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- // SPDX-License-Identifier: BSD-2-Clause
- /*
- * fdt_fixup.c - Flat Device Tree parsing helper routines
- * Implement helper routines to parse FDT nodes on top of
- * libfdt for OpenSBI usage
- *
- * Copyright (C) 2020 Bin Meng <bmeng.cn@gmail.com>
- */
- #include <libfdt.h>
- #include <sbi/sbi_console.h>
- #include <sbi/sbi_domain.h>
- #include <sbi/sbi_math.h>
- #include <sbi/sbi_hart.h>
- #include <sbi/sbi_scratch.h>
- #include <sbi/sbi_string.h>
- #include <sbi/sbi_error.h>
- #include <sbi_utils/fdt/fdt_fixup.h>
- #include <sbi_utils/fdt/fdt_pmu.h>
- #include <sbi_utils/fdt/fdt_helper.h>
- int fdt_add_cpu_idle_states(void *fdt, const struct sbi_cpu_idle_state *state)
- {
- int cpu_node, cpus_node, err, idle_states_node;
- uint32_t count, phandle;
- err = fdt_open_into(fdt, fdt, fdt_totalsize(fdt) + 1024);
- if (err < 0)
- return err;
- err = fdt_find_max_phandle(fdt, &phandle);
- phandle++;
- if (err < 0)
- return err;
- cpus_node = fdt_path_offset(fdt, "/cpus");
- if (cpus_node < 0)
- return cpus_node;
- /* Do nothing if the idle-states node already exists. */
- idle_states_node = fdt_subnode_offset(fdt, cpus_node, "idle-states");
- if (idle_states_node >= 0)
- return 0;
- /* Create the idle-states node and its child nodes. */
- idle_states_node = fdt_add_subnode(fdt, cpus_node, "idle-states");
- if (idle_states_node < 0)
- return idle_states_node;
- for (count = 0; state->name; count++, phandle++, state++) {
- int idle_state_node;
- idle_state_node = fdt_add_subnode(fdt, idle_states_node,
- state->name);
- if (idle_state_node < 0)
- return idle_state_node;
- fdt_setprop_string(fdt, idle_state_node, "compatible",
- "riscv,idle-state");
- fdt_setprop_u32(fdt, idle_state_node,
- "riscv,sbi-suspend-param",
- state->suspend_param);
- if (state->local_timer_stop)
- fdt_setprop_empty(fdt, idle_state_node,
- "local-timer-stop");
- fdt_setprop_u32(fdt, idle_state_node, "entry-latency-us",
- state->entry_latency_us);
- fdt_setprop_u32(fdt, idle_state_node, "exit-latency-us",
- state->exit_latency_us);
- fdt_setprop_u32(fdt, idle_state_node, "min-residency-us",
- state->min_residency_us);
- if (state->wakeup_latency_us)
- fdt_setprop_u32(fdt, idle_state_node,
- "wakeup-latency-us",
- state->wakeup_latency_us);
- fdt_setprop_u32(fdt, idle_state_node, "phandle", phandle);
- }
- if (count == 0)
- return 0;
- /* Link each cpu node to the idle state nodes. */
- fdt_for_each_subnode(cpu_node, fdt, cpus_node) {
- const char *device_type;
- fdt32_t *value;
- /* Only process child nodes with device_type = "cpu". */
- device_type = fdt_getprop(fdt, cpu_node, "device_type", NULL);
- if (!device_type || strcmp(device_type, "cpu"))
- continue;
- /* Allocate space for the list of phandles. */
- err = fdt_setprop_placeholder(fdt, cpu_node, "cpu-idle-states",
- count * sizeof(phandle),
- (void **)&value);
- if (err < 0)
- return err;
- /* Fill in the phandles of the idle state nodes. */
- for (uint32_t i = 0; i < count; ++i)
- value[i] = cpu_to_fdt32(phandle - count + i);
- }
- return 0;
- }
- void fdt_cpu_fixup(void *fdt)
- {
- struct sbi_domain *dom = sbi_domain_thishart_ptr();
- int err, cpu_offset, cpus_offset, len;
- const char *mmu_type;
- u32 hartid;
- err = fdt_open_into(fdt, fdt, fdt_totalsize(fdt) + 32);
- if (err < 0)
- return;
- cpus_offset = fdt_path_offset(fdt, "/cpus");
- if (cpus_offset < 0)
- return;
- fdt_for_each_subnode(cpu_offset, fdt, cpus_offset) {
- err = fdt_parse_hart_id(fdt, cpu_offset, &hartid);
- if (err)
