[PATCH v4 03/16] powerpc/vas: Add platform specific user window operations

[Haren Myneni <haren@linux.ibm.com>]

PowerNV uses registers to open/close VAS windows, and getting the
paste address. Whereas the hypervisor calls are used on PowerVM.

This patch adds the platform specific user space window operations
and register with the common VAS user space interface.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 arch/powerpc/include/asm/vas.h              | 14 +++++-
 arch/powerpc/platforms/book3s/vas-api.c     | 52 ++++++++++++---------
 arch/powerpc/platforms/powernv/vas-window.c | 46 +++++++++++++++++-
 3 files changed, 89 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index 6076adf9ab4f..668303198772 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -5,6 +5,7 @@
 
 #ifndef _ASM_POWERPC_VAS_H
 #define _ASM_POWERPC_VAS_H
+#include <uapi/asm/vas-api.h>
 
 struct vas_window;
 
@@ -48,6 +49,16 @@ enum vas_cop_type {
 	VAS_COP_TYPE_MAX,
 };
 
+/*
+ * User space window operations used for powernv and powerVM
+ */
+struct vas_user_win_ops {
+	struct vas_window * (*open_win)(struct vas_tx_win_open_attr *,
+				enum vas_cop_type);
+	u64 (*paste_addr)(void *);
+	int (*close_win)(void *);
+};
+
 /*
  * Receive window attributes specified by the (in-kernel) owner of window.
  */
@@ -177,7 +188,8 @@ void vas_unregister_api_powernv(void);
  * used for others in future.
  */
 int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
-				const char *name);
+			    const char *name,
+			    struct vas_user_win_ops *vops);
 void vas_unregister_coproc_api(void);
 
 #endif /* __ASM_POWERPC_VAS_H */
diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c
index 72c126d87216..6c39320bfb9b 100644
--- a/arch/powerpc/platforms/book3s/vas-api.c
+++ b/arch/powerpc/platforms/book3s/vas-api.c
@@ -42,6 +42,7 @@ static struct coproc_dev {
 	dev_t devt;
 	struct class *class;
 	enum vas_cop_type cop_type;
+	struct vas_user_win_ops *vops;
 } coproc_device;
 
 struct coproc_instance {
@@ -72,11 +73,10 @@ static int coproc_open(struct inode *inode, struct file *fp)
 static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 {
 	void __user *uptr = (void __user *)arg;
-	struct vas_tx_win_attr txattr = {};
 	struct vas_tx_win_open_attr uattr;
 	struct coproc_instance *cp_inst;
 	struct vas_window *txwin;
-	int rc, vasid;
+	int rc;
 
 	cp_inst = fp->private_data;
 
@@ -93,27 +93,20 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 	}
 
 	if (uattr.version != 1) {
-		pr_err("Invalid version\n");
+		pr_err("Invalid window open API version\n");
 		return -EINVAL;
 	}
 
-	vasid = uattr.vas_id;
-
-	vas_init_tx_win_attr(&txattr, cp_inst->coproc->cop_type);
-
-	txattr.lpid = mfspr(SPRN_LPID);
-	txattr.pidr = mfspr(SPRN_PID);
-	txattr.user_win = true;
-	txattr.rsvd_txbuf_count = false;
-	txattr.pswid = false;
-
-	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
-				mfspr(SPRN_PID));
+	if (!cp_inst->coproc->vops && !cp_inst->coproc->vops->open_win) {
+		pr_err("VAS API is not registered\n");
+		return -EACCES;
+	}
 
-	txwin = vas_tx_win_open(vasid, cp_inst->coproc->cop_type, &txattr);
+	txwin = cp_inst->coproc->vops->open_win(&uattr,
+						cp_inst->coproc->cop_type);
 	if (IS_ERR(txwin)) {
-		pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
-					PTR_ERR(txwin));
+		pr_err("%s() VAS window open failed, %ld\n", __func__,
+				PTR_ERR(txwin));
 		return PTR_ERR(txwin);
 	}
 
