[PATCH] powerpc: Kill _machine and hard-coded platform numbers

This removes statically assigned platform numbers and reworks the
powerpc platform probe code to use a better mechanism.  With this,
board support files can simply declare a new machine type with a
macro, and implement a probe() function that uses the flattened
device-tree to detect if they apply for a given machine.

We now have a machine_is() macro that replaces the comparisons of
_machine with the various PLATFORM_* constants.  This commit also
changes various drivers to use the new macro instead of looking at
_machine.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

63 files changed, 560 insertions, 543 deletions

diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index ee551c6ea23..217e51768b8 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -719,6 +719,11 @@ address which can extend beyond that limit.
     - model : this is your board name/model
     - #address-cells : address representation for "root" devices
     - #size-cells: the size representation for "root" devices
+    - device_type : This property shouldn't be necessary. However, if
+      you decide to create a device_type for your root node, make sure it
+      is _not_ "chrp" unless your platform is a pSeries or PAPR compliant
+      one for 64-bit, or a CHRP-type machine for 32-bit as this will
+      matched by the kernel this way.
 
   Additionally, some recommended properties are:
 
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 882889b1592..54b48f33005 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -105,8 +105,6 @@ int main(void)
 	DEFINE(ICACHEL1LINESIZE, offsetof(struct ppc64_caches, iline_size));
 	DEFINE(ICACHEL1LOGLINESIZE, offsetof(struct ppc64_caches, log_iline_size));
 	DEFINE(ICACHEL1LINESPERPAGE, offsetof(struct ppc64_caches, ilines_per_page));
-	DEFINE(PLATFORM_LPAR, PLATFORM_LPAR);
-
 	/* paca */
 	DEFINE(PACA_SIZE, sizeof(struct paca_struct));
 	DEFINE(PACAPACAINDEX, offsetof(struct paca_struct, paca_index));
diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
index 6c3989f6247..ada50aa5b60 100644
--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -160,7 +160,7 @@ static int dev_nvram_ioctl(struct inode *inode, struct file *file,
 	case IOC_NVRAM_GET_OFFSET: {
 		int part, offset;
 
-		if (_machine != PLATFORM_POWERMAC)
+		if (!machine_is(powermac))
 			return -EINVAL;
 		if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
 			return -EFAULT;
@@ -444,7 +444,7 @@ static int nvram_setup_partition(void)
 	 * in our nvram, as Apple defined partitions use pretty much
 	 * all of the space
 	 */
-	if (_machine == PLATFORM_POWERMAC)
+	if (machine_is(powermac))
 		return -ENOSPC;
 
 	/* see if we have an OS partition that meets our needs.
diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index 704c846b2b0..b129d2e4b75 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c
@@ -787,7 +787,7 @@ pci_busdev_to_OF_node(struct pci_bus *bus, int devfn)
 	 * fix has to be done by making the remapping per-host and always
 	 * filling the pci_to_OF map. --BenH
 	 */
-	if (_machine == _MACH_Pmac && busnr >= 0xf0)
+	if (machine_is(powermac) && busnr >= 0xf0)
 		busnr -= 0xf0;
 	else
 #endif
@@ -1728,7 +1728,7 @@ long sys_pciconfig_iobase(long which, unsigned long bus, unsigned long devfn)
 	 * (bus 0 is HT root), we return the AGP one instead.
 	 */
 #ifdef CONFIG_PPC_PMAC
-	if (_machine == _MACH_Pmac && machine_is_compatible("MacRISC4"))
+	if (machine_is(powermac) && machine_is_compatible("MacRISC4"))
 		if (bus == 0)
 			bus = 0xf0;
 #endif /* CONFIG_PPC_PMAC */
diff --git a/arch/powerpc/kernel/proc_ppc64.c b/arch/powerpc/kernel/proc_ppc64.c
index 7ba42a405f4..3c2cf661f6d 100644
--- a/arch/powerpc/kernel/proc_ppc64.c
+++ b/arch/powerpc/kernel/proc_ppc64.c
@@ -23,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/kernel.h>
 
