[PATCH] COMPLETELY UNTESTED: highmem: Remove direct calls to flush_kernel_dcache_page
From: Ira Weiny
Date: Fri Jun 11 2021 - 21:24:27 EST
When to call flush_kernel_dcache_page() is confusing and inconsistent. For
architectures which may need to do something the core kmap code should be
leveraged to handle this when direct kernel access is needed.
Like parisc define kunmap_flush_on_unmap() to be called when pages are
unmapped on arm, csky, mpis, nds32, and sh.
Remove all direct calls to flush_kernel_dcache_page() and let the
kunmap() code do this for the users.
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-csky@xxxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: linux-sh@xxxxxxxxxxxxxxx
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: linux-mmc@xxxxxxxxxxxxxxx
Cc: linux-scsi@xxxxxxxxxxxxxxx
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
Documentation/core-api/cachetlb.rst | 13 -------------
arch/arm/include/asm/cacheflush.h | 6 ++++++
arch/csky/abiv1/inc/abi/cacheflush.h | 6 ++++++
arch/mips/include/asm/cacheflush.h | 6 ++++++
arch/nds32/include/asm/cacheflush.h | 6 ++++++
arch/sh/include/asm/cacheflush.h | 6 ++++++
drivers/crypto/omap-crypto.c | 3 ---
drivers/mmc/host/mmc_spi.c | 3 ---
drivers/scsi/aacraid/aachba.c | 1 -
fs/exec.c | 3 ---
include/linux/highmem.h | 3 ---
lib/scatterlist.c | 4 ----
12 files changed, 30 insertions(+), 30 deletions(-)
diff --git a/Documentation/core-api/cachetlb.rst b/Documentation/core-api/cachetlb.rst
index fe4290e26729..5c39de30e91f 100644
--- a/Documentation/core-api/cachetlb.rst
+++ b/Documentation/core-api/cachetlb.rst
@@ -351,19 +351,6 @@ maps this page at its virtual address.
architectures). For incoherent architectures, it should flush
the cache of the page at vmaddr.
- ``void flush_kernel_dcache_page(struct page *page)``
-
- When the kernel needs to modify a user page is has obtained
- with kmap, it calls this function after all modifications are
- complete (but before kunmapping it) to bring the underlying
- page up to date. It is assumed here that the user has no
- incoherent cached copies (i.e. the original page was obtained
- from a mechanism like get_user_pages()). The default
- implementation is a nop and should remain so on all coherent
- architectures. On incoherent architectures, this should flush
- the kernel cache for page (using page_address(page)).
-
-
``void flush_icache_range(unsigned long start, unsigned long end)``
When the kernel stores into addresses that it will execute
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index 2e24e765e6d3..1b7cb0af707f 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -315,6 +315,12 @@ static inline void flush_anon_page(struct vm_area_struct *vma,
#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
extern void flush_kernel_dcache_page(struct page *);
+#define ARCH_HAS_FLUSH_ON_KUNMAP
+static inline void kunmap_flush_on_unmap(void *addr)
+{
+ flush_kernel_dcache_page_addr(addr);
+}
+
#define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages)
#define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages)
diff --git a/arch/csky/abiv1/inc/abi/cacheflush.h b/arch/csky/abiv1/inc/abi/cacheflush.h
index 6cab7afae962..e1ff554850f8 100644
--- a/arch/csky/abiv1/inc/abi/cacheflush.h
+++ b/arch/csky/abiv1/inc/abi/cacheflush.h
@@ -17,6 +17,12 @@ extern void flush_dcache_page(struct page *);
#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
extern void flush_kernel_dcache_page(struct page *);
+#define ARCH_HAS_FLUSH_ON_KUNMAP
+static inline void kunmap_flush_on_unmap(void *addr)
+{
+ flush_kernel_dcache_page_addr(addr);
+}
+
#define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages)
#define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages)
diff --git a/arch/mips/include/asm/cacheflush.h b/arch/mips/include/asm/cacheflush.h
index d687b40b9fbb..c3043b600008 100644
--- a/arch/mips/include/asm/cacheflush.h
+++ b/arch/mips/include/asm/cacheflush.h
@@ -132,6 +132,12 @@ static inline void flush_kernel_dcache_page(struct page *page)
flush_dcache_page(page);
}
+#define ARCH_HAS_FLUSH_ON_KUNMAP
+static inline void kunmap_flush_on_unmap(void *addr)
+{
+ flush_kernel_dcache_page_addr(addr);
+}
+
/*
* For now flush_kernel_vmap_range and invalidate_kernel_vmap_range both do a
* cache writeback and invalidate operation.
