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Subject[PATCH 08/13] ocxl: Add a kernel API for other opencapi drivers
Date
Some of the functions done by the generic driver should also be needed
by other opencapi drivers: attaching a context to an adapter,
translation fault handling, AFU interrupt allocation...

So to avoid code duplication, the driver provides a kernel API that
other drivers can use, similar to calling a in-kernel library.

It is still a bit theoretical, for lack of real hardware, and will
likely need adjustements down the road. But we used the cxlflash
driver as a guinea pig.

Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
---
drivers/misc/ocxl/config.c | 13 ++-
drivers/misc/ocxl/link.c | 7 ++
drivers/misc/ocxl/ocxl_internal.h | 71 +-----------
include/misc/ocxl.h | 221 ++++++++++++++++++++++++++++++++++++++
4 files changed, 241 insertions(+), 71 deletions(-)
create mode 100644 include/misc/ocxl.h

diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
index bb2fde5967e2..2326e8da4029 100644
--- a/drivers/misc/ocxl/config.c
+++ b/drivers/misc/ocxl/config.c
@@ -9,8 +9,8 @@

#include <linux/pci.h>
#include <asm/pnv-ocxl.h>
+#include <misc/ocxl.h>
#include <misc/ocxl-config.h>
-#include "ocxl_internal.h"

#define EXTRACT_BIT(val, bit) (!!(val & BIT(bit)))
#define EXTRACT_BITS(val, s, e) ((val & GENMASK(e, s)) >> s)
@@ -250,6 +250,7 @@ int ocxl_config_read_function(struct pci_dev *dev, struct ocxl_fn_config *fn)
rc = validate_function(dev, fn);
return rc;
}
+EXPORT_SYMBOL_GPL(ocxl_config_read_function);

static int read_afu_info(struct pci_dev *dev, struct ocxl_fn_config *fn,
int offset, u32 *data)
@@ -308,6 +309,7 @@ int ocxl_config_check_afu_index(struct pci_dev *dev,
}
return 1;
}
+EXPORT_SYMBOL_GPL(ocxl_config_check_afu_index);

static int read_afu_name(struct pci_dev *dev, struct ocxl_fn_config *fn,
struct ocxl_afu_config *afu)
@@ -505,6 +507,7 @@ int ocxl_config_read_afu(struct pci_dev *dev, struct ocxl_fn_config *fn,
rc = validate_afu(dev, afu);
return rc;
}
+EXPORT_SYMBOL_GPL(ocxl_config_read_afu);

int ocxl_config_get_actag_info(struct pci_dev *dev, u16 *base, u16 *enabled,
u16 *supported)
@@ -523,6 +526,7 @@ int ocxl_config_get_actag_info(struct pci_dev *dev, u16 *base, u16 *enabled,
}
return 0;
}
+EXPORT_SYMBOL_GPL(ocxl_config_get_actag_info);

void ocxl_config_set_afu_actag(struct pci_dev *dev, int pos, int actag_base,
int actag_count)
@@ -535,11 +539,13 @@ void ocxl_config_set_afu_actag(struct pci_dev *dev, int pos, int actag_base,
val = actag_base & OCXL_DVSEC_ACTAG_MASK;
pci_write_config_dword(dev, pos + OCXL_DVSEC_AFU_CTRL_ACTAG_BASE, val);
}
+EXPORT_SYMBOL_GPL(ocxl_config_set_afu_actag);

int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count)
{
return pnv_ocxl_get_pasid_count(dev, count);
}
+EXPORT_SYMBOL_GPL(ocxl_config_get_pasid_info);

void ocxl_config_set_afu_pasid(struct pci_dev *dev, int pos, int pasid_base,
u32 pasid_count_log)
@@ -557,6 +563,7 @@ void ocxl_config_set_afu_pasid(struct pci_dev *dev, int pos, int pasid_base,
pci_write_config_dword(dev, pos + OCXL_DVSEC_AFU_CTRL_PASID_BASE,
val32);
}
+EXPORT_SYMBOL_GPL(ocxl_config_set_afu_pasid);

