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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_utils/fdt/fdt_fixup.h>
- #include <sbi_utils/fdt/fdt_pmu.h>
- #include <sbi_utils/fdt/fdt_helper.h>
- 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 addr, size;
- int err, parent, i;
- 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_READABLE)
- continue;
- if (reg->flags & SBI_DOMAIN_MEMREGION_WRITEABLE)
- continue;
- if (reg->flags & SBI_DOMAIN_MEMREGION_EXECUTABLE)
- continue;
- addr = reg->base;
- size = 1UL << reg->order;
- fdt_resv_memory_update_node(fdt, addr, size, i, parent,
- (sbi_hart_pmp_count(scratch)) ? false : true);
- i++;
- }
- 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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