Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 997 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
new file mode 100644
index 000000000..8537c354c
--- /dev/null
+++ b/arch/powerpc/kernel/prom.c
@@ -0,0 +1,997 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Procedures for creating, accessing and interpreting the device tree.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ * 
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com 
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/threads.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/initrd.h>
+#include <linux/bitops.h>
+#include <linux/export.h>
+#include <linux/kexec.h>
+#include <linux/irq.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <linux/cpu.h>
+#include <linux/pgtable.h>
+#include <linux/seq_buf.h>
+
+#include <asm/rtas.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <asm/irq.h>
+#include <asm/io.h>
+#include <asm/kdump.h>
+#include <asm/smp.h>
+#include <asm/mmu.h>
+#include <asm/paca.h>
+#include <asm/powernv.h>
+#include <asm/iommu.h>
+#include <asm/btext.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/pci-bridge.h>
+#include <asm/kexec.h>
+#include <asm/opal.h>
+#include <asm/fadump.h>
+#include <asm/epapr_hcalls.h>
+#include <asm/firmware.h>
+#include <asm/dt_cpu_ftrs.h>
+#include <asm/drmem.h>
+#include <asm/ultravisor.h>
+#include <asm/prom.h>
+
+#include <mm/mmu_decl.h>
+
+#ifdef DEBUG
+#define DBG(fmt...) printk(KERN_ERR fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+int *chip_id_lookup_table;
+
+#ifdef CONFIG_PPC64
+int __initdata iommu_is_off;
+int __initdata iommu_force_on;
+unsigned long tce_alloc_start, tce_alloc_end;
+u64 ppc64_rma_size;
+#endif
+static phys_addr_t first_memblock_size;
+static int __initdata boot_cpu_count;
+
+static int __init early_parse_mem(char *p)
+{
+	if (!p)
+		return 1;
+
+	memory_limit = PAGE_ALIGN(memparse(p, &p));
+	DBG("memory limit = 0x%llx\n", memory_limit);
+
+	return 0;
+}
+early_param("mem", early_parse_mem);
+
+/*
+ * overlaps_initrd - check for overlap with page aligned extension of
+ * initrd.
+ */
+static inline int overlaps_initrd(unsigned long start, unsigned long size)
+{
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (!initrd_start)
+		return 0;
+
+	return	(start + size) > ALIGN_DOWN(initrd_start, PAGE_SIZE) &&
+			start <= ALIGN(initrd_end, PAGE_SIZE);
+#else
+	return 0;
+#endif
+}
+
+/**
+ * move_device_tree - move tree to an unused area, if needed.
+ *
+ * The device tree may be allocated beyond our memory limit, or inside the
+ * crash kernel region for kdump, or within the page aligned range of initrd.
+ * If so, move it out of the way.
+ */
+static void __init move_device_tree(void)
+{
+	unsigned long start, size;
+	void *p;
+
+	DBG("-> move_device_tree\n");
+
+	start = __pa(initial_boot_params);
+	size = fdt_totalsize(initial_boot_params);
+
+	if ((memory_limit && (start + size) > PHYSICAL_START + memory_limit) ||
+	    !memblock_is_memory(start + size - 1) ||
+	    overlaps_crashkernel(start, size) || overlaps_initrd(start, size)) {
+		p = memblock_alloc_raw(size, PAGE_SIZE);
+		if (!p)
+			panic("Failed to allocate %lu bytes to move device tree\n",
+			      size);
+		memcpy(p, initial_boot_params, size);
+		initial_boot_params = p;
+		DBG("Moved device tree to 0x%px\n", p);
+	}
+
+	DBG("<- move_device_tree\n");
+}
+
+/*
+ * ibm,pa/pi-features is a per-cpu property that contains a string of
+ * attribute descriptors, each of which has a 2 byte header plus up
+ * to 254 bytes worth of processor attribute bits.  First header
+ * byte specifies the number of bytes following the header.
+ * Second header byte is an "attribute-specifier" type, of which
+ * zero is the only currently-defined value.
