prom_init.c

linux-2.6.15.6

 * Early parsing of the command line passed to the kernel, used for
 * "mem=x" and the options that affect the iommu
 */
static void __init early_cmdline_parse(void)
{
	struct prom_t *_prom = &RELOC(prom);
	char *opt, *p;
	int l = 0;

	RELOC(prom_cmd_line[0]) = 0;
	p = RELOC(prom_cmd_line);
	if ((long)_prom->chosen > 0)
		l = prom_getprop(_prom->chosen, "bootargs", p, COMMAND_LINE_SIZE-1);
#ifdef CONFIG_CMDLINE
	if (l == 0) /* dbl check */
		strlcpy(RELOC(prom_cmd_line),
			RELOC(CONFIG_CMDLINE), sizeof(prom_cmd_line));
#endif /* CONFIG_CMDLINE */
	prom_printf("command line: %s\n", RELOC(prom_cmd_line));

#ifdef CONFIG_PPC64
	opt = strstr(RELOC(prom_cmd_line), RELOC("iommu="));
	if (opt) {
		prom_printf("iommu opt is: %s\n", opt);
		opt += 6;
		while (*opt && *opt == ' ')
			opt++;
		if (!strncmp(opt, RELOC("off"), 3))
			RELOC(ppc64_iommu_off) = 1;
		else if (!strncmp(opt, RELOC("force"), 5))
			RELOC(iommu_force_on) = 1;
	}
#endif

	opt = strstr(RELOC(prom_cmd_line), RELOC("mem="));
	if (opt) {
		opt += 4;
		RELOC(prom_memory_limit) = prom_memparse(opt, (const char **)&opt);
#ifdef CONFIG_PPC64
		/* Align to 16 MB == size of ppc64 large page */
		RELOC(prom_memory_limit) = ALIGN(RELOC(prom_memory_limit), 0x1000000);
#endif
	}
}

#ifdef CONFIG_PPC_PSERIES
/*
 * To tell the firmware what our capabilities are, we have to pass
 * it a fake 32-bit ELF header containing a couple of PT_NOTE sections
 * that contain structures that contain the actual values.
 */
static struct fake_elf {
	Elf32_Ehdr	elfhdr;
	Elf32_Phdr	phdr[2];
	struct chrpnote {
		u32	namesz;
		u32	descsz;
		u32	type;
		char	name[8];	/* "PowerPC" */
		struct chrpdesc {
			u32	real_mode;
			u32	real_base;
			u32	real_size;
			u32	virt_base;
			u32	virt_size;
			u32	load_base;
		} chrpdesc;
	} chrpnote;
	struct rpanote {
		u32	namesz;
		u32	descsz;
		u32	type;
		char	name[24];	/* "IBM,RPA-Client-Config" */
		struct rpadesc {
			u32	lpar_affinity;
			u32	min_rmo_size;
			u32	min_rmo_percent;
			u32	max_pft_size;
			u32	splpar;
			u32	min_load;
			u32	new_mem_def;
			u32	ignore_me;
		} rpadesc;
	} rpanote;
} fake_elf = {
	.elfhdr = {
		.e_ident = { 0x7f, 'E', 'L', 'F',
			     ELFCLASS32, ELFDATA2MSB, EV_CURRENT },
		.e_type = ET_EXEC,	/* yeah right */
		.e_machine = EM_PPC,
		.e_version = EV_CURRENT,
		.e_phoff = offsetof(struct fake_elf, phdr),
		.e_phentsize = sizeof(Elf32_Phdr),
		.e_phnum = 2
	},
	.phdr = {
		[0] = {
			.p_type = PT_NOTE,
			.p_offset = offsetof(struct fake_elf, chrpnote),
			.p_filesz = sizeof(struct chrpnote)
		}, [1] = {
			.p_type = PT_NOTE,
			.p_offset = offsetof(struct fake_elf, rpanote),
			.p_filesz = sizeof(struct rpanote)
		}
	},
	.chrpnote = {
		.namesz = sizeof("PowerPC"),
		.descsz = sizeof(struct chrpdesc),
		.type = 0x1275,
		.name = "PowerPC",
		.chrpdesc = {
			.real_mode = ~0U,	/* ~0 means "don't care" */
			.real_base = ~0U,
			.real_size = ~0U,
			.virt_base = ~0U,
			.virt_size = ~0U,
			.load_base = ~0U
		},
	},
	.rpanote = {
		.namesz = sizeof("IBM,RPA-Client-Config"),
		.descsz = sizeof(struct rpadesc),
		.type = 0x12759999,
		.name = "IBM,RPA-Client-Config",
		.rpadesc = {
			.lpar_affinity = 0,
			.min_rmo_size = 64,	/* in megabytes */
			.min_rmo_percent = 0,
			.max_pft_size = 48,	/* 2^48 bytes max PFT size */
			.splpar = 1,
			.min_load = ~0U,
			.new_mem_def = 0
		}
	}
};

