Within the Linux kernel source tree, there is a directory called
/arch/machinetype which contains the
architecture-specific versions of certain subroutines for a particular
machinetype such as
arm or
x86 or
i8080 
.
These files may be in C or in architecture-specific assembler language, or, most commonly, in C files with large blocks of
asm{...} code inside.
What you are looking at is a string that might be used with the
ls command to find any file-names that begin with
mach- and end with
.c, in any directory within
/arch/arm whose name begins with
mach-. This string will match the names of zero-or-more files, which are "the files you are looking for."