+ * Implementation:  Pass in the byte and bit offset for the feature
+ * that we are interested in.  The function will return -1 if the
+ * pa-features property is missing, or a 1/0 to indicate if the feature
+ * is supported/not supported.  Note that the bit numbers are
+ * big-endian to match the definition in PAPR.
+ */
+struct ibm_feature {
+	unsigned long	cpu_features;	/* CPU_FTR_xxx bit */
+	unsigned long	mmu_features;	/* MMU_FTR_xxx bit */
+	unsigned int	cpu_user_ftrs;	/* PPC_FEATURE_xxx bit */
+	unsigned int	cpu_user_ftrs2;	/* PPC_FEATURE2_xxx bit */
+	unsigned char	pabyte;		/* byte number in ibm,pa/pi-features */
+	unsigned char	pabit;		/* bit number (big-endian) */
+	unsigned char	invert;		/* if 1, pa bit set => clear feature */
+};
+
+static struct ibm_feature ibm_pa_features[] __initdata = {
+	{ .pabyte = 0,  .pabit = 0, .cpu_user_ftrs = PPC_FEATURE_HAS_MMU },
+	{ .pabyte = 0,  .pabit = 1, .cpu_user_ftrs = PPC_FEATURE_HAS_FPU },
+	{ .pabyte = 0,  .pabit = 3, .cpu_features  = CPU_FTR_CTRL },
+	{ .pabyte = 0,  .pabit = 6, .cpu_features  = CPU_FTR_NOEXECUTE },
+	{ .pabyte = 1,  .pabit = 2, .mmu_features  = MMU_FTR_CI_LARGE_PAGE },
+#ifdef CONFIG_PPC_RADIX_MMU
+	{ .pabyte = 40, .pabit = 0, .mmu_features  = MMU_FTR_TYPE_RADIX | MMU_FTR_GTSE },
+#endif
+	{ .pabyte = 5,  .pabit = 0, .cpu_features  = CPU_FTR_REAL_LE,
+				    .cpu_user_ftrs = PPC_FEATURE_TRUE_LE },
+	/*
+	 * If the kernel doesn't support TM (ie CONFIG_PPC_TRANSACTIONAL_MEM=n),
+	 * we don't want to turn on TM here, so we use the *_COMP versions
+	 * which are 0 if the kernel doesn't support TM.
+	 */
+	{ .pabyte = 22, .pabit = 0, .cpu_features = CPU_FTR_TM_COMP,
+	  .cpu_user_ftrs2 = PPC_FEATURE2_HTM_COMP | PPC_FEATURE2_HTM_NOSC_COMP },
+
+	{ .pabyte = 64, .pabit = 0, .cpu_features = CPU_FTR_DAWR1 },
+};
+
+/*
+ * ibm,pi-features property provides the support of processor specific
+ * options not described in ibm,pa-features. Right now use byte 0, bit 3
+ * which indicates the occurrence of DSI interrupt when the paste operation
+ * on the suspended NX window.
+ */
+static struct ibm_feature ibm_pi_features[] __initdata = {
+	{ .pabyte = 0, .pabit = 3, .mmu_features  = MMU_FTR_NX_DSI },
+};
+
+static void __init scan_features(unsigned long node, const unsigned char *ftrs,
+				 unsigned long tablelen,
+				 struct ibm_feature *fp,
+				 unsigned long ft_size)
+{
+	unsigned long i, len, bit;
+
+	/* find descriptor with type == 0 */
+	for (;;) {
+		if (tablelen < 3)
+			return;
+		len = 2 + ftrs[0];
+		if (tablelen < len)
+			return;		/* descriptor 0 not found */
+		if (ftrs[1] == 0)
+			break;
+		tablelen -= len;
+		ftrs += len;
+	}
+
+	/* loop over bits we know about */
+	for (i = 0; i < ft_size; ++i, ++fp) {
+		if (fp->pabyte >= ftrs[0])
+			continue;
+		bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
+		if (bit ^ fp->invert) {
+			cur_cpu_spec->cpu_features |= fp->cpu_features;
+			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
+			cur_cpu_spec->cpu_user_features2 |= fp->cpu_user_ftrs2;
+			cur_cpu_spec->mmu_features |= fp->mmu_features;
+		} else {
+			cur_cpu_spec->cpu_features &= ~fp->cpu_features;
+			cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
+			cur_cpu_spec->cpu_user_features2 &= ~fp->cpu_user_ftrs2;
