Re: [patch] x86 CPU detection for RDC

Re: [patch] x86 CPU detection for RDC

[Mark Kelly]

> ok, this definitely looks like a step in the right direction. The
> patch needs a few small fixes:

Sorry about that - try this one instead:

Signed-off-by: Mark Kelly <mark@bifferos.com>
diff --git a/Documentation/x86/rdc.txt b/Documentation/x86/rdc.txt
new file mode 100644
index 0000000..f9591af
--- /dev/null
+++ b/Documentation/x86/rdc.txt
@@ -0,0 +1,69 @@
+
+Introduction
+============
+
+RDC (http://www.rdc.com.tw) have been manufacturing x86-compatible SoC
+(system-on-chips) for a number of years.  They are not the fastest of
+CPUs (clock speeds ranging from 133-150MHz) but 486SX compatibility
+coupled with very low power consumption[1] and low cost make them ideal
+for embedded applications.
+
+
+Where to find
+=============
+
+RDC chips show up in numerous embedded devices, but be careful since
+many of them will not run Linux 2.6 without significant expertise.
+
+There are several variants of what the linux kernel refers to generically
+as RDC321X:  R8610, R321x, S3282 and AMRISC20000.
+
+R321x: Found in various routers, see the OpenWrt project for details,
+   http://wiki.openwrt.org/oldwiki/rdcport
+
+R8610: Found on the RDC evaluation board
+   http://www.ivankuten.com/system-on-chip-soc/rdc-r8610/
+
+AMRISC20000: Found in the MGB-100 wireless hard disk
+   http://tintuc.no-ip.com/linux/tipps/mgb100/
+
+S3282: Found in various NAS devices, including the Bifferboard
+   http://www.bifferos.com
+
+
+Kernel Configuration
+====================
+
+Add support for this CPU with CONFIG_X86_RDC321X.  Ensure that maths
+emulation is included (CONFIG_MATH_EMULATION selected) and avoid MCE
+(CONFIG_X86_MCE not selected).
+
+
+CPU detection
+=============
+
+None of these chips support the cpuid instruction, so as with some
+other x86 compatible SoCs, we must check the north bridge and look
+for specific 'signature' PCI device config.
+
+The current detection code has been tested only on the Bifferboard
+(S3282 CPU), please send bug reports or success stories with
+other devices to bifferos@yahoo.co.uk.
+
+
+Credits
+=======
+
+Many thanks to RDC for providing the customer codes to allow
+detection of all known variants, without which this detection code
+would have been very hard to ascertain.
+
+
+References
+==========
+
+[1] S3282 in certain NAS solutions consumes less than 1W
+
+
+mark@bifferos.com 2009
+
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c2cceae..6f9f853 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -121,7 +121,8 @@ struct cpuinfo_x86 {
 #define X86_VENDOR_CENTAUR	5
 #define X86_VENDOR_TRANSMETA	7
 #define X86_VENDOR_NSC		8
-#define X86_VENDOR_NUM		9
+#define X86_VENDOR_RDC		9
+#define X86_VENDOR_NUM		10

 #define X86_VENDOR_UNKNOWN	0xff

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 4e242f9..9906064 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
 obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
 obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
 obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
+obj-$(CONFIG_X86_RDC321X)		+= rdc.o

 obj-$(CONFIG_X86_MCE)	+= mcheck/
 obj-$(CONFIG_MTRR)	+= mtrr/
diff --git a/arch/x86/kernel/cpu/rdc.c b/arch/x86/kernel/cpu/rdc.c
new file mode 100644
index 0000000..6b02166
--- /dev/null
+++ b/arch/x86/kernel/cpu/rdc.c
@@ -0,0 +1,74 @@
+/*
+   See Documentation/x86/rdc.txt
+
+   mark@bifferos.com
+*/
+
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include "cpu.h"
+
+
+static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
+{
+	u16 vendor, device;
+	u32 customer_id;
+
+	/* RDC CPU is SoC (system-on-chip), Northbridge is always present. */
+	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
+	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
+
+	if (vendor != PCI_VENDOR_ID_RDC || device != PCI_DEVICE_ID_RDC_R6020)
+		return;  /* not RDC */
+
+	/* NB: We could go on and check other devices, e.g. r6040 NIC, but
+	   that's probably overkill */
+
+	strcpy(c->x86_vendor_id, "RDC");
+	c->x86_vendor = X86_VENDOR_RDC;
+
+	customer_id = read_pci_config(0, 0, 0, 0x90);
+
+	switch (customer_id) {
+		/* id names are from RDC */
+	case 0x00321000:
+		strcpy(c->x86_model_id, "R3210/R3211");
+		break;
+	case 0x00321001:
+		strcpy(c->x86_model_id, "AMITRISC20000/20010");
+		break;
+	case 0x00321002:
+		strcpy(c->x86_model_id, "R3210X/Edimax");
+		break;
+	case 0x00321003:
+		strcpy(c->x86_model_id, "R3210/Kcodes");
+		break;
+	case 0x00321004:  /* tested */
+		strcpy(c->x86_model_id, "S3282/CodeTek");
+		break;
+	case 0x00321007:
+		strcpy(c->x86_model_id, "R8610");
+		break;
+	default:
+		printk(KERN_INFO "Unrecognised Customer ID (0x%x) please "
+			"report to bifferos@yahoo.co.uk\n", customer_id);
+
+		/* We'll default to the R321x since that's mentioned
+		   elsewhere in the kernel sources */
+		strcpy(c->x86_model_id, "R321x");
+
+		/* blank the vendor_id, so we get a warning that this
+		   is unsupported, your system may be unstable etc...
+		   Is there a better way? */
+		strcpy(c->x86_vendor_id, "");
+	}
+}
+
+static const struct cpu_dev __cpuinitconst rdc_cpu_dev = {
+	.c_vendor	= "RDC",
+	.c_ident	= { "RDC" },
+	.c_identify	= rdc_identify,
+	.c_x86_vendor	= X86_VENDOR_RDC,
+};
+
+cpu_dev_register(rdc_cpu_dev);

Re: [patch] x86 CPU detection for RDC

[Mark Kelly]

On Sun, 16 Aug 2009, Ingo Molnar wrote:

> hm, the default should already be an empty string (i.e. \0) - why
> does this need to be cleared again?

