cxl: Introduce implementation-specific API

The backend API (in cxl.h) lists some low-level functions whose
implementation is different on bare-metal and in a guest. Each
environment implements its own functions, and the common code uses
them through function pointers, defined in cxl_backend_ops

Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 21 insertions, 11 deletions

diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c
index 02006f7109a8..300eafe4ed43 100644
--- a/drivers/misc/cxl/sysfs.c
+++ b/drivers/misc/cxl/sysfs.c
@@ -69,7 +69,7 @@ static ssize_t reset_adapter_store(struct device *device,
         if ((rc != 1) || (val != 1))
                 return -EINVAL;
 
-        if ((rc = cxl_reset(adapter)))
+        if ((rc = cxl_ops->adapter_reset(adapter)))
                 return rc;
         return count;
 }
@@ -211,7 +211,7 @@ static ssize_t reset_store_afu(struct device *device,
                 goto err;
         }
 
-        if ((rc = __cxl_afu_reset(afu)))
+        if ((rc = cxl_ops->afu_reset(afu)))
                 goto err;
 
         rc = count;
@@ -348,7 +348,7 @@ static ssize_t mode_store(struct device *device, struct device_attribute *attr,
         }
 
         /*
-         * cxl_afu_deactivate_mode needs to be done outside the lock, prevent
+         * afu_deactivate_mode needs to be done outside the lock, prevent
          * other contexts coming in before we are ready:
          */
         old_mode = afu->current_mode;
@@ -357,9 +357,9 @@ static ssize_t mode_store(struct device *device, struct device_attribute *attr,
 
         mutex_unlock(&afu->contexts_lock);
 
-        if ((rc = _cxl_afu_deactivate_mode(afu, old_mode)))
+        if ((rc = cxl_ops->afu_deactivate_mode(afu, old_mode)))
                 return rc;
-        if ((rc = cxl_afu_activate_mode(afu, mode)))
+        if ((rc = cxl_ops->afu_activate_mode(afu, mode)))
                 return rc;
 
         return count;
@@ -389,7 +389,7 @@ static ssize_t afu_eb_read(struct file *filp, struct kobject *kobj,
         struct cxl_afu *afu = to_cxl_afu(container_of(kobj,
                                                       struct device, kobj));
 
-        return cxl_afu_read_err_buffer(afu, buf, off, count);
+        return cxl_ops->afu_read_err_buffer(afu, buf, off, count);
 }
 
 static struct device_attribute afu_attrs[] = {
@@ -469,10 +469,12 @@ static ssize_t afu_read_config(struct file *filp, struct kobject *kobj,
         struct afu_config_record *cr = to_cr(kobj);
         struct cxl_afu *afu = to_cxl_afu(container_of(kobj->parent, struct device, kobj));
 
-        u64 i, j, val;
+        u64 i, j, val, rc;
 
         for (i = 0; i < count;) {
-                val = cxl_afu_cr_read64(afu, cr->cr, off & ~0x7);
+                rc = cxl_ops->afu_cr_read64(afu, cr->cr, off & ~0x7, &val);
+                if (rc)
+                        val = ~0ULL;
                 for (j = off & 0x7; j < 8 && i < count; i++, j++, off++)
                         buf[i] = (val >> (j * 8)) & 0xff;
         }
@@ -517,9 +519,17 @@ static struct afu_config_record *cxl_sysfs_afu_new_cr(struct cxl_afu *afu, int c
                 return ERR_PTR(-ENOMEM);
 
         cr->cr = cr_idx;
-        cr->device = cxl_afu_cr_read16(afu, cr_idx, PCI_DEVICE_ID);
-        cr->vendor = cxl_afu_cr_read16(afu, cr_idx, PCI_VENDOR_ID);
-        cr->class = cxl_afu_cr_read32(afu, cr_idx, PCI_CLASS_REVISION) >> 8;
+
+        rc = cxl_ops->afu_cr_read16(afu, cr_idx, PCI_DEVICE_ID, &cr->device);
+        if (rc)
+                goto err;
+        rc = cxl_ops->afu_cr_read16(afu, cr_idx, PCI_VENDOR_ID, &cr->vendor);
+        if (rc)
+                goto err;
+        rc = cxl_ops->afu_cr_read32(afu, cr_idx, PCI_CLASS_REVISION, &cr->class);
+        if (rc)
+                goto err;
+        cr->class >>= 8;
 
         /*
          * Export raw AFU PCIe like config record. For now this is read only by