From: Thierry Reding treding@nvidia.com

Clock code is not relevant on all Tegra SoC generations, so guard it with a Kconfig symbol that can be selected by the generations that need it.

This is in preparation for unifying Tegra186 code with the code used on older generations.

Signed-off-by: Thierry Reding treding@nvidia.com --- arch/arm/mach-tegra/Kconfig | 5 +++++ arch/arm/mach-tegra/Makefile | 2 +- arch/arm/mach-tegra/board.c | 2 ++ arch/arm/mach-tegra/board2.c | 12 ++++++++++-- 4 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig index 86b1cd11f752..ee078fec9adc 100644 --- a/arch/arm/mach-tegra/Kconfig +++ b/arch/arm/mach-tegra/Kconfig @@ -12,6 +12,9 @@ config SPL_LIBGENERIC_SUPPORT config SPL_SERIAL_SUPPORT default y

+config TEGRA_CLKRST + bool + config TEGRA_IVC bool "Tegra IVC protocol" help @@ -55,6 +58,7 @@ config TEGRA_ARMV7_COMMON select SPL select SPL_BOARD_INIT if SPL select SUPPORT_SPL + select TEGRA_CLKRST select TEGRA_COMMON select TEGRA_GPIO select TEGRA_NO_BPMP @@ -100,6 +104,7 @@ config TEGRA124 config TEGRA210 bool "Tegra210 family" select TEGRA_ARMV8_COMMON + select TEGRA_CLKRST select TEGRA_GPIO select TEGRA_NO_BPMP

diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index d4b4666fb1e2..0e812818d7a2 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -16,7 +16,7 @@ endif obj-y += ap.o obj-y += board.o board2.o obj-y += cache.o -obj-y += clock.o +obj-$(CONFIG_TEGRA_CLKRST) += clock.o obj-y += pinmux-common.o obj-y += powergate.o obj-y += xusb-padctl-dummy.o diff --git a/arch/arm/mach-tegra/board.c b/arch/arm/mach-tegra/board.c index f8fc042a1dcc..ecd5001de4c5 100644 --- a/arch/arm/mach-tegra/board.c +++ b/arch/arm/mach-tegra/board.c @@ -9,7 +9,9 @@ #include <ns16550.h> #include <spl.h> #include <asm/io.h> +#if IS_ENABLED(CONFIG_TEGRA_CLKRST) #include <asm/arch/clock.h> +#endif #include <asm/arch/funcmux.h> #include <asm/arch/mc.h> #include <asm/arch/tegra.h> diff --git a/arch/arm/mach-tegra/board2.c b/arch/arm/mach-tegra/board2.c index b8d5ef0322cb..b94077221f77 100644 --- a/arch/arm/mach-tegra/board2.c +++ b/arch/arm/mach-tegra/board2.c @@ -22,7 +22,9 @@ #include <asm/arch-tegra/gpu.h> #include <asm/arch-tegra/usb.h> #include <asm/arch-tegra/xusb-padctl.h> +#if IS_ENABLED(CONFIG_TEGRA_CLKRST) #include <asm/arch/clock.h> +#endif #include <asm/arch/funcmux.h> #include <asm/arch/pinmux.h> #include <asm/arch/tegra.h> @@ -109,8 +111,10 @@ int board_init(void) __maybe_unused int board_id;

/* Do clocks and UART first so that printf() works */ +#if IS_ENABLED(CONFIG_TEGRA_CLKRST) clock_init(); clock_verify(); +#endif

tegra_gpu_config();

@@ -181,8 +185,10 @@ void gpio_early_init(void) __attribute__((weak, alias("__gpio_early_init")));

int board_early_init_f(void) { +#if IS_ENABLED(CONFIG_TEGRA_CLKRST) if (!clock_early_init_done()) clock_early_init(); +#endif

#if defined(CONFIG_TEGRA_DISCONNECT_UDC_ON_BOOT) #define USBCMD_FS2 (1 << 15) @@ -193,10 +199,12 @@ int board_early_init_f(void) #endif

/* Do any special system timer/TSC setup */ -#if defined(CONFIG_TEGRA_SUPPORT_NON_SECURE) +#if IS_ENABLED(CONFIG_TEGRA_CLKRST) +# if defined(CONFIG_TEGRA_SUPPORT_NON_SECURE) if (!tegra_cpu_is_non_secure()) -#endif +# endif arch_timer_init(); +#endif

pinmux_init(); board_init_uart_f();

From: Thierry Reding treding@nvidia.com

Memory controller code is not relevant on all Tegra SoC generations, so guard it with a Kconfig symbol that can be selected by the generations that need it.

This is in preparation for unifying Tegra186 code with the code used on older generations.

Signed-off-by: Thierry Reding treding@nvidia.com --- arch/arm/mach-tegra/Kconfig | 5 +++++ arch/arm/mach-tegra/board.c | 7 +++++++ 2 files changed, 12 insertions(+)

diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig index 265051b18aaf..5763c4ae3cd1 100644 --- a/arch/arm/mach-tegra/Kconfig +++ b/arch/arm/mach-tegra/Kconfig @@ -26,6 +26,9 @@ config TEGRA_IVC U-Boot, it is typically used for communication between the main CPU and various auxiliary processors.

+config TEGRA_MC + bool + config TEGRA_COMMON bool "Tegra common options" select BINMAN @@ -65,6 +68,7 @@ config TEGRA_ARMV7_COMMON select TEGRA_COMMON select TEGRA_GPIO select TEGRA_GP_PADCTRL + select TEGRA_MC select TEGRA_NO_BPMP

config TEGRA_ARMV8_COMMON @@ -111,6 +115,7 @@ config TEGRA210 select TEGRA_CLKRST select TEGRA_GPIO select TEGRA_GP_PADCTRL + select TEGRA_MC select TEGRA_NO_BPMP

config TEGRA186 diff --git a/arch/arm/mach-tegra/board.c b/arch/arm/mach-tegra/board.c index ecd5001de4c5..7ef5a67edd1f 100644 --- a/arch/arm/mach-tegra/board.c +++ b/arch/arm/mach-tegra/board.c @@ -13,7 +13,9 @@ #include <asm/arch/clock.h> #endif #include <asm/arch/funcmux.h> +#if IS_ENABLED(CONFIG_TEGRA_MC) #include <asm/arch/mc.h> +#endif #include <asm/arch/tegra.h> #include <asm/arch-tegra/ap.h> #include <asm/arch-tegra/board.h> @@ -68,6 +70,7 @@ bool tegra_cpu_is_non_secure(void) } #endif

