net: ethernet: ti: Fix mixed module-builtin object

With CONFIG_TI_K3_AM65_CPSW_NUSS=y and CONFIG_TI_ICSSG_PRUETH=m,
k3-cppi-desc-pool.o is linked to a module and also to vmlinux even though
the expected CFLAGS are different between builtins and modules.

The build system is complaining about the following:

k3-cppi-desc-pool.o is added to multiple modules: icssg-prueth
ti-am65-cpsw-nuss

Introduce the new module, k3-cppi-desc-pool, to provide the common
functions to ti-am65-cpsw-nuss and icssg-prueth.

Fixes: 128d5874c0 ("net: ti: icssg-prueth: Add ICSSG ethernet driver")
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Link: https://lore.kernel.org/r/20231018064936.3146846-1-danishanwar@ti.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/ti/Kconfig

@@ -90,12 +90,16 @@ config TI_CPTS
 	  The unit can time stamp PTP UDP/IPv4 and Layer 2 packets, and the
 	  driver offers a PTP Hardware Clock.
 
+config TI_K3_CPPI_DESC_POOL
+	tristate
+
 config TI_K3_AM65_CPSW_NUSS
 	tristate "TI K3 AM654x/J721E CPSW Ethernet driver"
 	depends on ARCH_K3 && OF && TI_K3_UDMA_GLUE_LAYER
 	select NET_DEVLINK
 	select TI_DAVINCI_MDIO
 	select PHYLINK
+	select TI_K3_CPPI_DESC_POOL
 	imply PHY_TI_GMII_SEL
 	depends on TI_K3_AM65_CPTS || !TI_K3_AM65_CPTS
 	help
@@ -187,6 +191,7 @@ config TI_ICSSG_PRUETH
 	tristate "TI Gigabit PRU Ethernet driver"
 	select PHYLIB
 	select TI_ICSS_IEP
+	select TI_K3_CPPI_DESC_POOL
 	depends on PRU_REMOTEPROC
 	depends on ARCH_K3 && OF && TI_K3_UDMA_GLUE_LAYER
 	help

drivers/net/ethernet/ti/Makefile

@@ -24,14 +24,15 @@ keystone_netcp-y := netcp_core.o cpsw_ale.o
 obj-$(CONFIG_TI_KEYSTONE_NETCP_ETHSS) += keystone_netcp_ethss.o
 keystone_netcp_ethss-y := netcp_ethss.o netcp_sgmii.o netcp_xgbepcsr.o cpsw_ale.o
 
+obj-$(CONFIG_TI_K3_CPPI_DESC_POOL) += k3-cppi-desc-pool.o
+
 obj-$(CONFIG_TI_K3_AM65_CPSW_NUSS) += ti-am65-cpsw-nuss.o
-ti-am65-cpsw-nuss-y := am65-cpsw-nuss.o cpsw_sl.o am65-cpsw-ethtool.o cpsw_ale.o k3-cppi-desc-pool.o am65-cpsw-qos.o
+ti-am65-cpsw-nuss-y := am65-cpsw-nuss.o cpsw_sl.o am65-cpsw-ethtool.o cpsw_ale.o am65-cpsw-qos.o
 ti-am65-cpsw-nuss-$(CONFIG_TI_K3_AM65_CPSW_SWITCHDEV) += am65-cpsw-switchdev.o
 obj-$(CONFIG_TI_K3_AM65_CPTS) += am65-cpts.o
 
 obj-$(CONFIG_TI_ICSSG_PRUETH) += icssg-prueth.o
-icssg-prueth-y := k3-cppi-desc-pool.o \
-		  icssg/icssg_prueth.o \
+icssg-prueth-y := icssg/icssg_prueth.o \
 		  icssg/icssg_classifier.o \
 		  icssg/icssg_queues.o \
 		  icssg/icssg_config.o \

drivers/net/ethernet/ti/k3-cppi-desc-pool.c

@@ -39,6 +39,7 @@ void k3_cppi_desc_pool_destroy(struct k3_cppi_desc_pool *pool)
 
 	gen_pool_destroy(pool->gen_pool);	/* frees pool->name */
 }
+EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_destroy);
 
 struct k3_cppi_desc_pool *
 k3_cppi_desc_pool_create_name(struct device *dev, size_t size,
@@ -98,29 +99,38 @@ gen_pool_create_fail:
 	devm_kfree(pool->dev, pool);
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_create_name);
 
 dma_addr_t k3_cppi_desc_pool_virt2dma(struct k3_cppi_desc_pool *pool,
 				      void *addr)
 {
 	return addr ? pool->dma_addr + (addr - pool->cpumem) : 0;
 }
+EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_virt2dma);
 
 void *k3_cppi_desc_pool_dma2virt(struct k3_cppi_desc_pool *pool, dma_addr_t dma)
 {
 	return dma ? pool->cpumem + (dma - pool->dma_addr) : NULL;
 }
+EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_dma2virt);
 
 void *k3_cppi_desc_pool_alloc(struct k3_cppi_desc_pool *pool)
 {
 	return (void *)gen_pool_alloc(pool->gen_pool, pool->desc_size);
 }
+EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_alloc);
 
 void k3_cppi_desc_pool_free(struct k3_cppi_desc_pool *pool, void *addr)
 {
 	gen_pool_free(pool->gen_pool, (unsigned long)addr, pool->desc_size);
 }
+EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_free);
 
 size_t k3_cppi_desc_pool_avail(struct k3_cppi_desc_pool *pool)
 {
 	return gen_pool_avail(pool->gen_pool) / pool->desc_size;
 }
+EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_avail);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TI K3 CPPI5 descriptors pool API");