[PATCH v5 11/16] asm/io.h: Add ioremap_host_shared fallback
From: Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>
Date: 2021-10-09 00:38:40
Also in:
linux-alpha, linux-arch, linux-mips, linux-pci, lkml, sparclinux
Subsystem:
alpha port, documentation, generic include/asm header files, mips, parisc architecture, sparc + ultrasparc (sparc/sparc64), the rest · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Jonathan Corbet, Arnd Bergmann, Thomas Bogendoerfer, "James E.J. Bottomley", Helge Deller, "David S. Miller", Andreas Larsson, Linus Torvalds
From: Andi Kleen <redacted> This function is for declaring memory that should be shared with a hypervisor in a confidential guest. If the architecture doesn't implement it it's just ioremap. Signed-off-by: Andi Kleen <redacted> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> --- Changes since v4: * Renamed ioremap_shared to ioremap_host_shared * Added documentation for ioremap_host_shared(). Documentation/driver-api/device-io.rst | 7 +++++++ arch/alpha/include/asm/io.h | 2 ++ arch/mips/include/asm/io.h | 2 ++ arch/parisc/include/asm/io.h | 2 ++ arch/sparc/include/asm/io_64.h | 2 ++ include/asm-generic/io.h | 5 +++++ 6 files changed, 20 insertions(+)
diff --git a/Documentation/driver-api/device-io.rst b/Documentation/driver-api/device-io.rst
index e9f04b1815d1..9f77a036fc2f 100644
--- a/Documentation/driver-api/device-io.rst
+++ b/Documentation/driver-api/device-io.rst@@ -429,6 +429,13 @@ of the linear kernel memory area to a regular pointer. Portable drivers should avoid the use of ioremap_cache(). +ioremap_host_shared() +--------------------- + +ioremap_host_shared() maps I/O memory so that it can be shared with the host +in a confidential guest platform. It is mainly used in platforms like +Trusted Domain Extensions (TDX). + Architecture example --------------------
diff --git a/arch/alpha/include/asm/io.h b/arch/alpha/include/asm/io.h
index 0fab5ac90775..81952ef50667 100644
--- a/arch/alpha/include/asm/io.h
+++ b/arch/alpha/include/asm/io.h@@ -283,6 +283,8 @@ static inline void __iomem *ioremap(unsigned long port, unsigned long size) } #define ioremap_wc ioremap +/* Share memory with host in confidential guest platforms */ +#define ioremap_host_shared ioremap #define ioremap_uc ioremap static inline void iounmap(volatile void __iomem *addr)
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 6f5c86d2bab4..83f638fb48c5 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h@@ -179,6 +179,8 @@ void iounmap(const volatile void __iomem *addr); #define ioremap(offset, size) \ ioremap_prot((offset), (size), _CACHE_UNCACHED) #define ioremap_uc ioremap +/* Share memory with host in confidential guest platforms */ +#define ioremap_host_shared ioremap /* * ioremap_cache - map bus memory into CPU space
diff --git a/arch/parisc/include/asm/io.h b/arch/parisc/include/asm/io.h
index 0b5259102319..ef516ee06238 100644
--- a/arch/parisc/include/asm/io.h
+++ b/arch/parisc/include/asm/io.h@@ -129,6 +129,8 @@ static inline void gsc_writeq(unsigned long long val, unsigned long addr) */ void __iomem *ioremap(unsigned long offset, unsigned long size); #define ioremap_wc ioremap +/* Share memory with host in confidential guest platforms */ +#define ioremap_host_shared ioremap #define ioremap_uc ioremap extern void iounmap(const volatile void __iomem *addr);
diff --git a/arch/sparc/include/asm/io_64.h b/arch/sparc/include/asm/io_64.h
index 5ffa820dcd4d..5b73b877f832 100644
--- a/arch/sparc/include/asm/io_64.h
+++ b/arch/sparc/include/asm/io_64.h@@ -409,6 +409,8 @@ static inline void __iomem *ioremap(unsigned long offset, unsigned long size) #define ioremap_uc(X,Y) ioremap((X),(Y)) #define ioremap_wc(X,Y) ioremap((X),(Y)) #define ioremap_wt(X,Y) ioremap((X),(Y)) +/* Share memory with host in confidential guest platforms */ +#define ioremap_host_shared(X, Y) ioremap((X), (Y)) static inline void __iomem *ioremap_np(unsigned long offset, unsigned long size) { return NULL;
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index e93375c710b9..26b48fe23769 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h@@ -982,6 +982,11 @@ static inline void __iomem *ioremap(phys_addr_t addr, size_t size) #define ioremap_wt ioremap #endif +/* Share memory with host in confidential guest platforms */ +#ifndef ioremap_host_shared +#define ioremap_host_shared ioremap +#endif + /* * ioremap_uc is special in that we do require an explicit architecture * implementation. In general you do not want to use this function in a
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2.25.1