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iwlwifi: pcie: remove TR/CR tail allocations

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The TR/CR tail data are meant to be per-queue-arrays, however,
we allocate them completely wrong (we have a separate allocation
per queue).

Looking at this more closely, it turns out that the hardware
never uses these - we have a separate free list per RX queue
and maintain a write pointer for that in a register, and the
RX itself is indicated in the RB status (rb_stts) DMA region.

Despite nothing using the tail pointers, the hardware will
unconditionally access them to write updates, even when we aren't
using CRs/TRs.

Give it dummy values that we never use/update so it can do that
without causing trouble.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210617110647.5f5764e04c46.I4d5de1929be048085767f1234a1e07b517ab6a2d@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
This commit is contained in:
Johannes Berg 2021-06-17 11:07:28 +03:00 committed by Luca Coelho
parent bef99c7d91
commit 8e08e191fc
3 changed files with 14 additions and 59 deletions
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28
drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info-gen3.c
View File

@ -138,8 +138,15 @@ int iwl_pcie_ctxt_info_gen3_init(struct iwl_trans *trans,
/* Allocate prph information
* currently we don't assign to the prph info anything, but it would get
* assigned later */
prph_info = dma_alloc_coherent(trans->dev, sizeof(*prph_info),
* assigned later
*
* We also use the second half of this page to give the device some
* dummy TR/CR tail pointers - which shouldn't be necessary as we don't
* use this, but the hardware still reads/writes there and we can't let
* it go do that with a NULL pointer.
*/
BUILD_BUG_ON(sizeof(*prph_info) > PAGE_SIZE / 2);
prph_info = dma_alloc_coherent(trans->dev, PAGE_SIZE,
&trans_pcie->prph_info_dma_addr,
GFP_KERNEL);
if (!prph_info) {
@ -166,13 +173,9 @@ int iwl_pcie_ctxt_info_gen3_init(struct iwl_trans *trans,
ctxt_info_gen3->cr_head_idx_arr_base_addr =
cpu_to_le64(trans_pcie->rxq->rb_stts_dma);
ctxt_info_gen3->tr_tail_idx_arr_base_addr =
cpu_to_le64(trans_pcie->rxq->tr_tail_dma);
cpu_to_le64(trans_pcie->prph_info_dma_addr + PAGE_SIZE / 2);
ctxt_info_gen3->cr_tail_idx_arr_base_addr =
cpu_to_le64(trans_pcie->rxq->cr_tail_dma);
ctxt_info_gen3->cr_idx_arr_size =
cpu_to_le16(IWL_NUM_OF_COMPLETION_RINGS);
ctxt_info_gen3->tr_idx_arr_size =
cpu_to_le16(IWL_NUM_OF_TRANSFER_RINGS);
cpu_to_le64(trans_pcie->prph_info_dma_addr + 3 * PAGE_SIZE / 4);
ctxt_info_gen3->mtr_base_addr =
cpu_to_le64(trans->txqs.txq[trans->txqs.cmd.q_id]->dma_addr);
ctxt_info_gen3->mcr_base_addr =
@ -216,10 +219,8 @@ int iwl_pcie_ctxt_info_gen3_init(struct iwl_trans *trans,
trans_pcie->ctxt_info_dma_addr);
trans_pcie->ctxt_info_gen3 = NULL;
err_free_prph_info:
dma_free_coherent(trans->dev,
sizeof(*prph_info),
prph_info,
trans_pcie->prph_info_dma_addr);
dma_free_coherent(trans->dev, PAGE_SIZE, prph_info,
trans_pcie->prph_info_dma_addr);
err_free_prph_scratch:
dma_free_coherent(trans->dev,
@ -251,8 +252,7 @@ void iwl_pcie_ctxt_info_gen3_free(struct iwl_trans *trans)
trans_pcie->prph_scratch_dma_addr = 0;
trans_pcie->prph_scratch = NULL;
dma_free_coherent(trans->dev, sizeof(*trans_pcie->prph_info),
trans_pcie->prph_info,
dma_free_coherent(trans->dev, PAGE_SIZE, trans_pcie->prph_info,
trans_pcie->prph_info_dma_addr);
trans_pcie->prph_info_dma_addr = 0;
trans_pcie->prph_info = NULL;