+#if IS_ENABLED(CONFIG_TEGRA_MC) /* Read the RAM size directly from the memory controller */ static phys_size_t query_sdram_size(void) { @@ -117,11 +120,15 @@ static phys_size_t query_sdram_size(void)

return size_bytes; } +#endif

int dram_init(void) { +#if IS_ENABLED(CONFIG_TEGRA_MC) /* We do not initialise DRAM here. We just query the size */ gd->ram_size = query_sdram_size(); +#endif + return 0; }

From: Thierry Reding treding@nvidia.com

Powergate code is not relevant on all Tegra SoC generations, so guard it with a Kconfig symbol that can be selected by the generations that need it.

This is in preparation for unifying Tegra186 code with the code used on older generations.

Signed-off-by: Thierry Reding treding@nvidia.com --- arch/arm/mach-tegra/Kconfig | 5 +++++ arch/arm/mach-tegra/Makefile | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig index be20ac2e804e..db9198348d3f 100644 --- a/arch/arm/mach-tegra/Kconfig +++ b/arch/arm/mach-tegra/Kconfig @@ -32,6 +32,9 @@ config TEGRA_MC config TEGRA_PINCTRL bool

+config TEGRA_PMC + bool + config TEGRA_COMMON bool "Tegra common options" select BINMAN @@ -74,6 +77,7 @@ config TEGRA_ARMV7_COMMON select TEGRA_MC select TEGRA_NO_BPMP select TEGRA_PINCTRL + select TEGRA_PMC

config TEGRA_ARMV8_COMMON bool "Tegra 64-bit common options" @@ -122,6 +126,7 @@ config TEGRA210 select TEGRA_MC select TEGRA_NO_BPMP select TEGRA_PINCTRL + select TEGRA_PMC

config TEGRA186 bool "Tegra186 family" diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index 395e0191a458..517be21ee5f5 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -18,7 +18,7 @@ obj-y += board.o board2.o obj-y += cache.o obj-$(CONFIG_TEGRA_CLKRST) += clock.o obj-$(CONFIG_TEGRA_PINCTRL) += pinmux-common.o -obj-y += powergate.o +obj-$(CONFIG_TEGRA_PMC) += powergate.o obj-y += xusb-padctl-dummy.o endif

From: Thierry Reding treding@nvidia.com

Boards may not support all the boot target devices in the default list for Tegra devices. Allow a board to override the list and default to the standard list only if the board hasn't specified one itself.

Signed-off-by: Thierry Reding treding@nvidia.com --- include/configs/tegra-common-post.h | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/include/configs/tegra-common-post.h b/include/configs/tegra-common-post.h index e54428ba43e2..9685ee5059ab 100644 --- a/include/configs/tegra-common-post.h +++ b/include/configs/tegra-common-post.h @@ -21,12 +21,14 @@ #define CONFIG_SYS_NONCACHED_MEMORY (1 << 20) /* 1 MiB */

#ifndef CONFIG_SPL_BUILD +#ifndef BOOT_TARGET_DEVICES #define BOOT_TARGET_DEVICES(func) \ func(MMC, mmc, 1) \ func(MMC, mmc, 0) \ func(USB, usb, 0) \ func(PXE, pxe, na) \ func(DHCP, dhcp, na) +#endif #include <config_distro_bootcmd.h> #else #define BOOTENV

From: Thierry Reding treding@nvidia.com

Resetting the USB device controller on boot is only necessary if the SoC actually has a UDC controller and U-Boot enables support for it. All the Tegra boards support UDC via the ChipIdea UDC driver, so make the UDC on boot workaround depend on the ChipIdea UDC driver.

This prevents a crash on Tegra186 which does not have the ChipIdea UDC.

Signed-off-by: Thierry Reding treding@nvidia.com --- arch/arm/mach-tegra/Kconfig | 1 + 1 file changed, 1 insertion(+)

diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig index 28914a34a1b5..faa73559fd42 100644 --- a/arch/arm/mach-tegra/Kconfig +++ b/arch/arm/mach-tegra/Kconfig @@ -148,6 +148,7 @@ endchoice

config TEGRA_DISCONNECT_UDC_ON_BOOT bool "Disconnect USB device mode controller on boot" + depends on CI_UDC default y help When loading U-Boot into RAM over USB protocols using tools such as

From: Thierry Reding treding@nvidia.com

Tegra186 build are currently dealt with in very special ways, which is because Tegra186 is fundamentally different in many respects. It is no longer necessary to do many of the low-level programming because early boot firmware will already have taken care of it.

Unfortunately, separating Tegra186 builds from the rest in this way makes it difficult to share code with prior generations of Tegra. With all of the low-level programming code behind Kconfig guards, the build for Tegra186 can again be unified.

As a side-effect, and partial reason for this change, other Tegra SoC generations can now make use of the code that deals with taking over a boot from earlier bootloaders. This used to be nvtboot, but has been replaced by cboot nowadays. Rename the files and functions related to this to avoid confusion. The implemented protocols are unchanged.