diff --git a/arch/nds32/include/asm/cacheflush.h b/arch/nds32/include/asm/cacheflush.h
index 7d6824f7c0e8..bae980846e2a 100644
--- a/arch/nds32/include/asm/cacheflush.h
+++ b/arch/nds32/include/asm/cacheflush.h
@@ -43,6 +43,12 @@ void invalidate_kernel_vmap_range(void *addr, int size);
#define flush_dcache_mmap_lock(mapping) xa_lock_irq(&(mapping)->i_pages)
#define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&(mapping)->i_pages)
+#define ARCH_HAS_FLUSH_ON_KUNMAP
+static inline void kunmap_flush_on_unmap(void *addr)
+{
+ flush_kernel_dcache_page_addr(addr);
+}
+
#else
void flush_icache_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long addr, int len);
diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h
index 4486a865ff62..2e23a8d71aa7 100644
--- a/arch/sh/include/asm/cacheflush.h
+++ b/arch/sh/include/asm/cacheflush.h
@@ -78,6 +78,12 @@ static inline void flush_kernel_dcache_page(struct page *page)
flush_dcache_page(page);
}
+#define ARCH_HAS_FLUSH_ON_KUNMAP
+static inline void kunmap_flush_on_unmap(void *addr)
+{
+ flush_kernel_dcache_page_addr(addr);
+}
+
extern void copy_to_user_page(struct vm_area_struct *vma,
struct page *page, unsigned long vaddr, void *dst, const void *src,
unsigned long len);
diff --git a/drivers/crypto/omap-crypto.c b/drivers/crypto/omap-crypto.c
index 94b2dba90f0d..cbc5a4151c3c 100644
--- a/drivers/crypto/omap-crypto.c
+++ b/drivers/crypto/omap-crypto.c
@@ -183,9 +183,6 @@ static void omap_crypto_copy_data(struct scatterlist *src,
memcpy(dstb, srcb, amt);
- if (!PageSlab(sg_page(dst)))
- flush_kernel_dcache_page(sg_page(dst));
-
kunmap_atomic(srcb);
kunmap_atomic(dstb);
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 9776a03a10f5..e1aafbc6a0a1 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -947,9 +947,6 @@ mmc_spi_data_do(struct mmc_spi_host *host, struct mmc_command *cmd,
break;
}
- /* discard mappings */
- if (direction == DMA_FROM_DEVICE)
- flush_kernel_dcache_page(sg_page(sg));
kunmap(sg_page(sg));
if (dma_dev)
dma_unmap_page(dma_dev, dma_addr, PAGE_SIZE, dir);
diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index f1f62b5da8b7..8897d4ad78c6 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -25,7 +25,6 @@
#include <linux/completion.h>
#include <linux/blkdev.h>
#include <linux/uaccess.h>
-#include <linux/highmem.h> /* For flush_kernel_dcache_page */
#include <linux/module.h>
#include <asm/unaligned.h>
diff --git a/fs/exec.c b/fs/exec.c
index 18594f11c31f..da9faa2da36b 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -577,7 +577,6 @@ static int copy_strings(int argc, struct user_arg_ptr argv,
}
if (kmapped_page) {
- flush_kernel_dcache_page(kmapped_page);
kunmap(kmapped_page);
put_arg_page(kmapped_page);
}
@@ -595,7 +594,6 @@ static int copy_strings(int argc, struct user_arg_ptr argv,
ret = 0;
out:
if (kmapped_page) {
- flush_kernel_dcache_page(kmapped_page);
kunmap(kmapped_page);
put_arg_page(kmapped_page);
}
@@ -637,7 +635,6 @@ int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
kaddr = kmap_atomic(page);
flush_arg_page(bprm, pos & PAGE_MASK, page);
memcpy(kaddr + offset_in_page(pos), arg, bytes_to_copy);
- flush_kernel_dcache_page(page);
kunmap_atomic(kaddr);
put_arg_page(page);
}
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 832b49b50c7b..7ef83bf52a6c 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -131,9 +131,6 @@ static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page
#endif
#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
-static inline void flush_kernel_dcache_page(struct page *page)
-{
-}
static inline void flush_kernel_vmap_range(void *vaddr, int size)
{
}
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index a59778946404..579b323a8042 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -887,10 +887,6 @@ void sg_miter_stop(struct sg_mapping_iter *miter)
miter->__offset += miter->consumed;
miter->__remaining -= miter->consumed;
- if ((miter->__flags & SG_MITER_TO_SG) &&
- !PageSlab(miter->page))
- flush_kernel_dcache_page(miter->page);
-
if (miter->__flags & SG_MITER_ATOMIC) {
WARN_ON_ONCE(preemptible());
kunmap_atomic(miter->addr);
--
2.28.0.rc0.12.gb6a658bd00c9