+			cur_cpu_spec->mmu_features &= ~fp->mmu_features;
+		}
+	}
+}
+
+static void __init check_cpu_features(unsigned long node, char *name,
+				      struct ibm_feature *fp,
+				      unsigned long size)
+{
+	const unsigned char *pa_ftrs;
+	int tablelen;
+
+	pa_ftrs = of_get_flat_dt_prop(node, name, &tablelen);
+	if (pa_ftrs == NULL)
+		return;
+
+	scan_features(node, pa_ftrs, tablelen, fp, size);
+}
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
+static void __init init_mmu_slb_size(unsigned long node)
+{
+	const __be32 *slb_size_ptr;
+
+	slb_size_ptr = of_get_flat_dt_prop(node, "slb-size", NULL) ? :
+			of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
+
+	if (slb_size_ptr)
+		mmu_slb_size = be32_to_cpup(slb_size_ptr);
+}
+#else
+#define init_mmu_slb_size(node) do { } while(0)
+#endif
+
+static struct feature_property {
+	const char *name;
+	u32 min_value;
+	unsigned long cpu_feature;
+	unsigned long cpu_user_ftr;
+} feature_properties[] __initdata = {
+#ifdef CONFIG_ALTIVEC
+	{"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
+	{"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_VSX
+	/* Yes, this _really_ is ibm,vmx == 2 to enable VSX */
+	{"ibm,vmx", 2, CPU_FTR_VSX, PPC_FEATURE_HAS_VSX},
+#endif /* CONFIG_VSX */
+#ifdef CONFIG_PPC64
+	{"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
+	{"ibm,purr", 1, CPU_FTR_PURR, 0},
+	{"ibm,spurr", 1, CPU_FTR_SPURR, 0},
+#endif /* CONFIG_PPC64 */
+};
+
+#if defined(CONFIG_44x) && defined(CONFIG_PPC_FPU)
+static __init void identical_pvr_fixup(unsigned long node)
+{
+	unsigned int pvr;
+	const char *model = of_get_flat_dt_prop(node, "model", NULL);
+
+	/*
+	 * Since 440GR(x)/440EP(x) processors have the same pvr,
+	 * we check the node path and set bit 28 in the cur_cpu_spec
+	 * pvr for EP(x) processor version. This bit is always 0 in
+	 * the "real" pvr. Then we call identify_cpu again with
+	 * the new logical pvr to enable FPU support.
+	 */
+	if (model && strstr(model, "440EP")) {
+		pvr = cur_cpu_spec->pvr_value | 0x8;
+		identify_cpu(0, pvr);
+		DBG("Using logical pvr %x for %s\n", pvr, model);
+	}
+}
+#else
+#define identical_pvr_fixup(node) do { } while(0)
+#endif
+
+static void __init check_cpu_feature_properties(unsigned long node)
+{
+	int i;
+	struct feature_property *fp = feature_properties;
+	const __be32 *prop;
+
+	for (i = 0; i < (int)ARRAY_SIZE(feature_properties); ++i, ++fp) {
+		prop = of_get_flat_dt_prop(node, fp->name, NULL);
+		if (prop && be32_to_cpup(prop) >= fp->min_value) {
+			cur_cpu_spec->cpu_features |= fp->cpu_feature;
+			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
+		}
+	}
+}
+
+static int __init early_init_dt_scan_cpus(unsigned long node,
+					  const char *uname, int depth,
+					  void *data)
+{
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const __be32 *prop;
+	const __be32 *intserv;
+	int i, nthreads;
+	int len;
+	int found = -1;
+	int found_thread = 0;
+
+	/* We are scanning "cpu" nodes only */
+	if (type == NULL || strcmp(type, "cpu") != 0)
+		return 0;
+
+	/* Get physical cpuid */
+	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
+	if (!intserv)
+		intserv = of_get_flat_dt_prop(node, "reg", &len);
+
+	nthreads = len / sizeof(int);
+
+	/*
+	 * Now see if any of these threads match our boot cpu.