void ocxl_config_set_afu_state(struct pci_dev *dev, int pos, int enable)
{
@@ -569,6 +576,7 @@ void ocxl_config_set_afu_state(struct pci_dev *dev, int pos, int enable)
val &= 0xFE;
pci_write_config_byte(dev, pos + OCXL_DVSEC_AFU_CTRL_ENABLE, val);
}
+EXPORT_SYMBOL_GPL(ocxl_config_set_afu_state);

int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec)
{
@@ -666,6 +674,7 @@ int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec)
kfree(recv_rate);
return rc;
}
+EXPORT_SYMBOL_GPL(ocxl_config_set_TL);

int ocxl_config_terminate_pasid(struct pci_dev *dev, int afu_control, int pasid)
{
@@ -705,6 +714,7 @@ int ocxl_config_terminate_pasid(struct pci_dev *dev, int afu_control, int pasid)
}
return 0;
}
+EXPORT_SYMBOL_GPL(ocxl_config_terminate_pasid);

void ocxl_config_set_actag(struct pci_dev *dev, int func_dvsec, u32 tag_first,
u32 tag_count)
@@ -716,3 +726,4 @@ void ocxl_config_set_actag(struct pci_dev *dev, int func_dvsec, u32 tag_first,
pci_write_config_dword(dev, func_dvsec + OCXL_DVSEC_FUNC_OFF_ACTAG,
val);
}
+EXPORT_SYMBOL_GPL(ocxl_config_set_actag);
diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
index 5f12564eea99..fda2c9def4ff 100644
--- a/drivers/misc/ocxl/link.c
+++ b/drivers/misc/ocxl/link.c
@@ -12,6 +12,7 @@
#include <linux/mmu_context.h>
#include <asm/copro.h>
#include <asm/pnv-ocxl.h>
+#include <misc/ocxl.h>
#include "ocxl_internal.h"


@@ -427,6 +428,7 @@ int ocxl_link_setup(struct pci_dev *dev, int PE_mask, void **link_handle)
mutex_unlock(&links_list_lock);
return rc;
}
+EXPORT_SYMBOL_GPL(ocxl_link_setup);

static void release_xsl(struct kref *ref)
{
@@ -446,6 +448,7 @@ void ocxl_link_release(struct pci_dev *dev, void *link_handle)
kref_put(&link->ref, release_xsl);
mutex_unlock(&links_list_lock);
}
+EXPORT_SYMBOL_GPL(ocxl_link_release);

static u64 calculate_cfg_state(bool kernel)
{
@@ -540,6 +543,7 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
mutex_unlock(&spa->spa_lock);
return rc;
}
+EXPORT_SYMBOL_GPL(ocxl_link_add_pe);

int ocxl_link_remove_pe(void *link_handle, int pasid)
{
@@ -608,6 +612,7 @@ int ocxl_link_remove_pe(void *link_handle, int pasid)
mutex_unlock(&spa->spa_lock);
return rc;
}
+EXPORT_SYMBOL_GPL(ocxl_link_remove_pe);

int ocxl_link_irq_alloc(void *link_handle, int *hw_irq, u64 *trigger_addr)
{
@@ -628,6 +633,7 @@ int ocxl_link_irq_alloc(void *link_handle, int *hw_irq, u64 *trigger_addr)
*trigger_addr = addr;
return 0;
}
+EXPORT_SYMBOL_GPL(ocxl_link_irq_alloc);

void ocxl_link_free_irq(void *link_handle, int hw_irq)
{
@@ -636,3 +642,4 @@ void ocxl_link_free_irq(void *link_handle, int hw_irq)
pnv_ocxl_free_xive_irq(hw_irq);
atomic_inc(&link->irq_available);
}
+EXPORT_SYMBOL_GPL(ocxl_link_free_irq);
diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
index 829369c5f004..18ec28c0a5cb 100644
--- a/drivers/misc/ocxl/ocxl_internal.h
+++ b/drivers/misc/ocxl/ocxl_internal.h
@@ -13,8 +13,8 @@
#include <linux/pci.h>
#include <linux/cdev.h>
#include <linux/list.h>
+#include <misc/ocxl.h>

