prom_init.c

linux 内核源代码

static int __init prom_setprop(phandle node, const char *nodename,
			       const char *pname, void *value, size_t valuelen)
{
	char cmd[256], *p;

	if (!(OF_WORKAROUNDS & OF_WA_LONGTRAIL))
		return call_prom("setprop", 4, 1, node, ADDR(pname),
				 (u32)(unsigned long) value, (u32) valuelen);

	/* gah... setprop doesn't work on longtrail, have to use interpret */
	p = cmd;
	add_string(&p, "dev");
	add_string(&p, nodename);
	add_string(&p, tohex((u32)(unsigned long) value));
	add_string(&p, tohex(valuelen));
	add_string(&p, tohex(ADDR(pname)));
	add_string(&p, tohex(strlen(RELOC(pname))));
	add_string(&p, "property");
	*p = 0;
	return call_prom("interpret", 1, 1, (u32)(unsigned long) cmd);
}

/* We can't use the standard versions because of RELOC headaches. */
#define isxdigit(c)	(('0' <= (c) && (c) <= '9') \
			 || ('a' <= (c) && (c) <= 'f') \
			 || ('A' <= (c) && (c) <= 'F'))

#define isdigit(c)	('0' <= (c) && (c) <= '9')
#define islower(c)	('a' <= (c) && (c) <= 'z')
#define toupper(c)	(islower(c) ? ((c) - 'a' + 'A') : (c))

unsigned long prom_strtoul(const char *cp, const char **endp)
{
	unsigned long result = 0, base = 10, value;

	if (*cp == '0') {
		base = 8;
		cp++;
		if (toupper(*cp) == 'X') {
			cp++;
			base = 16;
		}
	}

	while (isxdigit(*cp) &&
	       (value = isdigit(*cp) ? *cp - '0' : toupper(*cp) - 'A' + 10) < base) {
		result = result * base + value;
		cp++;
	}

	if (endp)
		*endp = cp;

	return result;
}

unsigned long prom_memparse(const char *ptr, const char **retptr)
{
	unsigned long ret = prom_strtoul(ptr, retptr);
	int shift = 0;

	/*
	 * We can't use a switch here because GCC *may* generate a
	 * jump table which won't work, because we're not running at
	 * the address we're linked at.
	 */
	if ('G' == **retptr || 'g' == **retptr)
		shift = 30;

	if ('M' == **retptr || 'm' == **retptr)
		shift = 20;

	if ('K' == **retptr || 'k' == **retptr)
		shift = 10;

	if (shift) {
		ret <<= shift;
		(*retptr)++;
	}

	return ret;
}

/*
 * 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);
#ifdef CONFIG_PPC64
	const char *opt;
#endif
	char *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 || p[0] == '\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(prom_iommu_off) = 1;
		else if (!strncmp(opt, RELOC("force"), 5))
			RELOC(prom_iommu_force_on) = 1;
	}
#endif
}

#ifdef CONFIG_PPC_PSERIES
/*
 * There are two methods for telling firmware what our capabilities are.
 * Newer machines have an "ibm,client-architecture-support" method on the
 * root node.  For older machines, we have to call the "process-elf-header"
 * method in the /packages/elf-loader node, passing it a fake 32-bit
 * ELF header containing a couple of PT_NOTE sections that contain
 * structures that contain various information.
 */

/*
 * New method - extensible architecture description vector.
 *
 * Because the description vector contains a mix of byte and word
 * values, we declare it as an unsigned char array, and use this
 * macro to put word values in.
 */
#define W(x)	((x) >> 24) & 0xff, ((x) >> 16) & 0xff, \
		((x) >> 8) & 0xff, (x) & 0xff

/* Option vector bits - generic bits in byte 1 */
#define OV_IGNORE		0x80	/* ignore this vector */
#define OV_CESSATION_POLICY	0x40	/* halt if unsupported option present*/

/* Option vector 1: processor architectures supported */
#define OV1_PPC_2_00		0x80	/* set if we support PowerPC 2.00 */
#define OV1_PPC_2_01		0x40	/* set if we support PowerPC 2.01 */
#define OV1_PPC_2_02		0x20	/* set if we support PowerPC 2.02 */
#define OV1_PPC_2_03		0x10	/* set if we support PowerPC 2.03 */
#define OV1_PPC_2_04		0x08	/* set if we support PowerPC 2.04 */
#define OV1_PPC_2_05		0x04	/* set if we support PowerPC 2.05 */