I've hopefully made this one a bit clearer by introducing another
local instead of doing a set-then-unset.


Here's the next attempt:


Signed-off-by: Mark Kelly <mark@bifferos.com>
diff --git a/Documentation/x86/rdc.txt b/Documentation/x86/rdc.txt
new file mode 100644
index 0000000..f9591af
--- /dev/null
+++ b/Documentation/x86/rdc.txt
@@ -0,0 +1,69 @@
+
+Introduction
+============
+
+RDC (http://www.rdc.com.tw) have been manufacturing x86-compatible SoC
+(system-on-chips) for a number of years.  They are not the fastest of
+CPUs (clock speeds ranging from 133-150MHz) but 486SX compatibility
+coupled with very low power consumption[1] and low cost make them ideal
+for embedded applications.
+
+
+Where to find
+=============
+
+RDC chips show up in numerous embedded devices, but be careful since
+many of them will not run Linux 2.6 without significant expertise.
+
+There are several variants of what the linux kernel refers to generically
+as RDC321X:  R8610, R321x, S3282 and AMRISC20000.
+
+R321x: Found in various routers, see the OpenWrt project for details,
+   http://wiki.openwrt.org/oldwiki/rdcport
+
+R8610: Found on the RDC evaluation board
+   http://www.ivankuten.com/system-on-chip-soc/rdc-r8610/
+
+AMRISC20000: Found in the MGB-100 wireless hard disk
+   http://tintuc.no-ip.com/linux/tipps/mgb100/
+
+S3282: Found in various NAS devices, including the Bifferboard
+   http://www.bifferos.com
+
+
+Kernel Configuration
+====================
+
+Add support for this CPU with CONFIG_X86_RDC321X.  Ensure that maths
+emulation is included (CONFIG_MATH_EMULATION selected) and avoid MCE
+(CONFIG_X86_MCE not selected).
+
+
+CPU detection
+=============
+
+None of these chips support the cpuid instruction, so as with some
+other x86 compatible SoCs, we must check the north bridge and look
+for specific 'signature' PCI device config.
+
+The current detection code has been tested only on the Bifferboard
+(S3282 CPU), please send bug reports or success stories with
+other devices to bifferos@yahoo.co.uk.
+
+
+Credits
+=======
+
+Many thanks to RDC for providing the customer codes to allow
+detection of all known variants, without which this detection code
+would have been very hard to ascertain.
+
+
+References
+==========
+
+[1] S3282 in certain NAS solutions consumes less than 1W
+
+
+mark@bifferos.com 2009
+
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c2cceae..6f9f853 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -121,7 +121,8 @@ struct cpuinfo_x86 {
 #define X86_VENDOR_CENTAUR	5
 #define X86_VENDOR_TRANSMETA	7
 #define X86_VENDOR_NSC		8
-#define X86_VENDOR_NUM		9
+#define X86_VENDOR_RDC		9
+#define X86_VENDOR_NUM		10

 #define X86_VENDOR_UNKNOWN	0xff

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 4e242f9..9906064 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
 obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
 obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
 obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
+obj-$(CONFIG_X86_RDC321X)		+= rdc.o

 obj-$(CONFIG_X86_MCE)	+= mcheck/
 obj-$(CONFIG_MTRR)	+= mtrr/
diff --git a/arch/x86/kernel/cpu/rdc.c b/arch/x86/kernel/cpu/rdc.c
new file mode 100644
index 0000000..6b1b2cf
--- /dev/null
+++ b/arch/x86/kernel/cpu/rdc.c
@@ -0,0 +1,77 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * mark@bifferos.com
+ */
+
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include "cpu.h"
+
+
+static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
+{
+	u16 vendor, device;
+	u32 customer_id;
+	int match;
+
+	/* RDC CPU is SoC (system-on-chip), Northbridge is always present */
+	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
+	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
+
+	if (vendor != PCI_VENDOR_ID_RDC || device != PCI_DEVICE_ID_RDC_R6020)
+		return;  /* not RDC */
+	/*
+	 * NB: We could go on and check other devices, e.g. r6040 NIC, but
+	 * that's probably overkill
+	 */
+
+	match = 1;
+	customer_id = read_pci_config(0, 0, 0, 0x90);
+
+	switch (customer_id) {
+		/* id names are from RDC */
+	case 0x00321000:
+		strcpy(c->x86_model_id, "R3210/R3211");
+		break;
+	case 0x00321001:
+		strcpy(c->x86_model_id, "AMITRISC20000/20010");
+		break;
+	case 0x00321002:
+		strcpy(c->x86_model_id, "R3210X/Edimax");
+		break;
+	case 0x00321003:
+		strcpy(c->x86_model_id, "R3210/Kcodes");
+		break;
+	case 0x00321004:  /* tested */
+		strcpy(c->x86_model_id, "S3282/CodeTek");
+		break;
+	case 0x00321007:
+		strcpy(c->x86_model_id, "R8610");
+		break;
+	default:
+		pr_info("RDC CPU: Unrecognised Customer ID (0x%x) please report to linux-kernel@vger.kernel.org\n", customer_id);
+
+		/*
+		 * We'll default to the R321x since that's mentioned
+		 * elsewhere in the kernel sources
+		 */
+		strcpy(c->x86_model_id, "R321x");
+		match = 0;
+	}
+
+	/* Only fill in the vendor ID if we got an exact match */
+	if (match)
+		strcpy(c->x86_vendor_id, "RDC");
+
+	c->x86_vendor = X86_VENDOR_RDC;
+}
+
+static const struct cpu_dev __cpuinitconst rdc_cpu_dev = {
+	.c_vendor	= "RDC",
+	.c_ident	= { "RDC" },
+	.c_identify	= rdc_identify,
+	.c_x86_vendor	= X86_VENDOR_RDC,
+};
+
+cpu_dev_register(rdc_cpu_dev);

[patch] x86 CPU detection for RDC

[Mark Kelly]

>From about 2.6.29, CPU detection appears to have changed such that a 
patch is required for RDC x86-compatible CPUs (possibly other undetected 
x86 CPUs as well).  A work-around was to add a couple of null checks to 
arch/x86/kernel/cpu/common.c, e.g.:

if (this_cpu && this_cpu->c_identify)
             ~~~~~~~~~~~~~~~~~~~~~~~
    this_cpu->c_identify(c);

However the patch below attempts to do this detection properly, and also
detect all variants of RDC CPUs. I have also added some documentation 
for this platform.