+	 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
+	 */
+	for (i = 0; i < nthreads; i++) {
+		if (be32_to_cpu(intserv[i]) ==
+			fdt_boot_cpuid_phys(initial_boot_params)) {
+			found = boot_cpu_count;
+			found_thread = i;
+		}
+#ifdef CONFIG_SMP
+		/* logical cpu id is always 0 on UP kernels */
+		boot_cpu_count++;
+#endif
+	}
+
+	/* Not the boot CPU */
+	if (found < 0)
+		return 0;
+
+	DBG("boot cpu: logical %d physical %d\n", found,
+	    be32_to_cpu(intserv[found_thread]));
+	boot_cpuid = found;
+
+	if (IS_ENABLED(CONFIG_PPC64))
+		boot_cpu_hwid = be32_to_cpu(intserv[found_thread]);
+
+	/*
+	 * PAPR defines "logical" PVR values for cpus that
+	 * meet various levels of the architecture:
+	 * 0x0f000001	Architecture version 2.04
+	 * 0x0f000002	Architecture version 2.05
+	 * If the cpu-version property in the cpu node contains
+	 * such a value, we call identify_cpu again with the
+	 * logical PVR value in order to use the cpu feature
+	 * bits appropriate for the architecture level.
+	 *
+	 * A POWER6 partition in "POWER6 architected" mode
+	 * uses the 0x0f000002 PVR value; in POWER5+ mode
+	 * it uses 0x0f000001.
+	 *
+	 * If we're using device tree CPU feature discovery then we don't
+	 * support the cpu-version property, and it's the responsibility of the
+	 * firmware/hypervisor to provide the correct feature set for the
+	 * architecture level via the ibm,powerpc-cpu-features binding.
+	 */
+	if (!dt_cpu_ftrs_in_use()) {
+		prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
+		if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000) {
+			identify_cpu(0, be32_to_cpup(prop));
+			seq_buf_printf(&ppc_hw_desc, "0x%04x ", be32_to_cpup(prop));
+		}
+
+		check_cpu_feature_properties(node);
+		check_cpu_features(node, "ibm,pa-features", ibm_pa_features,
+				   ARRAY_SIZE(ibm_pa_features));
+		check_cpu_features(node, "ibm,pi-features", ibm_pi_features,
+				   ARRAY_SIZE(ibm_pi_features));
+	}
+
+	identical_pvr_fixup(node);
+	init_mmu_slb_size(node);
+
+#ifdef CONFIG_PPC64
+	if (nthreads == 1)
+		cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
+	else if (!dt_cpu_ftrs_in_use())
+		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
+#endif
+
+	return 0;
+}
+
+static int __init early_init_dt_scan_chosen_ppc(unsigned long node,
+						const char *uname,
+						int depth, void *data)
+{
+	const unsigned long *lprop; /* All these set by kernel, so no need to convert endian */
+
+	/* Use common scan routine to determine if this is the chosen node */
+	if (early_init_dt_scan_chosen(data) < 0)
+		return 0;
+
+#ifdef CONFIG_PPC64
+	/* check if iommu is forced on or off */
+	if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
+		iommu_is_off = 1;
+	if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
+		iommu_force_on = 1;
+#endif
+
+	/* mem=x on the command line is the preferred mechanism */
+	lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
+	if (lprop)
+		memory_limit = *lprop;
+
+#ifdef CONFIG_PPC64
+	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
+	if (lprop)
+		tce_alloc_start = *lprop;
+	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
+	if (lprop)
+		tce_alloc_end = *lprop;
+#endif
+
+#ifdef CONFIG_KEXEC_CORE
+	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
+	if (lprop)
+		crashk_res.start = *lprop;
+
+	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
+	if (lprop)
+		crashk_res.end = crashk_res.start + *lprop - 1;
+#endif
+
+	/* break now */
+	return 1;
+}
+
+/*
+ * Compare the range against max mem limit and update
+ * size if it cross the limit.