Signed-off-by: Thierry Reding treding@nvidia.com --- Changes in v3: - load cboot DTB address to fdt_addr instead of fdtaddr

arch/arm/include/asm/arch-tegra/cboot.h | 39 ++++ arch/arm/mach-tegra/Makefile | 4 +- arch/arm/mach-tegra/board.c | 23 ++ arch/arm/mach-tegra/board186.c | 32 --- arch/arm/mach-tegra/board2.c | 21 ++ .../{tegra186/nvtboot_board.c => cboot.c} | 200 ++++++++++++++++-- .../{tegra186/nvtboot_ll.S => cboot_ll.S} | 12 +- arch/arm/mach-tegra/tegra186/Makefile | 4 - arch/arm/mach-tegra/tegra186/nvtboot_mem.c | 172 --------------- board/nvidia/p2771-0000/p2771-0000.c | 10 +- 10 files changed, 278 insertions(+), 239 deletions(-) create mode 100644 arch/arm/include/asm/arch-tegra/cboot.h delete mode 100644 arch/arm/mach-tegra/board186.c rename arch/arm/mach-tegra/{tegra186/nvtboot_board.c => cboot.c} (56%) rename arch/arm/mach-tegra/{tegra186/nvtboot_ll.S => cboot_ll.S} (57%) delete mode 100644 arch/arm/mach-tegra/tegra186/nvtboot_mem.c

diff --git a/arch/arm/include/asm/arch-tegra/cboot.h b/arch/arm/include/asm/arch-tegra/cboot.h new file mode 100644 index 000000000000..b3441ec178b3 --- /dev/null +++ b/arch/arm/include/asm/arch-tegra/cboot.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (c) 2019 NVIDIA Corporation. All rights reserved. + */ + +#ifndef _TEGRA_CBOOT_H_ +#define _TEGRA_CBOOT_H_ + +#ifdef CONFIG_ARM64 +extern unsigned long cboot_boot_x0; + +void cboot_save_boot_params(unsigned long x0, unsigned long x1, + unsigned long x2, unsigned long x3); +int cboot_dram_init(void); +int cboot_dram_init_banksize(void); +ulong cboot_get_usable_ram_top(ulong total_size); +#else +static inline void cboot_save_boot_params(unsigned long x0, unsigned long x1, + unsigned long x2, unsigned long x3) +{ +} + +static inline int cboot_dram_init(void) +{ + return -ENOSYS; +} + +static inline int cboot_dram_init_banksize(void) +{ + return -ENOSYS; +} + +static inline ulong cboot_get_usable_ram_top(ulong total_size) +{ + return 0; +} +#endif + +#endif diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index f8bc65aa8b18..41ba674edff4 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -5,7 +5,6 @@ # (C) Copyright 2000-2008 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.

-ifndef CONFIG_TEGRA186 ifdef CONFIG_SPL_BUILD obj-y += spl.o obj-y += cpu.o @@ -20,9 +19,8 @@ obj-$(CONFIG_TEGRA_CLKRST) += clock.o obj-$(CONFIG_TEGRA_PINCTRL) += pinmux-common.o obj-$(CONFIG_TEGRA_PMC) += powergate.o obj-y += xusb-padctl-dummy.o -endif

-obj-$(CONFIG_ARM64) += arm64-mmu.o +obj-$(CONFIG_ARM64) += arm64-mmu.o cboot_ll.o cboot.o obj-y += dt-setup.o obj-$(CONFIG_TEGRA_CLOCK_SCALING) += emc.o obj-$(CONFIG_TEGRA_GPU) += gpu.o diff --git a/arch/arm/mach-tegra/board.c b/arch/arm/mach-tegra/board.c index 59d2f347485d..c3ba00811e83 100644 --- a/arch/arm/mach-tegra/board.c +++ b/arch/arm/mach-tegra/board.c @@ -21,6 +21,7 @@ #include <asm/arch/tegra.h> #include <asm/arch-tegra/ap.h> #include <asm/arch-tegra/board.h> +#include <asm/arch-tegra/cboot.h> #include <asm/arch-tegra/pmc.h> #include <asm/arch-tegra/sys_proto.h> #include <asm/arch-tegra/warmboot.h> @@ -46,6 +47,21 @@ void save_boot_params(unsigned long r0, unsigned long r1, unsigned long r2, unsigned long r3) { from_spl = r0 != UBOOT_NOT_LOADED_FROM_SPL; + + /* + * The logic for this is somewhat indirect. The purpose of the marker + * (UBOOT_NOT_LOADED_FROM_SPL) is in fact used to determine if U-Boot + * was loaded from a read-only instance of itself, which is something + * that can happen in secure boot setups. So basically the presence + * of the marker is an indication that U-Boot was loaded by one such + * special variant of U-Boot. Conversely, the absence of the marker + * indicates that this instance of U-Boot was loaded by something + * other than a special U-Boot. This could be SPL, but it could just + * as well be one of any number of other first stage bootloaders. + */ + if (from_spl) + cboot_save_boot_params(r0, r1, r2, r3); + save_boot_params_ret(); } #endif @@ -127,6 +143,13 @@ static phys_size_t query_sdram_size(void)

int dram_init(void) { + int err; + + /* try to initialize DRAM from cboot DTB first */ + err = cboot_dram_init(); + if (err == 0) + return 0; + #if IS_ENABLED(CONFIG_TEGRA_MC) /* We do not initialise DRAM here. We just query the size */ gd->ram_size = query_sdram_size(); diff --git a/arch/arm/mach-tegra/board186.c b/arch/arm/mach-tegra/board186.c deleted file mode 100644 index 80b55707e90f..000000000000 --- a/arch/arm/mach-tegra/board186.c +++ /dev/null @@ -1,32 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0+ -/* - * Copyright (c) 2016, NVIDIA CORPORATION. - */ - -#include <common.h> -#include <asm/arch/tegra.h> - -int board_early_init_f(void) -{ - return 0; -} - -__weak int tegra_board_init(void) -{ - return 0; -} - -int board_init(void) -{ - return tegra_board_init(); -} - -__weak int tegra_soc_board_init_late(void) -{ - return 0; -} - -int board_late_init(void) -{ - return tegra_soc_board_init_late(); -} diff --git a/arch/arm/mach-tegra/board2.c b/arch/arm/mach-tegra/board2.c index ce1c9346959d..bbc487aa3bf6 100644 --- a/arch/arm/mach-tegra/board2.c +++ b/arch/arm/mach-tegra/board2.c @@ -13,6 +13,7 @@ #include <asm/io.h> #include <asm/arch-tegra/ap.h> #include <asm/arch-tegra/board.h> +#include <asm/arch-tegra/cboot.h> #include <asm/arch-tegra/clk_rst.h> #include <asm/arch-tegra/pmc.h> #include <asm/arch-tegra/pmu.h> @@ -51,6 +52,7 @@ __weak void pin_mux_mmc(void) {} __weak void gpio_early_init_uart(void) {} __weak void pin_mux_display(void) {} __weak void start_cpu_fan(void) {} +__weak void cboot_late_init(void) {}

