cxl: Export optional AFU configuration record in sysfs
An AFU may optionally contain one or more PCIe like configuration
records, which can be used to identify the AFU.
This patch adds support for exposing the raw config space and the
vendor, device and class code under sysfs. These will appear in a
subdirectory of the AFU device corresponding with the configuration
record number, e.g.
cat /sys/class/cxl/afu0.0/cr0/vendor
0x1014
cat /sys/class/cxl/afu0.0/cr0/device
0x4350
cat /sys/class/cxl/afu0.0/cr0/class
0x120000
hexdump -C /sys/class/cxl/afu0.0/cr0/config
00000000 14 10 50 43 00 00 00 00 06 00 00 12 00 00 00 00 |..PC............|
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000100
These files behave in much the same way as the equivalent files for PCI
devices, with one exception being that the config file is currently
read-only and restricted to the root user. It is not necessarily
required to be this strict, but we currently do not have a compelling
use-case to make it writable and/or world-readable, so I erred on the
side of being restrictive.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index cb25067..2b2e1b8 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -114,6 +114,24 @@
#define AFUD_EB_LEN(val) EXTRACT_PPC_BITS(val, 8, 63)
#define AFUD_READ_EB_OFF(afu) AFUD_READ(afu, 0x48)
+u16 cxl_afu_cr_read16(struct cxl_afu *afu, int cr, u64 off)
+{
+ u64 aligned_off = off & ~0x3L;
+ u32 val;
+
+ val = cxl_afu_cr_read32(afu, cr, aligned_off);
+ return (val >> ((off & 0x2) * 8)) & 0xffff;
+}
+
+u8 cxl_afu_cr_read8(struct cxl_afu *afu, int cr, u64 off)
+{
+ u64 aligned_off = off & ~0x3L;
+ u32 val;
+
+ val = cxl_afu_cr_read32(afu, cr, aligned_off);
+ return (val >> ((off & 0x3) * 8)) & 0xff;
+}
+
static DEFINE_PCI_DEVICE_TABLE(cxl_pci_tbl) = {
{ PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0477), },
{ PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x044b), },
@@ -556,6 +574,7 @@
val = AFUD_READ_INFO(afu);
afu->pp_irqs = AFUD_NUM_INTS_PER_PROC(val);
afu->max_procs_virtualised = AFUD_NUM_PROCS(val);
+ afu->crs_num = AFUD_NUM_CRS(val);
if (AFUD_AFU_DIRECTED(val))
afu->modes_supported |= CXL_MODE_DIRECTED;
@@ -570,6 +589,10 @@
if ((afu->pp_psa = AFUD_PPPSA_PP(val)))
afu->pp_offset = AFUD_READ_PPPSA_OFF(afu);
+ val = AFUD_READ_CR(afu);
+ afu->crs_len = AFUD_CR_LEN(val) * 256;
+ afu->crs_offset = AFUD_READ_CR_OFF(afu);
+
return 0;
}