+ */
+
+#ifdef CONFIG_SPARSEMEM
+static bool __init validate_mem_limit(u64 base, u64 *size)
+{
+	u64 max_mem = 1UL << (MAX_PHYSMEM_BITS);
+
+	if (base >= max_mem)
+		return false;
+	if ((base + *size) > max_mem)
+		*size = max_mem - base;
+	return true;
+}
+#else
+static bool __init validate_mem_limit(u64 base, u64 *size)
+{
+	return true;
+}
+#endif
+
+#ifdef CONFIG_PPC_PSERIES
+/*
+ * Interpret the ibm dynamic reconfiguration memory LMBs.
+ * This contains a list of memory blocks along with NUMA affinity
+ * information.
+ */
+static int  __init early_init_drmem_lmb(struct drmem_lmb *lmb,
+					const __be32 **usm,
+					void *data)
+{
+	u64 base, size;
+	int is_kexec_kdump = 0, rngs;
+
+	base = lmb->base_addr;
+	size = drmem_lmb_size();
+	rngs = 1;
+
+	/*
+	 * Skip this block if the reserved bit is set in flags
+	 * or if the block is not assigned to this partition.
+	 */
+	if ((lmb->flags & DRCONF_MEM_RESERVED) ||
+	    !(lmb->flags & DRCONF_MEM_ASSIGNED))
+		return 0;
+
+	if (*usm)
+		is_kexec_kdump = 1;
+
+	if (is_kexec_kdump) {
+		/*
+		 * For each memblock in ibm,dynamic-memory, a
+		 * corresponding entry in linux,drconf-usable-memory
+		 * property contains a counter 'p' followed by 'p'
+		 * (base, size) duple. Now read the counter from
+		 * linux,drconf-usable-memory property
+		 */
+		rngs = dt_mem_next_cell(dt_root_size_cells, usm);
+		if (!rngs) /* there are no (base, size) duple */
+			return 0;
+	}
+
+	do {
+		if (is_kexec_kdump) {
+			base = dt_mem_next_cell(dt_root_addr_cells, usm);
+			size = dt_mem_next_cell(dt_root_size_cells, usm);
+		}
+
+		if (iommu_is_off) {
+			if (base >= 0x80000000ul)
+				continue;
+			if ((base + size) > 0x80000000ul)
+				size = 0x80000000ul - base;
+		}
+
+		if (!validate_mem_limit(base, &size))
+			continue;
+
+		DBG("Adding: %llx -> %llx\n", base, size);
+		memblock_add(base, size);
+
+		if (lmb->flags & DRCONF_MEM_HOTREMOVABLE)
+			memblock_mark_hotplug(base, size);
+	} while (--rngs);
+
+	return 0;
+}
+#endif /* CONFIG_PPC_PSERIES */
+
+static int __init early_init_dt_scan_memory_ppc(void)
+{
+#ifdef CONFIG_PPC_PSERIES
+	const void *fdt = initial_boot_params;
+	int node = fdt_path_offset(fdt, "/ibm,dynamic-reconfiguration-memory");
+
+	if (node > 0)
+		walk_drmem_lmbs_early(node, NULL, early_init_drmem_lmb);
+
+#endif
+
+	return early_init_dt_scan_memory();
+}
+
+/*
+ * For a relocatable kernel, we need to get the memstart_addr first,
+ * then use it to calculate the virtual kernel start address. This has
+ * to happen at a very early stage (before machine_init). In this case,
+ * we just want to get the memstart_address and would not like to mess the
+ * memblock at this stage. So introduce a variable to skip the memblock_add()
+ * for this reason.