static void __init prom_send_capabilities(void)
{
	ihandle elfloader;

	elfloader = call_prom("open", 1, 1, ADDR("/packages/elf-loader"));
	if (elfloader == 0) {
		prom_printf("couldn't open /packages/elf-loader\n");
		return;
	}
	call_prom("call-method", 3, 1, ADDR("process-elf-header"),
			elfloader, ADDR(&fake_elf));
	call_prom("close", 1, 0, elfloader);
}
#endif

/*
 * Memory allocation strategy... our layout is normally:
 *
 *  at 14Mb or more we have vmlinux, then a gap and initrd.  In some
 *  rare cases, initrd might end up being before the kernel though.
 *  We assume this won't override the final kernel at 0, we have no
 *  provision to handle that in this version, but it should hopefully
 *  never happen.
 *
 *  alloc_top is set to the top of RMO, eventually shrink down if the
 *  TCEs overlap
 *
 *  alloc_bottom is set to the top of kernel/initrd
 *
 *  from there, allocations are done this way : rtas is allocated
 *  topmost, and the device-tree is allocated from the bottom. We try
 *  to grow the device-tree allocation as we progress. If we can't,
 *  then we fail, we don't currently have a facility to restart
 *  elsewhere, but that shouldn't be necessary.
 *
 *  Note that calls to reserve_mem have to be done explicitly, memory
 *  allocated with either alloc_up or alloc_down isn't automatically
 *  reserved.
 */


/*
 * Allocates memory in the RMO upward from the kernel/initrd
 *
 * When align is 0, this is a special case, it means to allocate in place
 * at the current location of alloc_bottom or fail (that is basically
 * extending the previous allocation). Used for the device-tree flattening
 */
static unsigned long __init alloc_up(unsigned long size, unsigned long align)
{
	unsigned long base = RELOC(alloc_bottom);
	unsigned long addr = 0;

	if (align)
		base = _ALIGN_UP(base, align);
	prom_debug("alloc_up(%x, %x)\n", size, align);
	if (RELOC(ram_top) == 0)
		prom_panic("alloc_up() called with mem not initialized\n");

	if (align)
		base = _ALIGN_UP(RELOC(alloc_bottom), align);
	else
		base = RELOC(alloc_bottom);

	for(; (base + size) <= RELOC(alloc_top); 
	    base = _ALIGN_UP(base + 0x100000, align)) {
		prom_debug("    trying: 0x%x\n\r", base);
		addr = (unsigned long)prom_claim(base, size, 0);
		if (addr != PROM_ERROR && addr != 0)
			break;
		addr = 0;
		if (align == 0)
			break;
	}
	if (addr == 0)
		return 0;
	RELOC(alloc_bottom) = addr;

	prom_debug(" -> %x\n", addr);
	prom_debug("  alloc_bottom : %x\n", RELOC(alloc_bottom));
	prom_debug("  alloc_top    : %x\n", RELOC(alloc_top));
	prom_debug("  alloc_top_hi : %x\n", RELOC(alloc_top_high));
	prom_debug("  rmo_top      : %x\n", RELOC(rmo_top));
	prom_debug("  ram_top      : %x\n", RELOC(ram_top));

