1 files changed, 36 insertions, 8 deletions

diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index 6a93bfbcd826..9b9e89fd02cc 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -531,6 +531,14 @@ struct cxl_process_element {
 	__be32 software_state;
 } __packed;
 
+static inline bool cxl_adapter_link_ok(struct cxl *cxl)
+{
+	struct pci_dev *pdev;
+
+	pdev = to_pci_dev(cxl->dev.parent);
+	return !pci_channel_offline(pdev);
+}
+
 static inline void __iomem *_cxl_p1_addr(struct cxl *cxl, cxl_p1_reg_t reg)
 {
 	WARN_ON(!cpu_has_feature(CPU_FTR_HVMODE));
@@ -539,12 +547,16 @@ static inline void __iomem *_cxl_p1_addr(struct cxl *cxl, cxl_p1_reg_t reg)
 
 static inline void cxl_p1_write(struct cxl *cxl, cxl_p1_reg_t reg, u64 val)
 {
-	out_be64(_cxl_p1_addr(cxl, reg), val);
+	if (likely(cxl_adapter_link_ok(cxl)))
+		out_be64(_cxl_p1_addr(cxl, reg), val);
 }
 
 static inline u64 cxl_p1_read(struct cxl *cxl, cxl_p1_reg_t reg)
 {
-	return in_be64(_cxl_p1_addr(cxl, reg));
+	if (likely(cxl_adapter_link_ok(cxl)))
+		return in_be64(_cxl_p1_addr(cxl, reg));
+	else
+		return ~0ULL;
 }
 
 static inline void __iomem *_cxl_p1n_addr(struct cxl_afu *afu, cxl_p1n_reg_t reg)
@@ -555,12 +567,16 @@ static inline void __iomem *_cxl_p1n_addr(struct cxl_afu *afu, cxl_p1n_reg_t reg
 
 static inline void cxl_p1n_write(struct cxl_afu *afu, cxl_p1n_reg_t reg, u64 val)
 {
-	out_be64(_cxl_p1n_addr(afu, reg), val);
+	if (likely(cxl_adapter_link_ok(afu->adapter)))
+		out_be64(_cxl_p1n_addr(afu, reg), val);
 }
 
 static inline u64 cxl_p1n_read(struct cxl_afu *afu, cxl_p1n_reg_t reg)
 {
-	return in_be64(_cxl_p1n_addr(afu, reg));
+	if (likely(cxl_adapter_link_ok(afu->adapter)))
+		return in_be64(_cxl_p1n_addr(afu, reg));
+	else
+		return ~0ULL;
 }
 
 static inline void __iomem *_cxl_p2n_addr(struct cxl_afu *afu, cxl_p2n_reg_t reg)
@@ -570,22 +586,34 @@ static inline void __iomem *_cxl_p2n_addr(struct cxl_afu *afu, cxl_p2n_reg_t reg
 
 static inline void cxl_p2n_write(struct cxl_afu *afu, cxl_p2n_reg_t reg, u64 val)
 {
-	out_be64(_cxl_p2n_addr(afu, reg), val);
+	if (likely(cxl_adapter_link_ok(afu->adapter)))
+		out_be64(_cxl_p2n_addr(afu, reg), val);
 }
 
 static inline u64 cxl_p2n_read(struct cxl_afu *afu, cxl_p2n_reg_t reg)
 {
-	return in_be64(_cxl_p2n_addr(afu, reg));
+	if (likely(cxl_adapter_link_ok(afu->adapter)))
+		return in_be64(_cxl_p2n_addr(afu, reg));
+	else
+		return ~0ULL;
 }
 
 static inline u64 cxl_afu_cr_read64(struct cxl_afu *afu, int cr, u64 off)
 {
-	return in_le64((afu)->afu_desc_mmio + (afu)->crs_offset + ((cr) * (afu)->crs_len) + (off));
+	if (likely(cxl_adapter_link_ok(afu->adapter)))
+		return in_le64((afu)->afu_desc_mmio + (afu)->crs_offset +
+			       ((cr) * (afu)->crs_len) + (off));
+	else
+		return ~0ULL;
 }
 
 static inline u32 cxl_afu_cr_read32(struct cxl_afu *afu, int cr, u64 off)
 {
-	return in_le32((afu)->afu_desc_mmio + (afu)->crs_offset + ((cr) * (afu)->crs_len) + (off));
+	if (likely(cxl_adapter_link_ok(afu->adapter)))
+		return in_le32((afu)->afu_desc_mmio + (afu)->crs_offset +
+			       ((cr) * (afu)->crs_len) + (off));
+	else
+		return 0xffffffff;
 }
 u16 cxl_afu_cr_read16(struct cxl_afu *afu, int cr, u64 off);
 u8 cxl_afu_cr_read8(struct cxl_afu *afu, int cr, u64 off);