Re: [PATCH 15/24] aspeed/smc: Add extra controls to request DMA

["Cédric Le Goater" <clg@kaod.org>]

On 4/9/21 8:54 AM, Joel Stanley wrote:
> On Wed, 7 Apr 2021 at 17:17, Cédric Le Goater <clg@kaod.org> wrote:
>>
>> The AST2600 SPI controllers have a set of bits to request/grant DMA
>> access. Add a new SMC feature for these controllers and use it to
>> check access to the DMA registers.
> 
> Ah this is why you added the features mask. Makes sense.

Yes. It's a bit redundant with the dma_ctrl() handler but it looks cleaner. 

> 
> Reviewed-by: Joel Stanley <joel@jms.id.au>


Thanks,

C.


>>
>> Cc: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
>> ---
>>  include/hw/ssi/aspeed_smc.h |  1 +
>>  hw/ssi/aspeed_smc.c         | 74 +++++++++++++++++++++++++++++++++----
>>  2 files changed, 68 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/hw/ssi/aspeed_smc.h b/include/hw/ssi/aspeed_smc.h
>> index 07879fd1c4a7..cdaf165300b6 100644
>> --- a/include/hw/ssi/aspeed_smc.h
>> +++ b/include/hw/ssi/aspeed_smc.h
>> @@ -55,6 +55,7 @@ typedef struct AspeedSMCController {
>>                                 const AspeedSegments *seg);
>>      void (*reg_to_segment)(const struct AspeedSMCState *s, uint32_t reg,
>>                             AspeedSegments *seg);
>> +    void (*dma_ctrl)(struct AspeedSMCState *s, uint32_t value);
>>  } AspeedSMCController;
>>
>>  typedef struct AspeedSMCFlash {
>> diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c
>> index 4521bbd4864e..189b35637c77 100644
>> --- a/hw/ssi/aspeed_smc.c
>> +++ b/hw/ssi/aspeed_smc.c
>> @@ -127,6 +127,8 @@
>>
>>  /* DMA Control/Status Register */
>>  #define R_DMA_CTRL        (0x80 / 4)
>> +#define   DMA_CTRL_REQUEST      (1 << 31)
>> +#define   DMA_CTRL_GRANT        (1 << 30)
>>  #define   DMA_CTRL_DELAY_MASK   0xf
>>  #define   DMA_CTRL_DELAY_SHIFT  8
>>  #define   DMA_CTRL_FREQ_MASK    0xf
>> @@ -228,6 +230,7 @@ static uint32_t aspeed_smc_segment_to_reg(const AspeedSMCState *s,
>>                                            const AspeedSegments *seg);
>>  static void aspeed_smc_reg_to_segment(const AspeedSMCState *s, uint32_t reg,
>>                                        AspeedSegments *seg);
>> +static void aspeed_smc_dma_ctrl(AspeedSMCState *s, uint32_t value);
>>
>>  /*
>>   * AST2600 definitions
>> @@ -257,7 +260,10 @@ static uint32_t aspeed_2600_smc_segment_to_reg(const AspeedSMCState *s,
>>                                                 const AspeedSegments *seg);
>>  static void aspeed_2600_smc_reg_to_segment(const AspeedSMCState *s,
>>                                             uint32_t reg, AspeedSegments *seg);
>> +static void aspeed_2600_smc_dma_ctrl(AspeedSMCState *s, uint32_t value);
>> +
>>  #define ASPEED_SMC_FEATURE_DMA       0x1
>> +#define ASPEED_SMC_FEATURE_DMA_GRANT 0x2
>>
>>  static inline bool aspeed_smc_has_dma(const AspeedSMCState *s)
>>  {
>> @@ -281,6 +287,7 @@ static const AspeedSMCController controllers[] = {
>>          .nregs             = ASPEED_SMC_R_SMC_MAX,
>>          .segment_to_reg    = aspeed_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.fmc-ast2400",
>>          .r_conf            = R_CONF,