+ */
+#ifdef CONFIG_RELOCATABLE
+static int add_mem_to_memblock = 1;
+#else
+#define add_mem_to_memblock 1
+#endif
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+#ifdef CONFIG_PPC64
+	if (iommu_is_off) {
+		if (base >= 0x80000000ul)
+			return;
+		if ((base + size) > 0x80000000ul)
+			size = 0x80000000ul - base;
+	}
+#endif
+	/* Keep track of the beginning of memory -and- the size of
+	 * the very first block in the device-tree as it represents
+	 * the RMA on ppc64 server
+	 */
+	if (base < memstart_addr) {
+		memstart_addr = base;
+		first_memblock_size = size;
+	}
+
+	/* Add the chunk to the MEMBLOCK list */
+	if (add_mem_to_memblock) {
+		if (validate_mem_limit(base, &size))
+			memblock_add(base, size);
+	}
+}
+
+static void __init early_reserve_mem_dt(void)
+{
+	unsigned long i, dt_root;
+	int len;
+	const __be32 *prop;
+
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+
+	dt_root = of_get_flat_dt_root();
+
+	prop = of_get_flat_dt_prop(dt_root, "reserved-ranges", &len);
+
+	if (!prop)
+		return;
+
+	DBG("Found new-style reserved-ranges\n");
+
+	/* Each reserved range is an (address,size) pair, 2 cells each,
+	 * totalling 4 cells per range. */
+	for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
+		u64 base, size;
+
+		base = of_read_number(prop + (i * 4) + 0, 2);
+		size = of_read_number(prop + (i * 4) + 2, 2);
+
+		if (size) {
+			DBG("reserving: %llx -> %llx\n", base, size);
+			memblock_reserve(base, size);
+		}
+	}
+}
+
+static void __init early_reserve_mem(void)
+{
+	__be64 *reserve_map;
+
+	reserve_map = (__be64 *)(((unsigned long)initial_boot_params) +
+			fdt_off_mem_rsvmap(initial_boot_params));
+
+	/* Look for the new "reserved-regions" property in the DT */
+	early_reserve_mem_dt();
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	/* Then reserve the initrd, if any */
+	if (initrd_start && (initrd_end > initrd_start)) {
+		memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
+			ALIGN(initrd_end, PAGE_SIZE) -
+			ALIGN_DOWN(initrd_start, PAGE_SIZE));
+	}
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+	if (!IS_ENABLED(CONFIG_PPC32))
+		return;
+
+	/* 
+	 * Handle the case where we might be booting from an old kexec
+	 * image that setup the mem_rsvmap as pairs of 32-bit values
+	 */
+	if (be64_to_cpup(reserve_map) > 0xffffffffull) {
+		u32 base_32, size_32;
+		__be32 *reserve_map_32 = (__be32 *)reserve_map;
+
+		DBG("Found old 32-bit reserve map\n");
+
+		while (1) {
+			base_32 = be32_to_cpup(reserve_map_32++);
+			size_32 = be32_to_cpup(reserve_map_32++);
+			if (size_32 == 0)
+				break;
+			DBG("reserving: %x -> %x\n", base_32, size_32);
+			memblock_reserve(base_32, size_32);
+		}
+		return;
+	}
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+static bool tm_disabled __initdata;
+
+static int __init parse_ppc_tm(char *str)
+{
+	bool res;
+
+	if (kstrtobool(str, &res))
+		return -EINVAL;
+
+	tm_disabled = !res;
+
+	return 0;
+}
+early_param("ppc_tm", parse_ppc_tm);
+
+static void __init tm_init(void)
+{
+	if (tm_disabled) {
+		pr_info("Disabling hardware transactional memory (HTM)\n");
+		cur_cpu_spec->cpu_user_features2 &=
+			~(PPC_FEATURE2_HTM_NOSC | PPC_FEATURE2_HTM);
+		cur_cpu_spec->cpu_features &= ~CPU_FTR_TM;
+		return;
+	}
+
+	pnv_tm_init();
+}
+#else
+static void tm_init(void) { }
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
+static int __init
+early_init_dt_scan_model(unsigned long node, const char *uname,
+			 int depth, void *data)
+{
+	const char *prop;
+
+	if (depth != 0)
+		return 0;
+
+	prop = of_get_flat_dt_prop(node, "model", NULL);
+	if (prop)
+		seq_buf_printf(&ppc_hw_desc, "%s ", prop);
+
+	/* break now */
+	return 1;
+}
+
+#ifdef CONFIG_PPC64
+static void __init save_fscr_to_task(void)
+{
+	/*
+	 * Ensure the init_task (pid 0, aka swapper) uses the value of FSCR we
+	 * have configured via the device tree features or via __init_FSCR().
+	 * That value will then be propagated to pid 1 (init) and all future
+	 * processes.
