[PATCH v2 0/2] android: colibri_imx7: reserve DDR memory for Cortex-M4
i.MX 7's Cortex-M4 core can run from DDR and uses DDR memory for the rpmsg communication. Both use cases need a fixed location of memory reserved. For the rpmsg use case the reserved area needs to be in sync with the kernel's hardcoded vring descriptor location.
Introduce support for adding linux,usable-memory property to carve out 1MB of memory in case the M4 core is running. Also make sure that the i.MX 7 specific rpmsg driver does not get loaded in case we do not carve out memory.
v2: - fixed build where CONFIG_ARCH_FIXUP_FDT_MEMORY is not set.
Igor Opaniuk (2): common: fdt_support: add support for setting usable memory board: colibri_imx7: reserve DDR memory for Cortex-M4
arch/arm/include/asm/mach-imx/sys_proto.h | 2 ++ board/toradex/colibri_imx7/colibri_imx7.c | 37 +++++++++++++++++++++++ common/fdt_support.c | 35 +++++++++++++++++++++ include/fdt_support.h | 1 + 4 files changed, 75 insertions(+)
From: Igor Opaniuk igor.opaniuk@toradex.com
Add support for setting linux,usable-memory property in the memory node of device tree for the kernel [1].
This property holds a base address and size, describing a limited region in which memory may be considered available for use by the kernel. Memory outside of this range is not available for use.
[1] https://www.kernel.org/doc/Documentation/devicetree/bindings/chosen.txt
Signed-off-by: Igor Opaniuk igor.opaniuk@toradex.com Signed-off-by: Sanchayan Maity maitysanchayan@gmail.com Signed-off-by: Stefan Agner stefan.agner@toradex.com Reviewed-by: Oleksandr Suvorov oleksandr.suvorov@toradex.com ---
common/fdt_support.c | 35 +++++++++++++++++++++++++++++++++++ include/fdt_support.h | 1 + 2 files changed, 36 insertions(+)
diff --git a/common/fdt_support.c b/common/fdt_support.c index 6834399039..02cf5c6241 100644 --- a/common/fdt_support.c +++ b/common/fdt_support.c @@ -467,6 +467,41 @@ int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks) } return 0; } + +int fdt_set_usable_memory(void *blob, u64 start[], u64 size[], int areas) +{ + int err, nodeoffset; + int len; + u8 tmp[8 * 16]; /* Up to 64-bit address + 64-bit size */ + + if (areas > 8) { + printf("%s: num areas %d exceeds hardcoded limit %d\n", + __func__, areas, 8); + return -1; + } + + err = fdt_check_header(blob); + if (err < 0) { + printf("%s: %s\n", __func__, fdt_strerror(err)); + return err; + } + + /* find or create "/memory" node. */ + nodeoffset = fdt_find_or_add_subnode(blob, 0, "memory"); + if (nodeoffset < 0) + return nodeoffset; + + len = fdt_pack_reg(blob, tmp, start, size, areas); + + err = fdt_setprop(blob, nodeoffset, "linux,usable-memory", tmp, len); + if (err < 0) { + printf("WARNING: could not set %s %s.\n", + "reg", fdt_strerror(err)); + return err; + } + + return 0; +} #endif
int fdt_fixup_memory(void *blob, u64 start, u64 size) diff --git a/include/fdt_support.h b/include/fdt_support.h index cefb2b2cce..2286ea7793 100644 --- a/include/fdt_support.h +++ b/include/fdt_support.h @@ -94,6 +94,7 @@ int fdt_fixup_memory(void *blob, u64 start, u64 size); */ #ifdef CONFIG_ARCH_FIXUP_FDT_MEMORY int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks); +int fdt_set_usable_memory(void *blob, u64 start[], u64 size[], int banks); #else static inline int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks)
On Tue, 2019-12-03 at 14:04 +0200, Igor Opaniuk wrote:
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.
From: Igor Opaniuk igor.opaniuk@toradex.com
Add support for setting linux,usable-memory property in the memory node of device tree for the kernel [1].
Isn't this same/similar to fdt_add_mem_rsv() ?
