Re: [Sound-open-firmware] [RFC PATCH 3/6] dma: introduce new API for requesting DMAC

On 2018年06月06日 14:00, Ranjani Sridharan wrote:

On Wed, 2018-06-06 at 11:20 +0800, Keyon Jie wrote:

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On 2018年06月06日 03:18, Ranjani Sridharan wrote:

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On Tue, 2018-06-05 at 19:05 +0800, Keyon Jie wrote:

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On 2018年06月05日 12:23, Ranjani Sridharan wrote:

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This patch introduces a new API for procuring DMAC for various user based on the type of DMAC, copy direction and other flags for share/exclusive access. It defines the necessary DMAC user types, copy direction and the flags to suuport the new API.It also adds two new members to dma_plat_data to differentiate the DMAC based on usage and copy direction.

Finally, it also contains the platform specific implementation of the new dma_get() API.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel .com

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---

src/include/sof/dma.h         | 26 ++++++++++++++++-
src/platform/apollolake/dma.c | 53

++++++++++++++++++++++++++++++++--- src/platform/baytrail/dma.c | 41 ++++++++++++++++++++++++- -- src/platform/cannonlake/dma.c | 53 ++++++++++++++++++++++++++++++++--- src/platform/haswell/dma.c | 49

++++++++++++++++++++++++++--

5 files changed, 201 insertions(+), 21 deletions(-)

diff --git a/src/include/sof/dma.h b/src/include/sof/dma.h index 1de9efc..25581e6 100644 --- a/src/include/sof/dma.h +++ b/src/include/sof/dma.h @@ -48,6 +48,28 @@ enum dma_copy_dir { DMA_DIR_DEV_TO_DEV, };

+/*

• • DMAC copy directions
• • These are used to specify the copy direction while

requesting a DMAC

• */

+enum dmac_copy_dir {

• DMAC_DIR_READ = 0,
• DMAC_DIR_WRITE,
• DMAC_DIR_DUPLEX,

+};

I can't understand this, what is read and what is write? For DMA, it always read from some buffer and write them to another buffer.

[edit] after reading the patch, I got your point. maybe naming it with

+enum dmac_dir_cap {

• DMAC_CAP_READ = 0,
• DMAC_CAP_WRITE,
• DMAC_CAP_DUPLEX,

+};

or we can use bit mask for that, which can be reused with user type below also, e.g.

bit 0: cap_read bit 1: cap_write bit 2: host/link bit 3: lp/hp. bit 4: share/exclusive

I can rename the enum but I'd like to stick with the arguments for the dma_get API. It is really only 3 arguments and it makes deciphering code much easier than applying bitmasks.

Unless, you have a compelling reason for me not to use separate arguments?

I think using the bitmasks is more object oriented, e.g. for direction, what directions does your dmac supported? host_mem_to_mem(1)? mem_to_mem(2)? mem_to_dev(3)? dev_to_dev(4)? mem_to_link(5)? or the opposite? The combination of these can be up to 10.

Is it only 8 or 10? mem_to hostmem (6), dev_to_mem(7) and link_to_mem(8). What am I missing?

right, it should be 8 as mem2mem and dev2dev are duplicated.

...

for byt/bdw, we can support (1)(2)(3)(4)(6)(7)(8)(9);

please also be noticed here that as Rander experimented, on bdw, gpdmac0 and gpdmac1 may have different caps, and all those gpdma can't support (5) and (8) we noted above.

Thanks, ~Keyon

...

for apl/cnl, host_dmac_output can support (1) only, host_dmac_input can support (6) only, gpdma can support (2)(3)(4)(7)(8)(9), link_dmac_output can support (5), link_dmac_input can support (10) only.

if you tell these clear enough, you will be able to use unify logic in a

With the above definitions, I can unify the type/dir arguments but I'd still need the access flags.

Thanks for this. I can incorporate this change in v2.