@@ -125,9 +118,15 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 static int coproc_release(struct inode *inode, struct file *fp)
 {
 	struct coproc_instance *cp_inst = fp->private_data;
+	int rc;
 
 	if (cp_inst->txwin) {
-		vas_win_close(cp_inst->txwin);
+		if (cp_inst->coproc->vops &&
+			cp_inst->coproc->vops->close_win) {
+			rc = cp_inst->coproc->vops->close_win(cp_inst->txwin);
+			if (rc)
+				return rc;
+		}
 		cp_inst->txwin = NULL;
 	}
 
@@ -168,7 +167,17 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
 		return -EINVAL;
 	}
 
-	vas_win_paste_addr(txwin, &paste_addr, NULL);
+	if (!cp_inst->coproc->vops && !cp_inst->coproc->vops->paste_addr) {
+		pr_err("%s(): VAS API is not registered\n", __func__);
+		return -EACCES;
+	}
+
+	paste_addr = cp_inst->coproc->vops->paste_addr(txwin);
+	if (!paste_addr) {
+		pr_err("%s(): Window paste address failed\n", __func__);
+		return -EINVAL;
+	}
+
 	pfn = paste_addr >> PAGE_SHIFT;
 
 	/* flags, page_prot from cxl_mmap(), except we want cachable */
@@ -208,7 +217,7 @@ static struct file_operations coproc_fops = {
  * extended to other coprocessor types later.
  */
 int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
-				const char *name)
+			    const char *name, struct vas_user_win_ops *vops)
 {
 	int rc = -EINVAL;
 	dev_t devno;
@@ -230,6 +239,7 @@ int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
 	}
 	coproc_device.class->devnode = coproc_devnode;
 	coproc_device.cop_type = cop_type;
+	coproc_device.vops = vops;
 
 	coproc_fops.owner = mod;
 	cdev_init(&coproc_device.cdev, &coproc_fops);
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 2fc0fbc4a3d1..3ccd3edcaf1a 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -16,6 +16,7 @@
 #include <linux/mmu_context.h>
 #include <asm/switch_to.h>
 #include <asm/ppc-opcode.h>
+#include <asm/vas.h>
 #include "vas.h"
 #include "copy-paste.h"
 
@@ -1442,6 +1443,49 @@ struct vas_window *vas_pswid_to_window(struct vas_instance *vinst,
 	return window;
 }
 
+static struct vas_window *vas_user_win_open(struct vas_tx_win_open_attr *uattr,
+				enum vas_cop_type cop_type)
+{
+	struct vas_tx_win_attr txattr = {};
+
+	vas_init_tx_win_attr(&txattr, cop_type);
+
+	txattr.lpid = mfspr(SPRN_LPID);
+	txattr.pidr = mfspr(SPRN_PID);
+	txattr.user_win = true;
+	txattr.rsvd_txbuf_count = false;
+	txattr.pswid = false;
+
+	pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
+				mfspr(SPRN_PID));
+
+	return vas_tx_win_open(uattr->vas_id, cop_type, &txattr);
+}
+
+static u64 vas_user_win_paste_addr(void *addr)
+{
+	u64 paste_addr;
+
+	vas_win_paste_addr((struct vas_window *)addr, &paste_addr, NULL);
+
+	return paste_addr;
+}
+
+static int vas_user_win_close(void *addr)
+{
+	struct vas_window *txwin = addr;
+
+	vas_win_close(txwin);
+
+	return 0;
+}
+
+static struct vas_user_win_ops vops =  {
+	.open_win	=	vas_user_win_open,
+	.paste_addr	=	vas_user_win_paste_addr,
+	.close_win	=	vas_user_win_close,
+};
+
 /*
  * Supporting only nx-gzip coprocessor type now, but this API code
  * extended to other coprocessor types later.
@@ -1450,7 +1494,7 @@ int vas_register_api_powernv(struct module *mod, enum vas_cop_type cop_type,
 			     const char *name)
 {
 
-	return vas_register_coproc_api(mod, cop_type, name);
+	return vas_register_coproc_api(mod, cop_type, name, &vops);
 }
 EXPORT_SYMBOL_GPL(vas_register_api_powernv);
 
-- 
2.18.2