cxl: Allow a default context to be associated with an external pci_dev

The cxl kernel API has a concept of a default context associated with
each PCI device under the virtual PHB. The Mellanox CX4 will also use
the cxl kernel API, but it does not use a virtual PHB - rather, the AFU
appears as a physical function as a peer to the networking functions.

In order to allow the kernel API to work with those networking
functions, we will need to associate a default context with them as
well. To this end, refactor the corresponding code to do this in vphb.c
and export it so that it can be called from the PHB code.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/drivers/misc/cxl/Makefile b/drivers/misc/cxl/Makefile
index 8a55c1aa11aa1eeeb33246ab81e2ccfa6743b637..56e9a4732ef09b8c62ab80150cd7dab3ad7d4f64 100644 (file)
--- a/drivers/misc/cxl/Makefile
+++ b/drivers/misc/cxl/Makefile
@@ -3,7 +3,7 @@ ccflags-$(CONFIG_PPC_WERROR)    += -Werror
 
 cxl-y                          += main.o file.o irq.o fault.o native.o
 cxl-y                          += context.o sysfs.o debugfs.o pci.o trace.o
-cxl-y                          += vphb.o api.o
+cxl-y                          += vphb.o phb.o api.o
 cxl-$(CONFIG_PPC_PSERIES)      += flash.o guest.o of.o hcalls.o
 obj-$(CONFIG_CXL)              += cxl.o
 obj-$(CONFIG_CXL_BASE)         += base.o

diff --git a/drivers/misc/cxl/base.c b/drivers/misc/cxl/base.c
index 7557835cdfcd6c37e071f3be6fc66df7ab8822a8..e1e80cb99ad9ff4fdb273e1f9e67955dc5adad49 100644 (file)
--- a/drivers/misc/cxl/base.c
+++ b/drivers/misc/cxl/base.c
@@ -106,6 +106,41 @@ int cxl_update_properties(struct device_node *dn,
 }
 EXPORT_SYMBOL_GPL(cxl_update_properties);
 
+/*
+ * API calls into the driver that may be called from the PHB code and must be
+ * built in.
+ */
+bool cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu)
+{
+       bool ret;
+       struct cxl_calls *calls;
+
+       calls = cxl_calls_get();
+       if (!calls)
+               return false;
+
+       ret = calls->cxl_pci_associate_default_context(dev, afu);
+
+       cxl_calls_put(calls);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(cxl_pci_associate_default_context);
+
+void cxl_pci_disable_device(struct pci_dev *dev)
+{
+       struct cxl_calls *calls;
+
+       calls = cxl_calls_get();
+       if (!calls)
+               return;
+
+       calls->cxl_pci_disable_device(dev);
+
+       cxl_calls_put(calls);
+}
+EXPORT_SYMBOL_GPL(cxl_pci_disable_device);
+
 static int __init cxl_base_init(void)
 {
        struct device_node *np;

diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index d4aae6f855a8f2f8b258aa192a108794e7c052d0..b81f476a2b9fcf1155455de22378a0b1f1d10daf 100644 (file)
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -719,9 +719,15 @@ static inline u64 cxl_p2n_read(struct cxl_afu *afu, cxl_p2n_reg_t reg)
 ssize_t cxl_pci_afu_read_err_buffer(struct cxl_afu *afu, char *buf,
                                loff_t off, size_t count);
 
+/* Internal functions wrapped in cxl_base to allow PHB to call them */
+bool _cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu);
+void _cxl_pci_disable_device(struct pci_dev *dev);
 
 struct cxl_calls {
        void (*cxl_slbia)(struct mm_struct *mm);
+       bool (*cxl_pci_associate_default_context)(struct pci_dev *dev, struct cxl_afu *afu);
+       void (*cxl_pci_disable_device)(struct pci_dev *dev);
+
        struct module *owner;
 };
 int register_cxl_calls(struct cxl_calls *calls);

diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index ae68c320115674e70c00f1ddc98b6f4dfa7d4321..4e5474b00b285d9838386fded3d4a27662adc119 100644 (file)
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -110,6 +110,8 @@ static inline void cxl_slbia_core(struct mm_struct *mm)
 
 static struct cxl_calls cxl_calls = {
        .cxl_slbia = cxl_slbia_core,
+       .cxl_pci_associate_default_context = _cxl_pci_associate_default_context,
+       .cxl_pci_disable_device = _cxl_pci_disable_device,
        .owner = THIS_MODULE,
 };
 