...

common dma_get(): /* check DMAC copy dir */ if (dma[i].plat_data.caps & require_cap == require_cap) retrun dma[i]; // very simple, isn't it?

for the user: byt/bdw: playback, host: dma_get(host_mem_to_mem); dai: dma_get(mem_to_dev); capture, host: dma_get(mem_to_hostmem); dai: dma_get(dev_to_mem_); page_table_parsing, dma_get(host_mem_to_mem); dma_trace, dma_get(mem_to_host_mem). apl/cnl: playback, host: dma_get(host_mem_to_mem); dai: dma_get(mem_to_dev); capture, host: dma_get(mem_to_hostmem); dai: dma_get(dev_to_mem_); page_table_parsing, dma_get(host_mem_to_mem); dma_trace, dma_get(mem_to_host_mem).

can you see what? with this, you can make the code very clean/unified in host/dai/dma_trace...

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...

...

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+/* DMAC user types */ +enum dmac_user {

• DMAC_USER_HOST_DMA = 0,
• DMAC_USER_LINK_DMA,

do we need split into output and input for these?

...

• DMAC_USER_GP_LP_DMA,
• DMAC_USER_GP_HP_DMA,

+};

+/* DMAC flags */ +#define DMAC_FLAGS_SHARED 0 +#define DMAC_FLAGS_EXCLUSIVE (1 << 0)

Can you explain what is shared and how channels are shared? Are you meaning channel reservation for specific user with exclusive? I can't image the use case for this.

Shared is the most common usage, where we share DMAC between users.

Exclusive as Liam explained will be fore critical usages that require that only one user will use the DMAC at any time. ie there will only be one channel draining at any time.

Hi Liam, can you explain more about this? Where is the limitation about only one channel draining at the same time, from DMAC or the user? Per my understanding, channels of the same DMAC are quite independent, they can in draining at the same time from the point of DMAC. And, we event don't use the DMA draining feature yet.

Thanks, ~Keyon

...

I havent seen the need for exclusive access so far. But we might need it in the future.

...

...

• /* DMA IRQ types */ #define DMA_IRQ_TYPE_BLOCK (1 << 0) #define DMA_IRQ_TYPE_LLIST (1 << 1)

@@ -119,6 +141,8 @@ struct dma_ops { /* DMA platform data */ struct dma_plat_data { uint32_t id;

• enum dmac_user type;
• enum dmac_copy_dir copy_dir; uint32_t base; uint32_t channels; uint32_t irq;

@@ -139,7 +163,7 @@ struct dma_int { uint32_t irq; };

-struct dma *dma_get(int dmac_id); +struct dma *dma_get(enum dmac_user, enum dmac_copy_dir, int flags);

/* initialize all platform DMAC's */
void dmac_init(void);

diff --git a/src/platform/apollolake/dma.c b/src/platform/apollolake/dma.c index 001bb67..1ae097e 100644 --- a/src/platform/apollolake/dma.c +++ b/src/platform/apollolake/dma.c @@ -112,6 +112,8 @@ static struct dma dma[] = { { /* Low Power GP DMAC 0 */ .plat_data = { .id = DMA_GP_LP_DMAC0,

• .type		= DMAC_USER_GP_LP_DMA,
  

• .copy_dir	= DMAC_DIR_DUPLEX,
  	.base		= LP_GP_DMA_BASE(0),
  	.channels	= 8,
  	.irq		=
  

IRQ_EXT_LP_GPDMA0_LVL5(0, 0), @@ -122,6 +124,8 @@ static struct dma dma[] = { { /* Low Power GP DMAC 1 */ .plat_data = { .id = DMA_GP_LP_DMAC1,

• .type		= DMAC_USER_GP_LP_DMA,
  

• .copy_dir	= DMAC_DIR_DUPLEX,
  	.base		= LP_GP_DMA_BASE(1),
  	.channels	= 8,
  	.irq		=
  

IRQ_EXT_LP_GPDMA1_LVL5(0, 0), @@ -132,6 +136,8 @@ static struct dma dma[] = { { /* Host In DMAC */ .plat_data = { .id = DMA_HOST_IN_DMAC,

