mailbox: pcc: Drop unnecessary endianness conversion of pcc_hdr.flags

The Sparse static checker flags a type mismatch warning related to
endianness conversion:

  |  warning: incorrect type in argument 1 (different base types)
  |     expected restricted __le32 const [usertype] *p
  |     got unsigned int *

This is because an explicit endianness conversion (le32_to_cpu()) was
applied unnecessarily to a pcc_hdr.flags field that is already in
little-endian format.

The PCC driver is only enabled on little-endian kernels due to its
dependency on ACPI and EFI, making the explicit conversion unnecessary.

The redundant conversion occurs in pcc_chan_check_and_ack() for the
pcc_hdr.flags field. Drop this unnecessary endianness conversion of
pcc_hdr.flags.

Also drop the redundant PCC_ACK_FLAG_MASK definition and use the
more appropriate and already defined PCC_CMD_COMPLETION_NOTIFY.

Acked-by: Huisong Li <lihuisong@huawei.com>
Tested-by: Adam Young <admiyo@os.amperecomputing.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index f8215a8f656a460b38806d4c002470c3fe1e3c9c..9cf0ca772c1adb73ceb91d25a2abd1d12c678d90 100644 (file)
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -292,7 +292,7 @@ static void check_and_ack(struct pcc_chan_info *pchan, struct mbox_chan *chan)
         *
         * The PCC master subspace channel clears chan_in_use to free channel.
         */
-       if (le32_to_cpup(&pcc_hdr.flags) & PCC_ACK_FLAG_MASK)
+       if (pcc_hdr.flags & PCC_CMD_COMPLETION_NOTIFY)
                pcc_send_data(chan, NULL);
        else
                pcc_chan_reg_read_modify_write(&pchan->cmd_update);

diff --git a/include/acpi/pcc.h b/include/acpi/pcc.h
index 699c1a37b8e7846362bae35477eb5736be15d79e..d1e506f041c5a80857d4a025fa3c1803746ba4b9 100644 (file)
--- a/include/acpi/pcc.h
+++ b/include/acpi/pcc.h
@@ -32,7 +32,6 @@ struct pcc_mbox_chan {
 #define PCC_CMD_COMPLETION_NOTIFY      BIT(0)
 
 #define MAX_PCC_SUBSPACES      256
-#define PCC_ACK_FLAG_MASK      0x1
 
 #ifdef CONFIG_PCC
 extern struct pcc_mbox_chan *