#if defined(CONFIG_TEGRA_NAND) __weak void pin_mux_nand(void) @@ -243,6 +245,7 @@ int board_late_init(void) } #endif start_cpu_fan(); + cboot_late_init();

return 0; } @@ -337,6 +340,15 @@ static ulong usable_ram_size_below_4g(void) */ int dram_init_banksize(void) { + int err; + + /* try to compute DRAM bank size based on cboot DTB first */ + err = cboot_dram_init_banksize(); + if (err == 0) + return err; + + /* fall back to default DRAM bank size computation */ + gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE; gd->bd->bi_dram[0].size = usable_ram_size_below_4g();

@@ -370,5 +382,14 @@ int dram_init_banksize(void) */ ulong board_get_usable_ram_top(ulong total_size) { + ulong ram_top; + + /* try to get top of usable RAM based on cboot DTB first */ + ram_top = cboot_get_usable_ram_top(total_size); + if (ram_top > 0) + return ram_top; + + /* fall back to default usable RAM computation */ + return CONFIG_SYS_SDRAM_BASE + usable_ram_size_below_4g(); } diff --git a/arch/arm/mach-tegra/tegra186/nvtboot_board.c b/arch/arm/mach-tegra/cboot.c similarity index 56% rename from arch/arm/mach-tegra/tegra186/nvtboot_board.c rename to arch/arm/mach-tegra/cboot.c index 83c0e931ea24..95a097584ac6 100644 --- a/arch/arm/mach-tegra/tegra186/nvtboot_board.c +++ b/arch/arm/mach-tegra/cboot.c @@ -3,14 +3,182 @@ * Copyright (c) 2016-2018, NVIDIA CORPORATION. */

-#include <stdlib.h> #include <common.h> #include <fdt_support.h> #include <fdtdec.h> +#include <stdlib.h> + +#include <linux/sizes.h> + #include <asm/arch/tegra.h> +#include <asm/arch-tegra/cboot.h> #include <asm/armv8/mmu.h>

-extern unsigned long nvtboot_boot_x0; +/* + * Size of a region that's large enough to hold the relocated U-Boot and all + * other allocations made around it (stack, heap, page tables, etc.) + * In practice, running "bdinfo" at the shell prompt, the stack reaches about + * 5MB from the address selected for ram_top as of the time of writing, + * so a 16MB region should be plenty. + */ +#define MIN_USABLE_RAM_SIZE SZ_16M +/* + * The amount of space we expect to require for stack usage. Used to validate + * that all reservations fit into the region selected for the relocation target + */ +#define MIN_USABLE_STACK_SIZE SZ_1M + +DECLARE_GLOBAL_DATA_PTR; + +extern struct mm_region tegra_mem_map[]; + +/* + * These variables are written to before relocation, and hence cannot be + * in.bss, since .bss overlaps the DTB that's appended to the U-Boot binary. + * The section attribute forces this into .data and avoids this issue. This + * also has the nice side-effect of the content being valid after relocation. + */ + +/* The number of valid entries in ram_banks[] */ +static int ram_bank_count __attribute__((section(".data"))); + +/* + * The usable top-of-RAM for U-Boot. This is both: + * a) Below 4GB to avoid issues with peripherals that use 32-bit addressing. + * b) At the end of a region that has enough space to hold the relocated U-Boot + * and all other allocations made around it (stack, heap, page tables, etc.) + */ +static u64 ram_top __attribute__((section(".data"))); +/* The base address of the region of RAM that ends at ram_top */ +static u64 region_base __attribute__((section(".data"))); + +int cboot_dram_init(void) +{ + unsigned int na, ns; + const void *cboot_blob = (void *)cboot_boot_x0; + int node, len, i; + const u32 *prop; + + if (!cboot_blob) + return -EINVAL; + + na = fdtdec_get_uint(cboot_blob, 0, "#address-cells", 2); + ns = fdtdec_get_uint(cboot_blob, 0, "#size-cells", 2); + + node = fdt_path_offset(cboot_blob, "/memory"); + if (node < 0) { + pr_err("Can't find /memory node in cboot DTB"); + hang(); + } + prop = fdt_getprop(cboot_blob, node, "reg", &len); + if (!prop) { + pr_err("Can't find /memory/reg property in cboot DTB"); + hang(); + } + + /* Calculate the true # of base/size pairs to read */ + len /= 4; /* Convert bytes to number of cells */ + len /= (na + ns); /* Convert cells to number of banks */ + if (len > CONFIG_NR_DRAM_BANKS) + len = CONFIG_NR_DRAM_BANKS; + + /* Parse the /memory node, and save useful entries */ + gd->ram_size = 0; + ram_bank_count = 0; + for (i = 0; i < len; i++) { + u64 bank_start, bank_end, bank_size, usable_bank_size; + + /* Extract raw memory region data from DTB */ + bank_start = fdt_read_number(prop, na); + prop += na; + bank_size = fdt_read_number(prop, ns); + prop += ns; + gd->ram_size += bank_size; + bank_end = bank_start + bank_size; + debug("Bank %d: %llx..%llx (+%llx)\n", i, + bank_start, bank_end, bank_size); + + /* + * Align the bank to MMU section size. This is not strictly + * necessary, since the translation table construction code + * handles page granularity without issue. However, aligning + * the MMU entries reduces the size and number of levels in the + * page table, so is worth it. + */ + bank_start = ROUND(bank_start, SZ_2M); + bank_end = bank_end & ~(SZ_2M - 1); + bank_size = bank_end - bank_start; + debug(" aligned: %llx..%llx (+%llx)\n", + bank_start, bank_end, bank_size); + if (bank_end <= bank_start) + continue; + + /* Record data used to create MMU translation tables */ + ram_bank_count++; + /* Index below is deliberately 1-based to skip MMIO entry */ + tegra_mem_map[ram_bank_count].virt = bank_start; + tegra_mem_map[ram_bank_count].phys = bank_start; + tegra_mem_map[ram_bank_count].size = bank_size; + tegra_mem_map[ram_bank_count].attrs = + PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_INNER_SHARE; + + /* Determine best bank to relocate U-Boot into */ + if (bank_end > SZ_4G) + bank_end = SZ_4G; + debug(" end %llx (usable)\n", bank_end); + usable_bank_size = bank_end - bank_start; + debug(" size %llx (usable)\n", usable_bank_size); + if ((usable_bank_size >= MIN_USABLE_RAM_SIZE) && + (bank_end > ram_top)) { + ram_top = bank_end; + region_base = bank_start; + debug("ram top now %llx\n", ram_top); + } + } + + /* Ensure memory map contains the desired sentinel entry */ + tegra_mem_map[ram_bank_count + 1].virt = 0; + tegra_mem_map[ram_bank_count + 1].phys = 0; + tegra_mem_map[ram_bank_count + 1].size = 0; + tegra_mem_map[ram_bank_count + 1].attrs = 0; + + /* Error out if a relocation target couldn't be found */ + if (!ram_top) { + pr_err("Can't find a usable RAM top"); + hang(); + } + + return 0; +} + +int cboot_dram_init_banksize(void) +{ + int i; + + if (ram_bank_count == 0) + return -EINVAL; + + if ((gd->start_addr_sp - region_base) < MIN_USABLE_STACK_SIZE) { + pr_err("Reservations exceed chosen region size"); + hang(); + } + + for (i = 0; i < ram_bank_count; i++) { + gd->bd->bi_dram[i].start = tegra_mem_map[1 + i].virt; + gd->bd->bi_dram[i].size = tegra_mem_map[1 + i].size; + } + +#ifdef CONFIG_PCI + gd->pci_ram_top = ram_top; +#endif + + return 0; +} + +ulong cboot_get_usable_ram_top(ulong total_size) +{ + return ram_top; +}