• .type		= DMAC_USER_HOST_DMA,
  

• .copy_dir	= DMAC_DIR_WRITE,
  	.base		=
  

GTW_HOST_IN_STREAM_BASE(0), .channels = 7, .irq = IRQ_EXT_HOST_DMA_IN_LVL3(0, 0), @@ -142,6 +148,8 @@ static struct dma dma[] = { { /* Host out DMAC */ .plat_data = { .id = DMA_HOST_OUT_DMAC,

• .type		= DMAC_USER_HOST_DMA,
  

• .copy_dir	= DMAC_DIR_READ,
  	.base		=
  

GTW_HOST_OUT_STREAM_BASE(0), .channels = 6, .irq = IRQ_EXT_HOST_DMA_OUT_LVL3(0, 0), @@ -152,6 +160,8 @@ static struct dma dma[] = { { /* Link In DMAC */ .plat_data = { .id = DMA_LINK_IN_DMAC,

• .type		= DMAC_USER_LINK_DMA,
  

• .copy_dir	= DMAC_DIR_WRITE,
  	.base		=
  

GTW_LINK_IN_STREAM_BASE(0), .channels = 8, .irq = IRQ_EXT_LINK_DMA_IN_LVL4(0, 0), @@ -162,6 +172,8 @@ static struct dma dma[] = { { /* Link out DMAC */ .plat_data = { .id = DMA_LINK_OUT_DMAC,

• .type		= DMAC_USER_LINK_DMA,
  

• .copy_dir	= DMAC_DIR_READ,
  	.base		=
  

GTW_LINK_OUT_STREAM_BASE(0), .channels = 8, .irq = IRQ_EXT_LINK_DMA_OUT_LVL4(0, 0), @@ -170,15 +182,48 @@ static struct dma dma[] = { .ops = &hda_link_dma_ops, },};

-struct dma *dma_get(int dmac_id) +/*

• • get DMAC based on user type, copy dir and flags
• • "flags" is used to set the type of access requested
• • (ex: shared/exclusive access)
• */

+struct dma *dma_get(enum dmac_user user, enum dmac_copy_dir dir, int flags) {

• int i;

• int i, ch_count;

• int dma_index = -1;

• int min_ch_count = INT32_MAX;

  for (i = 0; i < ARRAY_SIZE(dma); i++) {
  

• if (dma[i].plat_data.id == dmac_id)
  

• 	return &dma[i];
  

• /* check DMAC user type */
  

• if (dma[i].plat_data.type != user)
  

• 	continue;
  

• /* check DMAC copy dir */
  

• if (dma[i].plat_data.copy_dir != dir)
  

• 	continue;
  

• /* if exclusive access is requested */
  

• if (flags & DMAC_FLAGS_EXCLUSIVE) {
  

• 	/* ret DMA with no channel in use */
  

• 	if (!dma_channel_status(&dma[i]))
  

• 		return &dma[i];
  

• } else {
  

• 	/* get number of channels in use */
  

• 	ch_count =
  

dma_channel_status(&dma[i]);

• 	/* Use this DMAC if its channel count
  

is lower */

• 	if (ch_count < min_ch_count) {
  

• 		dma_index = i;
  

• 		min_ch_count = ch_count;
  

• 	}
  

• }
  }
  
  

• if (dma_index >= 0)

• return &dma[dma_index];
  

• return NULL;
  

  }

diff --git a/src/platform/baytrail/dma.c b/src/platform/baytrail/dma.c index 5a0b650..71ea241 100644 --- a/src/platform/baytrail/dma.c +++ b/src/platform/baytrail/dma.c @@ -175,15 +175,48 @@ static struct dma dma[] = { #endif };

-struct dma *dma_get(int dmac_id) +/*

• • get DMAC based on user type, copy dir and flags
• • For BYT/CHT, ignore the dmac_user and copy_dir arguments
• • "flags" is used to set the type of access requested
• • (ex: shared/exclusive access)
• */

+struct dma *dma_get(enum dmac_user user, enum dmac_copy_dir dir, int flags) {

• int i;

