Commit 87db7579 authored by Philippe Bergheaud's avatar Philippe Bergheaud Committed by Michael Ellerman
Browse files

ocxl: control via sysfs whether the FPGA is reloaded on a link reset 



Some opencapi FPGA images allow to control if the FPGA should be reloaded
on the next adapter reset. If it is supported, the image specifies it
through a Vendor Specific DVSEC in the config space of function 0.

Signed-off-by: default avatarPhilippe Bergheaud <felix@linux.ibm.com>
Signed-off-by: default avatarFrederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: default avatarAndrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200619140439.153962-1-fbarrat@linux.ibm.com
parent acccc984

Documentation/ABI/testing/sysfs-class-ocxl

+11 −0
Original line number Diff line number Diff line
@@ -33,3 +33,14 @@ Date: January 2018 
Contact:	linuxppc-dev@lists.ozlabs.org

Description:	read/write

		Give access the global mmio area for the AFU



What:		/sys/class/ocxl/<afu name>/reload_on_reset

Date:		February 2020

Contact:	linuxppc-dev@lists.ozlabs.org

Description:	read/write

		Control whether the FPGA is reloaded on a link reset. Enabled

		through a vendor-specific logic block on the FPGA.

			0	Do not reload FPGA image from flash

			1	Reload FPGA image from flash

			unavailable

				The device does not support this capability

drivers/misc/ocxl/config.c

+76 −5
Original line number Diff line number Diff line
@@ -71,6 +71,20 @@ static int find_dvsec_afu_ctrl(struct pci_dev *dev, u8 afu_idx) 
	return 0;

}



/**

 * get_function_0() - Find a related PCI device (function 0)

 * @device: PCI device to match

 *

 * Returns a pointer to the related device, or null if not found

 */

static struct pci_dev *get_function_0(struct pci_dev *dev)

{

	unsigned int devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0);



	return pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),

					   dev->bus->number, devfn);

}



static void read_pasid(struct pci_dev *dev, struct ocxl_fn_config *fn)

{

	u16 val;
@@ -159,14 +173,15 @@ static int read_dvsec_afu_info(struct pci_dev *dev, struct ocxl_fn_config *fn) 
static int read_dvsec_vendor(struct pci_dev *dev)

{

	int pos;

	u32 cfg, tlx, dlx;

	u32 cfg, tlx, dlx, reset_reload;



	/*

	 * vendor specific DVSEC is optional

	 * vendor specific DVSEC, for IBM images only. Some older

	 * images may not have it

	 *

	 * It's currently only used on function 0 to specify the

	 * version of some logic blocks. Some older images may not

	 * even have it so we ignore any errors

	 * It's only used on function 0 to specify the version of some

	 * logic blocks and to give access to special registers to

	 * enable host-based flashing.

	 */

	if (PCI_FUNC(dev->devfn) != 0)

		return 0;
@@ -178,11 +193,67 @@ static int read_dvsec_vendor(struct pci_dev *dev) 
	pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_CFG_VERS, &cfg);

	pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_TLX_VERS, &tlx);

	pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_DLX_VERS, &dlx);

	pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,

			      &reset_reload);



	dev_dbg(&dev->dev, "Vendor specific DVSEC:\n");

	dev_dbg(&dev->dev, "  CFG version = 0x%x\n", cfg);

	dev_dbg(&dev->dev, "  TLX version = 0x%x\n", tlx);

	dev_dbg(&dev->dev, "  DLX version = 0x%x\n", dlx);

	dev_dbg(&dev->dev, "  ResetReload = 0x%x\n", reset_reload);

	return 0;

}



static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0,

			     int *out_pos)

{

	int pos;



	if (PCI_FUNC(dev->devfn) != 0) {

		dev = get_function_0(dev);

		if (!dev)

			return -1;

	}

	pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID);

	if (!pos)

		return -1;

	*dev0 = dev;

	*out_pos = pos;

	return 0;

}



int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val)

{

	struct pci_dev *dev0;

	u32 reset_reload;

	int pos;



	if (get_dvsec_vendor0(dev, &dev0, &pos))

		return -1;



	pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,

			      &reset_reload);

	*val = !!(reset_reload & BIT(0));

	return 0;

}



int ocxl_config_set_reset_reload(struct pci_dev *dev, int val)

{

	struct pci_dev *dev0;

	u32 reset_reload;

	int pos;



	if (get_dvsec_vendor0(dev, &dev0, &pos))

		return -1;



	pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,

			      &reset_reload);

	if (val)

		reset_reload |= BIT(0);

	else

		reset_reload &= ~BIT(0);

	pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,

			       reset_reload);

	return 0;

}

drivers/misc/ocxl/ocxl_internal.h

+6 −0
Original line number Diff line number Diff line
@@ -112,6 +112,12 @@ void ocxl_actag_afu_free(struct ocxl_fn *fn, u32 start, u32 size); 
 */

int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count);



/*

 * Control whether the FPGA is reloaded on a link reset

 */

int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val);

int ocxl_config_set_reset_reload(struct pci_dev *dev, int val);



/*

 * Check if an AFU index is valid for the given function.

 *

drivers/misc/ocxl/sysfs.c

+35 −0
Original line number Diff line number Diff line
@@ -51,11 +51,46 @@ static ssize_t contexts_show(struct device *device, 
			afu->pasid_count, afu->pasid_max);

}



static ssize_t reload_on_reset_show(struct device *device,

				    struct device_attribute *attr,

				    char *buf)

{

	struct ocxl_afu *afu = to_afu(device);

	struct ocxl_fn *fn = afu->fn;

	struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent);

	int val;



	if (ocxl_config_get_reset_reload(pci_dev, &val))

		return scnprintf(buf, PAGE_SIZE, "unavailable\n");



	return scnprintf(buf, PAGE_SIZE, "%d\n", val);

}



static ssize_t reload_on_reset_store(struct device *device,

				     struct device_attribute *attr,

				     const char *buf, size_t count)

{

	struct ocxl_afu *afu = to_afu(device);

	struct ocxl_fn *fn = afu->fn;

	struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent);

	int rc, val;



	rc = kstrtoint(buf, 0, &val);

	if (rc || (val != 0 && val != 1))

		return -EINVAL;



	if (ocxl_config_set_reset_reload(pci_dev, val))

		return -ENODEV;



	return count;

}



static struct device_attribute afu_attrs[] = {

	__ATTR_RO(global_mmio_size),

	__ATTR_RO(pp_mmio_size),

	__ATTR_RO(afu_version),

	__ATTR_RO(contexts),

	__ATTR_RW(reload_on_reset),

};



static ssize_t global_mmio_read(struct file *filp, struct kobject *kobj,

include/misc/ocxl-config.h

+1 −0
Original line number Diff line number Diff line
@@ -41,5 +41,6 @@ 
#define   OCXL_DVSEC_VENDOR_CFG_VERS            0x0C

#define   OCXL_DVSEC_VENDOR_TLX_VERS            0x10

#define   OCXL_DVSEC_VENDOR_DLX_VERS            0x20

#define   OCXL_DVSEC_VENDOR_RESET_RELOAD        0x38



#endif /* _OCXL_CONFIG_H_ */