[PATCH 0/2] ZONE_DEVICE cleanups

[PATCH 0/2] ZONE_DEVICE cleanups

[Dan Williams]

Minor cleanups for CONFIG_ZONE_DEVICE.

Andrew, killing the CONFIG_EXPERT dependency might be worth applying for
4.7, but otherwise these can wait for 4.8. These have received a "build
success" notification from the kbuild robot over 58 configs.  Please
apply, or ack and I'll queue them with the rest of the libnvdimm-for-4.8
updates.

---

Dan Williams (2):
      mm: CONFIG_ZONE_DEVICE stop depending on CONFIG_EXPERT
      mm: cleanup ifdef guards for vmem_altmap


 include/linux/memremap.h |    2 +-
 kernel/memremap.c        |    8 --------
 mm/Kconfig               |    2 +-
 3 files changed, 2 insertions(+), 10 deletions(-)

[PATCH 1/2] mm: CONFIG_ZONE_DEVICE stop depending on CONFIG_EXPERT

[Dan Williams]

When it was first introduced CONFIG_ZONE_DEVICE depended on disabling
CONFIG_ZONE_DMA, a configuration choice reserved for "experts".
However, now that the ZONE_DMA conflict has been eliminated it no longer
makes sense to require CONFIG_EXPERT.

Reported-by: Eric Sandeen <sandeen@redhat.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 mm/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/Kconfig b/mm/Kconfig
index 3e2daef3c946..d109a7a0c1c4 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -673,7 +673,7 @@ config IDLE_PAGE_TRACKING
 	  See Documentation/vm/idle_page_tracking.txt for more details.
 
 config ZONE_DEVICE
-	bool "Device memory (pmem, etc...) hotplug support" if EXPERT
+	bool "Device memory (pmem, etc...) hotplug support"
 	depends on MEMORY_HOTPLUG
 	depends on MEMORY_HOTREMOVE
 	depends on SPARSEMEM_VMEMMAP

[PATCH 2/2] mm: cleanup ifdef guards for vmem_altmap

[Dan Williams]

Now that ZONE_DEVICE depends on SPARSEMEM_VMEMMAP we can simplify some
ifdef guards to just ZONE_DEVICE.

Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 include/linux/memremap.h |    2 +-
 kernel/memremap.c        |    8 --------
 2 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index bcaa634139a9..93416196ba64 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -26,7 +26,7 @@ struct vmem_altmap {
 unsigned long vmem_altmap_offset(struct vmem_altmap *altmap);
 void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns);
 
-#if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_ZONE_DEVICE)
+#ifdef CONFIG_ZONE_DEVICE
 struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start);
 #else
 static inline struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 017532193fb1..ddb3247a872a 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -308,12 +308,6 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
 	if (is_ram == REGION_INTERSECTS)
 		return __va(res->start);
 
-	if (altmap && !IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) {
-		dev_err(dev, "%s: altmap requires CONFIG_SPARSEMEM_VMEMMAP=y\n",
-				__func__);
-		return ERR_PTR(-ENXIO);
-	}
-
 	if (!ref)
 		return ERR_PTR(-EINVAL);
 
@@ -401,7 +395,6 @@ void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns)
 	altmap->alloc -= nr_pfns;
 }
 
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
 struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
 {
 	/*
@@ -427,5 +420,4 @@ struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
 
 	return pgmap ? pgmap->altmap : NULL;
 }
-#endif /* CONFIG_SPARSEMEM_VMEMMAP */
 #endif /* CONFIG_ZONE_DEVICE */

Re: [PATCH 1/2] mm: CONFIG_ZONE_DEVICE stop depending on CONFIG_EXPERT

[Jeff Moyer]

Dan Williams <dan.j.williams@intel.com> writes:

> When it was first introduced CONFIG_ZONE_DEVICE depended on disabling
> CONFIG_ZONE_DMA, a configuration choice reserved for "experts".
> However, now that the ZONE_DMA conflict has been eliminated it no longer
> makes sense to require CONFIG_EXPERT.
>
> Reported-by: Eric Sandeen <sandeen@redhat.com>
> Reported-by: Jeff Moyer <jmoyer@redhat.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Acked-by: Jeff Moyer <jmoyer@redhat.com>

> ---
>  mm/Kconfig |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 3e2daef3c946..d109a7a0c1c4 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -673,7 +673,7 @@ config IDLE_PAGE_TRACKING
>  	  See Documentation/vm/idle_page_tracking.txt for more details.
>  
>  config ZONE_DEVICE
> -	bool "Device memory (pmem, etc...) hotplug support" if EXPERT
> +	bool "Device memory (pmem, etc...) hotplug support"
>  	depends on MEMORY_HOTPLUG
>  	depends on MEMORY_HOTREMOVE
>  	depends on SPARSEMEM_VMEMMAP