remoteproc/pru: Add pru_rproc_set_ctable() function

Some firmwares expect the OS drivers to configure the CTABLE
entries publishing dynamically allocated memory regions. For
example, the PRU Ethernet firmwares use the C28 and C30 entries
for retrieving the Shared RAM and System SRAM (OCMC) areas
allocated by the PRU Ethernet client driver.

Provide a way for users to do that through a new API,
pru_rproc_set_ctable(). The API returns 0 on success and
a negative value on error.

NOTE:
The programmable CTABLE entries are typically re-programmed by
the PRU firmwares when dealing with a certain block of memory
during block processing. This API provides an interface to the
PRU client drivers to publish a dynamically allocated memory
block with the PRU firmware using a CTABLE entry instead of a
negotiated address in shared memory. Additional synchronization
may be needed between the PRU client drivers and firmwares if
different addresses needs to be published at run-time reusing
the same CTABLE entry.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
[s-anna@ti.com: add the NOTE: on patch description, minor cleanups]
Signed-off-by: Suman Anna <s-anna@ti.com>

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index a7c6e523726c4122116c0d7e536c61a09eedf213..76beefdb7e0dd3146310e1017649968d4c2888fd 100644 (file)
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -69,6 +69,7 @@ enum pru_iomem {
  * @irq_kick: IRQ number to use to perform virtio kick
  * @mem_regions: data for each of the PRU memory regions
  * @intc_config: PRU INTC configuration data
+ * @rmw_lock: lock for read, modify, write operations on registers
  * @iram_da: device address of Instruction RAM for this PRU
  * @pdram_da: device address of primary Data RAM for this PRU
  * @sdram_da: device address of secondary Data RAM for this PRU
@@ -89,6 +90,7 @@ struct pru_rproc {
        int irq_kick;
        struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
        struct pruss_intc_config intc_config;
+       spinlock_t rmw_lock; /* register access lock */
        u32 iram_da;
        u32 pdram_da;
        u32 sdram_da;
@@ -112,6 +114,23 @@ void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
        writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
 }
 
+static inline
+void pru_control_set_reg(struct pru_rproc *pru, unsigned int reg,
+                        u32 mask, u32 set)
+{
+       u32 val;
+       unsigned long flags;
+
+       spin_lock_irqsave(&pru->rmw_lock, flags);
+
+       val = pru_control_read_reg(pru, reg);
+       val &= ~mask;
+       val |= (set & mask);
+       pru_control_write_reg(pru, reg, val);
+
+       spin_unlock_irqrestore(&pru->rmw_lock, flags);
+}
+
 static struct rproc *__pru_rproc_get(struct device_node *np, int index)
 {
        struct device_node *rproc_np = NULL;
@@ -221,6 +240,37 @@ void pru_rproc_put(struct rproc *rproc)
 }
 EXPORT_SYMBOL_GPL(pru_rproc_put);
 
+/**
+ * pru_rproc_set_ctable() - set the constant table index for the PRU
+ * @rproc: the rproc instance of the PRU
+ * @c: constant table index to set
+ * @addr: physical address to set it to
+ */
+int pru_rproc_set_ctable(struct rproc *rproc, enum pru_ctable_idx c, u32 addr)
+{
+       struct pru_rproc *pru = rproc->priv;
+       unsigned int reg;
+       u32 mask, set;
+       u16 idx;
+       u16 idx_mask;
+
+       /* pointer is 16 bit and index is 8-bit so mask out the rest */
+       idx_mask = (c >= PRU_C28) ? 0xFFFF : 0xFF;
+
+       /* ctable uses bit 8 and upwards only */
+       idx = (addr >> 8) & idx_mask;
+
+       /* configurable ctable (i.e. C24) starts at PRU_CTRL_CTBIR0 */
+       reg = PRU_CTRL_CTBIR0 + 4 * (c >> 1);
+       mask = idx_mask << (16 * (c & 1));
+       set = idx << (16 * (c & 1));
+
+       pru_control_set_reg(pru, reg, mask, set);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(pru_rproc_set_ctable);
+
 static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
 {
        return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
@@ -760,6 +810,7 @@ static int pru_rproc_probe(struct platform_device *pdev)
        pru->pruss = platform_get_drvdata(ppdev);
        pru->rproc = rproc;
        pru->fw_name = fw_name;
+       spin_lock_init(&pru->rmw_lock);
        mutex_init(&pru->lock);
 
        /* XXX: get this from match data if different in the future */

diff --git a/include/linux/pruss.h b/include/linux/pruss.h
index 59fb1ab069b603d2f65598348426e628fdc264ba..7975790b8895b502c4060c9972acc9a33a01fad9 100644 (file)
--- a/include/linux/pruss.h
+++ b/include/linux/pruss.h
@@ -9,6 +9,22 @@
 #ifndef __LINUX_PRUSS_H
 #define __LINUX_PRUSS_H
 
+/**
+ * enum pru_ctable_idx - Configurable Constant table index identifiers
+ */
+enum pru_ctable_idx {
+       PRU_C24 = 0,
+       PRU_C25,
+       PRU_C26,
+       PRU_C27,
+       PRU_C28,
+       PRU_C29,
+       PRU_C30,
+       PRU_C31,
+};
+
+struct rproc;
+
 #if IS_ENABLED(CONFIG_TI_PRUSS)
 
 int pruss_intc_trigger(unsigned int irq);
@@ -26,6 +42,7 @@ static inline int pruss_intc_trigger(unsigned int irq)
 
 struct rproc *pru_rproc_get(struct device_node *node, int index);
 void pru_rproc_put(struct rproc *rproc);
+int pru_rproc_set_ctable(struct rproc *rproc, enum pru_ctable_idx c, u32 addr);
 
 #else
 
@@ -36,6 +53,12 @@ static inline struct rproc *pru_rproc_get(struct device_node *node, int index)
 
 static inline void pru_rproc_put(struct rproc *rproc) { }
 
+static inline int pru_rproc_set_ctable(struct rproc *rproc,
+                                      enum pru_ctable_idx c, u32 addr)
+{
+       return -ENOTSUPP;
+}
+
 #endif /* CONFIG_PRU_REMOTEPROC */
 
 #endif /* __LINUX_PRUSS_H */