/* * The following few functions run late during the boot process and dynamically @@ -23,8 +191,6 @@ extern unsigned long nvtboot_boot_x0; * list of RAM banks into some private data structure before running. */

-extern struct mm_region tegra_mem_map[]; - static char *gen_varname(const char *var, const char *ext) { size_t len_var = strlen(var); @@ -235,7 +401,7 @@ static void set_calculated_env_vars(void) dump_ram_banks(); #endif

- reserve_ram(nvtboot_boot_x0, fdt_totalsize(nvtboot_boot_x0)); + reserve_ram(cboot_boot_x0, fdt_totalsize(cboot_boot_x0));

#ifdef DEBUG printf("RAM after reserving cboot DTB:\n"); @@ -262,7 +428,7 @@ static void set_calculated_env_vars(void) debug("%s: var: %s\n", __func__, var); set_calculated_env_var(var); #ifdef DEBUG - printf("RAM banks affter allocating %s:\n", var); + printf("RAM banks after allocating %s:\n", var); dump_ram_banks(); #endif } @@ -274,7 +440,7 @@ static int set_fdt_addr(void) { int ret;

- ret = env_set_hex("fdt_addr", nvtboot_boot_x0); + ret = env_set_hex("fdt_addr", cboot_boot_x0); if (ret) { printf("Failed to set fdt_addr to point at DTB: %d\n", ret); return ret; @@ -284,12 +450,12 @@ static int set_fdt_addr(void) }

/* - * Attempt to use /chosen/nvidia,ether-mac in the nvtboot DTB to U-Boot's + * Attempt to use /chosen/nvidia,ethernet-mac in the cboot DTB to U-Boot's * ethaddr environment variable if possible. */ -static int set_ethaddr_from_nvtboot(void) +static int set_ethaddr_from_cboot(void) { - const void *nvtboot_blob = (void *)nvtboot_boot_x0; + const void *cboot_blob = (void *)cboot_boot_x0; int ret, node, len; const u32 *prop;

@@ -297,27 +463,27 @@ static int set_ethaddr_from_nvtboot(void) if (env_get("ethaddr")) return 0;

- node = fdt_path_offset(nvtboot_blob, "/chosen"); + node = fdt_path_offset(cboot_blob, "/chosen"); if (node < 0) { - printf("Can't find /chosen node in nvtboot DTB\n"); + printf("Can't find /chosen node in cboot DTB\n"); return node; } - prop = fdt_getprop(nvtboot_blob, node, "nvidia,ether-mac", &len); + prop = fdt_getprop(cboot_blob, node, "nvidia,ethernet-mac", &len); if (!prop) { - printf("Can't find nvidia,ether-mac property in nvtboot DTB\n"); + printf("Can't find nvidia,ether-mac property in cboot DTB\n"); return -ENOENT; }

ret = env_set("ethaddr", (void *)prop); if (ret) { - printf("Failed to set ethaddr from nvtboot DTB: %d\n", ret); + printf("Failed to set ethaddr from cboot DTB: %d\n", ret); return ret; }

return 0; }

-int tegra_soc_board_init_late(void) +int cboot_late_init(void) { set_calculated_env_vars(); /* @@ -326,7 +492,7 @@ int tegra_soc_board_init_late(void) */ set_fdt_addr(); /* Ignore errors here; not all cases care about Ethernet addresses */ - set_ethaddr_from_nvtboot(); + set_ethaddr_from_cboot();

return 0; } diff --git a/arch/arm/mach-tegra/tegra186/nvtboot_ll.S b/arch/arm/mach-tegra/cboot_ll.S similarity index 57% rename from arch/arm/mach-tegra/tegra186/nvtboot_ll.S rename to arch/arm/mach-tegra/cboot_ll.S index aa7a863d9702..4c9ddacc2b39 100644 --- a/arch/arm/mach-tegra/tegra186/nvtboot_ll.S +++ b/arch/arm/mach-tegra/cboot_ll.S @@ -1,6 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0+ */ /* - * Save nvtboot-related boot-time CPU state + * Save cboot-related boot-time CPU state * * (C) Copyright 2015-2016 NVIDIA Corporation <www.nvidia.com> */ @@ -9,12 +9,12 @@ #include <linux/linkage.h>

.align 8 -.globl nvtboot_boot_x0 -nvtboot_boot_x0: +.globl cboot_boot_x0 +cboot_boot_x0: .dword 0