See also:
http://sites.google.com/site/bifferboard/Home/s3282-kernel-issues

kind regards,
Mark.




Signed-off-by: Mark Kelly <mark@bifferos.com>


diff --git a/Documentation/x86/rdc.txt b/Documentation/x86/rdc.txt
new file mode 100644
index 0000000..9c6baaa
--- /dev/null
+++ b/Documentation/x86/rdc.txt
@@ -0,0 +1,69 @@
+
+Introduction
+============
+
+RDC (http://www.rdc.com.tw) have been manufacturing x86-compatible SoC
+(system-on-chips) for a number of years.  They are not the fastest of 
+CPUs (clock speeds ranging from 133-150MHz) but 486SX compatibility 
+coupled with very low power consumption[1] and low cost make them ideal 
+for embedded applications.
+
+
+Where to find
+=============
+
+RDC chips show up in numerous embedded devices, but be careful since
+many of them will not run Linux 2.6 without significant expertise.
+
+There are several variants of what the linux kernel refers to generically 
+as RDC321X:  R8610, R321x, S3282 and AMRISC20000.
+
+R321x: Found in various routers, see the OpenWrt project for details,
+   http://wiki.openwrt.org/oldwiki/rdcport
+
+R8610: Found on the RDC evaluation board
+   http://www.ivankuten.com/system-on-chip-soc/rdc-r8610/
+
+AMRISC20000: Found in the MGB-100 wireless hard disk
+   http://tintuc.no-ip.com/linux/tipps/mgb100/
+
+S3282: Found in various NAS devices, including the Bifferboard
+   http://www.bifferos.com   
+
+
+Kernel Configuration
+====================
+
+Add support for this CPU with CONFIG_X86_RDC321X.  Ensure that maths
+emulation is included (CONFIG_MATH_EMULATION selected) and avoid MCE
+(CONFIG_X86_MCE not selected).
+
+
+CPU detection
+=============
+
+None of these chips support the cpuid instruction, so as with some
+other x86 compatible SoCs, we must check the north bridge and look 
+for specific 'signature' PCI device config.
+
+The current detection code has been tested only on the Bifferboard
+(S3282 CPU), please send bug reports or success stories with
+other devices to bifferos@yahoo.co.uk.
+
+
+Refs
+====
+
+[1] S3282 in certain NAS solutions consumes less than 1W
+
+
+Credits
+=======
+
+Many thanks to RDC for providing the customer codes to allow
+detection of all known variants, without which this detection code
+would have been very hard to ascertain.
+
+
+mark@bifferos.com 2009
+
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c2cceae..6f9f853 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -121,7 +121,8 @@ struct cpuinfo_x86 {
 #define X86_VENDOR_CENTAUR	5
 #define X86_VENDOR_TRANSMETA	7
 #define X86_VENDOR_NSC		8
-#define X86_VENDOR_NUM		9
+#define X86_VENDOR_RDC		9
+#define X86_VENDOR_NUM		10
 
 #define X86_VENDOR_UNKNOWN	0xff
 
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 4e242f9..9906064 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
 obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
 obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
 obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
+obj-$(CONFIG_X86_RDC321X)		+= rdc.o
 
 obj-$(CONFIG_X86_MCE)	+= mcheck/
 obj-$(CONFIG_MTRR)	+= mtrr/
diff --git a/arch/x86/kernel/cpu/rdc.c b/arch/x86/kernel/cpu/rdc.c
new file mode 100644
index 0000000..5a6aea7
--- /dev/null
+++ b/arch/x86/kernel/cpu/rdc.c
@@ -0,0 +1,72 @@
+/*
+   See Documentation/x86/rdc.txt
+
+   mark@bifferos.com
+*/
+
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include "cpu.h"
+
+
+static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
+{
+	u16 vendor, device;
+	
+	/* RDC CPU is SoC (system-on-chip), Northbridge is always present. */
+	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
+	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
+
+	/* We could go on and check other devices, e.g. r6040 NIC, but that's probably
overkill */
+	if (vendor == PCI_VENDOR_ID_RDC && device == PCI_DEVICE_ID_RDC_R6020) 
+	{
+		u32 customer_id;
+
+		strcpy(c->x86_vendor_id, "RDC");
+		c->x86_vendor = X86_VENDOR_RDC;
+
+		customer_id = read_pci_config(0, 0, 0, 0x90);
+		
+		switch (customer_id)
+		{
+			// id names are from RDC.
+			case 0x00321000 :
+				strcpy(c->x86_model_id, "R3210/R3211");
+				break;
+			case 0x00321001 :
+				strcpy(c->x86_model_id, "AMITRISC20000/20010");
+				break;
+			case 0x00321002 :
+				strcpy(c->x86_model_id, "R3210X/Edimax");
+				break;
+			case 0x00321003 :
+				strcpy(c->x86_model_id, "R3210/Kcodes");
+				break;
+			case 0x00321004 :  // tested
+				strcpy(c->x86_model_id, "S3282/CodeTek");
+				break;
+			case 0x00321007 :
+				strcpy(c->x86_model_id, "R8610");
+				break;
+			default :
+				printk(KERN_INFO "Unrecognised Customer ID (0x%x) please report to
bifferos@yahoo.co.uk\n", customer_id);
+
+				/* We'll default to the R321x since that's mentioned elsewhere in the 
+				   kernel sources. */
+				strcpy(c->x86_model_id, "R321x");
+				
+				/* blank the vendor_id, so we get a warning that this is unsupported, your 
+				   system may be unstable etc...  Is there a better way? */
+				strcpy(c->x86_vendor_id, "");
+		}
+	}
+}
+
+static const struct cpu_dev __cpuinitconst rdc_cpu_dev = {
+	.c_vendor	= "RDC",
+	.c_ident	= { "RDC" },
+	.c_identify	= rdc_identify,
+	.c_x86_vendor	= X86_VENDOR_RDC,
+};
+
+cpu_dev_register(rdc_cpu_dev);

Re: [patch] x86 CPU detection for RDC

[Ingo Molnar]

* Mark Kelly <mark@bifferos.com> wrote:

 > From about 2.6.29, CPU detection appears to have changed such 
 > that
> a patch is required for RDC x86-compatible CPUs (possibly other 
> undetected x86 CPUs as well).  A work-around was to add a couple 
> of null checks to arch/x86/kernel/cpu/common.c, e.g.:
> 
> if (this_cpu && this_cpu->c_identify)
>              ~~~~~~~~~~~~~~~~~~~~~~~
>     this_cpu->c_identify(c);
> 
> However the patch below attempts to do this detection properly, 
> and also detect all variants of RDC CPUs. I have also added some 
> documentation for this platform.
> 
> See also:
> http://sites.google.com/site/bifferboard/Home/s3282-kernel-issues

ok, this definitely looks like a step in the right direction. The 
patch needs a few small fixes:

 - the one you sent was line-wrapped. (please see
   Documentation/email-clients.txt about how to send plain-text 
   patches.)

