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Commit 1423877b authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Mark Brown
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spi: fsl-espi: pre-allocate message buffer 



Currently the driver allocates a 64kb buffer for each single message.
On systems with little and fragmented memory this can result in
memory allocation errors. Solve this by pre-allocating a buffer.

This patch was developed in OpenWRT long ago, however it never
made it upstream.

I slightly modified the original patch to re-initialize the buffer
at the beginning of each transfer.

Signed-off-by: default avatarGabor Juhos <juhosg@openwrt.org>
Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 71581a15

drivers/spi/spi-fsl-espi.c

+18 −23
Original line number Diff line number Diff line
@@ -297,57 +297,44 @@ static void fsl_espi_do_trans(struct spi_message *m, 
static void fsl_espi_cmd_trans(struct spi_message *m,

				struct fsl_espi_transfer *trans, u8 *rx_buff)

{

	struct mpc8xxx_spi *mspi = spi_master_get_devdata(m->spi->master);

	struct spi_transfer *t;

	u8 *local_buf;

	int i = 0;

	struct fsl_espi_transfer *espi_trans = trans;



	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);

	if (!local_buf) {

		espi_trans->status = -ENOMEM;

		return;

	}



	list_for_each_entry(t, &m->transfers, transfer_list) {

		if (t->tx_buf) {

			memcpy(local_buf + i, t->tx_buf, t->len);

			memcpy(mspi->local_buf + i, t->tx_buf, t->len);

			i += t->len;

		}

	}



	espi_trans->tx_buf = local_buf;

	espi_trans->rx_buf = local_buf;

	espi_trans->tx_buf = mspi->local_buf;

	espi_trans->rx_buf = mspi->local_buf;

	fsl_espi_do_trans(m, espi_trans);



	espi_trans->actual_length = espi_trans->len;

	kfree(local_buf);

}



static void fsl_espi_rw_trans(struct spi_message *m,

				struct fsl_espi_transfer *trans, u8 *rx_buff)

{

	struct mpc8xxx_spi *mspi = spi_master_get_devdata(m->spi->master);

	struct spi_transfer *t;

	u8 *local_buf;

	unsigned int tx_only = 0;

	int i = 0;



	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);

	if (!local_buf) {

		trans->status = -ENOMEM;

		return;

	}



	list_for_each_entry(t, &m->transfers, transfer_list) {

		if (t->tx_buf) {

			memcpy(local_buf + i, t->tx_buf, t->len);

			memcpy(mspi->local_buf + i, t->tx_buf, t->len);

			i += t->len;

			if (!t->rx_buf)

				tx_only += t->len;

		}

	}



	trans->tx_buf = local_buf;

	trans->rx_buf = local_buf;

	trans->tx_buf = mspi->local_buf;

	trans->rx_buf = mspi->local_buf;

	fsl_espi_do_trans(m, trans);



	if (!trans->status) {
@@ -357,18 +344,19 @@ static void fsl_espi_rw_trans(struct spi_message *m, 
			       trans->len - tx_only);

		trans->actual_length += trans->len;

	}



	kfree(local_buf);

}



static int fsl_espi_do_one_msg(struct spi_master *master,

			       struct spi_message *m)

{

	struct mpc8xxx_spi *mspi = spi_master_get_devdata(master);

	struct spi_transfer *t;

	u8 *rx_buf = NULL;

	unsigned int xfer_len = 0;

	struct fsl_espi_transfer espi_trans;



	memset(mspi->local_buf, 0, SPCOM_TRANLEN_MAX);



	list_for_each_entry(t, &m->transfers, transfer_list) {

		if (t->rx_buf)

			rx_buf = t->rx_buf;
@@ -614,6 +602,13 @@ static struct spi_master * fsl_espi_probe(struct device *dev, 


	mpc8xxx_spi = spi_master_get_devdata(master);



	mpc8xxx_spi->local_buf =

		devm_kmalloc(dev, SPCOM_TRANLEN_MAX, GFP_KERNEL);

	if (!mpc8xxx_spi->local_buf) {

		ret = -ENOMEM;

		goto err_probe;

	}



	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);

	if (IS_ERR(mpc8xxx_spi->reg_base)) {

		ret = PTR_ERR(mpc8xxx_spi->reg_base);

drivers/spi/spi-fsl-lib.h

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ struct mpc8xxx_spi { 
	void *rx;

#if IS_ENABLED(CONFIG_SPI_FSL_ESPI)

	int len;

	u8 *local_buf;

#endif



	int subblock;