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.
diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h
index 3b5a49d..976b1d7 100644
--- a/arch/xtensa/include/asm/page.h
+++ b/arch/xtensa/include/asm/page.h
@@ -31,10 +31,9 @@
#define MAX_LOW_PFN (PHYS_PFN(XCHAL_KSEG_PADDR) + \
PHYS_PFN(XCHAL_KSEG_SIZE))
#else
-#define PAGE_OFFSET __XTENSA_UL_CONST(0)
-#define PHYS_OFFSET __XTENSA_UL_CONST(0)
-#define MAX_LOW_PFN (PHYS_PFN(PLATFORM_DEFAULT_MEM_START) + \
- PHYS_PFN(PLATFORM_DEFAULT_MEM_SIZE))
+#define PAGE_OFFSET PLATFORM_DEFAULT_MEM_START
+#define PHYS_OFFSET PLATFORM_DEFAULT_MEM_START
+#define MAX_LOW_PFN PHYS_PFN(0xfffffffful)
#endif
#define PGTABLE_START 0x80000000
@@ -163,7 +162,7 @@
* addresses.
*/
-#define ARCH_PFN_OFFSET (PLATFORM_DEFAULT_MEM_START >> PAGE_SHIFT)
+#define ARCH_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
#define __pa(x) \
((unsigned long) (x) - PAGE_OFFSET + PHYS_OFFSET)
diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h
index d2e40d3..b42d68b 100644
--- a/arch/xtensa/include/asm/processor.h
+++ b/arch/xtensa/include/asm/processor.h
@@ -37,7 +37,7 @@
#ifdef CONFIG_MMU
#define TASK_SIZE __XTENSA_UL_CONST(0x40000000)
#else
-#define TASK_SIZE (PLATFORM_DEFAULT_MEM_START + PLATFORM_DEFAULT_MEM_SIZE)
+#define TASK_SIZE __XTENSA_UL_CONST(0xffffffff)
#endif
#define STACK_TOP TASK_SIZE
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 9735691..0e59b89 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -188,7 +188,6 @@
}
#ifdef CONFIG_OF
-bool __initdata dt_memory_scan = false;
#if !XCHAL_HAVE_PTP_MMU || XCHAL_HAVE_SPANNING_WAY
unsigned long xtensa_kio_paddr = XCHAL_KIO_DEFAULT_PADDR;
@@ -228,9 +227,6 @@
void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
- if (!dt_memory_scan)
- return;
-
size &= PAGE_MASK;
add_sysmem_bank(base, base + size);
}
@@ -242,9 +238,6 @@
void __init early_init_devtree(void *params)
{
- if (sysmem.nr_banks == 0)
- dt_memory_scan = true;
-
early_init_dt_scan(params);
of_scan_flat_dt(xtensa_dt_io_area, NULL);
@@ -278,12 +271,6 @@
early_init_devtree(dtb_start);
#endif
- if (sysmem.nr_banks == 0) {
- add_sysmem_bank(PLATFORM_DEFAULT_MEM_START,
- PLATFORM_DEFAULT_MEM_START +
- PLATFORM_DEFAULT_MEM_SIZE);
- }
-
#ifdef CONFIG_CMDLINE_BOOL
if (!command_line[0])
strlcpy(command_line, default_command_line, COMMAND_LINE_SIZE);