mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-18 10:48:51 +00:00
8b2eb776b1
With new SMP-enabled CPUs with ARC HS38 cores and corresponding support in Linux kernel it's required to add basic SMP support in U-Boot. Currently we assume the one and only core starts execution after power-on. So most of things in U-Boot is handled in UP mode. But when U-Boot is used for loading and starting Linux kernel right before jumping to kernel's entry point U-Boot: [1] Sets all slave cores to jump to the same address [kernel's entry point] [2] Really starts all slav cores In ARC's implemetation of SMP in Linux kernel all cores are supposed to run the same start-up code. But only core with ID 0 (master core) processes further while others are looping waiting for master core to complete some initialization. That means it's safe to un-pause slave cores and let them execute kernel - they will wait for master anyway. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Vineet Gupta <vgupta@synopsys.com>
112 lines
2.4 KiB
C
112 lines
2.4 KiB
C
/*
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* Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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DECLARE_GLOBAL_DATA_PTR;
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static ulong get_sp(void)
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{
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ulong ret;
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asm("mov %0, sp" : "=r"(ret) : );
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return ret;
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}
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void arch_lmb_reserve(struct lmb *lmb)
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{
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ulong sp;
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/*
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* Booting a (Linux) kernel image
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*
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* Allocate space for command line and board info - the
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* address should be as high as possible within the reach of
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* the kernel (see CONFIG_SYS_BOOTMAPSZ settings), but in unused
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* memory, which means far enough below the current stack
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* pointer.
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*/
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sp = get_sp();
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debug("## Current stack ends at 0x%08lx ", sp);
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/* adjust sp by 4K to be safe */
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sp -= 4096;
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lmb_reserve(lmb, sp, (CONFIG_SYS_SDRAM_BASE + gd->ram_size - sp));
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}
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static int cleanup_before_linux(void)
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{
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disable_interrupts();
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flush_dcache_all();
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invalidate_icache_all();
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return 0;
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}
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/* Subcommand: PREP */
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static void boot_prep_linux(bootm_headers_t *images)
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{
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if (image_setup_linux(images))
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hang();
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}
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__weak void smp_set_core_boot_addr(unsigned long addr, int corenr) {}
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__weak void smp_kick_all_cpus(void) {}
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/* Subcommand: GO */
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static void boot_jump_linux(bootm_headers_t *images, int flag)
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{
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void (*kernel_entry)(int zero, int arch, uint params);
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unsigned int r0, r2;
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int fake = (flag & BOOTM_STATE_OS_FAKE_GO);
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kernel_entry = (void (*)(int, int, uint))images->ep;
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debug("## Transferring control to Linux (at address %08lx)...\n",
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(ulong) kernel_entry);
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bootstage_mark(BOOTSTAGE_ID_RUN_OS);
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printf("\nStarting kernel ...%s\n\n", fake ?
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"(fake run for tracing)" : "");
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bootstage_mark_name(BOOTSTAGE_ID_BOOTM_HANDOFF, "start_kernel");
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cleanup_before_linux();
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if (IMAGE_ENABLE_OF_LIBFDT && images->ft_len) {
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r0 = 2;
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r2 = (unsigned int)images->ft_addr;
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} else {
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r0 = 1;
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r2 = (unsigned int)getenv("bootargs");
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}
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smp_set_core_boot_addr((unsigned long)kernel_entry, -1);
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smp_kick_all_cpus();
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if (!fake)
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kernel_entry(r0, 0, r2);
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}
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int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
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{
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/* No need for those on ARC */
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if ((flag & BOOTM_STATE_OS_BD_T) || (flag & BOOTM_STATE_OS_CMDLINE))
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return -1;
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if (flag & BOOTM_STATE_OS_PREP) {
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boot_prep_linux(images);
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return 0;
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}
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if (flag & (BOOTM_STATE_OS_GO | BOOTM_STATE_OS_FAKE_GO)) {
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boot_jump_linux(images, flag);
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return 0;
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}
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boot_prep_linux(images);
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boot_jump_linux(images, flag);
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return 0;
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}
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