 - there's a few stylistic errors in the patch, 
   scripts/checkpatch.pl reports:

     total: 24 errors, 5 warnings, 0 checks, 157 lines checked

	Ingo

Re: [patch] x86 CPU detection for RDC

[Ingo Molnar]

* Mark Kelly <mark@bifferos.com> wrote:

> +static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
> +{
> +	u16 vendor, device;
> +	u32 customer_id;
> +
> +	/* RDC CPU is SoC (system-on-chip), Northbridge is always present. */
> +	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
> +	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
> +
> +	if (vendor != PCI_VENDOR_ID_RDC || device != PCI_DEVICE_ID_RDC_R6020)
> +		return;  /* not RDC */
> +
> +	/* NB: We could go on and check other devices, e.g. r6040 NIC, but
> +	   that's probably overkill */

please use the customary (multi-line) comment style:

  /*
   * Comment .....
   * ...... goes here.
   */

specified in Documentation/CodingStyle.

> +	strcpy(c->x86_vendor_id, "RDC");
> +	c->x86_vendor = X86_VENDOR_RDC;
> +
> +	customer_id = read_pci_config(0, 0, 0, 0x90);
> +
> +	switch (customer_id) {
> +		/* id names are from RDC */
> +	case 0x00321000:
> +		strcpy(c->x86_model_id, "R3210/R3211");
> +		break;
> +	case 0x00321001:
> +		strcpy(c->x86_model_id, "AMITRISC20000/20010");
> +		break;
> +	case 0x00321002:
> +		strcpy(c->x86_model_id, "R3210X/Edimax");
> +		break;
> +	case 0x00321003:
> +		strcpy(c->x86_model_id, "R3210/Kcodes");
> +		break;
> +	case 0x00321004:  /* tested */
> +		strcpy(c->x86_model_id, "S3282/CodeTek");
> +		break;
> +	case 0x00321007:
> +		strcpy(c->x86_model_id, "R8610");
> +		break;
> +	default:
> +		printk(KERN_INFO "Unrecognised Customer ID (0x%x) please "
> +			"report to bifferos@yahoo.co.uk\n", customer_id);

I'd rather see them reported to linux-kernel@vger.kernel.org. Also, 
please concatenate the string on a single line (and ignore the 
checkpatch warning in this case, even if the line is over-long).

Also, please use pr_info() here. Plus, put 'RDC' into the printout 
so that people know that the RDC cpu is unknown. (it's not clear 
from this printk)

> +		/* We'll default to the R321x since that's mentioned
> +		   elsewhere in the kernel sources */
> +		strcpy(c->x86_model_id, "R321x");
> +
> +		/* blank the vendor_id, so we get a warning that this
> +		   is unsupported, your system may be unstable etc...
> +		   Is there a better way? */

(these multi-line comments too need to be fixed.)

> +		strcpy(c->x86_vendor_id, "");

hm, the default should already be an empty string (i.e. \0) - why 
does this need to be cleared again?

	Ingo

[patch, v2] x86: CPU detection for RDC

[Mark Kelly]

On Mon, 17 Aug 2009, H. Peter Anvin wrote:

> On 08/17/2009 02:31 PM, Andi Kleen wrote:
> >
> > I thought it was to prevent oopses for zero cpu according
> > to the reporter?
> >
> > But these oopses should be probably separately fixed anyways.
> >
>
> They should.

Perhaps, but they don't need to be.  Unfortunately I was testing up to
2.6.30.5 (which gives the Oops), but someone must have changed the
detection code for 486 in Linus' tree, because when I tried that (at
Ingo's suggestion) I magically got a boot, and a correctly recognised
486 without my patch.  This does rather remove my reason for the patch
submission, but I will carry on if people think this is still worthwhile.

With the above in mind we can give up on detection without fear of a
subsequent Oops, so I've simplified the code to not bother with
the unrecognised variants (still gives a warning).

I've added the PCI config dependency, and the runtime check.  I'll call
this v2, please ignore all the previous patches.  It's against
2.6.31-rc6-tip.

regards,
Mark.



Signed-off-by: Mark Kelly <mark@bifferos.com>
diff --git a/Documentation/x86/rdc.txt b/Documentation/x86/rdc.txt
new file mode 100644
index 0000000..f9591af
--- /dev/null
+++ b/Documentation/x86/rdc.txt
@@ -0,0 +1,69 @@
+
+Introduction
+============
+
+RDC (http://www.rdc.com.tw) have been manufacturing x86-compatible SoC
+(system-on-chips) for a number of years.  They are not the fastest of
+CPUs (clock speeds ranging from 133-150MHz) but 486SX compatibility
+coupled with very low power consumption[1] and low cost make them ideal
+for embedded applications.
+
+
+Where to find
+=============
+
+RDC chips show up in numerous embedded devices, but be careful since
+many of them will not run Linux 2.6 without significant expertise.
+
+There are several variants of what the linux kernel refers to generically
+as RDC321X:  R8610, R321x, S3282 and AMRISC20000.
+
+R321x: Found in various routers, see the OpenWrt project for details,
+   http://wiki.openwrt.org/oldwiki/rdcport
+
+R8610: Found on the RDC evaluation board
+   http://www.ivankuten.com/system-on-chip-soc/rdc-r8610/
+
+AMRISC20000: Found in the MGB-100 wireless hard disk
+   http://tintuc.no-ip.com/linux/tipps/mgb100/
+
+S3282: Found in various NAS devices, including the Bifferboard
+   http://www.bifferos.com
+
+
+Kernel Configuration
+====================
+
+Add support for this CPU with CONFIG_X86_RDC321X.  Ensure that maths
+emulation is included (CONFIG_MATH_EMULATION selected) and avoid MCE
+(CONFIG_X86_MCE not selected).
+
+
+CPU detection
+=============
+
+None of these chips support the cpuid instruction, so as with some
+other x86 compatible SoCs, we must check the north bridge and look
+for specific 'signature' PCI device config.
+
+The current detection code has been tested only on the Bifferboard
+(S3282 CPU), please send bug reports or success stories with
+other devices to bifferos@yahoo.co.uk.
+
+
+Credits
+=======
+
+Many thanks to RDC for providing the customer codes to allow
+detection of all known variants, without which this detection code
+would have been very hard to ascertain.
+
+
+References
+==========
+
+[1] S3282 in certain NAS solutions consumes less than 1W
+
+
+mark@bifferos.com 2009
+
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1655b77..5d2bcaa 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -382,6 +382,7 @@ config X86_RDC321X
 	bool "RDC R-321x SoC"
 	depends on X86_32
 	depends on X86_EXTENDED_PLATFORM
+	select PCI
 	select M486
 	select X86_REBOOTFIXUPS
 	---help---
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 2b03f70..75b96e9 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -122,7 +122,8 @@ struct cpuinfo_x86 {
 #define X86_VENDOR_CENTAUR	5
 #define X86_VENDOR_TRANSMETA	7
 #define X86_VENDOR_NSC		8
-#define X86_VENDOR_NUM		9
+#define X86_VENDOR_RDC		9
+#define X86_VENDOR_NUM		10

