powerpc fixes for 4.6 #3

- cxl: Keep IRQ mappings on context teardown from Michael Neuling
  - cxl: Poll for outstanding IRQs when detaching a context from Michael Neuling
  - Wire up preadv2 and pwritev2 syscalls from Rui Salvaterra
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Merge tag 'powerpc-4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "A few more powerpc fixes for 4.6:

   - cxl: Keep IRQ mappings on context teardown from Michael Neuling

   - cxl: Poll for outstanding IRQs when detaching a context from
     Michael Neuling

   - Wire up preadv2 and pwritev2 syscalls from Rui Salvaterra"

* tag 'powerpc-4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: wire up preadv2 and pwritev2 syscalls
  cxl: Poll for outstanding IRQs when detaching a context
  cxl: Keep IRQ mappings on context teardown

arch/powerpc/include/asm/systbl.h

@@ -384,3 +384,5 @@ SYSCALL(ni_syscall)
 SYSCALL(ni_syscall)
 SYSCALL(mlock2)
 SYSCALL(copy_file_range)
+COMPAT_SYS_SPU(preadv2)
+COMPAT_SYS_SPU(pwritev2)

arch/powerpc/include/asm/unistd.h

@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define NR_syscalls		380
+#define NR_syscalls		382
 
 #define __NR__exit __NR_exit
 

arch/powerpc/include/uapi/asm/unistd.h

@@ -390,5 +390,7 @@
 #define __NR_membarrier		365
 #define __NR_mlock2		378
 #define __NR_copy_file_range	379
+#define __NR_preadv2		380
+#define __NR_pwritev2		381
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */

drivers/misc/cxl/context.c

@@ -223,6 +223,13 @@ int __detach_context(struct cxl_context *ctx)
 		cxl_ops->link_ok(ctx->afu->adapter, ctx->afu));
 	flush_work(&ctx->fault_work); /* Only needed for dedicated process */
 
+	/*
+	 * Wait until no further interrupts are presented by the PSL
+	 * for this context.
+	 */
+	if (cxl_ops->irq_wait)
+		cxl_ops->irq_wait(ctx);
+
 	/* release the reference to the group leader and mm handling pid */
 	put_pid(ctx->pid);
 	put_pid(ctx->glpid);

drivers/misc/cxl/cxl.h

@@ -274,6 +274,7 @@ static const cxl_p2n_reg_t CXL_PSL_WED_An     = {0x0A0};
 #define CXL_PSL_DSISR_An_PE (1ull << (63-4))  /* PSL Error (implementation specific) */
 #define CXL_PSL_DSISR_An_AE (1ull << (63-5))  /* AFU Error */
 #define CXL_PSL_DSISR_An_OC (1ull << (63-6))  /* OS Context Warning */
+#define CXL_PSL_DSISR_PENDING (CXL_PSL_DSISR_TRANS | CXL_PSL_DSISR_An_PE | CXL_PSL_DSISR_An_AE | CXL_PSL_DSISR_An_OC)
 /* NOTE: Bits 32:63 are undefined if DSISR[DS] = 1 */
 #define CXL_PSL_DSISR_An_M  DSISR_NOHPTE      /* PTE not found */
 #define CXL_PSL_DSISR_An_P  DSISR_PROTFAULT   /* Storage protection violation */
@@ -855,6 +856,7 @@ struct cxl_backend_ops {
 					u64 dsisr, u64 errstat);
 	irqreturn_t (*psl_interrupt)(int irq, void *data);
 	int (*ack_irq)(struct cxl_context *ctx, u64 tfc, u64 psl_reset_mask);
+	void (*irq_wait)(struct cxl_context *ctx);
 	int (*attach_process)(struct cxl_context *ctx, bool kernel,
 			u64 wed, u64 amr);
 	int (*detach_process)(struct cxl_context *ctx);

drivers/misc/cxl/irq.c

@@ -203,7 +203,6 @@ unsigned int cxl_map_irq(struct cxl *adapter, irq_hw_number_t hwirq,
 void cxl_unmap_irq(unsigned int virq, void *cookie)
 {
 	free_irq(virq, cookie);
-	irq_dispose_mapping(virq);
 }
 
 int cxl_register_one_irq(struct cxl *adapter,

drivers/misc/cxl/native.c

@@ -14,6 +14,7 @@
 #include <linux/mutex.h>
 #include <linux/mm.h>
 #include <linux/uaccess.h>
+#include <linux/delay.h>
 #include <asm/synch.h>
 #include <misc/cxl-base.h>
 
@@ -797,6 +798,35 @@ static irqreturn_t native_irq_multiplexed(int irq, void *data)
 	return fail_psl_irq(afu, &irq_info);
 }
 
+void native_irq_wait(struct cxl_context *ctx)
+{
+	u64 dsisr;
+	int timeout = 1000;
+	int ph;
+
+	/*
+	 * Wait until no further interrupts are presented by the PSL
+	 * for this context.
+	 */
+	while (timeout--) {
+		ph = cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) & 0xffff;
+		if (ph != ctx->pe)
+			return;
+		dsisr = cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An);
+		if ((dsisr & CXL_PSL_DSISR_PENDING) == 0)
+			return;
+		/*
+		 * We are waiting for the workqueue to process our
+		 * irq, so need to let that run here.
+		 */
+		msleep(1);
+	}
+
+	dev_warn(&ctx->afu->dev, "WARNING: waiting on DSI for PE %i"
+		 " DSISR %016llx!\n", ph, dsisr);
+	return;
+}
+
 static irqreturn_t native_slice_irq_err(int irq, void *data)
 {
 	struct cxl_afu *afu = data;
@@ -1076,6 +1106,7 @@ const struct cxl_backend_ops cxl_native_ops = {
 	.handle_psl_slice_error = native_handle_psl_slice_error,
 	.psl_interrupt = NULL,
 	.ack_irq = native_ack_irq,
+	.irq_wait = native_irq_wait,
 	.attach_process = native_attach_process,
 	.detach_process = native_detach_process,
 	.support_attributes = native_support_attributes,