11
drivers/net/wireless/intel/iwlwifi/pcie/internal.h
View File

@ -111,10 +111,6 @@ struct iwl_rx_completion_desc {
* @bd_dma: bus address of buffer of receive buffer descriptors (rbd)
* @used_bd: driver's pointer to buffer of used receive buffer descriptors (rbd)
* @used_bd_dma: physical address of buffer of used receive buffer descriptors (rbd)
* @tr_tail: driver's pointer to the transmission ring tail buffer
* @tr_tail_dma: physical address of the buffer for the transmission ring tail
* @cr_tail: driver's pointer to the completion ring tail buffer
* @cr_tail_dma: physical address of the buffer for the completion ring tail
* @read: Shared index to newest available Rx buffer
* @write: Shared index to oldest written Rx packet
* @free_count: Number of pre-allocated buffers in rx_free
@ -142,10 +138,6 @@ struct iwl_rxq {
struct iwl_rx_completion_desc *cd;
};
dma_addr_t used_bd_dma;
__le16 *tr_tail;
dma_addr_t tr_tail_dma;
__le16 *cr_tail;
dma_addr_t cr_tail_dma;
u32 read;
u32 write;
u32 free_count;
@ -533,9 +525,6 @@ static inline void _iwl_disable_interrupts(struct iwl_trans *trans)
IWL_DEBUG_ISR(trans, "Disabled interrupts\n");
}
#define IWL_NUM_OF_COMPLETION_RINGS 31
#define IWL_NUM_OF_TRANSFER_RINGS 527
static inline int iwl_pcie_get_num_sections(const struct fw_img *fw,
int start)
{

34
drivers/net/wireless/intel/iwlwifi/pcie/rx.c
View File

@ -663,7 +663,6 @@ static int iwl_pcie_free_bd_size(struct iwl_trans *trans, bool use_rx_td)
static void iwl_pcie_free_rxq_dma(struct iwl_trans *trans,
struct iwl_rxq *rxq)
{
struct device *dev = trans->dev;
bool use_rx_td = (trans->trans_cfg->device_family >=
IWL_DEVICE_FAMILY_AX210);
int free_size = iwl_pcie_free_bd_size(trans, use_rx_td);
@ -685,21 +684,6 @@ static void iwl_pcie_free_rxq_dma(struct iwl_trans *trans,
rxq->used_bd, rxq->used_bd_dma);
rxq->used_bd_dma = 0;
rxq->used_bd = NULL;
if (trans->trans_cfg->device_family < IWL_DEVICE_FAMILY_AX210)
return;
if (rxq->tr_tail)
dma_free_coherent(dev, sizeof(__le16),
rxq->tr_tail, rxq->tr_tail_dma);
rxq->tr_tail_dma = 0;
rxq->tr_tail = NULL;
if (rxq->cr_tail)
dma_free_coherent(dev, sizeof(__le16),
rxq->cr_tail, rxq->cr_tail_dma);
rxq->cr_tail_dma = 0;
rxq->cr_tail = NULL;
}
static int iwl_pcie_alloc_rxq_dma(struct iwl_trans *trans,
@ -744,21 +728,6 @@ static int iwl_pcie_alloc_rxq_dma(struct iwl_trans *trans,
rxq->rb_stts_dma =
trans_pcie->base_rb_stts_dma + rxq->id * rb_stts_size;
if (!use_rx_td)
return 0;
/* Allocate the driver's pointer to TR tail */
rxq->tr_tail = dma_alloc_coherent(dev, sizeof(__le16),
&rxq->tr_tail_dma, GFP_KERNEL);
if (!rxq->tr_tail)
goto err;
/* Allocate the driver's pointer to CR tail */
rxq->cr_tail = dma_alloc_coherent(dev, sizeof(__le16),
&rxq->cr_tail_dma, GFP_KERNEL);
if (!rxq->cr_tail)
goto err;
return 0;
err:
@ -1590,9 +1559,6 @@ static int iwl_pcie_rx_handle(struct iwl_trans *trans, int queue, int budget)
out:
/* Backtrack one entry */
rxq->read = i;
/* update cr tail with the rxq read pointer */
if (trans->trans_cfg->device_family >= IWL_DEVICE_FAMILY_AX210)
*rxq->cr_tail = cpu_to_le16(r);
spin_unlock(&rxq->lock);
/*