 #define X86_VENDOR_UNKNOWN	0xff

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 3efcb2b..55ba09a 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
 obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
 obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
 obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
+obj-$(CONFIG_X86_RDC321X)		+= rdc.o

 obj-$(CONFIG_PERF_COUNTERS)		+= perf_counter.o

diff --git a/arch/x86/kernel/cpu/rdc.c b/arch/x86/kernel/cpu/rdc.c
new file mode 100644
index 0000000..369a671
--- /dev/null
+++ b/arch/x86/kernel/cpu/rdc.c
@@ -0,0 +1,69 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * mark@bifferos.com
+ */
+
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include "cpu.h"
+
+
+static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
+{
+	u16 vendor, device;
+	u32 customer_id;
+
+	if (!early_pci_allowed())
+		return;
+
+	/* RDC CPU is SoC (system-on-chip), Northbridge is always present */
+	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
+	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
+
+	if (vendor != PCI_VENDOR_ID_RDC || device != PCI_DEVICE_ID_RDC_R6020)
+		return;  /* not RDC */
+	/*
+	 * NB: We could go on and check other devices, e.g. r6040 NIC, but
+	 * that's probably overkill
+	 */
+
+	customer_id = read_pci_config(0, 0, 0, 0x90);
+
+	switch (customer_id) {
+		/* id names are from RDC */
+	case 0x00321000:
+		strcpy(c->x86_model_id, "R3210/R3211");
+		break;
+	case 0x00321001:
+		strcpy(c->x86_model_id, "AMITRISC20000/20010");
+		break;
+	case 0x00321002:
+		strcpy(c->x86_model_id, "R3210X/Edimax");
+		break;
+	case 0x00321003:
+		strcpy(c->x86_model_id, "R3210/Kcodes");
+		break;
+	case 0x00321004:  /* tested */
+		strcpy(c->x86_model_id, "S3282/CodeTek");
+		break;
+	case 0x00321007:
+		strcpy(c->x86_model_id, "R8610");
+		break;
+	default:
+		pr_info("RDC CPU: Unrecognised Customer ID (0x%x) please report to linux-kernel@vger.kernel.org\n", customer_id);
+		return;
+	}
+
+	strcpy(c->x86_vendor_id, "RDC");
+	c->x86_vendor = X86_VENDOR_RDC;
+}
+
+static const struct cpu_dev __cpuinitconst rdc_cpu_dev = {
+	.c_vendor	= "RDC",
+	.c_ident	= { "RDC" },
+	.c_identify	= rdc_identify,
+	.c_x86_vendor	= X86_VENDOR_RDC,
+};
+
+cpu_dev_register(rdc_cpu_dev);

Re: [patch] x86 CPU detection for RDC

[Andi Kleen]

Mark Kelly <mark@bifferos.com> writes:
> +{
> +	u16 vendor, device;
> +	
> +	/* RDC CPU is SoC (system-on-chip), Northbridge is always present. */
> +	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
> +	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);

This needs some check first if PCI is even enabled. You can use
early_pci_allowed() for this or just add a handler in early quirks
that sets a flag you test here.

Also I would suggest to not hard code your own email addresses
in printk (which might go away), but use some list like linux-kernel.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

Re: [patch] x86 CPU detection for RDC

[H. Peter Anvin]

On 08/15/2009 08:35 PM, Mark Kelly wrote:
> diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
> index 4e242f9..9906064 100644
> --- a/arch/x86/kernel/cpu/Makefile
> +++ b/arch/x86/kernel/cpu/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
>  obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
>  obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
>  obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
> +obj-$(CONFIG_X86_RDC321X)		+= rdc.o
> 
>  obj-$(CONFIG_X86_MCE)	+= mcheck/
>  obj-$(CONFIG_MTRR)	+= mtrr/

I don't see this defined anywhere.  Where it is defined, it needs to
depend on or select CONFIG_PCI, since the detection code you're
proposing is using unguarded PCI references.

	-hpa

Re: [patch] x86 CPU detection for RDC

[Ingo Molnar]

* H. Peter Anvin <hpa@zytor.com> wrote:

> On 08/15/2009 08:35 PM, Mark Kelly wrote:
> > diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
> > index 4e242f9..9906064 100644
> > --- a/arch/x86/kernel/cpu/Makefile
> > +++ b/arch/x86/kernel/cpu/Makefile
> > @@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
> >  obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
> >  obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
> >  obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
> > +obj-$(CONFIG_X86_RDC321X)		+= rdc.o
> > 
> >  obj-$(CONFIG_X86_MCE)	+= mcheck/
> >  obj-$(CONFIG_MTRR)	+= mtrr/
> 
> I don't see this defined anywhere.  Where it is defined, it needs 
> to depend on or select CONFIG_PCI, since the detection code 
> you're proposing is using unguarded PCI references.

