Re: [PATCH v2 3/9] ntb: intel: Constify ioreadX() iomem argument (as in generic implementation)

From: Dave Jiang
Date: Wed Jan 08 2020 - 15:29:14 EST




On 1/8/20 1:05 PM, Krzysztof Kozlowski wrote:
The ioreadX() helpers have inconsistent interface. On some architectures
void *__iomem address argument is a pointer to const, on some not.

Implementations of ioreadX() do not modify the memory under the address
so they can be converted to a "const" version for const-safety and
consistency among architectures.

Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Acked-by: Dave Jiang <dave.jiang@xxxxxxxxx>


---

Changes since v1:
1. Add Geert's review.
---
drivers/ntb/hw/intel/ntb_hw_gen1.c | 2 +-
drivers/ntb/hw/intel/ntb_hw_gen3.h | 2 +-
drivers/ntb/hw/intel/ntb_hw_intel.h | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/ntb/hw/intel/ntb_hw_gen1.c b/drivers/ntb/hw/intel/ntb_hw_gen1.c
index bb57ec239029..9202502a9787 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen1.c
+++ b/drivers/ntb/hw/intel/ntb_hw_gen1.c
@@ -1202,7 +1202,7 @@ int intel_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx, int sidx,
ndev->peer_reg->spad);
}
-static u64 xeon_db_ioread(void __iomem *mmio)
+static u64 xeon_db_ioread(const void __iomem *mmio)
{
return (u64)ioread16(mmio);
}
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen3.h b/drivers/ntb/hw/intel/ntb_hw_gen3.h
index 75fb86ca27bb..d1455f24ec99 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen3.h
+++ b/drivers/ntb/hw/intel/ntb_hw_gen3.h
@@ -91,7 +91,7 @@
#define GEN3_DB_TOTAL_SHIFT 33
#define GEN3_SPAD_COUNT 16
-static inline u64 gen3_db_ioread(void __iomem *mmio)
+static inline u64 gen3_db_ioread(const void __iomem *mmio)
{
return ioread64(mmio);
}
diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.h b/drivers/ntb/hw/intel/ntb_hw_intel.h
index e071e28bca3f..3c0a5a2da241 100644
--- a/drivers/ntb/hw/intel/ntb_hw_intel.h
+++ b/drivers/ntb/hw/intel/ntb_hw_intel.h
@@ -102,7 +102,7 @@ struct intel_ntb_dev;
struct intel_ntb_reg {
int (*poll_link)(struct intel_ntb_dev *ndev);
int (*link_is_up)(struct intel_ntb_dev *ndev);
- u64 (*db_ioread)(void __iomem *mmio);
+ u64 (*db_ioread)(const void __iomem *mmio);
void (*db_iowrite)(u64 db_bits, void __iomem *mmio);
unsigned long ntb_ctl;
resource_size_t db_size;