-ENTRY(save_boot_params) - adr x8, nvtboot_boot_x0 +ENTRY(cboot_save_boot_params) + adr x8, cboot_boot_x0 str x0, [x8] b save_boot_params_ret -ENDPROC(save_boot_params) +ENDPROC(cboot_save_boot_params) diff --git a/arch/arm/mach-tegra/tegra186/Makefile b/arch/arm/mach-tegra/tegra186/Makefile index 56f3378ecea3..3a2405027704 100644 --- a/arch/arm/mach-tegra/tegra186/Makefile +++ b/arch/arm/mach-tegra/tegra186/Makefile @@ -2,8 +2,4 @@ # # SPDX-License-Identifier: GPL-2.0

-obj-y += ../board186.o obj-y += cache.o -obj-y += nvtboot_board.o -obj-y += nvtboot_ll.o -obj-y += nvtboot_mem.o diff --git a/arch/arm/mach-tegra/tegra186/nvtboot_mem.c b/arch/arm/mach-tegra/tegra186/nvtboot_mem.c deleted file mode 100644 index 62142821a595..000000000000 --- a/arch/arm/mach-tegra/tegra186/nvtboot_mem.c +++ /dev/null @@ -1,172 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0+ -/* - * Copyright (c) 2016-2018, NVIDIA CORPORATION. - */ - -#include <common.h> -#include <fdt_support.h> -#include <fdtdec.h> -#include <linux/sizes.h> -#include <asm/arch/tegra.h> -#include <asm/armv8/mmu.h> - -/* - * Size of a region that's large enough to hold the relocated U-Boot and all - * other allocations made around it (stack, heap, page tables, etc.) - * In practice, running "bdinfo" at the shell prompt, the stack reaches about - * 5MB from the address selected for ram_top as of the time of writing, - * so a 16MB region should be plenty. - */ -#define MIN_USABLE_RAM_SIZE SZ_16M -/* - * The amount of space we expect to require for stack usage. Used to validate - * that all reservations fit into the region selected for the relocation target - */ -#define MIN_USABLE_STACK_SIZE SZ_1M - -DECLARE_GLOBAL_DATA_PTR; - -extern unsigned long nvtboot_boot_x0; -extern struct mm_region tegra_mem_map[]; - -/* - * These variables are written to before relocation, and hence cannot be - * in.bss, since .bss overlaps the DTB that's appended to the U-Boot binary. - * The section attribute forces this into .data and avoids this issue. This - * also has the nice side-effect of the content being valid after relocation. - */ - -/* The number of valid entries in ram_banks[] */ -static int ram_bank_count __attribute__((section(".data"))); - -/* - * The usable top-of-RAM for U-Boot. This is both: - * a) Below 4GB to avoid issues with peripherals that use 32-bit addressing. - * b) At the end of a region that has enough space to hold the relocated U-Boot - * and all other allocations made around it (stack, heap, page tables, etc.) - */ -static u64 ram_top __attribute__((section(".data"))); -/* The base address of the region of RAM that ends at ram_top */ -static u64 region_base __attribute__((section(".data"))); - -int dram_init(void) -{ - unsigned int na, ns; - const void *nvtboot_blob = (void *)nvtboot_boot_x0; - int node, len, i; - const u32 *prop; - - na = fdtdec_get_uint(nvtboot_blob, 0, "#address-cells", 2); - ns = fdtdec_get_uint(nvtboot_blob, 0, "#size-cells", 2); - - node = fdt_path_offset(nvtboot_blob, "/memory"); - if (node < 0) { - pr_err("Can't find /memory node in nvtboot DTB"); - hang(); - } - prop = fdt_getprop(nvtboot_blob, node, "reg", &len); - if (!prop) { - pr_err("Can't find /memory/reg property in nvtboot DTB"); - hang(); - } - - /* Calculate the true # of base/size pairs to read */ - len /= 4; /* Convert bytes to number of cells */ - len /= (na + ns); /* Convert cells to number of banks */ - if (len > CONFIG_NR_DRAM_BANKS) - len = CONFIG_NR_DRAM_BANKS; - - /* Parse the /memory node, and save useful entries */ - gd->ram_size = 0; - ram_bank_count = 0; - for (i = 0; i < len; i++) { - u64 bank_start, bank_end, bank_size, usable_bank_size; - - /* Extract raw memory region data from DTB */ - bank_start = fdt_read_number(prop, na); - prop += na; - bank_size = fdt_read_number(prop, ns); - prop += ns; - gd->ram_size += bank_size; - bank_end = bank_start + bank_size; - debug("Bank %d: %llx..%llx (+%llx)\n", i, - bank_start, bank_end, bank_size); - - /* - * Align the bank to MMU section size. This is not strictly - * necessary, since the translation table construction code - * handles page granularity without issue. However, aligning - * the MMU entries reduces the size and number of levels in the - * page table, so is worth it. - */ - bank_start = ROUND(bank_start, SZ_2M); - bank_end = bank_end & ~(SZ_2M - 1); - bank_size = bank_end - bank_start; - debug(" aligned: %llx..%llx (+%llx)\n", - bank_start, bank_end, bank_size); - if (bank_end <= bank_start) - continue; - - /* Record data used to create MMU translation tables */ - ram_bank_count++; - /* Index below is deliberately 1-based to skip MMIO entry */ - tegra_mem_map[ram_bank_count].virt = bank_start; - tegra_mem_map[ram_bank_count].phys = bank_start; - tegra_mem_map[ram_bank_count].size = bank_size; - tegra_mem_map[ram_bank_count].attrs = - PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_INNER_SHARE; - - /* Determine best bank to relocate U-Boot into */ - if (bank_end > SZ_4G) - bank_end = SZ_4G; - debug(" end %llx (usable)\n", bank_end); - usable_bank_size = bank_end - bank_start; - debug(" size %llx (usable)\n", usable_bank_size); - if ((usable_bank_size >= MIN_USABLE_RAM_SIZE) && - (bank_end > ram_top)) { - ram_top = bank_end; - region_base = bank_start; - debug("ram top now %llx\n", ram_top); - } - } - - /* Ensure memory map contains the desired sentinel entry */ - tegra_mem_map[ram_bank_count + 1].virt = 0; - tegra_mem_map[ram_bank_count + 1].phys = 0; - tegra_mem_map[ram_bank_count + 1].size = 0; - tegra_mem_map[ram_bank_count + 1].attrs = 0; - - /* Error out if a relocation target couldn't be found */ - if (!ram_top) { - pr_err("Can't find a usable RAM top"); - hang(); - } - - return 0; -} - -int dram_init_banksize(void) -{ - int i; - - if ((gd->start_addr_sp - region_base) < MIN_USABLE_STACK_SIZE) { - pr_err("Reservations exceed chosen region size"); - hang(); - } - - for (i = 0; i < ram_bank_count; i++) { - gd->bd->bi_dram[i].start = tegra_mem_map[1 + i].virt; - gd->bd->bi_dram[i].size = tegra_mem_map[1 + i].size; - } - -#ifdef CONFIG_PCI - gd->pci_ram_top = ram_top; -#endif - - return 0; -} - -ulong board_get_usable_ram_top(ulong total_size) -{ - return ram_top; -} diff --git a/board/nvidia/p2771-0000/p2771-0000.c b/board/nvidia/p2771-0000/p2771-0000.c index 496e8a02111e..6f88010c18c3 100644 --- a/board/nvidia/p2771-0000/p2771-0000.c +++ b/board/nvidia/p2771-0000/p2771-0000.c @@ -7,7 +7,7 @@ #include <i2c.h> #include "../p2571/max77620_init.h"