- continue;
- if (!fdt_node_is_enabled(fdt, cpu_offset))
- continue;
- /*
- * Disable a HART DT node if one of the following is true:
- * 1. The HART is not assigned to the current domain
- * 2. MMU is not available for the HART
- */
- mmu_type = fdt_getprop(fdt, cpu_offset, "mmu-type", &len);
- if (!sbi_domain_is_assigned_hart(dom, hartid) ||
- !mmu_type || !len)
- fdt_setprop_string(fdt, cpu_offset, "status",
- "disabled");
- }
- }
- static void fdt_domain_based_fixup_one(void *fdt, int nodeoff)
- {
- int rc;
- uint64_t reg_addr, reg_size;
- struct sbi_domain *dom = sbi_domain_thishart_ptr();
- rc = fdt_get_node_addr_size(fdt, nodeoff, 0, ®_addr, ®_size);
- if (rc < 0 || !reg_addr || !reg_size)
- return;
- if (!sbi_domain_check_addr(dom, reg_addr, dom->next_mode,
- SBI_DOMAIN_READ | SBI_DOMAIN_WRITE)) {
- rc = fdt_open_into(fdt, fdt, fdt_totalsize(fdt) + 32);
- if (rc < 0)
- return;
- fdt_setprop_string(fdt, nodeoff, "status", "disabled");
- }
- }
- static void fdt_fixup_node(void *fdt, const char *compatible)
- {
- int noff = 0;
- while ((noff = fdt_node_offset_by_compatible(fdt, noff,
- compatible)) >= 0)
- fdt_domain_based_fixup_one(fdt, noff);
- }
- void fdt_aplic_fixup(void *fdt)
- {
- fdt_fixup_node(fdt, "riscv,aplic");
- }
- void fdt_imsic_fixup(void *fdt)
- {
- fdt_fixup_node(fdt, "riscv,imsics");
- }
- void fdt_plic_fixup(void *fdt)
- {
- u32 *cells;
- int i, cells_count;
- int plic_off;
- plic_off = fdt_node_offset_by_compatible(fdt, 0, "sifive,plic-1.0.0");
- if (plic_off < 0) {
- plic_off = fdt_node_offset_by_compatible(fdt, 0, "riscv,plic0");
- if (plic_off < 0)
- return;
- }
- cells = (u32 *)fdt_getprop(fdt, plic_off,
- "interrupts-extended", &cells_count);
- if (!cells)
- return;
- cells_count = cells_count / sizeof(u32);
- if (!cells_count)
- return;
- for (i = 0; i < (cells_count / 2); i++) {
- if (fdt32_to_cpu(cells[2 * i + 1]) == IRQ_M_EXT)
- cells[2 * i + 1] = cpu_to_fdt32(0xffffffff);
- }
- }
- static int fdt_resv_memory_update_node(void *fdt, unsigned long addr,
- unsigned long size, int index,
- int parent, bool no_map)
- {
- int na = fdt_address_cells(fdt, 0);
- int ns = fdt_size_cells(fdt, 0);
- fdt32_t addr_high, addr_low;
- fdt32_t size_high, size_low;
- int subnode, err;
- fdt32_t reg[4];
- fdt32_t *val;
- char name[32];
- addr_high = (u64)addr >> 32;
- addr_low = addr;
- size_high = (u64)size >> 32;
- size_low = size;
- if (na > 1 && addr_high)
- sbi_snprintf(name, sizeof(name),
- "mmode_resv%d@%x,%x", index,
- addr_high, addr_low);
- else
- sbi_snprintf(name, sizeof(name),
- "mmode_resv%d@%x", index,
- addr_low);
- subnode = fdt_add_subnode(fdt, parent, name);
- if (subnode < 0)
- return subnode;
- if (no_map) {
- /*
- * Tell operating system not to create a virtual
- * mapping of the region as part of its standard
- * mapping of system memory.
- */
- err = fdt_setprop_empty(fdt, subnode, "no-map");
- if (err < 0)
- return err;
- }
- /* encode the <reg> property value */
- val = reg;
- if (na > 1)
- *val++ = cpu_to_fdt32(addr_high);
- *val++ = cpu_to_fdt32(addr_low);
- if (ns > 1)
- *val++ = cpu_to_fdt32(size_high);
- *val++ = cpu_to_fdt32(size_low);
- err = fdt_setprop(fdt, subnode, "reg", reg,
- (na + ns) * sizeof(fdt32_t));
- if (err < 0)
- return err;
- return 0;
- }
- /**
- * We use PMP to protect OpenSBI firmware to safe-guard it from buggy S-mode
- * software, see pmp_init() in lib/sbi/sbi_hart.c. The protected memory region
- * information needs to be conveyed to S-mode software (e.g.: operating system)
- * via some well-known method.