• int i, ch_count;

• int min_ch_count = INT32_MAX;

• int dma_index = -1;

  for (i = 0; i < ARRAY_SIZE(dma); i++) {
  

• if (dma[i].plat_data.id == dmac_id)
  

• 	return &dma[i];
  

• /* if exclusive access is requested */
  

• if (flags & DMAC_FLAGS_EXCLUSIVE) {
  

• 	/* ret DMA with no channel in use */
  

• 	if (!dma_channel_status(&dma[i]))
  

• 		return &dma[i];
  

• } else {
  

• 	/*
  

• 	 * for shared access requests, return
  

DMAC

• 	 * with the least number of channels
  

in use

• 	 */
  

• 	/* get number of channels in use for
  

this DMAC*/

• 	ch_count =
  

dma_channel_status(&dma[i]);

• 	/* Use this DMAC if its channel count
  

is lower */

• 	if (ch_count < min_ch_count) {
  

• 		dma_index = i;
  

• 		min_ch_count = ch_count;
  

• 	}
  

• }
  }
  
  

• /* return DMAC */

• if (dma_index >= 0)

• return &dma[dma_index];
  

• return NULL;
  

  }

again, this function can be shared also?

Thanks, ~Keyon

...

diff --git a/src/platform/cannonlake/dma.c b/src/platform/cannonlake/dma.c index 9031c17..697b9a8 100644 --- a/src/platform/cannonlake/dma.c +++ b/src/platform/cannonlake/dma.c @@ -113,6 +113,8 @@ static struct dma dma[] = { { /* Low Power GP DMAC 0 */ .plat_data = { .id = DMA_GP_LP_DMAC0,

• .type		= DMAC_USER_GP_LP_DMA,
  

• .copy_dir	= DMAC_DIR_DUPLEX,
  	.base		= LP_GP_DMA_BASE(0),
  	.channels	= 8,
  	.irq = IRQ_EXT_LP_GPDMA0_LVL5(0, 0),
  

@@ -123,6 +125,8 @@ static struct dma dma[] = { { /* Low Power GP DMAC 1 */ .plat_data = { .id = DMA_GP_LP_DMAC1,

• .type		= DMAC_USER_GP_LP_DMA,
  

• .copy_dir	= DMAC_DIR_DUPLEX,
  	.base		= LP_GP_DMA_BASE(1),
  	.channels	= 8,
  	.irq = IRQ_EXT_LP_GPDMA1_LVL5(0, 0),
  

@@ -133,6 +137,8 @@ static struct dma dma[] = { { /* Host In DMAC */ .plat_data = { .id = DMA_HOST_IN_DMAC,

• .type		= DMAC_USER_HOST_DMA,
  

• .copy_dir	= DMAC_DIR_WRITE,
  	.base		=
  

GTW_HOST_IN_STREAM_BASE(0), .channels = 7, .irq = IRQ_EXT_HOST_DMA_IN_LVL3(0, 0), @@ -143,6 +149,8 @@ static struct dma dma[] = { { /* Host out DMAC */ .plat_data = { .id = DMA_HOST_OUT_DMAC,

• .type		= DMAC_USER_HOST_DMA,
  

• .copy_dir	= DMAC_DIR_READ,
  	.base		=
  

GTW_HOST_OUT_STREAM_BASE(0), .channels = 9, .irq = IRQ_EXT_HOST_DMA_OUT_LVL3(0, 0), @@ -153,6 +161,8 @@ static struct dma dma[] = { { /* Link In DMAC */ .plat_data = { .id = DMA_LINK_IN_DMAC,

• .type		= DMAC_USER_LINK_DMA,
  

• .copy_dir	= DMAC_DIR_WRITE,
  	.base		=
  

GTW_LINK_IN_STREAM_BASE(0), .channels = 9, .irq = IRQ_EXT_LINK_DMA_IN_LVL4(0, 0), @@ -163,6 +173,8 @@ static struct dma dma[] = { { /* Link out DMAC */ .plat_data = { .id = DMA_LINK_OUT_DMAC,