+	 */
+	if (early_cpu_has_feature(CPU_FTR_ARCH_207S))
+		init_task.thread.fscr = mfspr(SPRN_FSCR);
+}
+#else
+static inline void save_fscr_to_task(void) {}
+#endif
+
+
+void __init early_init_devtree(void *params)
+{
+	phys_addr_t limit;
+
+	DBG(" -> early_init_devtree(%px)\n", params);
+
+	/* Too early to BUG_ON(), do it by hand */
+	if (!early_init_dt_verify(params))
+		panic("BUG: Failed verifying flat device tree, bad version?");
+
+	of_scan_flat_dt(early_init_dt_scan_model, NULL);
+
+#ifdef CONFIG_PPC_RTAS
+	/* Some machines might need RTAS info for debugging, grab it now. */
+	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
+#endif
+
+#ifdef CONFIG_PPC_POWERNV
+	/* Some machines might need OPAL info for debugging, grab it now. */
+	of_scan_flat_dt(early_init_dt_scan_opal, NULL);
+
+	/* Scan tree for ultravisor feature */
+	of_scan_flat_dt(early_init_dt_scan_ultravisor, NULL);
+#endif
+
+#if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
+	/* scan tree to see if dump is active during last boot */
+	of_scan_flat_dt(early_init_dt_scan_fw_dump, NULL);
+#endif
+
+	/* Retrieve various informations from the /chosen node of the
+	 * device-tree, including the platform type, initrd location and
+	 * size, TCE reserve, and more ...
+	 */
+	of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line);
+
+	/* Scan memory nodes and rebuild MEMBLOCKs */
+	early_init_dt_scan_root();
+	early_init_dt_scan_memory_ppc();
+
+	/*
+	 * As generic code authors expect to be able to use static keys
+	 * in early_param() handlers, we initialize the static keys just
+	 * before parsing early params (it's fine to call jump_label_init()
+	 * more than once).
+	 */
+	jump_label_init();
+	parse_early_param();
+
+	/* make sure we've parsed cmdline for mem= before this */
+	if (memory_limit)
+		first_memblock_size = min_t(u64, first_memblock_size, memory_limit);
+	setup_initial_memory_limit(memstart_addr, first_memblock_size);
+	/* Reserve MEMBLOCK regions used by kernel, initrd, dt, etc... */
+	memblock_reserve(PHYSICAL_START, __pa(_end) - PHYSICAL_START);
+	/* If relocatable, reserve first 32k for interrupt vectors etc. */
+	if (PHYSICAL_START > MEMORY_START)
+		memblock_reserve(MEMORY_START, 0x8000);
+	reserve_kdump_trampoline();
+#if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
+	/*
+	 * If we fail to reserve memory for firmware-assisted dump then
+	 * fallback to kexec based kdump.
+	 */
+	if (fadump_reserve_mem() == 0)
+#endif
+		reserve_crashkernel();
+	early_reserve_mem();
+
+	/* Ensure that total memory size is page-aligned. */
+	limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE);
+	memblock_enforce_memory_limit(limit);
+
+#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_4K_PAGES)
+	if (!early_radix_enabled())
+		memblock_cap_memory_range(0, 1UL << (H_MAX_PHYSMEM_BITS));
+#endif
+
+	memblock_allow_resize();
+	memblock_dump_all();
+
+	DBG("Phys. mem: %llx\n", (unsigned long long)memblock_phys_mem_size());
+
+	/* We may need to relocate the flat tree, do it now.
+	 * FIXME .. and the initrd too? */
+	move_device_tree();
+
+	DBG("Scanning CPUs ...\n");
+
+	dt_cpu_ftrs_scan();
+
+	// We can now add the CPU name & PVR to the hardware description
+	seq_buf_printf(&ppc_hw_desc, "%s 0x%04lx ", cur_cpu_spec->cpu_name, mfspr(SPRN_PVR));
+
+	/* Retrieve CPU related informations from the flat tree
+	 * (altivec support, boot CPU ID, ...)
