[PATCH v7 04/10] arm64: hyperv: Add memory alloc/free functions for Hyper-V size pages
From: Michael Kelley <hidden>
Date: 2020-08-24 16:52:56
Also in:
linux-arch, linux-efi, linux-hyperv, lkml
Subsystem:
arm64 port (aarch64 architecture), generic include/asm header files, hyper-v/azure core and drivers, the rest · Maintainers:
Catalin Marinas, Will Deacon, Arnd Bergmann, "K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds
Add ARM64-specific code to allocate memory with HV_HYP_PAGE_SIZE size and alignment. These are for use when pages need to be shared with Hyper-V. Separate functions are needed as the page size used by Hyper-V may not be the same as the guest page size. This code is built only when CONFIG_HYPERV is enabled. Signed-off-by: Michael Kelley <redacted> --- arch/arm64/hyperv/hv_core.c | 43 ++++++++++++++++++++++++++++++++++++++++++ include/asm-generic/mshyperv.h | 5 +++++ 2 files changed, 48 insertions(+)
diff --git a/arch/arm64/hyperv/hv_core.c b/arch/arm64/hyperv/hv_core.c
index 9b35011..14e41b7 100644
--- a/arch/arm64/hyperv/hv_core.c
+++ b/arch/arm64/hyperv/hv_core.c@@ -24,6 +24,49 @@ /* + * Functions for allocating and freeing memory with size and + * alignment HV_HYP_PAGE_SIZE. These functions are needed because + * the guest page size may not be the same as the Hyper-V page + * size. We depend upon kmalloc() aligning power-of-two size + * allocations to the allocation size boundary, so that the + * allocated memory appears to Hyper-V as a page of the size + * it expects. + * + * These functions are used by arm64 specific code as well as + * arch independent Hyper-V drivers. + */ + +void *hv_alloc_hyperv_page(void) +{ + BUILD_BUG_ON(PAGE_SIZE < HV_HYP_PAGE_SIZE); + + if (PAGE_SIZE == HV_HYP_PAGE_SIZE) + return (void *)__get_free_page(GFP_KERNEL); + else + return kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL); +} +EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page); + +void *hv_alloc_hyperv_zeroed_page(void) +{ + if (PAGE_SIZE == HV_HYP_PAGE_SIZE) + return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + else + return kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL); +} +EXPORT_SYMBOL_GPL(hv_alloc_hyperv_zeroed_page); + +void hv_free_hyperv_page(unsigned long addr) +{ + if (PAGE_SIZE == HV_HYP_PAGE_SIZE) + free_page(addr); + else + kfree((void *)addr); +} +EXPORT_SYMBOL_GPL(hv_free_hyperv_page); + + +/* * hv_do_hypercall- Invoke the specified hypercall */ u64 hv_do_hypercall(u64 control, void *input, void *output)
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index c577996..d345a59 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h@@ -101,6 +101,11 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type) extern int vmbus_interrupt; +void *hv_alloc_hyperv_page(void); +void *hv_alloc_hyperv_zeroed_page(void); +void hv_free_hyperv_page(unsigned long addr); + + #if IS_ENABLED(CONFIG_HYPERV) /* * Hypervisor's notion of virtual processor ID is different from
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1.8.3.1
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