[PATCH 6/7] net: ethernet: ti: cpsw: add support for descs_pool_size dt property

Grygorii Strashko
2016-12-01T23:34:31Z

The CPSW CPDMA can process buffer descriptors placed as in internal
CPPI RAM as in DDR. This patch adds support in CPSW and CPDMA for
descs_pool_size DT property, which defines total number of CPDMA CPPI
descriptors to be used for both ingress/egress packets processing:
- memory size required for CPDMA descriptor pool is calculated basing
on number of descriptors specified by user in descs_pool_size and
CPDMA descriptor size;
- allocate CPDMA descriptor pool in DDR if pool memory size >
internal CPPI RAM or use internal CPPI RAM otherwise;
- if descs_pool_size not specified in DT - the default value 256 will
be used which will allow to place CPDMA descriptors pool into the
internal CPPI RAM (current default behaviour);
- CPDMA will ignore descs_pool_size if descs_pool_size = 0 for
backward comaptiobility with davinci_emac.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
drivers/net/ethernet/ti/cpsw.c | 5 +++++
drivers/net/ethernet/ti/cpsw.h | 1 +
drivers/net/ethernet/ti/davinci_cpdma.c | 12 ++++++++++++
drivers/net/ethernet/ti/davinci_cpdma.h | 1 +
4 files changed, 19 insertions(+)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index dd5d830..a98c6260 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -145,6 +145,7 @@ do { \
cpsw->data.active_slave)
#define IRQ_NUM 2
#define CPSW_MAX_QUEUES 8
+#define CPSW_CPDMA_DESCS_POOL_SIZE_DEFAULT 256

static int debug_level;
module_param(debug_level, int, 0);
@@ -2557,6 +2558,9 @@ static int cpsw_probe_dt(struct cpsw_platform_data *data,
if (of_property_read_bool(node, "dual_emac"))
data->dual_emac = 1;

+ data->descs_pool_size = CPSW_CPDMA_DESCS_POOL_SIZE_DEFAULT;
+ of_property_read_u32(node, "descs_pool_size", &data->descs_pool_size);
+
/*
* Populate all the child nodes here...
*/
@@ -2967,6 +2971,7 @@ static int cpsw_probe(struct platform_device *pdev)
dma_params.has_ext_regs = true;
dma_params.desc_hw_addr = dma_params.desc_mem_phys;
dma_params.bus_freq_mhz = cpsw->bus_freq_mhz;
+ dma_params.descs_pool_size = cpsw->data.descs_pool_size;

cpsw->dma = cpdma_ctlr_create(&dma_params);
if (!cpsw->dma) {
diff --git a/drivers/net/ethernet/ti/cpsw.h b/drivers/net/ethernet/ti/cpsw.h
index 16b54c6..8835d79 100644
--- a/drivers/net/ethernet/ti/cpsw.h
+++ b/drivers/net/ethernet/ti/cpsw.h
@@ -38,6 +38,7 @@ struct cpsw_platform_data {
u32 mac_control; /* Mac control register */
u16 default_vlan; /* Def VLAN for ALE lookup in VLAN aware mode*/
bool dual_emac; /* Enable Dual EMAC mode */
+ u32 descs_pool_size; /* Number of Rx/Tx Descriptios */
};

void cpsw_phy_sel(struct device *dev, phy_interface_t phy_mode, int slave);
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index ba892bb..f45bb8a 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -219,6 +219,18 @@ int cpdma_desc_pool_create(struct cpdma_ctlr *ctlr)
cpdma_params->desc_align);
pool->num_desc = pool->mem_size / pool->desc_size;

+ if (cpdma_params->descs_pool_size) {
+ /* recalculate memory size required cpdma descriptor pool
+ * basing on number of descriptors specified by user and
+ * if memory size > CPPI internal RAM size (desc_mem_size)
+ * then switch to use DDR
+ */
+ pool->num_desc = cpdma_params->descs_pool_size;
+ pool->mem_size = pool->desc_size * pool->num_desc;
+ if (pool->mem_size > cpdma_params->desc_mem_size)
+ cpdma_params->desc_mem_phys = 0;
+ }
+
pool->gen_pool = devm_gen_pool_create(ctlr->dev, ilog2(pool->desc_size),
-1, "cpdma");
if (IS_ERR(pool->gen_pool)) {
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.h b/drivers/net/ethernet/ti/davinci_cpdma.h
index 4a167db..cb45f8f 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.h
+++ b/drivers/net/ethernet/ti/davinci_cpdma.h
@@ -37,6 +37,7 @@ struct cpdma_params {
int desc_mem_size;
int desc_align;
u32 bus_freq_mhz;
+ u32 descs_pool_size;

/*
* Some instances of embedded cpdma controllers have extra control and
--
2.10.1