-int tegra_board_init(void) +void pin_mux_mmc(void) { struct udevice *dev; uchar val; @@ -18,19 +18,18 @@ int tegra_board_init(void) ret = i2c_get_chip_for_busnum(0, MAX77620_I2C_ADDR_7BIT, 1, &dev); if (ret) { printf("%s: Cannot find MAX77620 I2C chip\n", __func__); - return ret; + return; } /* 0xF2 for 3.3v, enabled: bit7:6 = 11 = enable, bit5:0 = voltage */ val = 0xF2; ret = dm_i2c_write(dev, MAX77620_CNFG1_L3_REG, &val, 1); if (ret) { printf("i2c_write 0 0x3c 0x27 failed: %d\n", ret); - return ret; + return; } - - return 0; }

+#ifdef CONFIG_PCI_TEGRA int tegra_pcie_board_init(void) { struct udevice *dev; @@ -52,3 +51,4 @@ int tegra_pcie_board_init(void)

return 0; } +#endif

From: Thierry Reding treding@nvidia.com

This function will attempt to look up an ethernet address in the DTB that was passed in from cboot. It does so by first trying to locate the primary ethernet device for the board (identified by the "ethernet" alias) and if found, reads the "local-mac-address" property. If the "ethernet" alias does not exist, or if it points to a device tree node that doesn't exist, or if the device tree node that it points to does not have a "local-mac-address" property or if the value is invalid, it will fall back to the legacy mechanism of looking for the MAC address stored in the "nvidia,ethernet-mac" property of the "/chosen" node.

Signed-off-by: Thierry Reding treding@nvidia.com --- Changes in v2: - make dummy static inline to avoid duplicate definitions

arch/arm/include/asm/arch-tegra/cboot.h | 6 ++ arch/arm/mach-tegra/cboot.c | 78 ++++++++++++++++++++----- 2 files changed, 69 insertions(+), 15 deletions(-)

diff --git a/arch/arm/include/asm/arch-tegra/cboot.h b/arch/arm/include/asm/arch-tegra/cboot.h index b3441ec178b3..021c24617575 100644 --- a/arch/arm/include/asm/arch-tegra/cboot.h +++ b/arch/arm/include/asm/arch-tegra/cboot.h @@ -14,6 +14,7 @@ void cboot_save_boot_params(unsigned long x0, unsigned long x1, int cboot_dram_init(void); int cboot_dram_init_banksize(void); ulong cboot_get_usable_ram_top(ulong total_size); +int cboot_get_ethaddr(const void *fdt, uint8_t mac[ETH_ALEN]); #else static inline void cboot_save_boot_params(unsigned long x0, unsigned long x1, unsigned long x2, unsigned long x3) @@ -34,6 +35,11 @@ static inline ulong cboot_get_usable_ram_top(ulong total_size) { return 0; } + +static inline int cboot_get_ethaddr(const void *fdt, uint8_t mac[ETH_ALEN]) +{ + return -ENOSYS; +} #endif

#endif diff --git a/arch/arm/mach-tegra/cboot.c b/arch/arm/mach-tegra/cboot.c index acf33b4c4e0c..9735380bda59 100644 --- a/arch/arm/mach-tegra/cboot.c +++ b/arch/arm/mach-tegra/cboot.c @@ -4,6 +4,7 @@ */

#include <common.h> +#include <environment.h> #include <fdt_support.h> #include <fdtdec.h> #include <stdlib.h> @@ -465,46 +466,93 @@ static int set_fdt_addr(void) * Attempt to use /chosen/nvidia,ethernet-mac in the cboot DTB to U-Boot's * ethaddr environment variable if possible. */ -static int set_ethaddr_from_cboot(void) +static int cboot_get_ethaddr_legacy(const void *fdt, uint8_t mac[ETH_ALEN]) { - const void *cboot_blob = (void *)cboot_boot_x0; - int ret, node, len; - const u32 *prop; - - /* Already a valid address in the environment? If so, keep it */ - if (env_get("ethaddr")) - return 0; + const char *prop; + int node, len;

- node = fdt_path_offset(cboot_blob, "/chosen"); + node = fdt_path_offset(fdt, "/chosen"); if (node < 0) { printf("Can't find /chosen node in cboot DTB\n"); return node; } - prop = fdt_getprop(cboot_blob, node, "nvidia,ethernet-mac", &len); + + prop = fdt_getprop(fdt, node, "nvidia,ethernet-mac", &len); if (!prop) { printf("Can't find nvidia,ether-mac property in cboot DTB\n"); return -ENOENT; }

- ret = env_set("ethaddr", (void *)prop); - if (ret) { - printf("Failed to set ethaddr from cboot DTB: %d\n", ret); - return ret; + eth_parse_enetaddr(prop, mac); + + if (!is_valid_ethaddr(mac)) { + printf("Invalid MAC address: %s\n", prop); + return -EINVAL; }

