linux-kernel - [PATCH mm-unstable 14/17] mm: xtensa: Introduce arch_mmap

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Message-ID: <20241210024119.2488608-15-kaleshsingh@google.com>
Date: Mon,  9 Dec 2024 18:41:16 -0800
From: Kalesh Singh <kaleshsingh@...gle.com>
To: akpm@...ux-foundation.org, vbabka@...e.cz, yang@...amperecomputing.com, 
	riel@...riel.com, david@...hat.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 14/17] mm: xtensa: Introduce arch_mmap_hint()

Introduce xtensa arch_mmap_hint() and define HAVE_ARCH_MMAP_HINT.

If a sufficiently sized hole doesn't exist at the hint address,
fallback to searching the entire valid VA space instead of only
the VA space above the hint address.

Signed-off-by: Kalesh Singh <kaleshsingh@...gle.com>
---
 arch/xtensa/include/asm/pgtable.h |  1 +
 arch/xtensa/kernel/syscall.c      | 26 ++++++++++++++++++++++++--
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 1647a7cc3fbf..31b7da0805ec 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -425,5 +425,6 @@ void update_mmu_tlb_range(struct vm_area_struct *vma,
  * SHM area cache aliasing for userland.
  */
 #define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_MMAP_HINT
 
 #endif /* _XTENSA_PGTABLE_H */
diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index dc54f854c2f5..353cce1ac9f1 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -54,6 +54,24 @@ asmlinkage long xtensa_fadvise64_64(int fd, int advice,
 }
 
 #ifdef CONFIG_MMU
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+			     unsigned long len, unsigned long pgoff,
+			     unsigned long flags)
+{
+	if (!addr)
+		return 0;
+
+	if (len > TASK_SIZE)
+		return 0;
+
+	if (flags & MAP_SHARED)
+		addr = COLOUR_ALIGN(addr, pgoff);
+	else
+		addr = PAGE_ALIGN(addr);
+
+	return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags,
 		vm_flags_t vm_flags)
@@ -73,8 +91,12 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 
 	if (len > TASK_SIZE)
 		return -ENOMEM;
-	if (!addr)
-		addr = TASK_UNMAPPED_BASE;
+
+	addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+	if (addr)
+		return addr;
+
+	addr = TASK_UNMAPPED_BASE;
 
 	if (flags & MAP_SHARED)
 		addr = COLOUR_ALIGN(addr, pgoff);
-- 
2.47.0.338.g60cca15819-goog