Re: [PATCH v4 3/8] mailbox: mtk-cmdq: Add driver data to support for MT8196

CK Hu (胡俊光)
2025-02-18T09:26:07Z

On Tue, 2025-02-18 at 13:41 +0800, Jason-JH Lin wrote:
> MT8196 has 3 new hardware configuration compared with the previous SoC,
> which correspond to the 3 new driver data:
>
> 1. mminfra_offset: For GCE data plane control
> Since GCE has been moved into mminfra, GCE needs to append the
> mminfra offset to the DRAM address when accessing the DRAM.

It seems that GCE has iova and mminfra would mapping the iova to physical address.
Maybe let GCE be a iommu device or add iommus property in device node, and use dma_map_xxx() to get iova of GCE.
iommus property point to mminfra device (maybe another name) and mminfra device would process the mapping of iova and physical address.

>
> 2. gce_vm: For GCE hardware virtualization
> Currently, the first version of the mt8196 mailbox controller only
> requires setting the VM-related registers to enable the permissions
> of a host VM.

What's this? I know this patch would not implement the full VM function,
but describe more about what this is. Why need to enable permission?

Regards,
CK

>
> 3. dma_mask_bit: For dma address bit control
> In order to avoid the hardware limitations of MT8196 accessing DRAM,
> GCE needs to configure the DMA address to be less than 35 bits.
>
> Signed-off-by: Jason-JH Lin <jason-jh.lin@mediatek.com>
> ---
> drivers/mailbox/mtk-cmdq-mailbox.c | 90 +++++++++++++++++++++---
> include/linux/mailbox/mtk-cmdq-mailbox.h | 2 +
> 2 files changed, 84 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
> index d186865b8dce..0abe10a7fef9 100644
> --- a/drivers/mailbox/mtk-cmdq-mailbox.c
> +++ b/drivers/mailbox/mtk-cmdq-mailbox.c
> @@ -43,6 +43,17 @@
> #define GCE_CTRL_BY_SW GENMASK(2, 0)
> #define GCE_DDR_EN GENMASK(18, 16)
>
> +#define GCE_VM_ID_MAP0 0x5018
> +#define GCE_VM_MAP0_ALL_HOST GENMASK(29, 0)
> +#define GCE_VM_ID_MAP1 0x501c
> +#define GCE_VM_MAP1_ALL_HOST GENMASK(29, 0)
> +#define GCE_VM_ID_MAP2 0x5020
> +#define GCE_VM_MAP2_ALL_HOST GENMASK(29, 0)
> +#define GCE_VM_ID_MAP3 0x5024
> +#define GCE_VM_MAP3_ALL_HOST GENMASK(5, 0)
> +#define GCE_VM_CPR_GSIZE 0x50c4
> +#define GCE_VM_CPR_GSIZE_HSOT GENMASK(3, 0)
> +
> #define CMDQ_THR_ACTIVE_SLOT_CYCLES 0x3200
> #define CMDQ_THR_ENABLED 0x1
> #define CMDQ_THR_DISABLED 0x0
> @@ -87,11 +98,24 @@ struct cmdq {
> struct gce_plat {
> u32 thread_nr;
> u8 shift;
> + dma_addr_t mminfra_offset;
> bool control_by_sw;
> bool sw_ddr_en;
> + bool gce_vm;
> + u32 dma_mask_bit;
> u32 gce_num;
> };
>
> +static inline u32 cmdq_reg_shift_addr(dma_addr_t addr, const struct gce_plat *pdata)
> +{
> + return ((addr + pdata->mminfra_offset) >> pdata->shift);
> +}
> +
> +static inline u32 cmdq_reg_revert_addr(dma_addr_t addr, const struct gce_plat *pdata)
> +{
> + return ((addr << pdata->shift) - pdata->mminfra_offset);
> +}
> +
> static void cmdq_sw_ddr_enable(struct cmdq *cmdq, bool enable)
> {
> WARN_ON(clk_bulk_enable(cmdq->pdata->gce_num, cmdq->clocks));
> @@ -112,6 +136,30 @@ u8 cmdq_get_shift_pa(struct mbox_chan *chan)
> }
> EXPORT_SYMBOL(cmdq_get_shift_pa);
>
> +dma_addr_t cmdq_get_offset_pa(struct mbox_chan *chan)
> +{
> + struct cmdq *cmdq = container_of(chan->mbox, struct cmdq, mbox);
> +
> + return cmdq->pdata->mminfra_offset;
> +}
> +EXPORT_SYMBOL(cmdq_get_offset_pa);
> +
> +bool cmdq_addr_need_offset(struct mbox_chan *chan, dma_addr_t addr)
> +{
> + struct cmdq *cmdq = container_of(chan->mbox, struct cmdq, mbox);
> +
> + if (cmdq->pdata->mminfra_offset == 0)
> + return false;
> +
> + /*
> + * mminfra will recognize the addr that greater than the mminfra_offset
> + * as a transaction to DRAM.
> + * So the caller needs to append mminfra_offset for the true case.
> + */
> + return (addr >= cmdq->pdata->mminfra_offset);
> +}
> +EXPORT_SYMBOL(cmdq_addr_need_offset);
> +
> static int cmdq_thread_suspend(struct cmdq *cmdq, struct cmdq_thread *thread)
> {
> u32 status;
> @@ -143,6 +191,17 @@ static void cmdq_init(struct cmdq *cmdq)
> u32 gctl_regval = 0;
>
> WARN_ON(clk_bulk_enable(cmdq->pdata->gce_num, cmdq->clocks));
> +
> + if (cmdq->pdata->gce_vm) {
> + /* config cpr size for host vm */
> + writel(GCE_VM_CPR_GSIZE_HSOT, cmdq->base + GCE_VM_CPR_GSIZE);
