Replace the hardcoded context ID mask (0xFF0) with GENMASK(11, 4) to
improve readability and follow kernel bitfield conventions. Use
FIELD_PREP and FIELD_GET instead of manual shifts for setting and
extracting ctxid values.

Signed-off-by: Ekansh Gupta <[email protected]>
---
 drivers/misc/fastrpc.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 679cd8997a00..f7fb44a8e9c0 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -22,6 +22,7 @@
 #include <linux/firmware/qcom/qcom_scm.h>
 #include <uapi/misc/fastrpc.h>
 #include <linux/of_reserved_mem.h>
+#include <linux/bitfield.h>
 
 #define ADSP_DOMAIN_ID (0)
 #define MDSP_DOMAIN_ID (1)
@@ -37,7 +38,7 @@
 #define FASTRPC_CTX_MAX (256)
 #define FASTRPC_INIT_HANDLE    1
 #define FASTRPC_DSP_UTILITIES_HANDLE   2
-#define FASTRPC_CTXID_MASK (0xFF0)
+#define FASTRPC_CTXID_MASK GENMASK(11, 4)
 #define INIT_FILELEN_MAX (2 * 1024 * 1024)
 #define INIT_FILE_NAMELEN_MAX (128)
 #define FASTRPC_DEVICE_NAME    "fastrpc"
@@ -489,7 +490,7 @@ static void fastrpc_context_free(struct kref *ref)
                fastrpc_buf_free(ctx->buf);
 
        spin_lock_irqsave(&cctx->lock, flags);
-       idr_remove(&cctx->ctx_idr, ctx->ctxid >> 4);
+       idr_remove(&cctx->ctx_idr, FIELD_GET(FASTRPC_CTXID_MASK, ctx->ctxid));
        spin_unlock_irqrestore(&cctx->lock, flags);
 
        kfree(ctx->maps);
@@ -625,7 +626,7 @@ static struct fastrpc_invoke_ctx *fastrpc_context_alloc(
                spin_unlock_irqrestore(&cctx->lock, flags);
                goto err_idr;
        }
-       ctx->ctxid = ret << 4;
+       ctx->ctxid = FIELD_PREP(FASTRPC_CTXID_MASK, ret);
        spin_unlock_irqrestore(&cctx->lock, flags);
 
        kref_init(&ctx->refcount);
@@ -2451,7 +2452,7 @@ static int fastrpc_rpmsg_callback(struct rpmsg_device 
*rpdev, void *data,
        if (len < sizeof(*rsp))
                return -EINVAL;
 
-       ctxid = ((rsp->ctx & FASTRPC_CTXID_MASK) >> 4);
+       ctxid = FIELD_GET(FASTRPC_CTXID_MASK, rsp->ctx);
 
        spin_lock_irqsave(&cctx->lock, flags);
        ctx = idr_find(&cctx->ctx_idr, ctxid);
-- 
2.34.1

Reply via email to