[PATCH 06/16] arm64: mm: Support MAP_BELOW_HINT

Charlie Jenkins
2024-08-28T05:50:00Z

Add support for MAP_BELOW_HINT to arch_get_mmap_base() and
arch_get_mmap_end().

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
arch/arm64/include/asm/processor.h | 34 +++++++++++++++++++++++++++++-----
1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index a67ca119bb91..39aabb1619f6 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -92,12 +92,36 @@
#endif /* CONFIG_COMPAT */

#ifndef CONFIG_ARM64_FORCE_52BIT
-#define arch_get_mmap_end(addr, len, flags) \
- (((addr) > DEFAULT_MAP_WINDOW) ? TASK_SIZE : DEFAULT_MAP_WINDOW)
+#define arch_get_mmap_end(addr, len, flags) \
+({ \
+ unsigned long mmap_end; \
+ typeof(flags) _flags = (flags); \
+ typeof(addr) _addr = (addr); \
+ typeof(len) _len = (len); \
+ if (_flags & MAP_BELOW_HINT && _addr != 0 && ((_addr + _len) > BIT(VA_BITS - 1))) \
+ mmap_end = (_addr + _len); \
+ else \
+ mmap_end = ((_addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE : DEFAULT_MAP_WINDOW); \
+ mmap_end \
+})
+
+#define arch_get_mmap_base(addr, len, base, flags) \
+({ \
+ unsigned long mmap_base; \
+ typeof(flags) _flags = (flags); \
+ typeof(addr) _addr = (addr); \
+ typeof(base) _base = (base); \
+ typeof(len) _len = (len); \
+ unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \
+ if (_flags & MAP_BELOW_HINT && _addr != 0 && ((_addr + _len) > BIT(VA_BITS - 1)))\
+ mmap_base = (_addr + _len) - rnd_gap; \
+ else \
+ mmap_end = ((_addr > DEFAULT_MAP_WINDOW) ? \
+ _base + TASK_SIZE - DEFAULT_MAP_WINDOW : \
+ _base); \
+ mmap_end \
+})

-#define arch_get_mmap_base(addr, len, base, flags) ((addr > DEFAULT_MAP_WINDOW) ? \
- base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
- base)
#endif /* CONFIG_ARM64_FORCE_52BIT */

extern phys_addr_t arm64_dma_phys_limit;

--
2.45.0