platform: Remove the ipi_sync method from all platforms.

OpenSBI manages outstanding TLB flush requests by queueing
them in a fifo synchronously. An ipi sync which uses an
atomic operation on MMIO address is no longer required.

Remove the ipi sync method from platform header and all usage.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

include/sbi/sbi_platform.h

@@ -90,8 +90,6 @@ struct sbi_platform_operations {
 
 	/** Send IPI to a target HART */
 	void (*ipi_send)(u32 target_hart);
-	/** Wait for target HART to acknowledge IPI */
-	void (*ipi_sync)(u32 target_hart);
 	/** Clear IPI for a target HART */
 	void (*ipi_clear)(u32 target_hart);
 	/** Initialize IPI for current HART */
@@ -370,19 +368,6 @@ static inline void sbi_platform_ipi_send(const struct sbi_platform *plat,
 		sbi_platform_ops(plat)->ipi_send(target_hart);
 }
 
-/**
- * Wait for target HART to acknowledge IPI
- *
- * @param plat pointer to struct sbi_platform
- * @param target_hart HART ID of IPI target
- */
-static inline void sbi_platform_ipi_sync(const struct sbi_platform *plat,
-					 u32 target_hart)
-{
-	if (plat && sbi_platform_ops(plat)->ipi_sync)
-		sbi_platform_ops(plat)->ipi_sync(target_hart);
-}
-
 /**
  * Clear IPI for a target HART
  *

lib/utils/sys/clint.c

@@ -25,29 +25,6 @@ void clint_ipi_send(u32 target_hart)
 	writel(1, &clint_ipi[target_hart]);
 }
 
-void clint_ipi_sync(u32 target_hart)
-{
-	u32 target_ipi, incoming_ipi;
-	u32 source_hart = sbi_current_hartid();
-
-	if (clint_ipi_hart_count <= target_hart)
-		return;
-
-	/* Wait until target HART has handled IPI */
-	incoming_ipi = 0;
-	while (1) {
-		target_ipi = readl(&clint_ipi[target_hart]);
-		if (!target_ipi)
-			break;
-
-		incoming_ipi |=
-			atomic_raw_xchg_uint(&clint_ipi[source_hart], 0);
-	}
-
-	if (incoming_ipi)
-		writel(incoming_ipi, &clint_ipi[source_hart]);
-}
-
 void clint_ipi_clear(u32 target_hart)
 {
 	if (clint_ipi_hart_count <= target_hart)

platform/ariane-fpga/platform.c

@@ -185,7 +185,6 @@ const struct sbi_platform_operations platform_ops = {
 	.irqchip_init = ariane_irqchip_init,
 	.ipi_init = ariane_ipi_init,
 	.ipi_send = clint_ipi_send,
-	.ipi_sync = clint_ipi_sync,
 	.ipi_clear = clint_ipi_clear,
 	.timer_init = ariane_timer_init,
 	.timer_value = clint_timer_value,

platform/kendryte/k210/platform.c

@@ -102,7 +102,6 @@ const struct sbi_platform_operations platform_ops = {
 
 	.ipi_init  = k210_ipi_init,
 	.ipi_send  = clint_ipi_send,
-	.ipi_sync  = clint_ipi_sync,
 	.ipi_clear = clint_ipi_clear,
 
 	.timer_init	   = k210_timer_init,

platform/qemu/sifive_u/platform.c

@@ -136,7 +136,6 @@ const struct sbi_platform_operations platform_ops = {
 	.console_init		= sifive_u_console_init,
 	.irqchip_init		= sifive_u_irqchip_init,
 	.ipi_send		= clint_ipi_send,
-	.ipi_sync		= clint_ipi_sync,
 	.ipi_clear		= clint_ipi_clear,
 	.ipi_init		= sifive_u_ipi_init,
 	.timer_value		= clint_timer_value,

platform/qemu/virt/platform.c

@@ -141,7 +141,6 @@ const struct sbi_platform_operations platform_ops = {
 	.console_init		= virt_console_init,
 	.irqchip_init		= virt_irqchip_init,
 	.ipi_send		= clint_ipi_send,
-	.ipi_sync		= clint_ipi_sync,
 	.ipi_clear		= clint_ipi_clear,
 	.ipi_init		= virt_ipi_init,
 	.timer_value		= clint_timer_value,

platform/sifive/fu540/platform.c

@@ -199,7 +199,6 @@ const struct sbi_platform_operations platform_ops = {
 	.console_init		= fu540_console_init,
 	.irqchip_init		= fu540_irqchip_init,
 	.ipi_send		= clint_ipi_send,
-	.ipi_sync		= clint_ipi_sync,
 	.ipi_clear		= clint_ipi_clear,
 	.ipi_init		= fu540_ipi_init,
 	.timer_value		= clint_timer_value,

platform/template/platform.c

@@ -124,15 +124,6 @@ static void platform_ipi_send(u32 target_hart)
 	clint_ipi_send(target_hart);
 }
 
-/*
- * Wait for target HART to acknowledge IPI.
- */
-static void platform_ipi_sync(u32 target_hart)
-{
-	/* Example if the generic CLINT driver is used */
-	clint_ipi_sync(target_hart);
-}
-
 /*
  * Clear IPI for a target HART.
  */
@@ -216,7 +207,6 @@ const struct sbi_platform_operations platform_ops = {
 	.console_init		= platform_console_init,
 	.irqchip_init		= platform_irqchip_init,
 	.ipi_send		= platform_ipi_send,
-	.ipi_sync		= platform_ipi_sync,
 	.ipi_clear		= platform_ipi_clear,
 	.ipi_init		= platform_ipi_init,
 	.timer_value		= platform_timer_value,