Messages in this thread Patch in this message | | | From | Alex Elder <> | Subject | [PATCH net-next 2/4] net: ipa: introduce dma_addr_high32() | Date | Wed, 17 Mar 2021 17:29:44 -0500 |
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Create a new helper function to encapsulate extracting the high-order 32 bits of a DMA address. It returns 0 for builds in which a DMA address is not 64 bits.
This avoids doing a 32-position shift on a DMA address if it happens not to be 64 bits wide.
Signed-off-by: Alex Elder <elder@linaro.org> --- drivers/net/ipa/gsi.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c index 2119367b93ea9..53698c64cf882 100644 --- a/drivers/net/ipa/gsi.c +++ b/drivers/net/ipa/gsi.c @@ -688,6 +688,16 @@ static void gsi_evt_ring_doorbell(struct gsi *gsi, u32 evt_ring_id, u32 index) iowrite32(val, gsi->virt + GSI_EV_CH_E_DOORBELL_0_OFFSET(evt_ring_id)); } +/* Encapsulate extracting high-order 32 bits of DMA address */ +static u32 dma_addr_high32(dma_addr_t addr) +{ +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT + return (u32)(addr >> 32); +#else /* !CONFIG_ARCH_DMA_ADDR_T_64BIT */ + return 0; +#endif /* !CONFIG_ARCH_DMA_ADDR_T_64BIT */ +} + /* Program an event ring for use */ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id) { @@ -711,7 +721,7 @@ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id) val = evt_ring->ring.addr & GENMASK(31, 0); iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_2_OFFSET(evt_ring_id)); - val = evt_ring->ring.addr >> 32; + val = dma_addr_high32(evt_ring->ring.addr); iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_3_OFFSET(evt_ring_id)); /* Enable interrupt moderation by setting the moderation delay */ @@ -819,7 +829,7 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell) val = channel->tre_ring.addr & GENMASK(31, 0); iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_2_OFFSET(channel_id)); - val = channel->tre_ring.addr >> 32; + val = dma_addr_high32(channel->tre_ring.addr); iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_3_OFFSET(channel_id)); /* Command channel gets low weighted round-robin priority */ -- 2.27.0
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