x86: CPU detection for RDC System-on-Chip

Quoted 6 lines

(quoted diff) +6 -0

+	case 0x00321004:  /* tested */
+		strcpy(c->x86_model_id, "S3282/CodeTek");
+		break;
+	case 0x00321007:
+		strcpy(c->x86_model_id, "R8610");
+		break;

Review

Quoted 4 lines

(quoted diff) +4 -0

+	default:
+		pr_info("RDC CPU: Unrecognised Customer ID (0x%x) please "
+			"report to: [email protected]\n",
+			customer_id);

Surely this should be a break as you want to set the vendor. You've established its an RDC at this point have you not - so you want to set x86_vendor.

arch/x86/kernel/cpu/rdc.c new file +47 -0

new file mode 100644
index 0000000..909c2b5
@@ -0,0 +1,71 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * [email protected]
+ */
+
+#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 */

arch/x86/kernel/cpu/rdc.c new file +4 -0

+	}
+
+	strcpy(c->x86_vendor_id, "RDC");
+	c->x86_vendor = X86_VENDOR_RDC;

Quoted 61 lines · Florian Fainelli

arch/x86/kernel/cpu/rdc.c new file +55 -0

new file mode 100644
index 0000000..909c2b5
@@ -0,0 +1,71 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * [email protected]
+ */
+
+#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: [email protected]\n",

arch/x86/kernel/cpu/rdc.c line 57

Quoted 2 lines

arch/x86/kernel/cpu/rdc.c new file +2 -0

+			customer_id);
+		break;

This pr_info() is completely useless... reporting things to LKML is very likely to get lost in the din. If someone (like yourself) wants to be the maintainer for it that's one thing, otherwise it's probably better to tell them to file a bugzilla... or just report it as "unknown" like we do for all other CPU vendors.

Quoted 5 lines

arch/x86/kernel/cpu/rdc.c new file +4 -0

+	}
+
+	strcpy(c->x86_vendor_id, "RDC");
+	c->x86_vendor = X86_VENDOR_RDC;

arch/x86/kernel/cpu/rdc.c line 71

Quoted 10 lines

arch/x86/kernel/cpu/rdc.c new file +10 -0

+}
+
+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);

.c_ident here is bogus: c_ident is supposed to represent the CPUID string, but this device apparently doesn't have CPUID.

This adds at least one PCI reference to every boot on every device. As such, at least please read vendor and device as a single 32-bit reference. Since this identification isn't actually used for any real purpose (like workarounds) we could also set it up as a PCI quirk... but it's probably better to just keep the same code flow.

Quoted 22 lines · Florian Fainelli

arch/x86/kernel/cpu/rdc.c new file +16 -0

new file mode 100644
index 0000000..909c2b5
@@ -0,0 +1,71 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * [email protected]
+ */
+
+#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;
+

arch/x86/kernel/cpu/rdc.c

Quoted 8 lines

arch/x86/kernel/cpu/rdc.c new file +8 -0

+	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 != 

Quoted 23 lines

arch/x86/kernel/cpu/rdc.c new file +23 -0

+		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 */

arch/x86/kernel/cpu/rdc.c line 57

Quoted 10 lines

arch/x86/kernel/cpu/rdc.c new file +10 -0

+		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: [email protected]\n",
+			customer_id);
+		break;

This pr_info() is completely useless... reporting things to LKML is very likely to get lost in the din. If someone (like yourself) wants to be the maintainer for it that's one thing, otherwise it's probably better to tell them to file a bugzilla... or just report it as "unknown" like we do for all other CPU vendors.

Quoted 9 lines

arch/x86/kernel/cpu/rdc.c new file +9 -0

+	}
+
+	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" },

arch/x86/kernel/cpu/rdc.c line 71

Quoted 5 lines

arch/x86/kernel/cpu/rdc.c new file +5 -0

+	.c_identify	= rdc_identify,
+	.c_x86_vendor	= X86_VENDOR_RDC,
+};
+
+cpu_dev_register(rdc_cpu_dev);

.c_ident here is bogus: c_ident is supposed to represent the CPUID string, but this device apparently doesn't have CPUID.

This adds at least one PCI reference to every boot on every device. As such, at least please read vendor and device as a single 32-bit reference. Since this identification isn't actually used for any real purpose (like workarounds) we could also set it up as a PCI quirk... but it's probably better to just keep the same code flow.

-hpa

From: Mark Kelly <[email protected]>

The RDC System-on-Chip i486 compatible core does not support the cpuid instruction and specific detection logic is required for this chip. The patch below adds proper vendor and SoC type detection.

