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Diffstat (limited to '')
-rw-r--r-- | plat/arm/board/arm_fpga/fpga_bl31_setup.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/plat/arm/board/arm_fpga/fpga_bl31_setup.c b/plat/arm/board/arm_fpga/fpga_bl31_setup.c new file mode 100644 index 0000000..e1b3abb --- /dev/null +++ b/plat/arm/board/arm_fpga/fpga_bl31_setup.c @@ -0,0 +1,402 @@ +/* + * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <assert.h> +#include <errno.h> + +#include <common/fdt_fixup.h> +#include <common/fdt_wrappers.h> +#include <drivers/arm/gicv3.h> +#include <drivers/delay_timer.h> +#include <drivers/generic_delay_timer.h> +#include <lib/extensions/spe.h> +#include <lib/mmio.h> +#include <libfdt.h> + +#include "fpga_private.h" +#include <plat/common/platform.h> +#include <platform_def.h> + +static entry_point_info_t bl33_image_ep_info; +static unsigned int system_freq; +volatile uint32_t secondary_core_spinlock; + +uintptr_t plat_get_ns_image_entrypoint(void) +{ +#ifdef PRELOADED_BL33_BASE + return PRELOADED_BL33_BASE; +#else + return 0ULL; +#endif +} + +uint32_t fpga_get_spsr_for_bl33_entry(void) +{ + return SPSR_64(MODE_EL2, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS); +} + +void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1, + u_register_t arg2, u_register_t arg3) +{ + /* Add this core to the VALID mpids list */ + fpga_valid_mpids[plat_my_core_pos()] = VALID_MPID; + + /* + * Notify the secondary CPUs that the C runtime is ready + * so they can announce themselves. + */ + secondary_core_spinlock = C_RUNTIME_READY_KEY; + dsbish(); + sev(); + + fpga_console_init(); + + bl33_image_ep_info.pc = plat_get_ns_image_entrypoint(); + bl33_image_ep_info.spsr = fpga_get_spsr_for_bl33_entry(); + SET_SECURITY_STATE(bl33_image_ep_info.h.attr, NON_SECURE); + + /* Set x0-x3 for the primary CPU as expected by the kernel */ + bl33_image_ep_info.args.arg0 = (u_register_t)FPGA_PRELOADED_DTB_BASE; + bl33_image_ep_info.args.arg1 = 0U; + bl33_image_ep_info.args.arg2 = 0U; + bl33_image_ep_info.args.arg3 = 0U; +} + +void bl31_plat_arch_setup(void) +{ +} + +void bl31_platform_setup(void) +{ + /* Write frequency to CNTCRL and initialize timer */ + generic_delay_timer_init(); + + /* + * Before doing anything else, wait for some time to ensure that + * the secondary CPUs have populated the fpga_valid_mpids array. + * As the number of secondary cores is unknown and can even be 0, + * it is not possible to rely on any signal from them, so use a + * delay instead. + */ + mdelay(5); + + /* + * On the event of a cold reset issued by, for instance, a reset pin + * assertion, we cannot guarantee memory to be initialized to zero. + * In such scenario, if the secondary cores reached + * plat_secondary_cold_boot_setup before the primary one initialized + * .BSS, we could end up having a race condition if the spinlock + * was not cleared before. + * + * Similarly, if there were a reset before the spinlock had been + * cleared, the secondary cores would find the lock opened before + * .BSS is cleared, causing another race condition. + * + * So clean the spinlock as soon as we think it is safe to reduce the + * chances of any race condition on a reset. + */ + secondary_core_spinlock = 0UL; + + /* Initialize the GIC driver, cpu and distributor interfaces */ + plat_fpga_gic_init(); +} + +entry_point_info_t *bl31_plat_get_next_image_ep_info(uint32_t type) +{ + entry_point_info_t *next_image_info; + next_image_info = &bl33_image_ep_info; + + /* Only expecting BL33: the