X86_RDC321X already exists in arch/x86/Kconfig. It should probably 
grow a 'depends on PCI' rline or so.

	Ingo

Re: [patch] x86 CPU detection for RDC

[H. Peter Anvin]

On 08/17/2009 11:08 AM, Ingo Molnar wrote:
> 
> X86_RDC321X already exists in arch/x86/Kconfig. It should probably 
> grow a 'depends on PCI' rline or so.
> 

Sounds like it.

	-hpa

Re: [patch] x86 CPU detection for RDC

[Andi Kleen]

"H. Peter Anvin" <hpa@zytor.com> writes:

> On 08/17/2009 11:08 AM, Ingo Molnar wrote:
>> 
>> X86_RDC321X already exists in arch/x86/Kconfig. It should probably 
>> grow a 'depends on PCI' rline or so.
>> 
>
> Sounds like it.

iirc the patch used early pci which is actually self contained
in its header. The main problem was that it didn't use it correctly.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

Re: [patch] x86 CPU detection for RDC

[H. Peter Anvin]

On 08/17/2009 11:46 AM, Andi Kleen wrote:
> "H. Peter Anvin" <hpa@zytor.com> writes:
> 
>> On 08/17/2009 11:08 AM, Ingo Molnar wrote:
>>> X86_RDC321X already exists in arch/x86/Kconfig. It should probably 
>>> grow a 'depends on PCI' rline or so.
>>>
>> Sounds like it.
> 
> iirc the patch used early pci which is actually self contained
> in its header. The main problem was that it didn't use it correctly.
> 

It isn't a matter of if compilation works, it is a matter of if we
should even try to probe PCI if the user has explicitly disabled
CONFIG_PCI.  arch/x86/kernel/cpu/cyrix.c disables its PCI probing if
CONFIG_PCI is off, even though it also uses <asm/pci-direct.h>.

Given that the benefit of this CPU detection patch is extremely small
(all it does it get better information in /proc/cpuinfo) and that blind
probing can have disastrous consequences, I would say it should not.

	-hpa

Re: [patch] x86 CPU detection for RDC

[H. Peter Anvin]

On 08/17/2009 11:46 AM, Andi Kleen wrote:
> "H. Peter Anvin" <hpa@zytor.com> writes:
> 
>> On 08/17/2009 11:08 AM, Ingo Molnar wrote:
>>> X86_RDC321X already exists in arch/x86/Kconfig. It should probably 
>>> grow a 'depends on PCI' rline or so.
>>>
>> Sounds like it.
> 
> iirc the patch used early pci which is actually self contained
> in its header. The main problem was that it didn't use it correctly.
> 

Just saw your other email.  early_pci_allowed() is defined in
arch/x86/pci/early.c which is only compiled (as is the whole
arch/x86/pci directory) if CONFIG_PCI is enabled, so the compile-time
guard is needed.

	-hpa

Re: [patch] x86 CPU detection for RDC

[Andi Kleen]

> It isn't a matter of if compilation works, it is a matter of if we

I was actually wrong -- someone moved the functions out of line.
So CONFIG_PCI is needed after all.

> should even try to probe PCI if the user has explicitly disabled
> CONFIG_PCI.  arch/x86/kernel/cpu/cyrix.c disables its PCI probing if
> CONFIG_PCI is off, even though it also uses <asm/pci-direct.h>.

Better would be if he used early_pci_allowed() then this could
be set at runtime.

> Given that the benefit of this CPU detection patch is extremely small
> (all it does it get better information in /proc/cpuinfo) and that blind
> probing can have disastrous consequences, I would say it should not.

I thought it was to prevent oopses for zero cpu according
to the reporter?

But these oopses should be probably separately fixed anyways.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

Re: [patch] x86 CPU detection for RDC

[H. Peter Anvin]

On 08/17/2009 02:31 PM, Andi Kleen wrote:
> 
> I thought it was to prevent oopses for zero cpu according
> to the reporter?
> 
> But these oopses should be probably separately fixed anyways.
> 

They should.

	-hpa

Re: [patch, v3] x86: CPU detection for RDC

[Mark Kelly]

On Tue, 18 Aug 2009, Ingo Molnar wrote:

> PCI is a complex interactive Kconfig switch and we dont select it
> in x86 code. Please add a 'depends on PCI' line instead, as i
> suggested in my mail.

Here you go.  That's the only change over v2.


Signed-off-by: Mark Kelly <mark@bifferos.com>
diff --git a/Documentation/x86/rdc.txt b/Documentation/x86/rdc.txt
new file mode 100644
index 0000000..f9591af
--- /dev/null
+++ b/Documentation/x86/rdc.txt
@@ -0,0 +1,69 @@
+
+Introduction
+============
+
+RDC (http://www.rdc.com.tw) have been manufacturing x86-compatible SoC
+(system-on-chips) for a number of years.  They are not the fastest of
+CPUs (clock speeds ranging from 133-150MHz) but 486SX compatibility
+coupled with very low power consumption[1] and low cost make them ideal
+for embedded applications.
+
+
+Where to find
+=============
+
+RDC chips show up in numerous embedded devices, but be careful since
+many of them will not run Linux 2.6 without significant expertise.
+
+There are several variants of what the linux kernel refers to generically
+as RDC321X:  R8610, R321x, S3282 and AMRISC20000.
+
+R321x: Found in various routers, see the OpenWrt project for details,
+   http://wiki.openwrt.org/oldwiki/rdcport
+
+R8610: Found on the RDC evaluation board
+   http://www.ivankuten.com/system-on-chip-soc/rdc-r8610/
+
+AMRISC20000: Found in the MGB-100 wireless hard disk
+   http://tintuc.no-ip.com/linux/tipps/mgb100/
+
+S3282: Found in various NAS devices, including the Bifferboard
+   http://www.bifferos.com
+
+
+Kernel Configuration
+====================
+
+Add support for this CPU with CONFIG_X86_RDC321X.  Ensure that maths
+emulation is included (CONFIG_MATH_EMULATION selected) and avoid MCE
+(CONFIG_X86_MCE not selected).
+
+
+CPU detection
+=============
+
+None of these chips support the cpuid instruction, so as with some
+other x86 compatible SoCs, we must check the north bridge and look
+for specific 'signature' PCI device config.
+
+The current detection code has been tested only on the Bifferboard
+(S3282 CPU), please send bug reports or success stories with
+other devices to bifferos@yahoo.co.uk.
+
+
+Credits
+=======
+
+Many thanks to RDC for providing the customer codes to allow
+detection of all known variants, without which this detection code
+would have been very hard to ascertain.
+
+
+References
+==========
+
+[1] S3282 in certain NAS solutions consumes less than 1W
+
+
+mark@bifferos.com 2009
+
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1655b77..c4ebc76 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -382,6 +382,7 @@ config X86_RDC321X
 	bool "RDC R-321x SoC"
 	depends on X86_32
 	depends on X86_EXTENDED_PLATFORM
+	depends on PCI
 	select M486
 	select X86_REBOOTFIXUPS
 	---help---
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 2b03f70..75b96e9 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -122,7 +122,8 @@ struct cpuinfo_x86 {
 #define X86_VENDOR_CENTAUR	5
 #define X86_VENDOR_TRANSMETA	7
 #define X86_VENDOR_NSC		8
-#define X86_VENDOR_NUM		9
+#define X86_VENDOR_RDC		9
+#define X86_VENDOR_NUM		10