Jocke
Hi Joakim,
On Tue, Dec 3, 2019 at 5:02 PM Joakim Tjernlund Joakim.Tjernlund@infinera.com wrote:
On Tue, 2019-12-03 at 14:04 +0200, Igor Opaniuk wrote:
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.
From: Igor Opaniuk igor.opaniuk@toradex.com
Add support for setting linux,usable-memory property in the memory node of device tree for the kernel [1].
Isn't this same/similar to fdt_add_mem_rsv() ?
I would say they are opposite :) - linux,usable-memory property let the kernel be aware about all the memory he can use. - memreserve - what memory to exclude.
I think both should be helpful.
Jocke
Thanks
From: Igor Opaniuk igor.opaniuk@toradex.com
i.MX 7's Cortex-M4 core can run from DDR and uses DDR memory for the rpmsg communication. Both use cases need a fixed location of memory reserved. For the rpmsg use case the reserved area needs to be in sync with the kernel's hardcoded vring descriptor location.
Use the linux,usable-memory property to carve out 1MB of memory in case the M4 core is running. Also make sure that the i.MX 7 specific rpmsg driver does not get loaded in case we do not carve out memory.
Signed-off-by: Stefan Agner stefan.agner@toradex.com Signed-off-by: Igor Opaniuk igor.opaniuk@toradex.com Reviewed-by: Oleksandr Suvorov oleksandr.suvorov@toradex.com ---
arch/arm/include/asm/mach-imx/sys_proto.h | 2 ++ board/toradex/colibri_imx7/colibri_imx7.c | 37 +++++++++++++++++++++++ 2 files changed, 39 insertions(+)
diff --git a/arch/arm/include/asm/mach-imx/sys_proto.h b/arch/arm/include/asm/mach-imx/sys_proto.h index 52c83ba9e4..c9b509e6a7 100644 --- a/arch/arm/include/asm/mach-imx/sys_proto.h +++ b/arch/arm/include/asm/mach-imx/sys_proto.h @@ -153,6 +153,8 @@ void init_src(void); void init_snvs(void); void imx_wdog_disable_powerdown(void);
+int arch_auxiliary_core_check_up(u32 core_id); + int board_mmc_get_env_dev(int devno);
int nxp_board_rev(void); diff --git a/board/toradex/colibri_imx7/colibri_imx7.c b/board/toradex/colibri_imx7/colibri_imx7.c index c001316591..b0914a9ead 100644 --- a/board/toradex/colibri_imx7/colibri_imx7.c +++ b/board/toradex/colibri_imx7/colibri_imx7.c @@ -333,6 +333,43 @@ int checkboard(void) #if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_OF_BOARD_SETUP) int ft_board_setup(void *blob, bd_t *bd) { +#if defined(CONFIG_IMX_BOOTAUX) && defined(CONFIG_ARCH_FIXUP_FDT_MEMORY) + int up; + + up = arch_auxiliary_core_check_up(0); + if (up) { + int ret; + int areas = 1; + u64 start[2], size[2]; + + /* + * Reserve 1MB of memory for M4 (1MiB is also the minimum + * alignment for Linux due to MMU section size restrictions). + */ + start[0] = gd->bd->bi_dram[0].start; + size[0] = SZ_256M - SZ_1M; + + /* If needed, create a second entry for memory beyond 256M */ + if (gd->bd->bi_dram[0].size > SZ_256M) { + start[1] = gd->bd->bi_dram[0].start + SZ_256M; + size[1] = gd->bd->bi_dram[0].size - SZ_256M; + areas = 2; + } + + ret = fdt_set_usable_memory(blob, start, size, areas); + if (ret) { + eprintf("Cannot set usable memory\n"); + return ret; + } + } else { + int off; + + off = fdt_node_offset_by_compatible(blob, -1, + "fsl,imx7d-rpmsg"); + if (off > 0) + fdt_status_disabled(blob, off); + } +#endif #if defined(CONFIG_FDT_FIXUP_PARTITIONS) static const struct node_info nodes[] = { { "fsl,imx7d-gpmi-nand", MTD_DEV_TYPE_NAND, }, /* NAND flash */
participants (2)
-
Igor Opaniuk -
Joakim Tjernlund