[PATCH] MIPS: correctly work with disabled CONFIG_MMU

[PATCH] MIPS: correctly work with disabled CONFIG_MMU

[Antony Pavlov]

There are some issues with CONFIG_MMU=n in MIPS configuration
(e.g. qemu-malta_defconfig):

  * "Cannot request SDRAM region for stack" error message on start;
  * empty kseg1_ram0 region in the iomem command output.

The patch fixes the problems by forcing KSEG1 memory region usage
for CONFIG_MMU=n MIPS configurations.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 arch/mips/include/asm/io.h | 6 +++++-
 arch/mips/lib/reloc.c      | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index c155199430..4df9853680 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -39,7 +39,11 @@ static inline unsigned long virt_to_phys(const void *address)
  */
 static inline void *phys_to_virt(unsigned long address)
 {
-	return (void *)CKSEG0ADDR(address);
+	if (IS_ENABLED(CONFIG_MMU)) {
+		return (void *)CKSEG0ADDR(address);
+	}
+
+	return (void *)CKSEG1ADDR(address);
 }
 
 #define	IO_SPACE_LIMIT	0
diff --git a/arch/mips/lib/reloc.c b/arch/mips/lib/reloc.c
index 4b0e252352..b084a88be7 100644
--- a/arch/mips/lib/reloc.c
+++ b/arch/mips/lib/reloc.c
@@ -120,7 +120,11 @@ void relocate_code(void *fdt, u32 fdt_size, u32 ram_size)
 
 	length = __bss_stop - __image_start;
 	relocaddr = ALIGN_DOWN(ram_size - length, SZ_64K);
-	relocaddr = KSEG0ADDR(relocaddr);
+	if (IS_ENABLED(CONFIG_MMU)) {
+		relocaddr = KSEG0ADDR(relocaddr);
+	} else {
+		relocaddr = KSEG1ADDR(relocaddr);
+	}
 	new_stack = relocaddr - MALLOC_SIZE - 16;
 
 	/*
-- 
2.26.2


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

Re: [PATCH] MIPS: correctly work with disabled CONFIG_MMU

[Sascha Hauer]

On Wed, Jun 03, 2020 at 09:20:32AM +0300, Antony Pavlov wrote:
> There are some issues with CONFIG_MMU=n in MIPS configuration
> (e.g. qemu-malta_defconfig):
> 
>   * "Cannot request SDRAM region for stack" error message on start;
>   * empty kseg1_ram0 region in the iomem command output.
> 
> The patch fixes the problems by forcing KSEG1 memory region usage
> for CONFIG_MMU=n MIPS configurations.
> 
> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> ---
>  arch/mips/include/asm/io.h | 6 +++++-
>  arch/mips/lib/reloc.c      | 6 +++++-
>  2 files changed, 10 insertions(+), 2 deletions(-)

Applied, thanks

Sascha


-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox