xtensa: minimize use of PLATFORM_DEFAULT_MEM_{ADDR,SIZE}
Now that the kernel load address and KSEG physical base address have
their own Kconfig symbols PLATFORM_DEFAULT_MEM seems redundant. It makes
little sense to use it in MMU configurations instead of KSEG_PADDR.
In noMMU configurations there's no explicit KSEG, so it's still useful
for the early cache initialization and definition of ARCH_PFN_OFFSET,
which affects mem_map size.
- limit it to noMMU; MMU variants have XCHAL_KSEG_PADDR and
XCHAL_KSEG_SIZE;
- don't use it to define TASK_SIZE or MAX_LOW_PFN: first doesn't make
any difference in noMMU, second is meaningless as there's no high
memory;
- don't add default physical memory region: memory layout should come
from the DT, bootloader tags, or memmap= command line parameter.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 9b1f8c3c..7a4c77b 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -394,7 +394,7 @@
config XTENSA_PLATFORM_XTFPGA
bool "XTFPGA"
select ETHOC if ETHERNET
- select PLATFORM_WANT_DEFAULT_MEM
+ select PLATFORM_WANT_DEFAULT_MEM if !MMU
select SERIAL_CONSOLE
select XTENSA_CALIBRATE_CCOUNT
help
@@ -502,11 +502,9 @@
default 0x00000000 if MMU
default 0x60000000 if !MMU
help
- This is a fallback start address of the default memory area, it is
- used when no physical memory size is passed through DTB or through
- boot parameter from bootloader.
-
- It's also used for TASK_SIZE calculation in noMMU configuration.
+ This is the base address of the default memory area.
+ Default memory area has platform-specific meaning, it may be used
+ for e.g. early cache initialization.
If unsure, leave the default value here.
@@ -515,11 +513,9 @@
depends on PLATFORM_WANT_DEFAULT_MEM
default 0x04000000
help
- This is a fallback size of the default memory area, it is used when
- no physical memory size is passed through DTB or through boot
- parameter from bootloader.
-
- It's also used for TASK_SIZE calculation in noMMU configuration.
+ This is the size of the default memory area.
+ Default memory area has platform-specific meaning, it may be used
+ for e.g. early cache initialization.
If unsure, leave the default value here.