+ debug("Legacy MAC address: %pM\n", mac); + return 0; }

+int cboot_get_ethaddr(const void *fdt, uint8_t mac[ETH_ALEN]) +{ + int node, len, err = 0; + const uchar *prop; + const char *path; + + path = fdt_get_alias(fdt, "ethernet"); + if (!path) { + err = -ENOENT; + goto out; + } + + debug("ethernet alias found: %s\n", path); + + node = fdt_path_offset(fdt, path); + if (node < 0) { + err = -ENOENT; + goto out; + } + + prop = fdt_getprop(fdt, node, "local-mac-address", &len); + if (!prop) { + err = -ENOENT; + goto out; + } + + if (len != ETH_ALEN) { + err = -EINVAL; + goto out; + } + + debug("MAC address: %pM\n", prop); + memcpy(mac, prop, ETH_ALEN); + +out: + if (err < 0) + err = cboot_get_ethaddr_legacy(fdt, mac); + + return err; +} + int cboot_late_init(void) { + const void *fdt = (const void *)cboot_boot_x0; + uint8_t mac[ETH_ALEN]; + int err; + set_calculated_env_vars(); /* * Ignore errors here; the value may not be used depending on * extlinux.conf or boot script content. */ set_fdt_addr(); + /* Ignore errors here; not all cases care about Ethernet addresses */ - set_ethaddr_from_cboot(); + err = cboot_get_ethaddr(fdt, mac); + if (!err) + eth_env_set_enetaddr("ethaddr", mac);

return 0; }

From: Thierry Reding treding@nvidia.com

Pass the ethernet MAC address to the kernel upon boot. This passes both the local-mac-address property (as passed to U-Boot from cboot) and the currently set MAC address via the mac-address property. The latter will only be set if it is different from the address that was already passed via the local-mac-address property.

Signed-off-by: Thierry Reding treding@nvidia.com --- board/nvidia/p2371-2180/p2371-2180.c | 50 ++++++++++++++++++++++++++++ configs/p2371-2180_defconfig | 1 + 2 files changed, 51 insertions(+)

diff --git a/board/nvidia/p2371-2180/p2371-2180.c b/board/nvidia/p2371-2180/p2371-2180.c index 212037da5ac0..a444d692d7ea 100644 --- a/board/nvidia/p2371-2180/p2371-2180.c +++ b/board/nvidia/p2371-2180/p2371-2180.c @@ -5,9 +5,12 @@ */

#include <common.h> +#include <environment.h> #include <i2c.h> +#include <linux/libfdt.h> #include <asm/arch/gpio.h> #include <asm/arch/pinmux.h> +#include <asm/arch-tegra/cboot.h> #include "../p2571/max77620_init.h" #include "pinmux-config-p2371-2180.h"

@@ -94,3 +97,50 @@ int tegra_pcie_board_init(void) return 0; } #endif /* PCI */ + +static void ft_mac_address_setup(void *fdt) +{ + const void *cboot_fdt = (const void *)cboot_boot_x0; + uint8_t mac[ETH_ALEN], local_mac[ETH_ALEN]; + const char *path; + int offset, err; + + err = cboot_get_ethaddr(cboot_fdt, local_mac); + if (err < 0) + memset(local_mac, 0, ETH_ALEN); + + path = fdt_get_alias(fdt, "ethernet"); + if (!path) + return; + + debug("ethernet alias found: %s\n", path); + + offset = fdt_path_offset(fdt, path); + if (offset < 0) { + printf("ethernet alias points to absent node %s\n", path); + return; + } + + if (is_valid_ethaddr(local_mac)) { + err = fdt_setprop(fdt, offset, "local-mac-address", local_mac, + ETH_ALEN); + if (!err) + debug("Local MAC address set: %pM\n", local_mac); + } + + if (eth_env_get_enetaddr("ethaddr", mac)) { + if (memcmp(local_mac, mac, ETH_ALEN) != 0) { + err = fdt_setprop(fdt, offset, "mac-address", mac, + ETH_ALEN); + if (!err) + debug("MAC address set: %pM\n", mac); + } + } +} + +int ft_board_setup(void *fdt, bd_t *bd) +{ + ft_mac_address_setup(fdt); + + return 0; +} diff --git a/configs/p2371-2180_defconfig b/configs/p2371-2180_defconfig index 2fac69917a92..16afbba68ae7 100644 --- a/configs/p2371-2180_defconfig +++ b/configs/p2371-2180_defconfig @@ -5,6 +5,7 @@ CONFIG_TEGRA210=y CONFIG_TARGET_P2371_2180=y CONFIG_NR_DRAM_BANKS=2 CONFIG_OF_SYSTEM_SETUP=y +CONFIG_OF_BOARD_SETUP=y CONFIG_CONSOLE_MUX=y CONFIG_SYS_STDIO_DEREGISTER=y CONFIG_SYS_PROMPT="Tegra210 (P2371-2180) # "

From: Thierry Reding treding@nvidia.com

Signed-off-by: Thierry Reding treding@nvidia.com --- include/linux/string.h | 1 + lib/string.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+)

diff --git a/include/linux/string.h b/include/linux/string.h index 36066207392e..5d63be4ce5b0 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -94,6 +94,7 @@ size_t strcspn(const char *s, const char *reject); #ifndef __HAVE_ARCH_STRDUP extern char * strdup(const char *); #endif +extern char * strndup(const char *, size_t); #ifndef __HAVE_ARCH_STRSWAB extern char * strswab(const char *); #endif diff --git a/lib/string.c b/lib/string.c index af17c16f616d..9b779ddc3bbe 100644 --- a/lib/string.c +++ b/lib/string.c @@ -326,6 +326,29 @@ char * strdup(const char *s) } #endif

+char * strndup(const char *s, size_t n) +{ + size_t len; + char *new; + + if (s == NULL) + return NULL; + + len = strlen(s); + + if (n < len) + len = n; + + new = malloc(len + 1); + if (new == NULL) + return NULL; + + strncpy(new, s, len); + new[len] = '\0'; + + return new; +} + #ifndef __HAVE_ARCH_STRSPN /** * strspn - Calculate the length of the initial substring of @s which only