> + /* config CPR_GSIZE before setting VM_ID_MAP to avoid data leakage */
> + writel(GCE_VM_MAP0_ALL_HOST, cmdq->base + GCE_VM_ID_MAP0);
> + writel(GCE_VM_MAP1_ALL_HOST, cmdq->base + GCE_VM_ID_MAP1);
> + writel(GCE_VM_MAP2_ALL_HOST, cmdq->base + GCE_VM_ID_MAP2);
> + writel(GCE_VM_MAP3_ALL_HOST, cmdq->base + GCE_VM_ID_MAP3);
> + }
> +
> if (cmdq->pdata->control_by_sw)
> gctl_regval = GCE_CTRL_BY_SW;
> if (cmdq->pdata->sw_ddr_en)
> @@ -199,7 +258,7 @@ static void cmdq_task_insert_into_thread(struct cmdq_task *task)
> prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
> prev_task_base[CMDQ_NUM_CMD(prev_task->pkt) - 1] =
> (u64)CMDQ_JUMP_BY_PA << 32 |
> - (task->pa_base >> task->cmdq->pdata->shift);
> + cmdq_reg_shift_addr(task->pa_base, task->cmdq->pdata);
> dma_sync_single_for_device(dev, prev_task->pa_base,
> prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
>
> @@ -264,7 +323,7 @@ static void cmdq_thread_irq_handler(struct cmdq *cmdq,
> else
> return;
>
> - curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) << cmdq->pdata->shift;
> + curr_pa = cmdq_reg_shift_addr(readl(thread->base + CMDQ_THR_CURR_ADDR), cmdq->pdata);
>
> list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
> list_entry) {
> @@ -416,9 +475,9 @@ static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
> */
> WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);
>
> - writel(task->pa_base >> cmdq->pdata->shift,
> + writel(cmdq_reg_shift_addr(task->pa_base, cmdq->pdata),
> thread->base + CMDQ_THR_CURR_ADDR);
> - writel((task->pa_base + pkt->cmd_buf_size) >> cmdq->pdata->shift,
> + writel(cmdq_reg_shift_addr(task->pa_base + pkt->cmd_buf_size, cmdq->pdata),
> thread->base + CMDQ_THR_END_ADDR);
>
> writel(thread->priority, thread->base + CMDQ_THR_PRIORITY);
> @@ -426,10 +485,10 @@ static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
> writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
> } else {
> WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
> - curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) <<
> - cmdq->pdata->shift;
> - end_pa = readl(thread->base + CMDQ_THR_END_ADDR) <<
> - cmdq->pdata->shift;
> + curr_pa = cmdq_reg_revert_addr(readl(thread->base + CMDQ_THR_CURR_ADDR),
> + cmdq->pdata);
> + end_pa = cmdq_reg_revert_addr(readl(thread->base + CMDQ_THR_END_ADDR),
> + cmdq->pdata);
> /* check boundary */
> if (curr_pa == end_pa - CMDQ_INST_SIZE ||
> curr_pa == end_pa) {
> @@ -663,6 +722,9 @@ static int cmdq_probe(struct platform_device *pdev)
> if (err)
> return err;
>
> + if (cmdq->pdata->dma_mask_bit)
> + dma_set_coherent_mask(dev, DMA_BIT_MASK(cmdq->pdata->dma_mask_bit));
> +
> cmdq->mbox.dev = dev;
> cmdq->mbox.chans = devm_kcalloc(dev, cmdq->pdata->thread_nr,
> sizeof(*cmdq->mbox.chans), GFP_KERNEL);
> @@ -782,6 +844,17 @@ static const struct gce_plat gce_plat_mt8195 = {
> .gce_num = 2
> };
>
> +static const struct gce_plat gce_plat_mt8196 = {
> + .thread_nr = 32,
> + .shift = 3,
> + .mminfra_offset = 0x80000000, /* 2GB */
> + .control_by_sw = true,
> + .sw_ddr_en = true,
> + .gce_vm = true,
> + .dma_mask_bit = 35,
> + .gce_num = 2
> +};
> +
> static const struct of_device_id cmdq_of_ids[] = {
> {.compatible = "mediatek,mt6779-gce", .data = (void *)&gce_plat_mt6779},
> {.compatible = "mediatek,mt8173-gce", .data = (void *)&gce_plat_mt8173},
> @@ -790,6 +863,7 @@ static const struct of_device_id cmdq_of_ids[] = {
> {.compatible = "mediatek,mt8188-gce", .data = (void *)&gce_plat_mt8188},
> {.compatible = "mediatek,mt8192-gce", .data = (void *)&gce_plat_mt8192},
> {.compatible = "mediatek,mt8195-gce", .data = (void *)&gce_plat_mt8195},
> + {.compatible = "mediatek,mt8196-gce", .data = (void *)&gce_plat_mt8196},
> {}
> };
> MODULE_DEVICE_TABLE(of, cmdq_of_ids);
> diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
> index a8f0070c7aa9..79398bf95f8d 100644
> --- a/include/linux/mailbox/mtk-cmdq-mailbox.h
> +++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
> @@ -79,5 +79,7 @@ struct cmdq_pkt {
> };
>
> u8 cmdq_get_shift_pa(struct mbox_chan *chan);
> +dma_addr_t cmdq_get_offset_pa(struct mbox_chan *chan);
> +bool cmdq_addr_need_offset(struct mbox_chan *chan, dma_addr_t addr);
>
> #endif /* __MTK_CMDQ_MAILBOX_H__ */