openwrtv4/target/linux/mpc85xx/patches-3.14/210-spi-fsl-espi-preallocate-local-buffer.patch

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From: Gabor Juhos <juhosg@openwrt.org>
Subject: spi-fsl-espi: avoid frequent high order allocations
The driver allocates 64KiB of memory fro a local buffer before
each transfer and releases that afterwards. When the memory is
fragmented this allocation often fails and causes a warning like
this:
kworker/u2:2: page allocation failure: order:4, mode:0x10c0d0
CPU: 0 PID: 7011 Comm: kworker/u2:2 Not tainted 3.10.24 #1
Workqueue: ffe07000.spi mpc8xxx_spi_work
Call Trace:
[c1c6dcf0] [c0006914] show_stack+0x50/0x170 (unreliable)
[c1c6dd30] [c0259858] dump_stack+0x24/0x34
[c1c6dd40] [c00672e8] warn_alloc_failed+0x120/0x13c
[c1c6dd90] [c0069920] __alloc_pages_nodemask+0x574/0x5c8
[c1c6de20] [c0069990] __get_free_pages+0x1c/0x4c
[c1c6de30] [c0185174] fsl_espi_do_one_msg+0x128/0x2a0
[c1c6de90] [c0184290] mpc8xxx_spi_work+0x50/0x7c
[c1c6dea0] [c0037af8] process_one_work+0x208/0x30c
[c1c6dec0] [c00387a0] worker_thread+0x20c/0x308
[c1c6def0] [c003de60] kthread+0xa4/0xa8
[c1c6df40] [c000c4bc] ret_from_kernel_thread+0x5c/0x64
m25p80 spi0.0: error -12 reading SR
end_request: I/O error, dev mtdblock3, sector 680
SQUASHFS error: squashfs_read_data failed to read block 0x54a4a
SQUASHFS error: Unable to read data cache entry [54a4a]
Preallocate the buffer from the probe routine to avoid
this.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
drivers/spi/spi-fsl-espi.c | 34 ++++++++++++++++------------------
drivers/spi/spi-fsl-lib.h | 1 +
2 files changed, 17 insertions(+), 18 deletions(-)
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -334,17 +334,13 @@ static void fsl_espi_do_trans(struct spi
static void fsl_espi_cmd_trans(struct spi_message *m,
struct fsl_espi_transfer *trans, u8 *rx_buff)
{
+ struct spi_device *spi = m->spi;
+ struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
struct spi_transfer *t;
- u8 *local_buf;
+ u8 *local_buf = mspi->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);
@@ -357,28 +353,23 @@ static void fsl_espi_cmd_trans(struct sp
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 spi_device *spi = m->spi;
+ struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
struct fsl_espi_transfer *espi_trans = trans;
unsigned int n_tx = espi_trans->n_tx;
unsigned int n_rx = espi_trans->n_rx;
struct spi_transfer *t;
- u8 *local_buf;
+ u8 *local_buf = mspi->local_buf;
u8 *rx_buf = rx_buff;
unsigned int trans_len;
unsigned int addr;
int i, pos, loop;
- local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
- if (!local_buf) {
- espi_trans->status = -ENOMEM;
- return;
- }
-
for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) {
trans_len = n_rx - pos;
if (trans_len > SPCOM_TRANLEN_MAX - n_tx)
@@ -412,8 +403,6 @@ static void fsl_espi_rw_trans(struct spi
else
espi_trans->actual_length += espi_trans->len;
}
-
- kfree(local_buf);
}
static void fsl_espi_do_one_msg(struct spi_message *m)
@@ -581,6 +570,7 @@ static irqreturn_t fsl_espi_irq(s32 irq,
static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
{
iounmap(mspi->reg_base);
+ kfree(mspi->local_buf);
}
static struct spi_master * fsl_espi_probe(struct device *dev,
@@ -612,10 +602,16 @@ static struct spi_master * fsl_espi_prob
mpc8xxx_spi->spi_do_one_msg = fsl_espi_do_one_msg;
mpc8xxx_spi->spi_remove = fsl_espi_remove;
+ mpc8xxx_spi->local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
+ if (!mpc8xxx_spi->local_buf) {
+ ret = -ENOMEM;
+ goto err_probe;
+ }
+
mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
if (!mpc8xxx_spi->reg_base) {
ret = -ENOMEM;
- goto err_probe;
+ goto free_buf;
}
reg_base = mpc8xxx_spi->reg_base;
@@ -658,6 +654,8 @@ unreg_master:
free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
free_irq:
iounmap(mpc8xxx_spi->reg_base);
+free_buf:
+ kfree(mpc8xxx_spi->local_buf);
err_probe:
spi_master_put(master);
err:
--- a/drivers/spi/spi-fsl-lib.h
+++ b/drivers/spi/spi-fsl-lib.h
@@ -30,6 +30,7 @@ struct mpc8xxx_spi {
void *rx;
#ifdef CONFIG_SPI_FSL_ESPI
int len;
+ u8 *local_buf;
#endif
int subblock;