From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- arch/powerpc/boot/devtree.c | 377 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 377 insertions(+) create mode 100644 arch/powerpc/boot/devtree.c (limited to 'arch/powerpc/boot/devtree.c') diff --git a/arch/powerpc/boot/devtree.c b/arch/powerpc/boot/devtree.c new file mode 100644 index 000000000..58fbcfcc9 --- /dev/null +++ b/arch/powerpc/boot/devtree.c @@ -0,0 +1,377 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * devtree.c - convenience functions for device tree manipulation + * Copyright 2007 David Gibson, IBM Corporation. + * Copyright (c) 2007 Freescale Semiconductor, Inc. + * + * Authors: David Gibson + * Scott Wood + */ +#include +#include +#include "types.h" +#include "string.h" +#include "stdio.h" +#include "ops.h" +#include "of.h" + +void dt_fixup_memory(u64 start, u64 size) +{ + void *root, *memory; + int naddr, nsize, i; + u32 memreg[4]; + + root = finddevice("/"); + if (getprop(root, "#address-cells", &naddr, sizeof(naddr)) < 0) + naddr = 2; + else + naddr = be32_to_cpu(naddr); + if (naddr < 1 || naddr > 2) + fatal("Can't cope with #address-cells == %d in /\n\r", naddr); + + if (getprop(root, "#size-cells", &nsize, sizeof(nsize)) < 0) + nsize = 1; + else + nsize = be32_to_cpu(nsize); + if (nsize < 1 || nsize > 2) + fatal("Can't cope with #size-cells == %d in /\n\r", nsize); + + i = 0; + if (naddr == 2) + memreg[i++] = cpu_to_be32(start >> 32); + memreg[i++] = cpu_to_be32(start & 0xffffffff); + if (nsize == 2) + memreg[i++] = cpu_to_be32(size >> 32); + memreg[i++] = cpu_to_be32(size & 0xffffffff); + + memory = finddevice("/memory"); + if (! memory) { + memory = create_node(NULL, "memory"); + setprop_str(memory, "device_type", "memory"); + } + + printf("Memory <- <0x%x", be32_to_cpu(memreg[0])); + for (i = 1; i < (naddr + nsize); i++) + printf(" 0x%x", be32_to_cpu(memreg[i])); + printf("> (%ldMB)\n\r", (unsigned long)(size >> 20)); + + setprop(memory, "reg", memreg, (naddr + nsize)*sizeof(u32)); +} + +#define MHZ(x) ((x + 500000) / 1000000) + +void dt_fixup_cpu_clocks(u32 cpu, u32 tb, u32 bus) +{ + void *devp = NULL; + + printf("CPU clock-frequency <- 0x%x (%dMHz)\n\r", cpu, MHZ(cpu)); + printf("CPU timebase-frequency <- 0x%x (%dMHz)\n\r", tb, MHZ(tb)); + if (bus > 0) + printf("CPU bus-frequency <- 0x%x (%dMHz)\n\r", bus, MHZ(bus)); + + while ((devp = find_node_by_devtype(devp, "cpu"))) { + setprop_val(devp, "clock-frequency", cpu_to_be32(cpu)); + setprop_val(devp, "timebase-frequency", cpu_to_be32(tb)); + if (bus > 0) + setprop_val(devp, "bus-frequency", cpu_to_be32(bus)); + } + + timebase_period_ns = 1000000000 / tb; +} + +void dt_fixup_clock(const char *path, u32 freq) +{ + void *devp = finddevice(path); + + if (devp) { + printf("%s: clock-frequency <- %x (%dMHz)\n\r", path, freq, MHZ(freq)); + setprop_val(devp, "clock-frequency", cpu_to_be32(freq)); + } +} + +void dt_fixup_mac_address_by_alias(const char *alias, const u8 *addr) +{ + void *devp = find_node_by_alias(alias); + + if (devp) { + printf("%s: local-mac-address <-" + " %02x:%02x:%02x:%02x:%02x:%02x\n\r", alias, + addr[0], addr[1], addr[2], + addr[3], addr[4], addr[5]); + + setprop(devp, "local-mac-address", addr, 6); + } +} + +void dt_fixup_mac_address(u32 index, const u8 *addr) +{ + void *devp = find_node_by_prop_value(NULL, "linux,network-index", + (void*)&index, sizeof(index)); + + if (devp) { + printf("ENET%d: local-mac-address <-" + " %02x:%02x:%02x:%02x:%02x:%02x\n\r", index, + addr[0], addr[1], addr[2], + addr[3], addr[4], addr[5]); + + setprop(devp, "local-mac-address", addr, 6); + } +} + +void __dt_fixup_mac_addresses(u32 startindex, ...) +{ + va_list ap; + u32 index = startindex; + const u8 *addr; + + va_start(ap, startindex); + + while ((addr = va_arg(ap, const u8 *))) + dt_fixup_mac_address(index++, addr); + + va_end(ap); +} + +#define MAX_ADDR_CELLS 4 + +void dt_get_reg_format(void *node, u32 *naddr, u32 *nsize) +{ + if (getprop(node, "#address-cells", naddr, 4) != 4) + *naddr = 2; + else + *naddr = be32_to_cpu(*naddr); + if (getprop(node, "#size-cells", nsize, 4) != 4) + *nsize = 1; + else + *nsize = be32_to_cpu(*nsize); +} + +static void copy_val(u32 *dest, u32 *src, int naddr) +{ + int pad = MAX_ADDR_CELLS - naddr; + + memset(dest, 0, pad * 4); + memcpy(dest + pad, src, naddr * 4); +} + +static int sub_reg(u32 *reg, u32 *sub) +{ + int i, borrow = 0; + + for (i = MAX_ADDR_CELLS - 1; i >= 0; i--) { + int prev_borrow = borrow; + borrow = reg[i] < sub[i] + prev_borrow; + reg[i] -= sub[i] + prev_borrow; + } + + return !borrow; +} + +static int add_reg(u32 *reg, u32 *add, int naddr) +{ + int i, carry = 0; + + for (i = MAX_ADDR_CELLS - 1; i >= MAX_ADDR_CELLS - naddr; i--) { + u64 tmp = (u64)be32_to_cpu(reg[i]) + be32_to_cpu(add[i]) + carry; + carry = tmp >> 32; + reg[i] = cpu_to_be32((u32)tmp); + } + + return !carry; +} + +/* It is assumed that if the first byte of reg fits in a + * range, then the whole reg block fits. + */ +static int compare_reg(u32 *reg, u32 *range, u32 *rangesize) +{ + int i; + u32 end; + + for (i = 0; i < MAX_ADDR_CELLS; i++) { + if (be32_to_cpu(reg[i]) < be32_to_cpu(range[i])) + return 0; + if (be32_to_cpu(reg[i]) > be32_to_cpu(range[i])) + break; + } + + for (i = 0; i < MAX_ADDR_CELLS; i++) { + end = be32_to_cpu(range[i]) + be32_to_cpu(rangesize[i]); + + if (be32_to_cpu(reg[i]) < end) + break; + if (be32_to_cpu(reg[i]) > end) + return 0; + } + + return reg[i] != end; +} + +/* reg must be MAX_ADDR_CELLS */ +static int find_range(u32 *reg, u32 *ranges, int nregaddr, + int naddr, int nsize, int buflen) +{ + int nrange = nregaddr + naddr + nsize; + int i; + + for (i = 0; i + nrange <= buflen; i += nrange) { + u32 range_addr[MAX_ADDR_CELLS]; + u32 range_size[MAX_ADDR_CELLS]; + + copy_val(range_addr, ranges + i, nregaddr); + copy_val(range_size, ranges + i + nregaddr + naddr, nsize); + + if (compare_reg(reg, range_addr, range_size)) + return i; + } + + return -1; +} + +/* Currently only generic buses without special encodings are supported. + * In particular, PCI is not supported. Also, only the beginning of the + * reg block is tracked; size