+#include <asm/machdep.h>
 #include <asm/vdso_datapage.h>
 #include <asm/rtas.h>
 #include <asm/uaccess.h>
@@ -51,7 +52,7 @@ static int __init proc_ppc64_create(void)
 	if (!root)
 		return 1;
 
-	if (!(platform_is_pseries() || _machine == PLATFORM_CELL))
+	if (!machine_is(pseries) && !machine_is(cell))
 		return 0;
 
 	if (!proc_mkdir("rtas", root))
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index a2bc433f361..4336390bcf3 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -383,14 +383,14 @@ static int __devinit finish_node_interrupts(struct device_node *np,
 			/* Apple uses bits in there in a different way, let's
 			 * only keep the real sense bit on macs
 			 */
-			if (_machine == PLATFORM_POWERMAC)
+			if (machine_is(powermac))
 				sense &= 0x1;
 			np->intrs[intrcount].sense = map_mpic_senses[sense];
 		}
 
 #ifdef CONFIG_PPC64
 		/* We offset irq numbers for the u3 MPIC by 128 in PowerMac */
-		if (_machine == PLATFORM_POWERMAC && ic && ic->parent) {
+		if (machine_is(powermac) && ic && ic->parent) {
 			char *name = get_property(ic->parent, "name", NULL);
 			if (name && !strcmp(name, "u3"))
 				np->intrs[intrcount].line += 128;
@@ -570,6 +570,18 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node,
 	return rc;
 }
 
+unsigned long __init of_get_flat_dt_root(void)
+{
+	unsigned long p = ((unsigned long)initial_boot_params) +
+		initial_boot_params->off_dt_struct;
+
+	while(*((u32 *)p) == OF_DT_NOP)
+		p += 4;
+	BUG_ON (*((u32 *)p) != OF_DT_BEGIN_NODE);
+	p += 4;
+	return _ALIGN(p + strlen((char *)p) + 1, 4);
+}
+
 /**
  * This  function can be used within scan_flattened_dt callback to get
  * access to properties
@@ -612,6 +624,25 @@ void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
 	} while(1);
 }
 
+int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+{
+	const char* cp;
+	unsigned long cplen, l;
+
+	cp = of_get_flat_dt_prop(node, "compatible", &cplen);
+	if (cp == NULL)
+		return 0;
+	while (cplen > 0) {
+		if (strncasecmp(cp, compat, strlen(compat)) == 0)
+			return 1;
+		l = strlen(cp) + 1;
+		cp += l;
+		cplen -= l;
+	}
+
+	return 0;
+}
+
 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
 				       unsigned long align)
 {
@@ -686,7 +717,7 @@ static unsigned long __init unflatten_dt_node(unsigned long mem,
 #ifdef DEBUG
 				if ((strlen(p) + l + 1) != allocl) {
 					DBG("%s: p: %d, l: %d, a: %d\n",
-					    pathp, strlen(p), l, allocl);
+					    pathp, (int)strlen(p), l, allocl);
 				}
 #endif
 				p += strlen(p);
@@ -951,7 +982,6 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 static int __init early_init_dt_scan_chosen(unsigned long node,
 					    const char *uname, int depth, void *data)
 {
-	u32 *prop;
 	unsigned long *lprop;
 	unsigned long l;
 	char *p;
@@ -962,14 +992,6 @@ static int __init early_init_dt_scan_chosen(unsigned long node,
 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 		return 0;
 
-	/* get platform type */
-	prop = (u32 *)of_get_flat_dt_prop(node, "linux,platform", NULL);
-	if (prop == NULL)
-		return 0;
-#ifdef CONFIG_PPC_MULTIPLATFORM
-	_machine = *prop;
-#endif
-
 #ifdef CONFIG_PPC64
 	/* check if iommu is forced on or off */
 	if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
@@ -996,15 +1018,15 @@ static int __init early_init_dt_scan_chosen(unsigned long node,
 	 * set of RTAS infos now if available
 	 */
 	{
-		u64 *basep, *entryp;
+		u64 *basep, *entryp, *sizep;
 
 		basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
 		entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
-		prop = of_get_flat_dt_prop(node, "linux,rtas-size", NULL);
-		if (basep && entryp && prop) {
+		sizep = of_get_flat_dt_prop(node, "linux,rtas-size", NULL);
+		if (basep && entryp && sizep) {
 			rtas.base = *basep;
 			rtas.entry = *entryp;
-			rtas.size = *prop;
+			rtas.size = *sizep;
 		}
 	}
 #endif /* CONFIG_PPC_RTAS */
@@ -1775,7 +1797,7 @@ static int of_finish_dynamic_node(struct device_node *node)
 	/* We don't support that function on PowerMac, at least
 	 * not yet
 	 */
-	if (_machine == PLATFORM_POWERMAC)
+	if (machine_is(powermac))
 		return -ENODEV;
 
