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| author | Max Filippov <jcmvbkbc@gmail.com> | 2016-07-22 23:47:58 (GMT) |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2016-07-24 03:33:59 (GMT) |
| commit | 3de00482b006daa110151ac6775adc52538a3d6a (patch) | |
| tree | bd7a17e41872fdd386b5f548af88ee626fcdaba6 /arch/xtensa/Kconfig | |
| parent | a9f2fc628e3a26a829fd79aff74eb49839d1e74b (diff) | |
| download | linux-3de00482b006daa110151ac6775adc52538a3d6a.tar.xz | |
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>
Diffstat (limited to 'arch/xtensa/Kconfig')
| -rw-r--r-- | arch/xtensa/Kconfig | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index 9b1f8c3..7a4c77b 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -394,7 +394,7 @@ config XTENSA_PLATFORM_XT2000 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 @@ config DEFAULT_MEM_START 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 @@ config DEFAULT_MEM_SIZE 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. |