Commit ddfe43cd authored by Yazen Ghannam's avatar Yazen Ghannam Committed by Thomas Gleixner
Browse files

x86/amd_nb: Add SMN and Indirect Data Fabric access for AMD Fam17h 



Some devices on Fam17h can only be accessed through the System Management
Network (SMN). The SMN is accessed by a pair of index/data registers in PCI
config space. Add a pair of functions to read from and write to the SMN.

The Data Fabric on Fam17h allows multiple devices to use the same register
space. The registers of a specific device are accessed indirectly using the
device's DF InstanceId. Currently, we only need to read from these devices,
so only define a read function for now.

Signed-off-by: default avatarYazen Ghannam <Yazen.Ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/1478812257-5424-5-git-send-email-Yazen.Ghannam@amd.com


[ Boris: make __amd_smn_rw() even more compact. ]
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent b791c6b6

arch/x86/include/asm/amd_nb.h

+5 −0
Original line number Diff line number Diff line
@@ -21,6 +21,10 @@ extern int amd_numa_init(void); 
extern int amd_get_subcaches(int);

extern int amd_set_subcaches(int, unsigned long);



extern int amd_smn_read(u16 node, u32 address, u32 *value);

extern int amd_smn_write(u16 node, u32 address, u32 value);

extern int amd_df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo);



struct amd_l3_cache {

	unsigned indices;

	u8	 subcaches[4];
@@ -55,6 +59,7 @@ struct threshold_bank { 
};



struct amd_northbridge {

	struct pci_dev *root;

	struct pci_dev *misc;

	struct pci_dev *link;

	struct amd_l3_cache l3_cache;

arch/x86/kernel/amd_nb.c

+106 −2
Original line number Diff line number Diff line
@@ -13,11 +13,20 @@ 
#include <linux/spinlock.h>

#include <asm/amd_nb.h>



#define PCI_DEVICE_ID_AMD_17H_ROOT	0x1450

#define PCI_DEVICE_ID_AMD_17H_DF_F3	0x1463

#define PCI_DEVICE_ID_AMD_17H_DF_F4	0x1464



/* Protect the PCI config register pairs used for SMN and DF indirect access. */

static DEFINE_MUTEX(smn_mutex);



static u32 *flush_words;



static const struct pci_device_id amd_root_ids[] = {

	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_ROOT) },

	{}

};



const struct pci_device_id amd_nb_misc_ids[] = {

	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },

	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
@@ -80,11 +89,104 @@ static struct pci_dev *next_northbridge(struct pci_dev *dev, 
	return dev;

}



static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write)

{

	struct pci_dev *root;

	int err = -ENODEV;



	if (node >= amd_northbridges.num)

		goto out;



	root = node_to_amd_nb(node)->root;

	if (!root)

		goto out;



	mutex_lock(&smn_mutex);



	err = pci_write_config_dword(root, 0x60, address);

	if (err) {

		pr_warn("Error programming SMN address 0x%x.\n", address);

		goto out_unlock;

	}



	err = (write ? pci_write_config_dword(root, 0x64, *value)

		     : pci_read_config_dword(root, 0x64, value));

	if (err)

		pr_warn("Error %s SMN address 0x%x.\n",

			(write ? "writing to" : "reading from"), address);



out_unlock:

	mutex_unlock(&smn_mutex);



out:

	return err;

}



int amd_smn_read(u16 node, u32 address, u32 *value)

{

	return __amd_smn_rw(node, address, value, false);

}

EXPORT_SYMBOL_GPL(amd_smn_read);



int amd_smn_write(u16 node, u32 address, u32 value)

{

	return __amd_smn_rw(node, address, &value, true);

}

EXPORT_SYMBOL_GPL(amd_smn_write);



/*

 * Data Fabric Indirect Access uses FICAA/FICAD.

 *

 * Fabric Indirect Configuration Access Address (FICAA): Constructed based

 * on the device's Instance Id and the PCI function and register offset of

 * the desired register.

 *

 * Fabric Indirect Configuration Access Data (FICAD): There are FICAD LO

 * and FICAD HI registers but so far we only need the LO register.

 */

int amd_df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)

{

	struct pci_dev *F4;

	u32 ficaa;

	int err = -ENODEV;



	if (node >= amd_northbridges.num)

		goto out;



	F4 = node_to_amd_nb(node)->link;

	if (!F4)

		goto out;



	ficaa  = 1;

	ficaa |= reg & 0x3FC;

	ficaa |= (func & 0x7) << 11;

	ficaa |= instance_id << 16;



	mutex_lock(&smn_mutex);



	err = pci_write_config_dword(F4, 0x5C, ficaa);

	if (err) {

		pr_warn("Error writing DF Indirect FICAA, FICAA=0x%x\n", ficaa);

		goto out_unlock;

	}



	err = pci_read_config_dword(F4, 0x98, lo);

	if (err)

		pr_warn("Error reading DF Indirect FICAD LO, FICAA=0x%x.\n", ficaa);



out_unlock:

	mutex_unlock(&smn_mutex);



out:

	return err;

}

EXPORT_SYMBOL_GPL(amd_df_indirect_read);



int amd_cache_northbridges(void)

{

	u16 i = 0;

	struct amd_northbridge *nb;

	struct pci_dev *misc, *link;

	struct pci_dev *root, *misc, *link;



	if (amd_northbridges.num)

		return 0;
@@ -103,8 +205,10 @@ int amd_cache_northbridges(void) 
	amd_northbridges.nb = nb;

	amd_northbridges.num = i;



	link = misc = NULL;

	link = misc = root = NULL;

	for (i = 0; i != amd_northbridges.num; i++) {

		node_to_amd_nb(i)->root = root =

			next_northbridge(root, amd_root_ids);

		node_to_amd_nb(i)->misc = misc =

			next_northbridge(misc, amd_nb_misc_ids);

		node_to_amd_nb(i)->link = link =

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