 	/* fix up new node's linux_phandle field */
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 0d088784450..d66c5e77fcf 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -180,6 +180,16 @@ static unsigned long __initdata prom_tce_alloc_start;
 static unsigned long __initdata prom_tce_alloc_end;
 #endif
 
+/* Platforms codes are now obsolete in the kernel. Now only used within this
+ * file and ultimately gone too. Feel free to change them if you need, they
+ * are not shared with anything outside of this file anymore
+ */
+#define PLATFORM_PSERIES	0x0100
+#define PLATFORM_PSERIES_LPAR	0x0101
+#define PLATFORM_LPAR		0x0001
+#define PLATFORM_POWERMAC	0x0400
+#define PLATFORM_GENERIC	0x0500
+
 static int __initdata of_platform;
 
 static char __initdata prom_cmd_line[COMMAND_LINE_SIZE];
@@ -1492,7 +1502,10 @@ static int __init prom_find_machine_type(void)
 	int len, i = 0;
 #ifdef CONFIG_PPC64
 	phandle rtas;
+	int x;
 #endif
+
+	/* Look for a PowerMac */
 	len = prom_getprop(_prom->root, "compatible",
 			   compat, sizeof(compat)-1);
 	if (len > 0) {
@@ -1505,28 +1518,36 @@ static int __init prom_find_machine_type(void)
 			if (strstr(p, RELOC("Power Macintosh")) ||
 			    strstr(p, RELOC("MacRISC")))
 				return PLATFORM_POWERMAC;
-#ifdef CONFIG_PPC64
-			if (strstr(p, RELOC("Momentum,Maple")))
-				return PLATFORM_MAPLE;
-			if (strstr(p, RELOC("IBM,CPB")))
-				return PLATFORM_CELL;
-#endif
 			i += sl + 1;
 		}
 	}
 #ifdef CONFIG_PPC64
+	/* If not a mac, try to figure out if it's an IBM pSeries or any other
+	 * PAPR compliant platform. We assume it is if :
+	 *  - /device_type is "chrp" (please, do NOT use that for future
+	 *    non-IBM designs !
+	 *  - it has /rtas
+	 */
+	len = prom_getprop(_prom->root, "model",
+			   compat, sizeof(compat)-1);
+	if (len <= 0)
+		return PLATFORM_GENERIC;
+	compat[len] = 0;
+	if (strcmp(compat, "chrp"))
+		return PLATFORM_GENERIC;
+
 	/* Default to pSeries. We need to know if we are running LPAR */
 	rtas = call_prom("finddevice", 1, 1, ADDR("/rtas"));
-	if (PHANDLE_VALID(rtas)) {
-		int x = prom_getproplen(rtas, "ibm,hypertas-functions");
-		if (x != PROM_ERROR) {
-			prom_printf("Hypertas detected, assuming LPAR !\n");
-			return PLATFORM_PSERIES_LPAR;
-		}
+	if (!PHANDLE_VALID(rtas))
+		return PLATFORM_GENERIC;
+	x = prom_getproplen(rtas, "ibm,hypertas-functions");
+	if (x != PROM_ERROR) {
+		prom_printf("Hypertas detected, assuming LPAR !\n");
+		return PLATFORM_PSERIES_LPAR;
 	}
 	return PLATFORM_PSERIES;
 #else
-	return PLATFORM_CHRP;
+	return PLATFORM_GENERIC;
 #endif
 }
 
@@ -2034,7 +2055,6 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 {	
        	struct prom_t *_prom;
 	unsigned long hdr;
-	u32 getprop_rval;
 	unsigned long offset = reloc_offset();
 