- *
- * With device tree, this can be done by inserting a child node of the reserved
- * memory node which is used to specify one or more regions of reserved memory.
- *
- * For the reserved memory node bindings, see Linux kernel documentation at
- * Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
- *
- * Some additional memory spaces may be protected by platform codes via PMP as
- * well, and corresponding child nodes will be inserted.
- */
- int fdt_reserved_memory_fixup(void *fdt)
- {
- struct sbi_domain_memregion *reg;
- struct sbi_domain *dom = sbi_domain_thishart_ptr();
- struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
- unsigned long filtered_base[PMP_COUNT] = { 0 };
- unsigned char filtered_order[PMP_COUNT] = { 0 };
- unsigned long addr, size;
- int err, parent, i, j;
- int na = fdt_address_cells(fdt, 0);
- int ns = fdt_size_cells(fdt, 0);
- /*
- * Expand the device tree to accommodate new node
- * by the following estimated size:
- *
- * Each PMP memory region entry occupies 64 bytes.
- * With 16 PMP memory regions we need 64 * 16 = 1024 bytes.
- */
- err = fdt_open_into(fdt, fdt, fdt_totalsize(fdt) + 1024);
- if (err < 0)
- return err;
- /* try to locate the reserved memory node */
- parent = fdt_path_offset(fdt, "/reserved-memory");
- if (parent < 0) {
- /* if such node does not exist, create one */
- parent = fdt_add_subnode(fdt, 0, "reserved-memory");
- if (parent < 0)
- return parent;
- /*
- * reserved-memory node has 3 required properties:
- * - #address-cells: the same value as the root node
- * - #size-cells: the same value as the root node
- * - ranges: should be empty
- */
- err = fdt_setprop_empty(fdt, parent, "ranges");
- if (err < 0)
- return err;
- err = fdt_setprop_u32(fdt, parent, "#size-cells", ns);
- if (err < 0)
- return err;
- err = fdt_setprop_u32(fdt, parent, "#address-cells", na);
- if (err < 0)
- return err;
- }
- /*
- * We assume the given device tree does not contain any memory region
- * child node protected by PMP. Normally PMP programming happens at
- * M-mode firmware. The memory space used by OpenSBI is protected.
- * Some additional memory spaces may be protected by domain memory
- * regions.
- *
- * With above assumption, we create child nodes directly.
- */
- i = 0;
- sbi_domain_for_each_memregion(dom, reg) {
- /* Ignore MMIO or READABLE or WRITABLE or EXECUTABLE regions */
- if (reg->flags & SBI_DOMAIN_MEMREGION_MMIO)
- continue;
- if (reg->flags & SBI_DOMAIN_MEMREGION_SU_READABLE)
- continue;
- if (reg->flags & SBI_DOMAIN_MEMREGION_SU_WRITABLE)
- continue;
- if (reg->flags & SBI_DOMAIN_MEMREGION_SU_EXECUTABLE)
- continue;
- if (i > PMP_COUNT) {
- sbi_printf("%s: Too many memory regions to fixup.\n",
- __func__);
- return SBI_ENOSPC;
- }
- bool overlap = false;
- addr = reg->base;
- for (j = 0; j < i; j++) {
- if (addr == filtered_base[j]
- && filtered_order[j] < reg->order) {
- overlap = true;
- filtered_order[j] = reg->order;
- break;
- }
- }
- if (!overlap) {
- filtered_base[i] = reg->base;
- filtered_order[i] = reg->order;
- i++;
- }
- }
- for (j = 0; j < i; j++) {
- addr = filtered_base[j];
- size = 1UL << filtered_order[j];
- fdt_resv_memory_update_node(fdt, addr, size, j, parent,
- (sbi_hart_pmp_count(scratch))
- ? false : true);
- }
- return 0;
- }
- int fdt_reserved_memory_nomap_fixup(void *fdt)
- {
- int parent, subnode;
- int err;
- /* Locate the reserved memory node */
- parent = fdt_path_offset(fdt, "/reserved-memory");
- if (parent < 0)
- return parent;
- fdt_for_each_subnode(subnode, fdt, parent) {
- /*
- * Tell operating system not to create a virtual
- * mapping of the region as part of its standard
- * mapping of system memory.
- */
- err = fdt_setprop_empty(fdt, subnode, "no-map");
- if (err < 0)
- return err;
- }
- return 0;
- }
- void fdt_fixups(void *fdt)
- {
- fdt_aplic_fixup(fdt);
- fdt_imsic_fixup(fdt);
- fdt_plic_fixup(fdt);
- fdt_reserved_memory_fixup(fdt);
- fdt_pmu_fixup(fdt);
- }
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