>> @@ -299,6 +306,7 @@ static const AspeedSMCController controllers[] = {
>>          .nregs             = ASPEED_SMC_R_MAX,
>>          .segment_to_reg    = aspeed_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.spi1-ast2400",
>>          .r_conf            = R_SPI_CONF,
>> @@ -315,6 +323,7 @@ static const AspeedSMCController controllers[] = {
>>          .nregs             = ASPEED_SMC_R_SPI_MAX,
>>          .segment_to_reg    = aspeed_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.fmc-ast2500",
>>          .r_conf            = R_CONF,
>> @@ -333,6 +342,7 @@ static const AspeedSMCController controllers[] = {
>>          .nregs             = ASPEED_SMC_R_MAX,
>>          .segment_to_reg    = aspeed_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.spi1-ast2500",
>>          .r_conf            = R_CONF,
>> @@ -349,6 +359,7 @@ static const AspeedSMCController controllers[] = {
>>          .nregs             = ASPEED_SMC_R_MAX,
>>          .segment_to_reg    = aspeed_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.spi2-ast2500",
>>          .r_conf            = R_CONF,
>> @@ -365,6 +376,7 @@ static const AspeedSMCController controllers[] = {
>>          .nregs             = ASPEED_SMC_R_MAX,
>>          .segment_to_reg    = aspeed_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.fmc-ast2600",
>>          .r_conf            = R_CONF,
>> @@ -383,6 +395,7 @@ static const AspeedSMCController controllers[] = {
>>          .nregs             = ASPEED_SMC_R_MAX,
>>          .segment_to_reg    = aspeed_2600_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_2600_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_2600_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.spi1-ast2600",
>>          .r_conf            = R_CONF,
>> @@ -395,12 +408,14 @@ static const AspeedSMCController controllers[] = {
>>          .segments          = aspeed_segments_ast2600_spi1,
>>          .flash_window_base = ASPEED26_SOC_SPI_FLASH_BASE,
>>          .flash_window_size = 0x10000000,
>> -        .features          = ASPEED_SMC_FEATURE_DMA,
>> +        .features          = ASPEED_SMC_FEATURE_DMA |
>> +                             ASPEED_SMC_FEATURE_DMA_GRANT,
>>          .dma_flash_mask    = 0x0FFFFFFC,
>>          .dma_dram_mask     = 0x3FFFFFFC,
>>          .nregs             = ASPEED_SMC_R_MAX,
>>          .segment_to_reg    = aspeed_2600_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_2600_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_2600_smc_dma_ctrl,
>>      }, {
>>          .name              = "aspeed.spi2-ast2600",
>>          .r_conf            = R_CONF,
>> @@ -413,12 +428,14 @@ static const AspeedSMCController controllers[] = {
>>          .segments          = aspeed_segments_ast2600_spi2,
>>          .flash_window_base = ASPEED26_SOC_SPI2_FLASH_BASE,
>>          .flash_window_size = 0x10000000,
>> -        .features          = ASPEED_SMC_FEATURE_DMA,
>> +        .features          = ASPEED_SMC_FEATURE_DMA |
>> +                             ASPEED_SMC_FEATURE_DMA_GRANT,
>>          .dma_flash_mask    = 0x0FFFFFFC,
>>          .dma_dram_mask     = 0x3FFFFFFC,
>>          .nregs             = ASPEED_SMC_R_MAX,