diff --git a/drivers/misc/cxl/phb.c b/drivers/misc/cxl/phb.c
new file mode 100644 (file)
index 0000000..0935d44
--- /dev/null
+++ b/drivers/misc/cxl/phb.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2014-2016 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/pci.h>
+#include "cxl.h"
+
+bool _cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu)
+{
+       struct cxl_context *ctx;
+
+       /*
+        * Allocate a context to do cxl things to. This is used for interrupts
+        * in the peer model using a real phb, and if we eventually do DMA ops
+        * in the virtual phb, we'll need a default context to attach them to.
+        */
+       ctx = cxl_dev_context_init(dev);
+       if (!ctx)
+               return false;
+       dev->dev.archdata.cxl_ctx = ctx;
+
+       return (cxl_ops->afu_check_and_enable(afu) == 0);
+}
+/* exported via cxl_base */
+
+void _cxl_pci_disable_device(struct pci_dev *dev)
+{
+       struct cxl_context *ctx = cxl_get_context(dev);
+
+       if (ctx) {
+               if (ctx->status == STARTED) {
+                       dev_err(&dev->dev, "Default context started\n");
+                       return;
+               }
+               dev->dev.archdata.cxl_ctx = NULL;
+               cxl_release_context(ctx);
+       }
+}
+/* exported via cxl_base */

diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c
index 012b6aa9fb3ec07cea94cbc4f7fed54a139aefd6..c8a759f4ccfaab4ca00c4c04f074e9e0f63d8424 100644 (file)
--- a/drivers/misc/cxl/vphb.c
+++ b/drivers/misc/cxl/vphb.c
@@ -44,7 +44,6 @@ static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
 {
        struct pci_controller *phb;
        struct cxl_afu *afu;
-       struct cxl_context *ctx;
 
        phb = pci_bus_to_host(dev->bus);
        afu = (struct cxl_afu *)phb->private_data;
@@ -57,30 +56,7 @@ static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
        set_dma_ops(&dev->dev, &dma_direct_ops);
        set_dma_offset(&dev->dev, PAGE_OFFSET);
 
-       /*
-        * Allocate a context to do cxl things too.  If we eventually do real
-        * DMA ops, we'll need a default context to attach them to
-        */
-       ctx = cxl_dev_context_init(dev);
-       if (!ctx)
-               return false;
-       dev->dev.archdata.cxl_ctx = ctx;
-
-       return (cxl_ops->afu_check_and_enable(afu) == 0);
-}
-
-static void cxl_pci_disable_device(struct pci_dev *dev)
-{
-       struct cxl_context *ctx = cxl_get_context(dev);
-
-       if (ctx) {
-               if (ctx->status == STARTED) {
-                       dev_err(&dev->dev, "Default context started\n");
-                       return;
-               }
-               dev->dev.archdata.cxl_ctx = NULL;
-               cxl_release_context(ctx);
-       }
+       return _cxl_pci_associate_default_context(dev, afu);
 }
 
 static resource_size_t cxl_pci_window_alignment(struct pci_bus *bus,
@@ -197,8 +173,8 @@ static struct pci_controller_ops cxl_pci_controller_ops =
 {
        .probe_mode = cxl_pci_probe_mode,
        .enable_device_hook = cxl_pci_enable_device_hook,
-       .disable_device = cxl_pci_disable_device,
-       .release_device = cxl_pci_disable_device,
+       .disable_device = _cxl_pci_disable_device,
+       .release_device = _cxl_pci_disable_device,
        .window_alignment = cxl_pci_window_alignment,
        .reset_secondary_bus = cxl_pci_reset_secondary_bus,
        .setup_msi_irqs = cxl_setup_msi_irqs,

diff --git a/include/misc/cxl-base.h b/include/misc/cxl-base.h
index f53808fa638ab6c90955a8c7bb8a280bbadbccaa..bb7e629ae492a8493d60bdb5250caa72d498b858 100644 (file)
--- a/include/misc/cxl-base.h
+++ b/include/misc/cxl-base.h
@@ -10,6 +10,8 @@
 #ifndef _MISC_CXL_BASE_H
 #define _MISC_CXL_BASE_H
 
+#include <misc/cxl.h>
+
 #ifdef CONFIG_CXL_BASE
 
 #define CXL_IRQ_RANGES 4
@@ -39,6 +41,8 @@ static inline void cxl_ctx_put(void)
 struct cxl_afu *cxl_afu_get(struct cxl_afu *afu);
 void cxl_afu_put(struct cxl_afu *afu);
 void cxl_slbia(struct mm_struct *mm);
+bool cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu);
+void cxl_pci_disable_device(struct pci_dev *dev);
 
 #else /* CONFIG_CXL_BASE */
 
@@ -46,6 +50,8 @@ static inline bool cxl_ctx_in_use(void) { return false; }
 static inline struct cxl_afu *cxl_afu_get(struct cxl_afu *afu) { return NULL; }
 static inline void cxl_afu_put(struct cxl_afu *afu) {}
 static inline void cxl_slbia(struct mm_struct *mm) {}
+static inline bool cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu) { return false; }
+static inline void cxl_pci_disable_device(struct pci_dev *dev) {}
 
 #endif /* CONFIG_CXL_BASE */