	return addr;
}

/*
 * Allocates memory downward, either from top of RMO, or if highmem
 * is set, from the top of RAM.  Note that this one doesn't handle
 * failures.  It does claim memory if highmem is not set.
 */
static unsigned long __init alloc_down(unsigned long size, unsigned long align,
				       int highmem)
{
	unsigned long base, addr = 0;

	prom_debug("alloc_down(%x, %x, %s)\n", size, align,
		   highmem ? RELOC("(high)") : RELOC("(low)"));
	if (RELOC(ram_top) == 0)
		prom_panic("alloc_down() called with mem not initialized\n");

	if (highmem) {
		/* Carve out storage for the TCE table. */
		addr = _ALIGN_DOWN(RELOC(alloc_top_high) - size, align);
		if (addr <= RELOC(alloc_bottom))
			return 0;
		/* Will we bump into the RMO ? If yes, check out that we
		 * didn't overlap existing allocations there, if we did,
		 * we are dead, we must be the first in town !
		 */
		if (addr < RELOC(rmo_top)) {
			/* Good, we are first */
			if (RELOC(alloc_top) == RELOC(rmo_top))
				RELOC(alloc_top) = RELOC(rmo_top) = addr;
			else
				return 0;
		}
		RELOC(alloc_top_high) = addr;
		goto bail;
	}

	base = _ALIGN_DOWN(RELOC(alloc_top) - size, align);
	for (; base > RELOC(alloc_bottom);
	     base = _ALIGN_DOWN(base - 0x100000, align))  {
		prom_debug("    trying: 0x%x\n\r", base);
		addr = (unsigned long)prom_claim(base, size, 0);
		if (addr != PROM_ERROR && addr != 0)
			break;
		addr = 0;
	}
	if (addr == 0)
		return 0;
	RELOC(alloc_top) = addr;

 bail:
	prom_debug(" -> %x\n", addr);
	prom_debug("  alloc_bottom : %x\n", RELOC(alloc_bottom));
	prom_debug("  alloc_top    : %x\n", RELOC(alloc_top));
	prom_debug("  alloc_top_hi : %x\n", RELOC(alloc_top_high));
	prom_debug("  rmo_top      : %x\n", RELOC(rmo_top));
	prom_debug("  ram_top      : %x\n", RELOC(ram_top));

	return addr;
}

/*
 * Parse a "reg" cell
 */
static unsigned long __init prom_next_cell(int s, cell_t **cellp)
{
	cell_t *p = *cellp;
	unsigned long r = 0;

	/* Ignore more than 2 cells */
	while (s > sizeof(unsigned long) / 4) {
		p++;
		s--;
	}
	r = *p++;
#ifdef CONFIG_PPC64
	if (s > 1) {
		r <<= 32;
		r |= *(p++);
	}
#endif
	*cellp = p;
	return r;
}

/*
 * Very dumb function for adding to the memory reserve list, but
 * we don't need anything smarter at this point
 *
 * XXX Eventually check for collisions.  They should NEVER happen.
 * If problems seem to show up, it would be a good start to track
 * them down.
 */
static void reserve_mem(unsigned long base, unsigned long size)
{
	unsigned long top = base + size;
	unsigned long cnt = RELOC(mem_reserve_cnt);

	if (size == 0)
		return;

	/* We need to always keep one empty entry so that we
	 * have our terminator with "size" set to 0 since we are
	 * dumb and just copy this entire array to the boot params
	 */
	base = _ALIGN_DOWN(base, PAGE_SIZE);
	top = _ALIGN_UP(top, PAGE_SIZE);
	size = top - base;

	if (cnt >= (MEM_RESERVE_MAP_SIZE - 1))
		prom_panic("Memory reserve map exhausted !\n");
	RELOC(mem_reserve_map)[cnt].base = base;
	RELOC(mem_reserve_map)[cnt].size = size;
	RELOC(mem_reserve_cnt) = cnt + 1;
}