+	 */
+	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
+	if (boot_cpuid < 0) {
+		printk("Failed to identify boot CPU !\n");
+		BUG();
+	}
+
+	save_fscr_to_task();
+
+#if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
+	/* We'll later wait for secondaries to check in; there are
+	 * NCPUS-1 non-boot CPUs  :-)
+	 */
+	spinning_secondaries = boot_cpu_count - 1;
+#endif
+
+	mmu_early_init_devtree();
+
+#ifdef CONFIG_PPC_POWERNV
+	/* Scan and build the list of machine check recoverable ranges */
+	of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
+#endif
+	epapr_paravirt_early_init();
+
+	/* Now try to figure out if we are running on LPAR and so on */
+	pseries_probe_fw_features();
+
+	/*
+	 * Initialize pkey features and default AMR/IAMR values
+	 */
+	pkey_early_init_devtree();
+
+#ifdef CONFIG_PPC_PS3
+	/* Identify PS3 firmware */
+	if (of_flat_dt_is_compatible(of_get_flat_dt_root(), "sony,ps3"))
+		powerpc_firmware_features |= FW_FEATURE_PS3_POSSIBLE;
+#endif
+
+	tm_init();
+
+	DBG(" <- early_init_devtree()\n");
+}
+
+#ifdef CONFIG_RELOCATABLE
+/*
+ * This function run before early_init_devtree, so we have to init
+ * initial_boot_params.
+ */
+void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
+{
+	/* Setup flat device-tree pointer */
+	initial_boot_params = params;
+
+	/*
+	 * Scan the memory nodes and set add_mem_to_memblock to 0 to avoid
+	 * mess the memblock.
+	 */
+	add_mem_to_memblock = 0;
+	early_init_dt_scan_root();
+	early_init_dt_scan_memory_ppc();
+	add_mem_to_memblock = 1;
+
+	if (size)
+		*size = first_memblock_size;
+}
+#endif
+
+/*******
+ *
+ * New implementation of the OF "find" APIs, return a refcounted
+ * object, call of_node_put() when done.  The device tree and list
+ * are protected by a rw_lock.
+ *
+ * Note that property management will need some locking as well,
+ * this isn't dealt with yet.
+ *
+ *******/
+
+/**
+ * of_get_ibm_chip_id - Returns the IBM "chip-id" of a device
+ * @np: device node of the device
+ *
+ * This looks for a property "ibm,chip-id" in the node or any
+ * of its parents and returns its content, or -1 if it cannot
+ * be found.
+ */
+int of_get_ibm_chip_id(struct device_node *np)
+{
+	of_node_get(np);
+	while (np) {
+		u32 chip_id;
+
+		/*
+		 * Skiboot may produce memory nodes that contain more than one
+		 * cell in chip-id, we only read the first one here.
+		 */
+		if (!of_property_read_u32(np, "ibm,chip-id", &chip_id)) {
+			of_node_put(np);
+			return chip_id;
+		}
+
+		np = of_get_next_parent(np);
+	}
+	return -1;
+}
+EXPORT_SYMBOL(of_get_ibm_chip_id);
+
+/**
+ * cpu_to_chip_id - Return the cpus chip-id
+ * @cpu: The logical cpu number.
+ *
+ * Return the value of the ibm,chip-id property corresponding to the given
+ * logical cpu number. If the chip-id can not be found, returns -1.
+ */
+int cpu_to_chip_id(int cpu)
+{
+	struct device_node *np;
+	int ret = -1, idx;
+
+	idx = cpu / threads_per_core;
+	if (chip_id_lookup_table && chip_id_lookup_table[idx] != -1)
+		return chip_id_lookup_table[idx];
+
+	np = of_get_cpu_node(cpu, NULL);
+	if (np) {
+		ret = of_get_ibm_chip_id(np);
+		of_node_put(np);
+
+		if (chip_id_lookup_table)
+			chip_id_lookup_table[idx] = ret;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(cpu_to_chip_id);
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+#ifdef CONFIG_SMP
+	/*
+	 * Early firmware scanning must use this rather than
+	 * get_hard_smp_processor_id because we don't have pacas allocated
+	 * until memory topology is discovered.
+	 */
+	if (cpu_to_phys_id != NULL)
+		return (int)phys_id == cpu_to_phys_id[cpu];
+#endif
+
+	return (int)phys_id == get_hard_smp_processor_id(cpu);
+}