From: Johannes Berg Date: Thu, 17 Jun 2021 08:07:28 +0000 (+0300) Subject: iwlwifi: pcie: remove TR/CR tail allocations X-Git-Tag: v5.15~843^2~30^2~3^2~20 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8e08e191fc932b4fc2de014c358f8946a4af57e1;p=platform%2Fkernel%2Flinux-starfive.git iwlwifi: pcie: remove TR/CR tail allocations 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 Signed-off-by: Luca Coelho Link: https://lore.kernel.org/r/iwlwifi.20210617110647.5f5764e04c46.I4d5de1929be048085767f1234a1e07b517ab6a2d@changeid Signed-off-by: Luca Coelho --- diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info-gen3.c b/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info-gen3.c index cecc32e..49560e5 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info-gen3.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info-gen3.c @@ -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 @@ err_free_ctxt_info: 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; diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h index 1c740c3..292b972 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h +++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h @@ -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) { diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c index fb84914..4f6f4b2 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c @@ -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 @@ restart: 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); /*