Currently code for exception/IRQ vectors is stored in kernel image as
initialization data and is copied to its working addresses during
startup. It doesn't always make sense. In many cases vectors location
can be automatically decided at kernel link time and code can be placed
right there. This is especially useful for XIP kernel.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Make kernel load address explicit, independent of the selected MMU
configuration and configurable from Kconfig. Do not restrict it to the
first 512MB of the physical address space.
Cleanup kernel memory layout macros:
- rename VECBASE_RESET_VADDR to VECBASE_VADDR, XC_VADDR to VECTOR_VADDR;
- drop VIRTUAL_MEMORY_ADDRESS and LOAD_MEMORY_ADDRESS;
- introduce PHYS_OFFSET and use it in __va and __pa definitions;
- synchronize MMU/noMMU vectors, drop unused NMI vector;
- replace hardcoded vectors offset of 0x3000 with Kconfig symbol.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Create a header dedicated to memory layout definitions. Include it from
places where these definitions are needed.
Express vmalloc area address, VIRTUAL_MEMORY_ADDRESS and KERNELOFFSET
through KSEG address.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There are no .bootstrap or .ResetVector.text sections linked to the
vmlinux image, drop these sections from vmlinux.ld.S. Drop
RESET_VECTOR_VADDR definition only used for .ResetVector.text.
Drop remapped copies of primary and secondary reset vectors, as modern
gdb don't have problems stepping through instructions at arbitrary
locations. Drop corresponding sections from the corresponding linker
scripts.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
There are multiple factors adding to the issue in different
configurations:
- commit 17290231df ("xtensa: add fixup for double exception raised
in window overflow") added function window_overflow_restore_a0_fixup to
double exception vector overlapping reset vector location of secondary
processor cores.
- on MMUv2 cores RESET_VECTOR1_VADDR may point to uncached kernel memory
making code overlapping depend on cache type and size, so that without
cache or with WT cache reset vector code overwrites double exception
code, making issue even harder to detect.
- on MMUv3 cores RESET_VECTOR1_VADDR may point to unmapped area, as
MMUv3 cores change virtual address map to match MMUv2 layout, but
reset vector virtual address is given for the original MMUv3 mapping.
- physical memory region of the secondary reset vector is not reserved
in the physical memory map, and thus may be allocated and overwritten
at arbitrary moment.
Fix it as follows:
- move window_overflow_restore_a0_fixup code to .text section.
- define RESET_VECTOR1_VADDR so that it points to reset vector in the
cacheable MMUv2 map for cores with MMU.
- reserve reset vector region in the physical memory map. Drop separate
literal section and build mxhead.S with text section literals.
Cc: <stable@vger.kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
KIO region location is different for noMMU cores. Provide different
default physical address and make KIO virtual address equal to physical.
Move xtensa_get_kio_paddr function close to XCHAL_KIO_PADDR definition
and define it not only for MMUv3, but for all MMU options except MMUv2.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Change KERNELOFFSET, LOAD_MEMORY_ADDRESS and VIRTUAL_MEMORY_ADDRESS to be
relative to the start of physical memory in noMMU configuration, as
there's no uniform memory remapping to KSEG starting at 0xd0000000.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Use the simple-bus node to discover the io area, and remap the cached and
bypass io ranges. The parent-bus-address value of the first triplet in the
"ranges" property is used. This value is rounded down to the nearest 256MB
boundary. The length of the io area is fixed at 256MB; the "ranges" property
length value is ignored.
Other limitations: (1) only the first simple-bus node is considered, and (2)
only the first triplet of the "ranges" property is considered.
See ePAPR 1.1 §6.5 for the simple-bus node description, and §2.3.8 for the
"ranges" property description.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Define IO addresses in a single place, to make it easier to change for
non-standard memory maps.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- drop unused PHYSICAL_MEMORY_ADDRESS and XC_PADDR
- fix NMI_VECTOR_VADDR and INTLEVEL7_VECTOR_VADDR definitions: there
should be no XCHAL_ prefix in them;
- fix the following warning seen with gcc-4.8.1:
arch/xtensa/include/asm/vectors.h:71:5: warning: "XCHAL_HAVE_VECBASE" is not defined [-Wundef]
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