 #define X86_VENDOR_UNKNOWN	0xff

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 3efcb2b..55ba09a 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
 obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
 obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
 obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
+obj-$(CONFIG_X86_RDC321X)		+= rdc.o

 obj-$(CONFIG_PERF_COUNTERS)		+= perf_counter.o

diff --git a/arch/x86/kernel/cpu/rdc.c b/arch/x86/kernel/cpu/rdc.c
new file mode 100644
index 0000000..369a671
--- /dev/null
+++ b/arch/x86/kernel/cpu/rdc.c
@@ -0,0 +1,69 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * mark@bifferos.com
+ */
+
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include "cpu.h"
+
+
+static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
+{
+	u16 vendor, device;
+	u32 customer_id;
+
+	if (!early_pci_allowed())
+		return;
+
+	/* RDC CPU is SoC (system-on-chip), Northbridge is always present */
+	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
+	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
+
+	if (vendor != PCI_VENDOR_ID_RDC || device != PCI_DEVICE_ID_RDC_R6020)
+		return;  /* not RDC */
+	/*
+	 * NB: We could go on and check other devices, e.g. r6040 NIC, but
+	 * that's probably overkill
+	 */
+
+	customer_id = read_pci_config(0, 0, 0, 0x90);
+
+	switch (customer_id) {
+		/* id names are from RDC */
+	case 0x00321000:
+		strcpy(c->x86_model_id, "R3210/R3211");
+		break;
+	case 0x00321001:
+		strcpy(c->x86_model_id, "AMITRISC20000/20010");
+		break;
+	case 0x00321002:
+		strcpy(c->x86_model_id, "R3210X/Edimax");
+		break;
+	case 0x00321003:
+		strcpy(c->x86_model_id, "R3210/Kcodes");
+		break;
+	case 0x00321004:  /* tested */
+		strcpy(c->x86_model_id, "S3282/CodeTek");
+		break;
+	case 0x00321007:
+		strcpy(c->x86_model_id, "R8610");
+		break;
+	default:
+		pr_info("RDC CPU: Unrecognised Customer ID (0x%x) please report to linux-kernel@vger.kernel.org\n", customer_id);
+		return;
+	}
+
+	strcpy(c->x86_vendor_id, "RDC");
+	c->x86_vendor = X86_VENDOR_RDC;
+}
+
+static const struct cpu_dev __cpuinitconst rdc_cpu_dev = {
+	.c_vendor	= "RDC",
+	.c_ident	= { "RDC" },
+	.c_identify	= rdc_identify,
+	.c_x86_vendor	= X86_VENDOR_RDC,
+};
+
+cpu_dev_register(rdc_cpu_dev);

Re: [patch, v2] x86: CPU detection for RDC

[Florian Fainelli]

Hi Mark,

Le Monday 17 August 2009 09:13:58 Mark Kelly, vous avez écrit :
> On Mon, 17 Aug 2009, H. Peter Anvin wrote:
> > On 08/17/2009 02:31 PM, Andi Kleen wrote:
> > > I thought it was to prevent oopses for zero cpu according
> > > to the reporter?
> > >
> > > But these oopses should be probably separately fixed anyways.
> >
> > They should.
>
> Perhaps, but they don't need to be.  Unfortunately I was testing up to
> 2.6.30.5 (which gives the Oops), but someone must have changed the
> detection code for 486 in Linus' tree, because when I tried that (at
> Ingo's suggestion) I magically got a boot, and a correctly recognised
> 486 without my patch.  This does rather remove my reason for the patch
> submission, but I will carry on if people think this is still worthwhile.
>
> With the above in mind we can give up on detection without fear of a
> subsequent Oops, so I've simplified the code to not bother with
> the unrecognised variants (still gives a warning).
>
> I've added the PCI config dependency, and the runtime check.  I'll call
> this v2, please ignore all the previous patches.  It's against
> 2.6.31-rc6-tip.

Thanks for doing that.

