diff options
| -rw-r--r-- | src/arch/x86/include/librm.h | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/src/arch/x86/include/librm.h b/src/arch/x86/include/librm.h index efc8b114a..d6214ac80 100644 --- a/src/arch/x86/include/librm.h +++ b/src/arch/x86/include/librm.h @@ -89,6 +89,15 @@ extern const unsigned long virt_offset; */ static inline __always_inline userptr_t UACCESS_INLINE ( librm, phys_to_user ) ( unsigned long phys_addr ) { + + /* In a 64-bit build, any valid physical address is directly + * usable as a virtual address, since the low 4GB is + * identity-mapped. + */ + if ( sizeof ( physaddr_t ) > sizeof ( uint32_t ) ) + return phys_addr; + + /* In a 32-bit build, subtract virt_offset */ return ( phys_addr - virt_offset ); } @@ -101,7 +110,20 @@ UACCESS_INLINE ( librm, phys_to_user ) ( unsigned long phys_addr ) { */ static inline __always_inline unsigned long UACCESS_INLINE ( librm, user_to_phys ) ( userptr_t userptr, off_t offset ) { - return ( userptr + offset + virt_offset ); + unsigned long addr = ( userptr + offset ); + + /* In a 64-bit build, any virtual address in the low 4GB is + * directly usable as a physical address, since the low 4GB is + * identity-mapped. + */ + if ( ( sizeof ( physaddr_t ) > sizeof ( uint32_t ) ) && + ( addr <= 0xffffffffUL ) ) + return addr; + + /* In a 32-bit build or in a 64-bit build with a virtual + * address above 4GB: add virt_offset + */ + return ( addr + virt_offset ); } static inline __always_inline userptr_t |