 #ifdef CONFIG_PPC32
@@ -2070,9 +2090,6 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
 	 * between pSeries SMP and pSeries LPAR
 	 */
 	RELOC(of_platform) = prom_find_machine_type();
-	getprop_rval = RELOC(of_platform);
-	prom_setprop(_prom->chosen, "/chosen", "linux,platform",
-		     &getprop_rval, sizeof(getprop_rval));
 
 	/* Bail if this is a kdump kernel. */
 	if (PHYSICAL_START > 0)
diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c
index 1f03fb28cc0..456286cf1d1 100644
--- a/arch/powerpc/kernel/rtas-proc.c
+++ b/arch/powerpc/kernel/rtas-proc.c
@@ -257,7 +257,7 @@ static int __init proc_rtas_init(void)
 {
 	struct proc_dir_entry *entry;
 
-	if (_machine != PLATFORM_PSERIES && _machine != PLATFORM_PSERIES_LPAR)
+	if (!machine_is(pseries))
 		return 1;
 
 	rtas_node = of_find_node_by_name(NULL, "rtas");
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 142d818a31a..4b78ee0e586 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -25,6 +25,7 @@
 #include <asm/hvcall.h>
 #include <asm/semaphore.h>
 #include <asm/machdep.h>
+#include <asm/firmware.h>
 #include <asm/page.h>
 #include <asm/param.h>
 #include <asm/system.h>
@@ -768,7 +769,7 @@ void __init rtas_initialize(void)
 	 * the stop-self token if any
 	 */
 #ifdef CONFIG_PPC64
-	if (_machine == PLATFORM_PSERIES_LPAR) {
+	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
 		rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
 		ibm_suspend_me_token = rtas_token("ibm,suspend-me");
 	}
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index b17630ad4ac..3473cb9cb0a 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -9,6 +9,9 @@
  *      as published by the Free Software Foundation; either version
  *      2 of the License, or (at your option) any later version.
  */
+
+#undef DEBUG
+
 #include <linux/config.h>
 #include <linux/module.h>
 #include <linux/string.h>
@@ -41,6 +44,7 @@
 #include <asm/time.h>
 #include <asm/cputable.h>
 #include <asm/sections.h>
+#include <asm/firmware.h>
 #include <asm/btext.h>
 #include <asm/nvram.h>
 #include <asm/setup.h>
@@ -56,8 +60,6 @@
 
 #include "setup.h"
 
-#undef DEBUG
-
 #ifdef DEBUG
 #include <asm/udbg.h>
 #define DBG(fmt...) udbg_printf(fmt)
@@ -65,10 +67,12 @@
 #define DBG(fmt...)
 #endif
 
-#ifdef CONFIG_PPC_MULTIPLATFORM
-int _machine = 0;
-EXPORT_SYMBOL(_machine);
-#endif
+/* The main machine-dep calls structure
+ */
+struct machdep_calls ppc_md;
+EXPORT_SYMBOL(ppc_md);
+struct machdep_calls *machine_id;
+EXPORT_SYMBOL(machine_id);
 
 unsigned long klimit = (unsigned long) _end;
 
@@ -168,7 +172,8 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 			   bogosum/(500000/HZ), bogosum/(5000/HZ) % 100);
 #endif /* CONFIG_SMP && CONFIG_PPC32 */
 		seq_printf(m, "timebase\t: %lu\n", ppc_tb_freq);
-
+		if (ppc_md.name)
+			seq_printf(m, "platform\t: %s\n", ppc_md.name);
 		if (ppc_md.show_cpuinfo != NULL)
 			ppc_md.show_cpuinfo(m);
 