kernel will run in EL2NS */ + assert(type == NON_SECURE); + + /* None of the images can have 0x0 as the entrypoint */ + if (next_image_info->pc) { + return next_image_info; + } else { + return NULL; + } +} + +/* + * Even though we sell the FPGA UART as an SBSA variant, it is actually + * a full fledged PL011. So the baudrate divider registers exist. + */ +#ifndef UARTIBRD +#define UARTIBRD 0x024 +#define UARTFBRD 0x028 +#endif + +/* Round an integer to the closest multiple of a value. */ +static unsigned int round_multiple(unsigned int x, unsigned int multiple) +{ + if (multiple < 2) { + return x; + } + + return ((x + (multiple / 2 - 1)) / multiple) * multiple; +} + +#define PL011_FRAC_SHIFT 6 +#define FPGA_DEFAULT_BAUDRATE 38400 +#define PL011_OVERSAMPLING 16 +static unsigned int pl011_freq_from_divider(unsigned int divider) +{ + unsigned int freq; + + freq = divider * FPGA_DEFAULT_BAUDRATE * PL011_OVERSAMPLING; + + return freq >> PL011_FRAC_SHIFT; +} + +/* + * The FPGAs run most peripherals from one main clock, among them the CPUs, + * the arch timer, and the UART baud base clock. + * The SCP knows this frequency and programs the UART clock divider for a + * 38400 bps baudrate. Recalculate the base input clock from there. + */ +static unsigned int fpga_get_system_frequency(void) +{ + const void *fdt = (void *)(uintptr_t)FPGA_PRELOADED_DTB_BASE; + int node, err; + + /* + * If the arch timer DT node has an explicit clock-frequency property + * set, use that, to allow people overriding auto-detection. + */ + node = fdt_node_offset_by_compatible(fdt, 0, "arm,armv8-timer"); + if (node >= 0) { + uint32_t freq; + + err = fdt_read_uint32(fdt, node, "clock-frequency", &freq); + if (err >= 0) { + return freq; + } + } + + node = fdt_node_offset_by_compatible(fdt, 0, "arm,pl011"); + if (node >= 0) { + uintptr_t pl011_base; + unsigned int divider; + + err = fdt_get_reg_props_by_index(fdt, node, 0, + &pl011_base, NULL); + if (err >= 0) { + divider = mmio_read_32(pl011_base + UARTIBRD); + divider <<= PL011_FRAC_SHIFT; + divider += mmio_read_32(pl011_base + UARTFBRD); + + /* + * The result won't be exact, due to rounding errors, + * but the input frequency was a multiple of 250 KHz. + */ + return round_multiple(pl011_freq_from_divider(divider), + 250000); + } else { + WARN("Cannot read PL011 MMIO base\n"); + } + } else { + WARN("No PL011 DT node\n"); + } + + /* No PL011 DT node or calculation failed. */ + return FPGA_DEFAULT_TIMER_FREQUENCY; +} + +unsigned int plat_get_syscnt_freq2(void) +{ + if (system_freq == 0U) { + system_freq = fpga_get_system_frequency(); + } + + return system_freq; +} + +static void fpga_dtb_update_clock(void *fdt, unsigned int freq) +{ + uint32_t freq_dtb = fdt32_to_cpu(freq); + uint32_t phandle; + int node, err; + + node = fdt_node_offset_by_compatible(fdt, 0, "arm,pl011"); + if (node < 0) { + WARN("%s(): No PL011 DT node found\n", __func__); + + return; + } + + err = fdt_read_uint32(fdt, node, "clocks", &phandle); + if (err != 0) { + WARN("Cannot find clocks property\n"); + + return; + } + + node = fdt_node_offset_by_phandle(fdt, phandle); + if (node < 0) { + WARN("Cannot get phandle\n"); + + return; + } + + err = fdt_setprop_inplace(fdt, node, + "clock-frequency", + &freq_dtb, + sizeof(freq_dtb)); + if (err < 0) { + WARN("Could not update DT baud clock frequency\n"); + + return; + } +} + +#define CMDLINE_SIGNATURE "CMD:" + +static int fpga_dtb_set_commandline(void *fdt, const char *cmdline) +{ + int chosen; + const char *eol; + char nul = 0; + int slen, err; + + chosen = fdt_add_subnode(fdt, 0, "chosen"); + if (chosen == -FDT_ERR_EXISTS) { + chosen = fdt_path_offset(fdt, "/chosen"); + } + + if (chosen < 0) { + return chosen; + } + + /* + * There is most likely an EOL at the end of the + * command line, make sure we terminate the line there. + * We can't replace the EOL with a NUL byte in the + * source, as this is in read-only memory. So we first + * create the property without any termination, then + * append a single NUL byte. + */ + eol = strchr(cmdline, '\n'); + if (eol == NULL) { + eol = strchr(cmdline, 0); + } + /* Skip the signature and omit the EOL/NUL byte. */ + slen = eol - (cmdline + strlen(CMDLINE_SIGNATURE)); + /* + * Let's limit the size of the property, just in case + * we find the signature by accident. The Linux kernel + * limits to 4096 characters at most (in fact 2048 for + * arm64), so that sounds like a reasonable number. + */ + if (slen > 4095) { + slen = 4095; + } + + err = fdt_setprop(fdt, chosen, "bootargs", + cmdline + strlen(CMDLINE_SIGNATURE), slen); + if (err != 0) { + return err; + } + + return fdt_appendprop(fdt, chosen, "bootargs", &nul, 1); +} + +static void fpga_prepare_dtb(void) +{ + void *fdt = (void *)(uintptr_t)FPGA_PRELOADED_DTB_BASE; + const char *cmdline = (void *)(uintptr_t)FPGA_PRELOADED_CMD_LINE; + int err; + + err = fdt_open_into(fdt, fdt, FPGA_MAX_DTB_SIZE); + if (err < 0) { + ERROR("cannot open devicetree at %p: %d\n", fdt, err); + panic(); + } + + /* Reserve memory used by Trusted Firmware. */ + if (fdt_add_reserved_memory(fdt, "tf-a@80000000", BL31_BASE, + BL31_LIMIT - BL31_BASE)) { + WARN("Failed to add reserved memory node to DT\n"); + } + + /* Check for the command line signature. */ + if (!strncmp(cmdline, CMDLINE_SIGNATURE, strlen(CMDLINE_SIGNATURE))) { + err = fpga_dtb_set_commandline(fdt, cmdline); + if (err == 0) { + INFO("using command line at 0x%x\n", + FPGA_PRELOADED_CMD_LINE); + } else { + ERROR("failed to put command line into DTB: %d\n", err); + } + } + + if (err < 0) { + ERROR("Error %d extending Device Tree\n", err); + panic(); + } + + err = fdt_add_cpus_node(fdt, FPGA_MAX_PE_PER_CPU, + FPGA_MAX_CPUS_PER_CLUSTER, + FPGA_MAX_CLUSTER_COUNT); + + if (err == -EEXIST) { + WARN("Not overwriting already existing /cpus node in DTB\n"); + } else { + if (err < 0) { + ERROR("Error %d creating the /cpus DT node\n", err); + panic(); + } else { + unsigned int nr_cores = fpga_get_nr_gic_cores(); + + INFO("Adjusting GICR DT region to cover %u cores\n", + nr_cores); + err = fdt_adjust_gic_redist(fdt, nr_cores, + fpga_get_redist_base(), + fpga_get_redist_size()); + if (err < 0) { + ERROR("Error %d fixing up GIC DT node\n", err); + } + } + } + + fpga_dtb_update_clock(fdt, system_freq); + + /* Check whether we support the SPE PMU. Remove the DT node if not. */ + if (!spe_supported()) { + int node = fdt_node_offset_by_compatible(fdt, 0, + "arm,statistical-profiling-extension-v1"); + + if (node >= 0) { + fdt_del_node(fdt, node); + } + } + + /* Check whether we have an ITS. Remove the DT node if not. */ + if (!fpga_has_its()) { + int node = fdt_node_offset_by_compatible(fdt, 0, + "arm,gic-v3-its"); + + if (node >= 0) { + fdt_del_node(fdt, node); + } + } + + err = fdt_pack(fdt); + if (err < 0) { + ERROR("Failed to pack Device Tree at %p: error %d\n", fdt, err); + } + + clean_dcache_range((uintptr_t)fdt, fdt_blob_size(fdt)); +} + +void bl31_plat_runtime_setup(void) +{ + fpga_prepare_dtb(); +} + +void bl31_plat_enable_mmu(uint32_t flags) +{ + /* TODO: determine if MMU needs to be enabled */ +} |