 130b2d59cec0 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic
function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That
change made the code overestimate it a bit by counting twice the space
required for the kernel command line and /chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.

Signed-off-by: Thiago Jung Bauermann <redacted>
Reviewed-by: Lakshmi Ramasubramanian <redacted>
---
  arch/powerpc/include/asm/kexec.h  |  2 +-
  arch/powerpc/kexec/elf_64.c       |  2 +-
  arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------
  3 files changed, 10 insertions(+), 20 deletions(-)
I ended up delaying the referenced series til 5.13, but have applied
it now. Can I get an ack from the powerpc maintainers on this one?
I'll fixup the commit log to make sense given the commit id's aren't
valid.
I checked the change applied in linux-next branch and also Device Tree's 
for-next branch - it looks like v1 of Thiago's patch has been applied. 
Could you please pick up the v2 patch?

thanks,
  -lakshmi

Re: [PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

From: Rob Herring <robh@kernel.org>
Date: 2021-03-10 03:10:24

On Tue, Mar 9, 2021 at 7:31 PM Lakshmi Ramasubramanian
[off-list ref] wrote:
On 3/9/21 6:08 PM, Rob Herring wrote:

Hi Rob,
quoted
On Fri, Feb 19, 2021 at 6:52 PM Thiago Jung Bauermann
[off-list ref] wrote:
quoted
Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump
kernel") fixed how elf64_load() estimates the FDT size needed by the
crashdump kernel.

At the same time, commit 130b2d59cec0 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic
function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That
change made the code overestimate it a bit by counting twice the space
required for the kernel command line and /chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.

Signed-off-by: Thiago Jung Bauermann <redacted>
Reviewed-by: Lakshmi Ramasubramanian <redacted>
---
  arch/powerpc/include/asm/kexec.h  |  2 +-
  arch/powerpc/kexec/elf_64.c       |  2 +-
  arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------
  3 files changed, 10 insertions(+), 20 deletions(-)
I ended up delaying the referenced series til 5.13, but have applied
it now. Can I get an ack from the powerpc maintainers on this one?
I'll fixup the commit log to make sense given the commit id's aren't
valid.
I checked the change applied in linux-next branch and also Device Tree's
for-next branch - it looks like v1 of Thiago's patch has been applied.
Could you please pick up the v2 patch?
Huh? This patch (v2) hasn't been applied to any tree AFAICT.

Rob

Re: [PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2021-03-10 05:04:12

Rob Herring [off-list ref] writes:
On Fri, Feb 19, 2021 at 6:52 PM Thiago Jung Bauermann
[off-list ref] wrote:
quoted
Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump
kernel") fixed how elf64_load() estimates the FDT size needed by the
crashdump kernel.

At the same time, commit 130b2d59cec0 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic
function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That
change made the code overestimate it a bit by counting twice the space
required for the kernel command line and /chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.

Signed-off-by: Thiago Jung Bauermann <redacted>
Reviewed-by: Lakshmi Ramasubramanian <redacted>
---
 arch/powerpc/include/asm/kexec.h  |  2 +-
 arch/powerpc/kexec/elf_64.c       |  2 +-
 arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------
 3 files changed, 10 insertions(+), 20 deletions(-)
I ended up delaying the referenced series til 5.13, but have applied
it now. Can I get an ack from the powerpc maintainers on this one?
I'll fixup the commit log to make sense given the commit id's aren't
valid.
Thanks for handling it.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>


cheers

Re: [PATCH v2] powerpc/kexec_file: Restore FDT size estimation for kdump kernel

From: Rob Herring <robh@kernel.org>
Date: 2021-03-11 16:54:07

On Fri, 19 Feb 2021 21:52:04 -0300, Thiago Jung Bauermann wrote:
Commit 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump
kernel") fixed how elf64_load() estimates the FDT size needed by the
crashdump kernel.

At the same time, commit 130b2d59cec0 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the same code to use the generic
function of_kexec_alloc_and_setup_fdt() to calculate the FDT size. That
change made the code overestimate it a bit by counting twice the space
required for the kernel command line and /chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.

Signed-off-by: Thiago Jung Bauermann <redacted>
Reviewed-by: Lakshmi Ramasubramanian <redacted>
---
 arch/powerpc/include/asm/kexec.h  |  2 +-
 arch/powerpc/kexec/elf_64.c       |  2 +-
 arch/powerpc/kexec/file_load_64.c | 26 ++++++++------------------
 3 files changed, 10 insertions(+), 20 deletions(-)

Applies on top of next-20210219.

Changes since v1:

- Adjusted comment describing kexec_extra_fdt_size_ppc64() as suggested
  by Lakshmi.
Applied, thanks!
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