[PATCH 52/70] mxser: alloc struct mxser_board dynamically

From: Jiri Slaby
Date: Fri Jun 18 2021 - 02:18:32 EST


There is no need to preallocate an array of four struct mxser_board's.
In most cases a single board or two will be present in a machine. So
allocate struct mxser_board as needed in ->probe.

This makes mxser_boards a bit array. There we store which indexes are
free (unallocated).

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/tty/mxser.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 30b3a5ab6bea..0e99225e260f 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -278,7 +278,7 @@ struct mxser_board {
struct mxser_port ports[MXSER_PORTS_PER_BOARD];
};

-static struct mxser_board mxser_boards[MXSER_BOARDS];
+static DECLARE_BITMAP(mxser_boards, MXSER_BOARDS);
static struct tty_driver *mxvar_sdriver;

static u8 __mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set,
@@ -1916,31 +1916,32 @@ static int mxser_probe(struct pci_dev *pdev,
struct device *tty_dev;
int retval = -EINVAL;

- for (i = 0; i < MXSER_BOARDS; i++)
- if (mxser_boards[i].nports == 0)
- break;
-
+ i = find_first_zero_bit(mxser_boards, MXSER_BOARDS);
if (i >= MXSER_BOARDS) {
dev_err(&pdev->dev, "too many boards found (maximum %d), board "
"not configured\n", MXSER_BOARDS);
goto err;
}

- brd = &mxser_boards[i];
+ brd = devm_kzalloc(&pdev->dev, sizeof(*brd), GFP_KERNEL);
+ if (!brd)
+ goto err;
+
brd->idx = i;
+ __set_bit(brd->idx, mxser_boards);
base = i * MXSER_PORTS_PER_BOARD;

retval = pcim_enable_device(pdev);
if (retval) {
dev_err(&pdev->dev, "PCI enable failed\n");
- goto err;
+ goto err_zero;
}

/* io address */
ioaddress = pci_resource_start(pdev, 2);
retval = pci_request_region(pdev, 2, "mxser(IO)");
if (retval)
- goto err;
+ goto err_zero;

brd->nports = nports;
for (i = 0; i < nports; i++)
@@ -1984,7 +1985,7 @@ static int mxser_probe(struct pci_dev *pdev,
for (i = 0; i < nports; i++)
tty_port_destroy(&brd->ports[i].port);
err_zero:
- brd->nports = 0;
+ __clear_bit(brd->idx, mxser_boards);
err:
return retval;
}
@@ -1999,7 +2000,7 @@ static void mxser_remove(struct pci_dev *pdev)
tty_port_destroy(&brd->ports[i].port);
}

- brd->nports = 0;
+ __clear_bit(brd->idx, mxser_boards);
}

static struct pci_driver mxser_driver = {
--
2.32.0