Re: [EXTERNAL] Re: [PATCH v10 3/6] remoteproc: pru: Add enum for PRU Core Indentifiers.

From: Md Danish Anwar
Date: Thu Dec 01 2022 - 08:44:05 EST


Hi Roger,

On 01/12/22 5:28 pm, Roger Quadros wrote:
Danish,

On 01/12/2022 13:04, MD Danish Anwar wrote:
Introducing enum pruss_pru_id for PRU Core Identifiers.
PRUSS_PRU0 indicates PRU Core 0.
PRUSS_PRU1 indicates PRU Core 1.
PRUSS_NUM_PRUS indicates the total number of PRU Cores.

Signed-off-by: MD Danish Anwar <danishanwar@xxxxxx>
---
drivers/remoteproc/pru_rproc.c | 16 ++++++++++++----
include/linux/pruss.h | 19 +++++++++++++++++--
2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index b4498a505108..7d4ed39b3772 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -186,6 +186,7 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
* pru_rproc_get() - get the PRU rproc instance from a device node
* @np: the user/client device node
* @index: index to use for the ti,prus property
+ * @pru_id: optional pointer to return the PRU remoteproc processor id
*
* This function looks through a client device node's "ti,prus" property at
* index @index and returns the rproc handle for a valid PRU remote processor if
@@ -193,13 +194,17 @@ static struct rproc *__pru_rproc_get(struct device_node *np, int index)
* time. Caller must call pru_rproc_put() when done with using the rproc, not
* required if the function returns a failure.
*
+ * When optional @pru_id pointer is passed the PRU remoteproc processor id is
+ * returned.
+ *
* Return: rproc handle on success, and an ERR_PTR on failure using one
* of the following error values
* -ENODEV if device is not found
* -EBUSY if PRU is already acquired by anyone
* -EPROBE_DEFER is PRU device is not probed yet
*/
-struct rproc *pru_rproc_get(struct device_node *np, int index)
+struct rproc *pru_rproc_get(struct device_node *np, int index,
+ enum pruss_pru_id *pru_id)

You just introduced pru_rproc_get() in the previous patch and are
now updating it here.


That's because there is dependency between these two patches. The enum pruss_pru_id is declared inside linux/pruss.h file which is introduced in pru_rproc_get() patch. But pru_rproc_get() and pru_rproc_put() APIs use the enum as function argument. So I decided to keep pru_rproc_get() patch as second patch of this series(as it introduces <linux/pruss.h> where eventually the enum will be introduced).

Then I kept the enum introduction patch as third patch of the series and with this patch I modified pru_rproc_get() API by adding pru_id field in the function argument.

Instead, what you need to do is, first introduce enum pruss_pru_id
and make any changes to code using hardcoded values for PRU ID.
This patch will have to introduce <linux/pruss.h> as it doesn't exist yet.

This also came to my mind. But I thought introduction of enum pruss_pru_id patch should just introduce the enum and modify APIs which uses the enum accordingly. I wanted to keep the introduction of <linux/pruss.h> file with the pru_rproc_get() patch as it was. That's why I kept pru_rproc_get() patch ahead of enum patch.

Hopefully this clears the chicken/egg situation.

Then introduce pru_rproc_get() patch with the final desired arguments.

{
struct rproc *rproc;
struct pru_rproc *pru;
@@ -226,6 +231,9 @@ struct rproc *pru_rproc_get(struct device_node *np, int index)
mutex_unlock(&pru->lock);
+ if (pru_id)
+ *pru_id = pru->id;
+
return rproc;
err_no_rproc_handle:
@@ -556,7 +564,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
/* PRU1 has its local RAM addresses reversed */
- if (pru->id == 1)
+ if (pru->id == PRUSS_PRU1)
swap(dram0, dram1);
shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
@@ -865,14 +873,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
case RTU0_IRAM_ADDR_MASK:
fallthrough;
case PRU0_IRAM_ADDR_MASK:
- pru->id = 0;
+ pru->id = PRUSS_PRU0;
break;
case TX_PRU1_IRAM_ADDR_MASK:
fallthrough;
case RTU1_IRAM_ADDR_MASK:
fallthrough;
case PRU1_IRAM_ADDR_MASK:
- pru->id = 1;
+ pru->id = PRUSS_PRU1;
break;
default:
ret = -EINVAL;
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
index 5c5d14b1249d..efe89c586b4b 100644
--- a/include/linux/pruss.h
+++ b/include/linux/pruss.h
@@ -14,17 +14,32 @@
#define PRU_RPROC_DRVNAME "pru-rproc"
+/**
+ * enum pruss_pru_id - PRU core identifiers
+ * @PRUSS_PRU0: PRU Core 0.
+ * @PRUSS_PRU1: PRU Core 1.
+ * @PRUSS_NUM_PRUS: Total number of PRU Cores available.
+ *
+ */
+
+enum pruss_pru_id {
+ PRUSS_PRU0 = 0,
+ PRUSS_PRU1,
+ PRUSS_NUM_PRUS,
+};
+
struct device_node;
#if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
-struct rproc *pru_rproc_get(struct device_node *np, int index);
+struct rproc *pru_rproc_get(struct device_node *np, int index,
+ enum pruss_pru_id *pru_id);
void pru_rproc_put(struct rproc *rproc);
#else
static inline struct rproc *
-pru_rproc_get(struct device_node *np, int index)
+pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
{
return ERR_PTR(-EOPNOTSUPP);
}

--
cheers,
-roger

Thanks,
Danish.