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Message-ID: <20241211232754.1583023-4-kaleshsingh@google.com>
Date: Wed, 11 Dec 2024 15:27:41 -0800
From: Kalesh Singh <kaleshsingh@...gle.com>
To: akpm@...ux-foundation.org, vbabka@...e.cz, yang@...amperecomputing.com,
riel@...riel.com, david@...hat.com, minchan@...nel.org, jyescas@...gle.com
Cc: linux@...linux.org.uk, tsbogend@...ha.franken.de,
James.Bottomley@...senPartnership.com, ysato@...rs.sourceforge.jp,
dalias@...c.org, glaubitz@...sik.fu-berlin.de, davem@...emloft.net,
andreas@...sler.com, tglx@...utronix.de, bp@...en8.de,
dave.hansen@...ux.intel.com, x86@...nel.org, chris@...kel.net,
jcmvbkbc@...il.com, bhelgaas@...gle.com, jason.andryuk@....com,
leitao@...ian.org, linux-alpha@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-snps-arc@...ts.infradead.org, linux-arm-kernel@...ts.infradead.org,
linux-csky@...r.kernel.org, loongarch@...ts.linux.dev,
linux-mips@...r.kernel.org, linux-parisc@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org, linux-s390@...r.kernel.org,
linux-sh@...r.kernel.org, sparclinux@...r.kernel.org, linux-mm@...ck.org,
kernel-team@...roid.com, android-mm@...gle.com,
Kalesh Singh <kaleshsingh@...gle.com>
Subject: [PATCH mm-unstable v2 03/16] mm: arm: Introduce arch_mmap_hint()
Introduce arm arch_mmap_hint() and define HAVE_ARCH_MMAP_HINT.
This is a preparatory patch, no functional change is introduced.
Signed-off-by: Kalesh Singh <kaleshsingh@...gle.com>
---
Changes in v2:
- MAP_FIXED case is also handled in arch_mmap_hint() since this is just a
special case of the hint addr being "enforced", per Yang Shi.
- Consolidate error handling in arch_mmap_hint().
arch/arm/include/asm/pgtable.h | 1 +
arch/arm/mm/mmap.c | 107 ++++++++++++++-------------------
2 files changed, 46 insertions(+), 62 deletions(-)
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index be91e376df79..1433b3ff4caa 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -330,6 +330,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
*/
#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+#define HAVE_ARCH_MMAP_HINT
#endif /* !__ASSEMBLY__ */
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 3dbb383c26d5..15e7e4348af7 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -17,6 +17,41 @@
((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
(((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ bool aliasing = cache_is_vipt_aliasing();
+ bool do_align;
+
+ /* requested length too big for entire address space */
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ /*
+ * We enforce the MAP_FIXED case.
+ */
+ if (flags & MAP_FIXED) {
+ if (aliasing && flags & MAP_SHARED &&
+ (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
+ return -EINVAL;
+ return addr;
+ }
+
+ /*
+ * We only need to do colour alignment if either the I or D
+ * caches alias.
+ */
+ do_align = aliasing && (filp || (flags & MAP_SHARED));
+
+ if (do_align)
+ addr = COLOUR_ALIGN(addr, pgoff);
+ else
+ addr = PAGE_ALIGN(addr);
+
+ return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
/*
* We need to ensure that shared mappings are correctly aligned to
* avoid aliasing issues with VIPT caches. We need to ensure that
@@ -32,42 +67,15 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long flags, vm_flags_t vm_flags)
{
struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
- int do_align = 0;
- int aliasing = cache_is_vipt_aliasing();
struct vm_unmapped_area_info info = {};
+ bool aliasing = cache_is_vipt_aliasing();
+ bool do_align;
- /*
- * We only need to do colour alignment if either the I or D
- * caches alias.
- */
- if (aliasing)
- do_align = filp || (flags & MAP_SHARED);
-
- /*
- * We enforce the MAP_FIXED case.
- */
- if (flags & MAP_FIXED) {
- if (aliasing && flags & MAP_SHARED &&
- (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
- return -EINVAL;
+ addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+ if (addr)
return addr;
- }
-
- if (len > TASK_SIZE)
- return -ENOMEM;
- if (addr) {
- if (do_align)
- addr = COLOUR_ALIGN(addr, pgoff);
- else
- addr = PAGE_ALIGN(addr);
-
- vma = find_vma(mm, addr);
- if (TASK_SIZE - len >= addr &&
- (!vma || addr + len <= vm_start_gap(vma)))
- return addr;
- }
+ do_align = aliasing && (filp || (flags & MAP_SHARED));
info.length = len;
info.low_limit = mm->mmap_base;
@@ -82,42 +90,17 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
const unsigned long len, const unsigned long pgoff,
const unsigned long flags, vm_flags_t vm_flags)
{
- struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
- int do_align = 0;
- int aliasing = cache_is_vipt_aliasing();
struct vm_unmapped_area_info info = {};
+ bool aliasing = cache_is_vipt_aliasing();
+ bool do_align;
- /*
- * We only need to do colour alignment if either the I or D
- * caches alias.
- */
- if (aliasing)
- do_align = filp || (flags & MAP_SHARED);
-
- /* requested length too big for entire address space */
- if (len > TASK_SIZE)
- return -ENOMEM;
-
- if (flags & MAP_FIXED) {
- if (aliasing && flags & MAP_SHARED &&
- (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
- return -EINVAL;
+ addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+ if (addr)
return addr;
- }
- /* requesting a specific address */
- if (addr) {
- if (do_align)
- addr = COLOUR_ALIGN(addr, pgoff);
- else
- addr = PAGE_ALIGN(addr);
- vma = find_vma(mm, addr);
- if (TASK_SIZE - len >= addr &&
- (!vma || addr + len <= vm_start_gap(vma)))
- return addr;
- }
+ do_align = aliasing && (filp || (flags & MAP_SHARED));
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
--
2.47.0.338.g60cca15819-goog
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