Signed-off-by Mark Kelly <[email protected]>

Tested-by Florian Fainelli <[email protected]>

---
Changes from v3:
- read vendor and device id with a single 32-bits read

Changes from v2:
- change report url to bugzilla.kernel.org
- set vendor name to RDC even if customer id is not known

Documentation/x86/rdc.txt new file +67 -0

new file mode 100644
index 0000000..f3dc7cf
@@ -0,0 +1,67 @@
+
+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.
+
+If you run a kernel on an unsupported customer id device, please file
+a bug with your customer id to: http://bugzilla.kernel.org/.
+
+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
+
+
[email protected] 2009
+

arch/x86/Kconfig +1 -0

index 39e8e10..21b02f2 100644
@@ -419,6 +419,7 @@ 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---

(quoted diff) +0 -0

b/arch/x86/include/asm/processor.h index 5a51379..eddf979 100644

arch/x86/include/asm/processor.h +2 -1

@@ -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
 

arch/x86/kernel/cpu/Makefile +1 -0

index 3a785da..af2d4a6 100644
@@ -25,6 +25,7 @@ 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_EVENTS)		+= perf_event.o
 

arch/x86/kernel/cpu/rdc.c new file +73 -0

new file mode 100644
index 0000000..c2bcdcc
@@ -0,0 +1,73 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * [email protected]
+ */
+
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include "cpu.h"
+
+
+static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
+{
+	u32 id;
+	u16 vendor, device;
+	u32 customer_id;
+
+	if (!early_pci_allowed())
+		return;
+
+	/* RDC CPU is SoC (system-on-chip), Northbridge is always present */
+	id = read_pci_config(0, 0, 0, PCI_VENDOR_ID);
+	vendor = id & 0xffff;
+	device = (id >> 16) & 0xffff;
+
+	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: http://bugzilla.kernel.org/\n",
+			customer_id);
+		break;
+	}
+
+	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);

Quoted 5 lines · On Wednesday 19 May 2010 09:27:12 Florian Fainelli wrote:

From: Mark Kelly <[email protected]>

The RDC System-on-Chip i486 compatible core does not support the cpuid instruction and specific detection logic is required for this chip. The patch below adds proper vendor and SoC type detection.

Is this version acceptable like it is now?

Thank you for your answer.

Quoted 153 lines

Signed-off-by Mark Kelly <[email protected]>

Tested-by Florian Fainelli <[email protected]>

---
Changes from v3:
- read vendor and device id with a single 32-bits read

Changes from v2:
- change report url to bugzilla.kernel.org
- set vendor name to RDC even if customer id is not known

Documentation/x86/rdc.txt new file +18 -0

new file mode 100644
index 0000000..f3dc7cf
@@ -0,0 +1,67 @@
+
+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.

Documentation/x86/rdc.txt new file +48 -0

+
+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.
+
+If you run a kernel on an unsupported customer id device, please file
+a bug with your customer id to: http://bugzilla.kernel.org/.
+
+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
+
+
[email protected] 2009
+

arch/x86/Kconfig +1 -0

index 39e8e10..21b02f2 100644
@@ -419,6 +419,7 @@ config X86_RDC321X
 
 	bool "RDC R-321x SoC"
 	depends on X86_32
 	depends on X86_EXTENDED_PLATFORM
 
+	select PCI
 

arch/x86/Kconfig +0 -0

 	select M486
 	select X86_REBOOTFIXUPS
 	---help---

(quoted diff) +0 -0

b/arch/x86/include/asm/processor.h index 5a51379..eddf979 100644

arch/x86/include/asm/processor.h +2 -1

@@ -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

arch/x86/kernel/cpu/Makefile +1 -0

index 3a785da..af2d4a6 100644
@@ -25,6 +25,7 @@ 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_EVENTS) += perf_event.o

arch/x86/kernel/cpu/rdc.c new file +18 -0

new file mode 100644
index 0000000..c2bcdcc
@@ -0,0 +1,73 @@
+/*
+ * See Documentation/x86/rdc.txt
+ *
+ * [email protected]
+ */
+
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include "cpu.h"
+
+
+static void __cpuinit rdc_identify(struct cpuinfo_x86 *c)
+{
+	u32 id;
+	u16 vendor, device;
+	u32 customer_id;
+
+	if (!early_pci_allowed())

arch/x86/kernel/cpu/rdc.c

Quoted 8 lines

arch/x86/kernel/cpu/rdc.c new file +8 -0

+		return;
+
+	/* RDC CPU is SoC (system-on-chip), Northbridge is always present */
+	id = read_pci_config(0, 0, 0, PCI_VENDOR_ID);
+	vendor = id & 0xffff;
+	device = (id >> 16) & 0xffff;
+
+	if (vendor != PCI_VENDOR_ID_RDC || device != 

Quoted 47 lines

arch/x86/kernel/cpu/rdc.c new file +47 -0

+		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: http://bugzilla.kernel.org/\n",
+			customer_id);
+		break;
+	}
+
+	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);

Quoted 10 lines

arch/x86/Kconfig +0 -0

index 39e8e10..21b02f2 100644
@@ -419,6 +419,7 @@ config X86_RDC321X
 
 	bool "RDC R-321x SoC"
 	depends on X86_32
 	depends on X86_EXTENDED_PLATFORM
 

arch/x86/Kconfig config X86_RDC321X · line 422

Quoted 1 line

arch/x86/Kconfig +1 -0

+	select PCI

If you don't actually need PCI in your SOC then you could easily remove that dependency with some minor work. Early PCI really is quite independent from the other code and can be just used on its own.

The only thing that would need sorting out is the command line interface for early_pci_enabled()

-Andi
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