• .type		= DMAC_USER_LINK_DMA,
  

• .copy_dir	= DMAC_DIR_READ,
  	.base		=
  

GTW_LINK_OUT_STREAM_BASE(0), .channels = 7, .irq = IRQ_EXT_LINK_DMA_OUT_LVL4(0, 0), @@ -171,15 +183,48 @@ static struct dma dma[] = { .ops = &hda_link_dma_ops, },};

-struct dma *dma_get(int dmac_id) +/*

• • get DMAC based on user type, copy dir and flags
• • "flags" is used to set the type of access requested
• • (ex: shared/exclusive access)
• */

+struct dma *dma_get(enum dmac_user user, enum dmac_copy_dir dir, int flags) {

• int i;

• int i, ch_count;

• int dma_index = -1;

• int min_ch_count = INT32_MAX;

  for (i = 0; i < ARRAY_SIZE(dma); i++) {
  

• if (dma[i].plat_data.id == dmac_id)
  

• 	return &dma[i];
  

• /* check DMAC user type */
  

• if (dma[i].plat_data.type != user)
  

• 	continue;
  

• /* check DMAC copy dir */
  

• if (dma[i].plat_data.copy_dir != dir)
  

• 	continue;
  

• /* if exclusive access is requested */
  

• if (flags & DMAC_FLAGS_EXCLUSIVE) {
  

• 	/* ret DMA with no channel in use */
  

• 	if (!dma_channel_status(&dma[i]))
  

• 		return &dma[i];
  

• } else {
  

• 	/* get number of channels in use */
  

• 	ch_count =
  

dma_channel_status(&dma[i]);

• 	/* Use this DMAC if its channel count
  

is lower */

• 	if (ch_count < min_ch_count) {
  

• 		dma_index = i;
  

• 		min_ch_count = ch_count;
  

• 	}
  

• }
  }
  
  

• if (dma_index >= 0)

• return &dma[dma_index];
  

• return NULL;
  

  }

diff --git a/src/platform/haswell/dma.c b/src/platform/haswell/dma.c index 5d1e308..9138e78 100644 --- a/src/platform/haswell/dma.c +++ b/src/platform/haswell/dma.c @@ -124,16 +124,49 @@ static struct dma dma[] = { .ops = &dw_dma_ops, },};

-struct dma *dma_get(int dmac_id) +/*

• • get DMAC based on user type, copy dir and flags
• • For BYT/CHT, ignore the dmac_user and copy_dir arguments
• • "flags" is used to set the type of access requested
• • (ex: shared/exclusive access)
• */

+struct dma *dma_get(enum dmac_user user, enum dmac_copy_dir dir, int flags) {

• switch (dmac_id) {
• case DMA_ID_DMAC0:

• return &dma[0];
  

• case DMA_ID_DMAC1:

• return &dma[1];
  

• default:

• return NULL;
  

• int i, ch_count;
• int min_ch_count = INT32_MAX;
• int dma_index = -1;
• for (i = 0; i < ARRAY_SIZE(dma); i++) {

• /* if exclusive access is requested */
  

• if (flags & DMAC_FLAGS_EXCLUSIVE) {
  

• 	/* ret DMA with no channel in use */
  

• 	if (!dma_channel_status(&dma[i]))
  

• 		return &dma[i];
  

• } else {
  

• 	/*
  

• 	 * for shared access requests, return
  

DMAC

• 	 * with the least number of channels
  

in use

• 	 */
  

• 	/* get number of channels in use for
  

this DMAC*/

• 	ch_count =
  

dma_channel_status(&dma[i]);

• 	/* Use this DMAC if its channel count
  

is lower */

• 	if (ch_count < min_ch_count) {
  

• 		dma_index = i;
  

• 		min_ch_count = ch_count;
  

• 	}
  

• }
  }
  

• /* return DMAC */

• if (dma_index >= 0)

• return &dma[dma_index];
  

• return NULL; }

  /* Initialize all platform DMAC's */

---

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