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spi: spi-mem: Add extra sanity checks on the op param

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Some combinations are simply not valid and should be rejected before
the op is passed to the SPI controller driver.

Add an spi_mem_check_op() helper and use it in spi_mem_exec_op() and
spi_mem_supports_op() to make sure the spi-mem operation is valid.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Boris Brezillon 2018-09-20 09:31:12 +02:00 committed by Mark Brown
parent f34ecdbd56
commit 380583227c
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 48 additions and 6 deletions
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54
drivers/spi/spi-mem.c
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@ -12,6 +12,8 @@
#include "internals.h"
#define SPI_MEM_MAX_BUSWIDTH 4
/**
* spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
* memory operation
@ -149,6 +151,44 @@ static bool spi_mem_default_supports_op(struct spi_mem *mem,
}
EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
static bool spi_mem_buswidth_is_valid(u8 buswidth)
{
if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
return false;
return true;
}
static int spi_mem_check_op(const struct spi_mem_op *op)
{
if (!op->cmd.buswidth)
return -EINVAL;
if ((op->addr.nbytes && !op->addr.buswidth) ||
(op->dummy.nbytes && !op->dummy.buswidth) ||
(op->data.nbytes && !op->data.buswidth))
return -EINVAL;
if (spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
spi_mem_buswidth_is_valid(op->addr.buswidth) ||
spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
spi_mem_buswidth_is_valid(op->data.buswidth))
return -EINVAL;
return 0;
}
static bool spi_mem_internal_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
struct spi_controller *ctlr = mem->spi->controller;
if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
return ctlr->mem_ops->supports_op(mem, op);
return spi_mem_default_supports_op(mem, op);
}
/**
* spi_mem_supports_op() - Check if a memory device and the controller it is
* connected to support a specific memory operation
@ -166,12 +206,10 @@ EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
*/
bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
{
struct spi_controller *ctlr = mem->spi->controller;
if (spi_mem_check_op(op))
return false;
if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
return ctlr->mem_ops->supports_op(mem, op);
return spi_mem_default_supports_op(mem, op);
return spi_mem_internal_supports_op(mem, op);
}
EXPORT_SYMBOL_GPL(spi_mem_supports_op);
@ -196,7 +234,11 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
u8 *tmpbuf;
int ret;
if (!spi_mem_supports_op(mem, op))
ret = spi_mem_check_op(op);
if (ret)
return ret;
if (!spi_mem_internal_supports_op(mem, op))
return -ENOTSUPP;
if (ctlr->mem_ops) {