is ignored except in ranges. + */ +static u32 prop_buf[MAX_PROP_LEN / 4]; + +static int dt_xlate(void *node, int res, int reglen, unsigned long *addr, + unsigned long *size) +{ + u32 last_addr[MAX_ADDR_CELLS]; + u32 this_addr[MAX_ADDR_CELLS]; + void *parent; + u64 ret_addr, ret_size; + u32 naddr, nsize, prev_naddr, prev_nsize; + int buflen, offset; + + parent = get_parent(node); + if (!parent) + return 0; + + dt_get_reg_format(parent, &naddr, &nsize); + if (nsize > 2) + return 0; + + offset = (naddr + nsize) * res; + + if (reglen < offset + naddr + nsize || + MAX_PROP_LEN < (offset + naddr + nsize) * 4) + return 0; + + copy_val(last_addr, prop_buf + offset, naddr); + + ret_size = be32_to_cpu(prop_buf[offset + naddr]); + if (nsize == 2) { + ret_size <<= 32; + ret_size |= be32_to_cpu(prop_buf[offset + naddr + 1]); + } + + for (;;) { + prev_naddr = naddr; + prev_nsize = nsize; + node = parent; + + parent = get_parent(node); + if (!parent) + break; + + dt_get_reg_format(parent, &naddr, &nsize); + + buflen = getprop(node, "ranges", prop_buf, + sizeof(prop_buf)); + if (buflen == 0) + continue; + if (buflen < 0 || buflen > sizeof(prop_buf)) + return 0; + + offset = find_range(last_addr, prop_buf, prev_naddr, + naddr, prev_nsize, buflen / 4); + if (offset < 0) + return 0; + + copy_val(this_addr, prop_buf + offset, prev_naddr); + + if (!sub_reg(last_addr, this_addr)) + return 0; + + copy_val(this_addr, prop_buf + offset + prev_naddr, naddr); + + if (!add_reg(last_addr, this_addr, naddr)) + return 0; + } + + if (naddr > 2) + return 0; + + ret_addr = ((u64)be32_to_cpu(last_addr[2]) << 32) | be32_to_cpu(last_addr[3]); + if (sizeof(void *) == 4 && + (ret_addr >= 0x100000000ULL || ret_size > 0x100000000ULL || + ret_addr + ret_size > 0x100000000ULL)) + return 0; + + *addr = ret_addr; + if (size) + *size = ret_size; + + return 1; +} + +int dt_xlate_reg(void *node, int res, unsigned long *addr, unsigned long *size) +{ + int reglen; + + reglen = getprop(node, "reg", prop_buf, sizeof(prop_buf)) / 4; + return dt_xlate(node, res, reglen, addr, size); +} + +int dt_xlate_addr(void *node, u32 *buf, int buflen, unsigned long *xlated_addr) +{ + + if (buflen > sizeof(prop_buf)) + return 0; + + memcpy(prop_buf, buf, buflen); + return dt_xlate(node, 0, buflen / 4, xlated_addr, NULL); +} + +int dt_is_compatible(void *node, const char *compat) +{ + char *buf = (char *)prop_buf; + int len, pos; + + len = getprop(node, "compatible", buf, MAX_PROP_LEN); + if (len < 0) + return 0; + + for (pos = 0; pos < len; pos++) { + if (!strcmp(buf + pos, compat)) + return 1; + + pos += strnlen(&buf[pos], len - pos); + } + + return 0; +} + +int dt_get_virtual_reg(void *node, void **addr, int nres) +{ + unsigned long xaddr; + int n, i; + + n = getprop(node, "virtual-reg", addr, nres * 4); + if (n > 0) { + for (i = 0; i < n/4; i ++) + ((u32 *)addr)[i] = be32_to_cpu(((u32 *)addr)[i]); + return n / 4; + } + + for (n = 0; n < nres; n++) { + if (!dt_xlate_reg(node, n, &xaddr, NULL)) + break; + + addr[n] = (void *)xaddr; + } + + return n; +} + -- cgit v1.3.1