b02e07015a
Commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a
DMA channel") changed sf_pdma_prep_dma_memcpy() to unconditionally
allocate a new sf_pdma_desc each time it is called.
The driver previously recycled descs, by checking the in_use flag, only
allocating additional descs if the existing one was in use. This logic
was removed in commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread
support for a DMA channel"), but sf_pdma_free_desc() was not changed to
handle the new behaviour.
As a result, each time sf_pdma_prep_dma_memcpy() is called, the previous
descriptor is leaked, over time leading to memory starvation:
unreferenced object 0xffffffe008447300 (size 192):
comm "irq/39-mchp_dsc", pid 343, jiffies 4294906910 (age 981.200s)
hex dump (first 32 bytes):
00 00 00 ff 00 00 00 00 b8 c1 00 00 00 00 00 00 ................
00 00 70 08 10 00 00 00 00 00 00 c0 00 00 00 00 ..p.............
backtrace:
[<00000000064a04f4>] kmemleak_alloc+0x1e/0x28
[<00000000018927a7>] kmem_cache_alloc+0x11e/0x178
[<000000002aea8d16>] sf_pdma_prep_dma_memcpy+0x40/0x112
Add the missing kfree() to sf_pdma_free_desc(), and remove the redundant
in_use flag.
Fixes: b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel")
Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230120100623.3530634-1-shravan.chippa@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
120 lines
2.9 KiB
C
120 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* SiFive FU540 Platform DMA driver
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* Copyright (C) 2019 SiFive
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*
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* Based partially on:
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* - drivers/dma/fsl-edma.c
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* - drivers/dma/dw-edma/
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* - drivers/dma/pxa-dma.c
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*
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* See the following sources for further documentation:
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* - Chapter 12 "Platform DMA Engine (PDMA)" of
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* SiFive FU540-C000 v1.0
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* https://static.dev.sifive.com/FU540-C000-v1.0.pdf
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*/
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#ifndef _SF_PDMA_H
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#define _SF_PDMA_H
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#include <linux/dmaengine.h>
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#include <linux/dma-direction.h>
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#include "../dmaengine.h"
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#include "../virt-dma.h"
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#define PDMA_MAX_NR_CH 4
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#define PDMA_BASE_ADDR 0x3000000
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#define PDMA_CHAN_OFFSET 0x1000
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/* Register Offset */
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#define PDMA_CTRL 0x000
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#define PDMA_XFER_TYPE 0x004
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#define PDMA_XFER_SIZE 0x008
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#define PDMA_DST_ADDR 0x010
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#define PDMA_SRC_ADDR 0x018
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#define PDMA_ACT_TYPE 0x104 /* Read-only */
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#define PDMA_REMAINING_BYTE 0x108 /* Read-only */
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#define PDMA_CUR_DST_ADDR 0x110 /* Read-only*/
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#define PDMA_CUR_SRC_ADDR 0x118 /* Read-only*/
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/* CTRL */
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#define PDMA_CLEAR_CTRL 0x0
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#define PDMA_CLAIM_MASK GENMASK(0, 0)
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#define PDMA_RUN_MASK GENMASK(1, 1)
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#define PDMA_ENABLE_DONE_INT_MASK GENMASK(14, 14)
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#define PDMA_ENABLE_ERR_INT_MASK GENMASK(15, 15)
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#define PDMA_DONE_STATUS_MASK GENMASK(30, 30)
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#define PDMA_ERR_STATUS_MASK GENMASK(31, 31)
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/* Transfer Type */
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#define PDMA_FULL_SPEED 0xFF000008
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/* Error Recovery */
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#define MAX_RETRY 1
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#define SF_PDMA_REG_BASE(ch) (pdma->membase + (PDMA_CHAN_OFFSET * (ch)))
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struct pdma_regs {
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/* read-write regs */
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void __iomem *ctrl; /* 4 bytes */
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void __iomem *xfer_type; /* 4 bytes */
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void __iomem *xfer_size; /* 8 bytes */
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void __iomem *dst_addr; /* 8 bytes */
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void __iomem *src_addr; /* 8 bytes */
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/* read-only */
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void __iomem *act_type; /* 4 bytes */
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void __iomem *residue; /* 8 bytes */
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void __iomem *cur_dst_addr; /* 8 bytes */
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void __iomem *cur_src_addr; /* 8 bytes */
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};
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struct sf_pdma_desc {
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u32 xfer_type;
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u64 xfer_size;
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u64 dst_addr;
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u64 src_addr;
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struct virt_dma_desc vdesc;
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struct sf_pdma_chan *chan;
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enum dma_transfer_direction dirn;
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struct dma_async_tx_descriptor *async_tx;
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};
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enum sf_pdma_pm_state {
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RUNNING = 0,
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SUSPENDED,
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};
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struct sf_pdma_chan {
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struct virt_dma_chan vchan;
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enum dma_status status;
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enum sf_pdma_pm_state pm_state;
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u32 slave_id;
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struct sf_pdma *pdma;
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struct sf_pdma_desc *desc;
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struct dma_slave_config cfg;
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u32 attr;
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dma_addr_t dma_dev_addr;
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u32 dma_dev_size;
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struct tasklet_struct done_tasklet;
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struct tasklet_struct err_tasklet;
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struct pdma_regs regs;
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spinlock_t lock; /* protect chan data */
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bool xfer_err;
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int txirq;
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int errirq;
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int retries;
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};
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struct sf_pdma {
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struct dma_device dma_dev;
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void __iomem *membase;
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void __iomem *mappedbase;
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u32 n_chans;
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struct sf_pdma_chan chans[];
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};
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#endif /* _SF_PDMA_H */
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