@@ -387,7 +392,7 @@ void __init smp_setup_cpu_maps(void)
 	 * On pSeries LPAR, we need to know how many cpus
 	 * could possibly be added to this partition.
 	 */
-	if (_machine == PLATFORM_PSERIES_LPAR &&
+	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR) &&
 	    (dn = of_find_node_by_path("/rtas"))) {
 		int num_addr_cell, num_size_cell, maxcpus;
 		unsigned int *ireg;
@@ -456,3 +461,34 @@ static int __init early_xmon(char *p)
 }
 early_param("xmon", early_xmon);
 #endif
+
+void probe_machine(void)
+{
+	extern struct machdep_calls __machine_desc_start;
+	extern struct machdep_calls __machine_desc_end;
+
+	/*
+	 * Iterate all ppc_md structures until we find the proper
+	 * one for the current machine type
+	 */
+	DBG("Probing machine type ...\n");
+
+	for (machine_id = &__machine_desc_start;
+	     machine_id < &__machine_desc_end;
+	     machine_id++) {
+		DBG("  %s ...", machine_id->name);
+		memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls));
+		if (ppc_md.probe()) {
+			DBG(" match !\n");
+			break;
+		}
+		DBG("\n");
+	}
+	/* What can we do if we didn't find ? */
+	if (machine_id >= &__machine_desc_end) {
+		DBG("No suitable machine found !\n");
+		for (;;);
+	}
+
+	printk(KERN_INFO "Using %s machine description\n", ppc_md.name);
+}
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index a2c89435abe..ae9c33d7073 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -67,10 +67,6 @@ unsigned int DMA_MODE_WRITE;
 int have_of = 1;
 
 #ifdef CONFIG_PPC_MULTIPLATFORM
-extern void prep_init(void);
-extern void pmac_init(void);
-extern void chrp_init(void);
-
 dev_t boot_dev;
 #endif /* CONFIG_PPC_MULTIPLATFORM */
 
@@ -82,9 +78,6 @@ unsigned long SYSRQ_KEY = 0x54;
 unsigned long vgacon_remap_base;
 #endif
 
-struct machdep_calls ppc_md;
-EXPORT_SYMBOL(ppc_md);
-
 /*
  * These are used in binfmt_elf.c to put aux entries on the stack
  * for each elf executable being started.
@@ -120,48 +113,6 @@ unsigned long __init early_init(unsigned long dt_ptr)
 	return KERNELBASE + offset;
 }
 
-#ifdef CONFIG_PPC_MULTIPLATFORM
-/*
- * The PPC_MULTIPLATFORM version of platform_init...
- */
-void __init platform_init(void)
-{
-	/* if we didn't get any bootinfo telling us what we are... */
-	if (_machine == 0) {
-		/* prep boot loader tells us if we're prep or not */
-		if ( *(unsigned long *)(KERNELBASE) == (0xdeadc0de) )
-			_machine = _MACH_prep;
-	}
-
-#ifdef CONFIG_PPC_PREP
-	/* not much more to do here, if prep */
-	if (_machine == _MACH_prep) {
-		prep_init();
-		return;
-	}
-#endif
-
-#ifdef CONFIG_ADB
-	if (strstr(cmd_line, "adb_sync")) {
-		extern int __adb_probe_sync;
-		__adb_probe_sync = 1;
-	}
-#endif /* CONFIG_ADB */
-
-	switch (_machine) {
-#ifdef CONFIG_PPC_PMAC
-	case _MACH_Pmac:
-		pmac_init();
-		break;
-#endif
-#ifdef CONFIG_PPC_CHRP
-	case _MACH_chrp:
-		chrp_init();
-		break;
-#endif
-	}
-}
-#endif
 
 /*
  * Find out what kind of machine we're on and save any data we need
@@ -187,8 +138,12 @@ void __init machine_init(unsigned long dt_ptr, unsigned long phys)
 		strlcpy(cmd_line, CONFIG_CMDLINE, sizeof(cmd_line));
 #endif /* CONFIG_CMDLINE */
 
-	/* Base init based on machine type */
+#ifdef CONFIG_PPC_MULTIPLATFORM
+	probe_machine();
+#else
+	/* Base init based on machine type. Obsoloete, please kill ! */
 	platform_init();
+#endif
 
 #ifdef CONFIG_6xx
 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
@@ -359,7 +314,4 @@ void __init setup_arch(char **cmdline_p)
 	if ( ppc_md.progress ) ppc_md.progress("arch: exit", 0x3eab);
 
 	paging_init();
-
-	/* this is for modules since _machine can be a define -- Cort */
-	ppc_md.ppc_machine = _machine;
 }
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 5b63a861ef4..6aea1fb74b6 100644
--- a/