/*
 * Initialize memory allocation mecanism, parse "memory" nodes and
 * obtain that way the top of memory and RMO to setup out local allocator
 */
static void __init prom_init_mem(void)
{
	phandle node;
	char *path, type[64];
	unsigned int plen;
	cell_t *p, *endp;
	struct prom_t *_prom = &RELOC(prom);
	u32 rac, rsc;

	/*
	 * We iterate the memory nodes to find
	 * 1) top of RMO (first node)
	 * 2) top of memory
	 */
	rac = 2;
	prom_getprop(_prom->root, "#address-cells", &rac, sizeof(rac));
	rsc = 1;
	prom_getprop(_prom->root, "#size-cells", &rsc, sizeof(rsc));
	prom_debug("root_addr_cells: %x\n", (unsigned long) rac);
	prom_debug("root_size_cells: %x\n", (unsigned long) rsc);

	prom_debug("scanning memory:\n");
	path = RELOC(prom_scratch);

	for (node = 0; prom_next_node(&node); ) {
		type[0] = 0;
		prom_getprop(node, "device_type", type, sizeof(type));

		if (type[0] == 0) {
			/*
			 * CHRP Longtrail machines have no device_type
			 * on the memory node, so check the name instead...
			 */
			prom_getprop(node, "name", type, sizeof(type));
		}
		if (strcmp(type, RELOC("memory")))
			continue;

		plen = prom_getprop(node, "reg", RELOC(regbuf), sizeof(regbuf));
		if (plen > sizeof(regbuf)) {
			prom_printf("memory node too large for buffer !\n");
			plen = sizeof(regbuf);
		}
		p = RELOC(regbuf);
		endp = p + (plen / sizeof(cell_t));

#ifdef DEBUG_PROM
		memset(path, 0, PROM_SCRATCH_SIZE);
		call_prom("package-to-path", 3, 1, node, path, PROM_SCRATCH_SIZE-1);
		prom_debug("  node %s :\n", path);
#endif /* DEBUG_PROM */

		while ((endp - p) >= (rac + rsc)) {
			unsigned long base, size;

			base = prom_next_cell(rac, &p);
			size = prom_next_cell(rsc, &p);

			if (size == 0)
				continue;
			prom_debug("    %x %x\n", base, size);
			if (base == 0)
				RELOC(rmo_top) = size;
			if ((base + size) > RELOC(ram_top))
				RELOC(ram_top) = base + size;
		}
	}

	RELOC(alloc_bottom) = PAGE_ALIGN((unsigned long)&RELOC(_end) + 0x4000);

	/* Check if we have an initrd after the kernel, if we do move our bottom
	 * point to after it
	 */
	if (RELOC(prom_initrd_start)) {
		if (RELOC(prom_initrd_end) > RELOC(alloc_bottom))
			RELOC(alloc_bottom) = PAGE_ALIGN(RELOC(prom_initrd_end));
	}

	/*
	 * If prom_memory_limit is set we reduce the upper limits *except* for
	 * alloc_top_high. This must be the real top of RAM so we can put
	 * TCE's up there.
	 */

	RELOC(alloc_top_high) = RELOC(ram_top);

	if (RELOC(prom_memory_limit)) {
		if (RELOC(prom_memory_limit) <= RELOC(alloc_bottom)) {
			prom_printf("Ignoring mem=%x <= alloc_bottom.\n",
				RELOC(prom_memory_limit));
			RELOC(prom_memory_limit) = 0;
		} else if (RELOC(prom_memory_limit) >= RELOC(ram_top)) {
			prom_printf("Ignoring mem=%x >= ram_top.\n",
				RELOC(prom_memory_limit));
			RELOC(prom_memory_limit) = 0;
		} else {
			RELOC(ram_top) = RELOC(prom_memory_limit);
			RELOC(rmo_top) = min(RELOC(rmo_top), RELOC(prom_memory_limit));
		}
	}

