[PATCH 24/25] mm: remove the HMM config option

Christoph Hellwig
2019-06-26T12:28:35Z

All the mm/hmm.c code is better keyed off HMM_MIRROR. Also let nouveau
depend on it instead of the mix of a dummy dependency symbol plus the
actually selected one. Drop various odd dependencies, as the code is
pretty portable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/gpu/drm/nouveau/Kconfig | 3 +--
include/linux/hmm.h | 5 +----
include/linux/mm_types.h | 2 +-
mm/Kconfig | 27 ++++-----------------------
mm/Makefile | 2 +-
mm/hmm.c | 2 --
6 files changed, 8 insertions(+), 33 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig
index 6303d203ab1d..66c839d8e9d1 100644
--- a/drivers/gpu/drm/nouveau/Kconfig
+++ b/drivers/gpu/drm/nouveau/Kconfig
@@ -84,11 +84,10 @@ config DRM_NOUVEAU_BACKLIGHT

config DRM_NOUVEAU_SVM
bool "(EXPERIMENTAL) Enable SVM (Shared Virtual Memory) support"
- depends on ARCH_HAS_HMM
depends on DEVICE_PRIVATE
depends on DRM_NOUVEAU
+ depends on HMM_MIRROR
depends on STAGING
- select HMM_MIRROR
default n
help
Say Y here if you want to enable experimental support for
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 3d00e9550e77..b697496e85ba 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -62,7 +62,7 @@
#include <linux/kconfig.h>
#include <asm/pgtable.h>

-#if IS_ENABLED(CONFIG_HMM)
+#ifdef CONFIG_HMM_MIRROR

#include <linux/device.h>
#include <linux/migrate.h>
@@ -332,9 +332,6 @@ static inline uint64_t hmm_pfn_from_pfn(const struct hmm_range *range,
return hmm_device_entry_from_pfn(range, pfn);
}

-
-
-#if IS_ENABLED(CONFIG_HMM_MIRROR)
/*
* Mirroring: how to synchronize device page table with CPU page table.
*
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index f33a1289c101..8d37182f8dbe 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -501,7 +501,7 @@ struct mm_struct {
#endif
struct work_struct async_put_work;

-#if IS_ENABLED(CONFIG_HMM)
+#ifdef CONFIG_HMM_MIRROR
/* HMM needs to track a few things per mm */
struct hmm *hmm;
#endif
diff --git a/mm/Kconfig b/mm/Kconfig
index eecf037a54b3..1e426c26b1d6 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -669,37 +669,18 @@ config ZONE_DEVICE

If FS_DAX is enabled, then say Y.

-config ARCH_HAS_HMM_MIRROR
- bool
- default y
- depends on (X86_64 || PPC64)
- depends on MMU && 64BIT
-
-config ARCH_HAS_HMM
- bool
- depends on (X86_64 || PPC64)
- depends on ZONE_DEVICE
- depends on MMU && 64BIT
- depends on MEMORY_HOTPLUG
- depends on MEMORY_HOTREMOVE
- depends on SPARSEMEM_VMEMMAP
- default y
-
config MIGRATE_VMA_HELPER
bool

config DEV_PAGEMAP_OPS
bool

-config HMM
- bool
- select MMU_NOTIFIER
- select MIGRATE_VMA_HELPER
-
config HMM_MIRROR
bool "HMM mirror CPU page table into a device page table"
- depends on ARCH_HAS_HMM
- select HMM
+ depends on (X86_64 || PPC64)
+ depends on MMU && 64BIT
+ select MMU_NOTIFIER
+ select MIGRATE_VMA_HELPER
help
Select HMM_MIRROR if you want to mirror range of the CPU page table of a
process into a device page table. Here, mirror means "keep synchronized".
diff --git a/mm/Makefile b/mm/Makefile
index ac5e5ba78874..91c99040065c 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -102,5 +102,5 @@ obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o
obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o
obj-$(CONFIG_HARDENED_USERCOPY) += usercopy.o
obj-$(CONFIG_PERCPU_STATS) += percpu-stats.o
-obj-$(CONFIG_HMM) += hmm.o
+obj-$(CONFIG_HMM_MIRROR) += hmm.o
obj-$(CONFIG_MEMFD_CREATE) += memfd.o
diff --git a/mm/hmm.c b/mm/hmm.c
index 90ca0cdab9db..d62ce64d6bca 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -25,7 +25,6 @@
#include <linux/mmu_notifier.h>
#include <linux/memory_hotplug.h>

-#if IS_ENABLED(CONFIG_HMM_MIRROR)
static const struct mmu_notifier_ops hmm_mmu_notifier_ops;

static inline struct hmm *mm_get_hmm(struct mm_struct *mm)
@@ -1326,4 +1325,3 @@ long hmm_range_dma_unmap(struct hmm_range *range,
return cpages;
}
EXPORT_SYMBOL(hmm_range_dma_unmap);
-#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */
--
2.20.1