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

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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: Philippe Bergheaud <felix@linux.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200619140439.153962-1-fbarrat@linux.ibm.com
This commit is contained in:
Philippe Bergheaud 2020-06-19 16:04:39 +02:00 committed by Michael Ellerman
parent acccc984c1
commit 87db7579eb
5 changed files with 129 additions and 5 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

11
Documentation/ABI/testing/sysfs-class-ocxl
View file

@ -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

81
drivers/misc/ocxl/config.c
View file

@ -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;
}

6
drivers/misc/ocxl/ocxl_internal.h
View file

@ -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.
*

35
drivers/misc/ocxl/sysfs.c
View file

@ -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,

1
include/misc/ocxl-config.h
View file

@ -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_ */