>>          .segment_to_reg    = aspeed_2600_smc_segment_to_reg,
>>          .reg_to_segment    = aspeed_2600_smc_reg_to_segment,
>> +        .dma_ctrl          = aspeed_2600_smc_dma_ctrl,
>>      },
>>  };
>>
>> @@ -1240,7 +1257,7 @@ static void aspeed_smc_dma_done(AspeedSMCState *s)
>>      }
>>  }
>>
>> -static void aspeed_smc_dma_ctrl(AspeedSMCState *s, uint64_t dma_ctrl)
>> +static void aspeed_smc_dma_ctrl(AspeedSMCState *s, uint32_t dma_ctrl)
>>  {
>>      if (!(dma_ctrl & DMA_CTRL_ENABLE)) {
>>          s->regs[R_DMA_CTRL] = dma_ctrl;
>> @@ -1265,6 +1282,46 @@ static void aspeed_smc_dma_ctrl(AspeedSMCState *s, uint64_t dma_ctrl)
>>      aspeed_smc_dma_done(s);
>>  }
>>
>> +static inline bool aspeed_smc_dma_granted(AspeedSMCState *s)
>> +{
>> +    if (!(s->ctrl->features & ASPEED_SMC_FEATURE_DMA_GRANT)) {
>> +        return true;
>> +    }
>> +
>> +    if (!(s->regs[R_DMA_CTRL] & DMA_CTRL_GRANT)) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: DMA not granted\n",  __func__);
>> +        return false;
>> +    }
>> +
>> +    return true;
>> +}
>> +
>> +static void aspeed_2600_smc_dma_ctrl(AspeedSMCState *s, uint32_t dma_ctrl)
>> +{
>> +    /* Preserve DMA bits  */
>> +    dma_ctrl |= s->regs[R_DMA_CTRL] & (DMA_CTRL_REQUEST | DMA_CTRL_GRANT);
>> +
>> +    if (dma_ctrl == 0xAEED0000) {
>> +        /* automatically grant request */
>> +        s->regs[R_DMA_CTRL] |= (DMA_CTRL_REQUEST | DMA_CTRL_GRANT);
>> +        return;
>> +    }
>> +
>> +    /* clear request */
>> +    if (dma_ctrl == 0xDEEA0000) {
>> +        s->regs[R_DMA_CTRL] &= ~(DMA_CTRL_REQUEST | DMA_CTRL_GRANT);
>> +        return;
>> +    }
>> +
>> +    if (!aspeed_smc_dma_granted(s)) {
>> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: DMA not granted\n",  __func__);
>> +        return;
>> +    }
>> +
>> +    aspeed_smc_dma_ctrl(s, dma_ctrl);
>> +    s->regs[R_DMA_CTRL] &= ~(DMA_CTRL_REQUEST | DMA_CTRL_GRANT);
>> +}
>> +
>>  static void aspeed_smc_write(void *opaque, hwaddr addr, uint64_t data,
>>                               unsigned int size)
>>  {
>> @@ -1297,12 +1354,15 @@ static void aspeed_smc_write(void *opaque, hwaddr addr, uint64_t data,
>>      } else if (addr == R_INTR_CTRL) {
>>          s->regs[addr] = value;
>>      } else if (aspeed_smc_has_dma(s) && addr == R_DMA_CTRL) {
>> -        aspeed_smc_dma_ctrl(s, value);
>> -    } else if (aspeed_smc_has_dma(s) && addr == R_DMA_DRAM_ADDR) {
>> +        s->ctrl->dma_ctrl(s, value);
>> +    } else if (aspeed_smc_has_dma(s) && addr == R_DMA_DRAM_ADDR &&
>> +               aspeed_smc_dma_granted(s)) {
>>          s->regs[addr] = DMA_DRAM_ADDR(s, value);
>> -    } else if (aspeed_smc_has_dma(s) && addr == R_DMA_FLASH_ADDR) {
>> +    } else if (aspeed_smc_has_dma(s) && addr == R_DMA_FLASH_ADDR &&
>> +               aspeed_smc_dma_granted(s)) {
>>          s->regs[addr] = DMA_FLASH_ADDR(s, value);
>> -    } else if (aspeed_smc_has_dma(s) && addr == R_DMA_LEN) {
>> +    } else if (aspeed_smc_has_dma(s) && addr == R_DMA_LEN &&
>> +               aspeed_smc_dma_granted(s)) {
>>          s->regs[addr] = DMA_LENGTH(value);
>>      } else {
>>          qemu_log_mask(LOG_UNIMP, "%s: not implemented: 0x%" HWADDR_PRIx "\n",
>> --
>> 2.26.3
>>