[tip: core/mm] io-mapping: Cleanup atomic iomap

From: tip-bot2 for Thomas Gleixner
Date: Fri Nov 06 2020 - 18:27:21 EST


The following commit has been merged into the core/mm branch of tip:

Commit-ID: 351191ad55c8a1eccaf23e4187c62056229c0779
Gitweb: https://git.kernel.org/tip/351191ad55c8a1eccaf23e4187c62056229c0779
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Tue, 03 Nov 2020 10:27:32 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 06 Nov 2020 23:14:58 +01:00

io-mapping: Cleanup atomic iomap

Switch the atomic iomap implementation over to kmap_local and stick the
preempt/pagefault mechanics into the generic code similar to the
kmap_atomic variants.

Rename the x86 map function in preparation for a non-atomic variant.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20201103095858.625310005@xxxxxxxxxxxxx

---
arch/x86/include/asm/iomap.h | 9 +--------
arch/x86/mm/iomap_32.c | 6 ++----
include/linux/io-mapping.h | 8 ++++++--
3 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h
index 0be7a30..e2de092 100644
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -13,14 +13,7 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>

-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot);
-
-static inline void iounmap_atomic(void __iomem *vaddr)
-{
- kunmap_local_indexed((void __force *)vaddr);
- pagefault_enable();
- preempt_enable();
-}
+void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot);

int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);

diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index e0a40d7..9aaa756 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -44,7 +44,7 @@ void iomap_free(resource_size_t base, unsigned long size)
}
EXPORT_SYMBOL_GPL(iomap_free);

-void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot)
+void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
{
/*
* For non-PAT systems, translate non-WB request to UC- just in
@@ -60,8 +60,6 @@ void __iomem *iomap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot)
/* Filter out unsupported __PAGE_KERNEL* bits: */
pgprot_val(prot) &= __default_kernel_pte_mask;

- preempt_disable();
- pagefault_disable();
return (void __force __iomem *)__kmap_local_pfn_prot(pfn, prot);
}
-EXPORT_SYMBOL_GPL(iomap_atomic_pfn_prot);
+EXPORT_SYMBOL_GPL(__iomap_local_pfn_prot);
diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index 3b0940b..60e7c83 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -69,13 +69,17 @@ io_mapping_map_atomic_wc(struct io_mapping *mapping,

BUG_ON(offset >= mapping->size);
phys_addr = mapping->base + offset;
- return iomap_atomic_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
+ preempt_disable();
+ pagefault_disable();
+ return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot);
}

static inline void
io_mapping_unmap_atomic(void __iomem *vaddr)
{
- iounmap_atomic(vaddr);
+ kunmap_local_indexed((void __force *)vaddr);
+ pagefault_enable();
+ preempt_enable();
}

static inline void __iomem *