	/*
	 * Setup our top alloc point, that is top of RMO or top of
	 * segment 0 when running non-LPAR.
	 * Some RS64 machines have buggy firmware where claims up at
	 * 1GB fail.  Cap at 768MB as a workaround.
	 * Since 768MB is plenty of room, and we need to cap to something
	 * reasonable on 32-bit, cap at 768MB on all machines.
	 */
	if (!RELOC(rmo_top))
		RELOC(rmo_top) = RELOC(ram_top);
	RELOC(rmo_top) = min(0x30000000ul, RELOC(rmo_top));
	RELOC(alloc_top) = RELOC(rmo_top);

	prom_printf("memory layout at init:\n");
	prom_printf("  memory_limit : %x (16 MB aligned)\n", RELOC(prom_memory_limit));
	prom_printf("  alloc_bottom : %x\n", RELOC(alloc_bottom));
	prom_printf("  alloc_top    : %x\n", RELOC(alloc_top));
	prom_printf("  alloc_top_hi : %x\n", RELOC(alloc_top_high));
	prom_printf("  rmo_top      : %x\n", RELOC(rmo_top));
	prom_printf("  ram_top      : %x\n", RELOC(ram_top));
}


/*
 * Allocate room for and instantiate RTAS
 */
static void __init prom_instantiate_rtas(void)
{
	phandle rtas_node;
	ihandle rtas_inst;
	u32 base, entry = 0;
	u32 size = 0;

	prom_debug("prom_instantiate_rtas: start...\n");

	rtas_node = call_prom("finddevice", 1, 1, ADDR("/rtas"));
	prom_debug("rtas_node: %x\n", rtas_node);
	if (!PHANDLE_VALID(rtas_node))
		return;

	prom_getprop(rtas_node, "rtas-size", &size, sizeof(size));
	if (size == 0)
		return;

	base = alloc_down(size, PAGE_SIZE, 0);
	if (base == 0) {
		prom_printf("RTAS allocation failed !\n");
		return;
	}

	rtas_inst = call_prom("open", 1, 1, ADDR("/rtas"));
	if (!IHANDLE_VALID(rtas_inst)) {
		prom_printf("opening rtas package failed (%x)\n", rtas_inst);
		return;
	}

	prom_printf("instantiating rtas at 0x%x ...", base);

	if (call_prom_ret("call-method", 3, 2, &entry,
			  ADDR("instantiate-rtas"),
			  rtas_inst, base) != 0
	    || entry == 0) {
		prom_printf(" failed\n");
		return;
	}
	prom_printf(" done\n");

	reserve_mem(base, size);

	prom_setprop(rtas_node, "/rtas", "linux,rtas-base",
		     &base, sizeof(base));
	prom_setprop(rtas_node, "/rtas", "linux,rtas-entry",
		     &entry, sizeof(entry));

	prom_debug("rtas base     = 0x%x\n", base);
	prom_debug("rtas entry    = 0x%x\n", entry);
	prom_debug("rtas size     = 0x%x\n", (long)size);

	prom_debug("prom_instantiate_rtas: end...\n");
}

#ifdef CONFIG_PPC64
/*
 * Allocate room for and initialize TCE tables
 */
static void __init prom_initialize_tce_table(void)
{
	phandle node;
	ihandle phb_node;
	char compatible[64], type[64], model[64];
	char *path = RELOC(prom_scratch);
	u64 base, align;
	u32 minalign, minsize;
	u64 tce_entry, *tce_entryp;
	u64 local_alloc_top, local_alloc_bottom;
	u64 i;

	if (RELOC(ppc64_iommu_off))
		return;

	prom_debug("starting prom_initialize_tce_table\n");

	/* Cache current top of allocs so we reserve a single block */
	local_alloc_top = RELOC(alloc_top_high);
	local_alloc_bottom = local_alloc_top;