ARM: decompress: Use /memreserve/ DTS nodes when validating memory
PATCH v2 1/1 ARM: decompress: Use /memreserve/ DTS nodes when validating memory
If the bootloader needs the start of memory to be preserved, for example because it dropped the Trusted Firmware blob there, this chunk of memory shouldn't be used by the kernel.
To avoid adding yet another SoC-specific text offset to arch/arm/Makefile, this patch allows for a /memreserve/ entry in the DTS to mark off the memory chunk instead.
--- arch/arm/boot/compressed/fdt_check_mem_start.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
arch/arm/boot/compressed/fdt_check_mem_start.c +14 -1
@@ -64,7 +64,7 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)uint32_t addr_cells, size_cells, base;uint32_t fdt_mem_start =0xffffffff ;const fdt32_t *reg, *endp; -uint64_t size, end; +uint64_t rsvaddr, size, end;const char *type;int offset, len;
@@ -74,6 +74,19 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)if (fdt_magic (fdt) !=FDT_MAGIC )return mem_start; +for (offset =fdt_off_mem_rsvmap (fdt); ; offset +=16 ) { + rsvaddr =get_val (fdt + offset,2 ); + size =get_val (fdt + offset +8 ,2 ); + +if (!rsvaddr && !size) +break ; + + end = rsvaddr + size; +if (mem_start >= rsvaddr && mem_start <= end) +/* Relocate past reserved block */ + mem_start =round_up (end,SZ_2M ); + } +/* There may be multiple cells on LPAE platforms */ addr_cells =get_cells (fdt,"#address-cells" ); size_cells =get_cells (fdt,"#size-cells" );
Signature · 1 line
2.25.1
Quoted 9 lines · Bert Vermeulen
If the bootloader needs the start of memory to be preserved, for example because it dropped the Trusted Firmware blob there, this chunk of memory shouldn't be used by the kernel.
To avoid adding yet another SoC-specific text offset to
arch/arm/Makefile, this patch allows for a /memreserve/ entry in the DTS to mark off the memory chunk instead.Signed-off-by Bert Vermeulen <[email protected]>
Gr{oetje,eeting}s,
Geert
Signature · 5 lines
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected] In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Quoted 10 lines · Bert Vermeulen
If the bootloader needs the start of memory to be preserved, for example because it dropped the Trusted Firmware blob there, this chunk of memory shouldn't be used by the kernel.
To avoid adding yet another SoC-specific text offset to
arch/arm/Makefile, this patch allows for a /memreserve/ entry in the DTS to mark off the memory chunk instead.Signed-off-by Bert Vermeulen <[email protected]>
Thanks for working on this - I hope this will allow us to phase out at least some of the existing text_offset hacks too.
Quoted 40 lines
--- arch/arm/boot/compressed/fdt_check_mem_start.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)arch/arm/boot/compressed/fdt_check_mem_start.c +14
-2@@ -64,7 +64,7 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)uint32_t addr_cells, size_cells, base;uint32_t fdt_mem_start =0xffffffff ;const fdt32_t *reg, *endp; -uint64_t size, end; +uint64_t rsvaddr, size, end;const char *type;int offset, len;@@ -74,6 +74,19 @@ uint32_t fdt_check_mem_start(uint32_t mem_start, const void *fdt)if (fdt_magic (fdt) !=FDT_MAGIC )return mem_start; +for (offset =fdt_off_mem_rsvmap (fdt); ; offset +=16 ) { + rsvaddr =get_val (fdt + offset,2 ); + size =get_val (fdt + offset +8 ,2 ); + +if (!rsvaddr && !size) +break ; + + end = rsvaddr + size; +if (mem_start >= rsvaddr && mem_start <= end) +/* Relocate past reserved block */ + mem_start =round_up (end,SZ_2M ); + } +/* There may be multiple cells on LPAE platforms */ addr_cells =get_cells (fdt,"#address-cells" ); size_cells =get_cells (fdt,"#size-cells" ); --2.25.1