>
> regards,
> Mark.
>
>
>
> Signed-off-by: Mark Kelly <mark@bifferos.com>

Acked-by: Florian Fainelli <florian@openwrt.org>

> diff --git a/Documentation/x86/rdc.txt b/Documentation/x86/rdc.txt
> new file mode 100644
> index 0000000..f9591af
> --- /dev/null
> +++ b/Documentation/x86/rdc.txt
> @@ -0,0 +1,69 @@
> +
> +Introduction
> +============
> +
> +RDC (http://www.rdc.com.tw) have been manufacturing x86-compatible SoC
> +(system-on-chips) for a number of years.  They are not the fastest of
> +CPUs (clock speeds ranging from 133-150MHz) but 486SX compatibility
> +coupled with very low power consumption[1] and low cost make them ideal
> +for embedded applications.
> +
> +
> +Where to find
> +=============
> +
> +RDC chips show up in numerous embedded devices, but be careful since
> +many of them will not run Linux 2.6 without significant expertise.
> +
> +There are several variants of what the linux kernel refers to generically
> +as RDC321X:  R8610, R321x, S3282 and AMRISC20000.
> +
> +R321x: Found in various routers, see the OpenWrt project for details,
> +   http://wiki.openwrt.org/oldwiki/rdcport
> +
> +R8610: Found on the RDC evaluation board
> +   http://www.ivankuten.com/system-on-chip-soc/rdc-r8610/
> +
> +AMRISC20000: Found in the MGB-100 wireless hard disk
> +   http://tintuc.no-ip.com/linux/tipps/mgb100/
> +
> +S3282: Found in various NAS devices, including the Bifferboard
> +   http://www.bifferos.com
> +
> +
> +Kernel Configuration
> +====================
> +
> +Add support for this CPU with CONFIG_X86_RDC321X.  Ensure that maths
> +emulation is included (CONFIG_MATH_EMULATION selected) and avoid MCE
> +(CONFIG_X86_MCE not selected).
> +
> +
> +CPU detection
> +=============
> +
> +None of these chips support the cpuid instruction, so as with some
> +other x86 compatible SoCs, we must check the north bridge and look
> +for specific 'signature' PCI device config.
> +
> +The current detection code has been tested only on the Bifferboard
> +(S3282 CPU), please send bug reports or success stories with
> +other devices to bifferos@yahoo.co.uk.
> +
> +
> +Credits
> +=======
> +
> +Many thanks to RDC for providing the customer codes to allow
> +detection of all known variants, without which this detection code
> +would have been very hard to ascertain.
> +
> +
> +References
> +==========
> +
> +[1] S3282 in certain NAS solutions consumes less than 1W
> +
> +
> +mark@bifferos.com 2009
> +
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 1655b77..5d2bcaa 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -382,6 +382,7 @@ config X86_RDC321X
>  	bool "RDC R-321x SoC"
>  	depends on X86_32
>  	depends on X86_EXTENDED_PLATFORM
> +	select PCI
>  	select M486
>  	select X86_REBOOTFIXUPS
>  	---help---
> diff --git a/arch/x86/include/asm/processor.h
> b/arch/x86/include/asm/processor.h index 2b03f70..75b96e9 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -122,7 +122,8 @@ struct cpuinfo_x86 {
>  #define X86_VENDOR_CENTAUR	5
>  #define X86_VENDOR_TRANSMETA	7
>  #define X86_VENDOR_NSC		8
> -#define X86_VENDOR_NUM		9
> +#define X86_VENDOR_RDC		9
> +#define X86_VENDOR_NUM		10
>
>  #define X86_VENDOR_UNKNOWN	0xff
>
> diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
> index 3efcb2b..55ba09a 100644
> --- a/arch/x86/kernel/cpu/Makefile
> +++ b/arch/x86/kernel/cpu/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
>  obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
>  obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o
>  obj-$(CONFIG_CPU_SUP_UMC_32)		+= umc.o
> +obj-$(CONFIG_X86_RDC321X)		+= rdc.o
>
>  obj-$(CONFIG_PERF_COUNTERS)		+= perf_counter.o
>
> diff --git a/arch/x86/kernel/cpu/rdc.c b/arch/x86/kernel/cpu/rdc.c
> new file mode 100644
> index 0000000..369a671
> --- /dev/null
> +++ b/arch/x86/kernel/cpu/rdc.c
> @@ -0,0 +1,69 @@
> +/*
> + * See Documentation/x86/rdc.txt
> + *
> + * mark@bifferos.com
> + */
> +
> +#include <linux/pci.h>
> +#include <asm/pci-direct.h>
> +#include "cpu.h"
> +
> +
> +static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
> +{
> +	u16 vendor, device;
> +	u32 customer_id;
> +
> +	if (!early_pci_allowed())
> +		return;
> +
> +	/* RDC CPU is SoC (system-on-chip), Northbridge is always present */
> +	vendor = read_pci_config_16(0, 0, 0, PCI_VENDOR_ID);
> +	device = read_pci_config_16(0, 0, 0, PCI_DEVICE_ID);
> +
> +	if (vendor != PCI_VENDOR_ID_RDC || device != PCI_DEVICE_ID_RDC_R6020)
> +		return;  /* not RDC */
> +	/*
> +	 * NB: We could go on and check other devices, e.g. r6040 NIC, but
> +	 * that's probably overkill
> +	 */
> +
> +	customer_id = read_pci_config(0, 0, 0, 0x90);
> +
> +	switch (customer_id) {
> +		/* id names are from RDC */
> +	case 0x00321000:
> +		strcpy(c->x86_model_id, "R3210/R3211");
> +		break;
> +	case 0x00321001:
> +		strcpy(c->x86_model_id, "AMITRISC20000/20010");
> +		break;
> +	case 0x00321002:
> +		strcpy(c->x86_model_id, "R3210X/Edimax");
> +		break;
> +	case 0x00321003:
> +		strcpy(c->x86_model_id, "R3210/Kcodes");
> +		break;
> +	case 0x00321004:  /* tested */
> +		strcpy(c->x86_model_id, "S3282/CodeTek");
> +		break;
> +	case 0x00321007:
> +		strcpy(c->x86_model_id, "R8610");
> +		break;
> +	default:
> +		pr_info("RDC CPU: Unrecognised Customer ID (0x%x) please report to
> linux-kernel@vger.kernel.org\n", customer_id); +		return;
> +	}
> +
> +	strcpy(c->x86_vendor_id, "RDC");
> +	c->x86_vendor = X86_VENDOR_RDC;
> +}
> +
> +static const struct cpu_dev __cpuinitconst rdc_cpu_dev = {
> +	.c_vendor	= "RDC",
> +	.c_ident	= { "RDC" },
> +	.c_identify	= rdc_identify,
> +	.c_x86_vendor	= X86_VENDOR_RDC,
> +};
> +
> +cpu_dev_register(rdc_cpu_dev);



-- 
Best regards, Florian Fainelli
Email: florian@openwrt.org
Web: http://openwrt.org
IRC: [florian] on irc.freenode.net
-------------------------------

Re: [patch, v2] x86: CPU detection for RDC

[Ingo Molnar]

* Mark Kelly <mark@bifferos.com> wrote:

> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -382,6 +382,7 @@ config X86_RDC321X
>  	bool "RDC R-321x SoC"
>  	depends on X86_32
>  	depends on X86_EXTENDED_PLATFORM
> +	select PCI
>  	select M486
>  	select X86_REBOOTFIXUPS

PCI is a complex interactive Kconfig switch and we dont select it 
in x86 code. Please add a 'depends on PCI' line instead, as i 
suggested in my mail.

	Ingo