/* Option vector 2: Open Firmware options supported */
#define OV2_REAL_MODE		0x20	/* set if we want OF in real mode */

/* Option vector 3: processor options supported */
#define OV3_FP			0x80	/* floating point */
#define OV3_VMX			0x40	/* VMX/Altivec */
#define OV3_DFP			0x20	/* decimal FP */

/* Option vector 5: PAPR/OF options supported */
#define OV5_LPAR		0x80	/* logical partitioning supported */
#define OV5_SPLPAR		0x40	/* shared-processor LPAR supported */
/* ibm,dynamic-reconfiguration-memory property supported */
#define OV5_DRCONF_MEMORY	0x20
#define OV5_LARGE_PAGES		0x10	/* large pages supported */
#define OV5_DONATE_DEDICATE_CPU 0x02	/* donate dedicated CPU support */
/* PCIe/MSI support.  Without MSI full PCIe is not supported */
#ifdef CONFIG_PCI_MSI
#define OV5_MSI			0x01	/* PCIe/MSI support */
#else
#define OV5_MSI			0x00
#endif /* CONFIG_PCI_MSI */

/*
 * The architecture vector has an array of PVR mask/value pairs,
 * followed by # option vectors - 1, followed by the option vectors.
 */
static unsigned char ibm_architecture_vec[] = {
	W(0xfffe0000), W(0x003a0000),	/* POWER5/POWER5+ */
	W(0xffff0000), W(0x003e0000),	/* POWER6 */
	W(0xffffffff), W(0x0f000002),	/* all 2.05-compliant */
	W(0xfffffffe), W(0x0f000001),	/* all 2.04-compliant and earlier */
	5 - 1,				/* 5 option vectors */

	/* option vector 1: processor architectures supported */
	3 - 2,				/* length */
	0,				/* don't ignore, don't halt */
	OV1_PPC_2_00 | OV1_PPC_2_01 | OV1_PPC_2_02 | OV1_PPC_2_03 |
	OV1_PPC_2_04 | OV1_PPC_2_05,

	/* option vector 2: Open Firmware options supported */
	34 - 2,				/* length */
	OV2_REAL_MODE,
	0, 0,
	W(0xffffffff),			/* real_base */
	W(0xffffffff),			/* real_size */
	W(0xffffffff),			/* virt_base */
	W(0xffffffff),			/* virt_size */
	W(0xffffffff),			/* load_base */
	W(64),				/* 128MB min RMA */
	W(0xffffffff),			/* full client load */
	0,				/* min RMA percentage of total RAM */
	48,				/* max log_2(hash table size) */

	/* option vector 3: processor options supported */
	3 - 2,				/* length */
	0,				/* don't ignore, don't halt */
	OV3_FP | OV3_VMX | OV3_DFP,

	/* option vector 4: IBM PAPR implementation */
	2 - 2,				/* length */
	0,				/* don't halt */

	/* option vector 5: PAPR/OF options */
	3 - 2,				/* length */
	0,				/* don't ignore, don't halt */
	OV5_LPAR | OV5_SPLPAR | OV5_LARGE_PAGES | OV5_DRCONF_MEMORY |
	OV5_DONATE_DEDICATE_CPU | OV5_MSI,
};

/* Old method - ELF header with PT_NOTE sections */
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, root;
	prom_arg_t ret;

	root = call_prom("open", 1, 1, ADDR("/"));
	if (root != 0) {
		/* try calling the ibm,client-architecture-support method */
		if (call_prom_ret("call-method", 3, 2, &ret,
				  ADDR("ibm,client-architecture-support"),
				  root,
				  ADDR(ibm_architecture_vec)) == 0) {
			/* the call exists... */
			if (ret)
				prom_printf("WARNING: ibm,client-architecture"
					    "-support call FAILED!\n");
			call_prom("close", 1, 0, root);
			return;
		}
		call_prom("close", 1, 0, root);
	}

	/* no ibm,client-architecture-support call, try the old way */
	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));