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- /*
- * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
- /*
- * Contains generic routines to fix up the device tree blob passed on to
- * payloads like BL32 and BL33 (and further down the boot chain).
- * This allows to easily add PSCI nodes, when the original DT does not have
- * it or advertises another method.
- * Also it supports to add reserved memory nodes to describe memory that
- * is used by the secure world, so that non-secure software avoids using
- * that.
- */
- #include <string.h>
- #include <libfdt.h>
- #include <common/debug.h>
- #include <drivers/console.h>
- #include <lib/psci/psci.h>
- #include <common/fdt_fixup.h>
- static int append_psci_compatible(void *fdt, int offs, const char *str)
- {
- return fdt_appendprop(fdt, offs, "compatible", str, strlen(str) + 1);
- }
- /*
- * Those defines are for PSCI v0.1 legacy clients, which we expect to use
- * the same execution state (AArch32/AArch64) as TF-A.
- * Kernels running in AArch32 on an AArch64 TF-A should use PSCI v0.2.
- */
- #ifdef __aarch64__
- #define PSCI_CPU_SUSPEND_FNID PSCI_CPU_SUSPEND_AARCH64
- #define PSCI_CPU_ON_FNID PSCI_CPU_ON_AARCH64
- #else
- #define PSCI_CPU_SUSPEND_FNID PSCI_CPU_SUSPEND_AARCH32
- #define PSCI_CPU_ON_FNID PSCI_CPU_ON_AARCH32
- #endif
- /*******************************************************************************
- * dt_add_psci_node() - Add a PSCI node into an existing device tree
- * @fdt: pointer to the device tree blob in memory
- *
- * Add a device tree node describing PSCI into the root level of an existing
- * device tree blob in memory.
- * This will add v0.1, v0.2 and v1.0 compatible strings and the standard
- * function IDs for v0.1 compatibility.
- * An existing PSCI node will not be touched, the function will return success
- * in this case. This function will not touch the /cpus enable methods, use
- * dt_add_psci_cpu_enable_methods() for that.
- *
- * Return: 0 on success, -1 otherwise.
- ******************************************************************************/
- int dt_add_psci_node(void *fdt)
- {
- int offs;
- if (fdt_path_offset(fdt, "/psci") >= 0) {
- WARN("PSCI Device Tree node already exists!\n");
- return 0;
- }
- offs = fdt_path_offset(fdt, "/");
- if (offs < 0)
- return -1;
- offs = fdt_add_subnode(fdt, offs, "psci");
- if (offs < 0)
- return -1;
- if (append_psci_compatible(fdt, offs, "arm,psci-1.0"))
- return -1;
- if (append_psci_compatible(fdt, offs, "arm,psci-0.2"))
- return -1;
- if (append_psci_compatible(fdt, offs, "arm,psci"))
- return -1;
- if (fdt_setprop_string(fdt, offs, "method", "smc"))
- return -1;
- if (fdt_setprop_u32(fdt, offs, "cpu_suspend", PSCI_CPU_SUSPEND_FNID))
- return -1;
- if (fdt_setprop_u32(fdt, offs, "cpu_off", PSCI_CPU_OFF))
- return -1;
- if (fdt_setprop_u32(fdt, offs, "cpu_on", PSCI_CPU_ON_FNID))
- return -1;
- return 0;
- }
- /*
- * Find the first subnode that has a "device_type" property with the value
- * "cpu" and which's enable-method is not "psci" (yet).
- * Returns 0 if no such subnode is found, so all have already been patched
- * or none have to be patched in the first place.
- * Returns 1 if *one* such subnode has been found and successfully changed
- * to "psci".
- * Returns -1 on error.
- *
- * Call in a loop until it returns 0. Recalculate the node offset after
- * it has returned 1.
- */
- static int dt_update_one_cpu_node(void *fdt, int offset)
- {
- int offs;
- /* Iterate over all subnodes to find those with device_type = "cpu". */
- for (offs = fdt_first_subnode(fdt, offset); offs >= 0;
- offs = fdt_next_subnode(fdt, offs)) {
- const char *prop;
- int len;
- prop = fdt_getprop(fdt, offs, "device_type", &len);
- if (!prop)
- continue;
- if (memcmp(prop, "cpu", 4) != 0 || len != 4)
- continue;
- /* Ignore any nodes which already use "psci". */
- prop = fdt_getprop(fdt, offs, "enable-method", &len);
- if (prop && memcmp(prop, "psci", 5) == 0 && len == 5)
- continue;
- if (fdt_setprop_string(fdt, offs, "enable-method", "psci"))
- return -1;
- /*
- * Subnode found and patched.
- * Restart to accommodate potentially changed offsets.
- */
- return 1;
- }
- if (offs == -FDT_ERR_NOTFOUND)
- return 0;
- return offs;
- }
- /*******************************************************************************
- * dt_add_psci_cpu_enable_methods() - switch CPU nodes in DT to use PSCI
- * @fdt: pointer to the device tree blob in memory
- *
- * Iterate over all CPU device tree nodes (/cpus/cpu@x) in memory to change
- * the enable-method to PSCI. This will add the enable-method properties, if
- * required, or will change existing properties to read "psci".
- *
- * Return: 0 on success, or a negative error value otherwise.
- ******************************************************************************/
- int dt_add_psci_cpu_enable_methods(void *fdt)
- {
- int offs, ret;
- do {
- offs = fdt_path_offset(fdt, "/cpus");
- if (offs < 0)
- return offs;
- ret = dt_update_one_cpu_node(fdt, offs);
- } while (ret > 0);
- return ret;
- }
- #define HIGH_BITS(x) ((sizeof(x) > 4) ? ((x) >> 32) : (typeof(x))0)
- /*******************************************************************************
- * fdt_add_reserved_memory() - reserve (secure) memory regions in DT
- * @dtb: pointer to the device tree blob in memory
- * @node_name: name of the subnode to be used
- * @base: physical base address of the reserved region
- * @size: size of the reserved region
- *
- * Add a region of memory to the /reserved-memory node in a device tree in
- * memory, creating that node if required. Each region goes into a subnode
- * of that node and has a @node_name, a @base address and a @size.
- * This will prevent any device tree consumer from using that memory. It
- * can be used to announce secure memory regions, as it adds the "no-map"
- * property to prevent mapping and speculative operations on that region.
- *
- * See reserved-memory/reserved-memory.txt in the (Linux kernel) DT binding
- * documentation for details.
- *
- * Return: 0 on success, a negative error value otherwise.
- ******************************************************************************/
- int fdt_add_reserved_memory(void *dtb, const char *node_name,
- uintptr_t base, size_t size)
- {
- int offs = fdt_path_offset(dtb, "/reserved-memory");
- uint32_t addresses[3];
- if (offs < 0) { /* create if not existing yet */
- offs = fdt_add_subnode(dtb, 0, "reserved-memory");
- if (offs < 0)
- return offs;
- fdt_setprop_u32(dtb, offs, "#address-cells", 2);
- fdt_setprop_u32(dtb, offs, "#size-cells", 1);
- fdt_setprop(dtb, offs, "ranges", NULL, 0);
- }
- addresses[0] = cpu_to_fdt32(HIGH_BITS(base));
- addresses[1] = cpu_to_fdt32(base & 0xffffffff);
- addresses[2] = cpu_to_fdt32(size & 0xffffffff);
- offs = fdt_add_subnode(dtb, offs, node_name);
- fdt_setprop(dtb, offs, "no-map", NULL, 0);
- fdt_setprop(dtb, offs, "reg", addresses, 12);
- return 0;
- }
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