-#define OCXL_AFU_NAME_SZ (24+1) /* add 1 for NULL termination */
#define MAX_IRQ_PER_LINK 2000
#define MAX_IRQ_PER_CONTEXT MAX_IRQ_PER_LINK

@@ -23,38 +23,6 @@

extern struct pci_driver ocxl_pci_driver;

-/*
- * The following 2 structures are a fairly generic way of representing
- * the configuration data for a function and AFU, as read from the
- * configuration space.
- */
-struct ocxl_afu_config {
- u8 idx;
- int dvsec_afu_control_pos;
- char name[OCXL_AFU_NAME_SZ];
- u8 version_major;
- u8 version_minor;
- u8 afuc_type;
- u8 afum_type;
- u8 profile;
- u8 global_mmio_bar;
- u64 global_mmio_offset;
- u32 global_mmio_size;
- u8 pp_mmio_bar;
- u64 pp_mmio_offset;
- u32 pp_mmio_stride;
- u8 log_mem_size;
- u8 pasid_supported_log;
- u16 actag_supported;
-};
-
-struct ocxl_fn_config {
- int dvsec_tl_pos;
- int dvsec_function_pos;
- int dvsec_afu_info_pos;
- s8 max_pasid_log;
- s8 max_afu_index;
-};

struct ocxl_fn {
struct device dev;
@@ -142,43 +110,6 @@ extern void ocxl_unregister_afu(struct ocxl_afu *afu);
extern int ocxl_file_init(void);
extern void ocxl_file_exit(void);

-extern int ocxl_config_read_function(struct pci_dev *dev,
- struct ocxl_fn_config *fn);
-
-extern int ocxl_config_check_afu_index(struct pci_dev *dev,
- struct ocxl_fn_config *fn, int afu_idx);
-extern int ocxl_config_read_afu(struct pci_dev *dev,
- struct ocxl_fn_config *fn,
- struct ocxl_afu_config *afu,
- u8 afu_idx);
-extern int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count);
-extern void ocxl_config_set_afu_pasid(struct pci_dev *dev,
- int afu_control,
- int pasid_base, u32 pasid_count_log);
-extern int ocxl_config_get_actag_info(struct pci_dev *dev,
- u16 *base, u16 *enabled, u16 *supported);
-extern void ocxl_config_set_actag(struct pci_dev *dev, int func_dvsec,
- u32 tag_first, u32 tag_count);
-extern void ocxl_config_set_afu_actag(struct pci_dev *dev, int afu_control,
- int actag_base, int actag_count);
-extern void ocxl_config_set_afu_state(struct pci_dev *dev, int afu_control,
- int enable);
-extern int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec);
-extern int ocxl_config_terminate_pasid(struct pci_dev *dev, int afu_control,
- int pasid);
-
-extern int ocxl_link_setup(struct pci_dev *dev, int PE_mask,
- void **link_handle);
-extern void ocxl_link_release(struct pci_dev *dev, void *link_handle);
-extern int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
- u64 amr, struct mm_struct *mm,
- void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),
- void *xsl_err_data);
-extern int ocxl_link_remove_pe(void *link_handle, int pasid);
-extern int ocxl_link_irq_alloc(void *link_handle, int *hw_irq,
- u64 *addr);
-extern void ocxl_link_free_irq(void *link_handle, int hw_irq);
-
extern int ocxl_pasid_afu_alloc(struct ocxl_fn *fn, u32 size);
extern void ocxl_pasid_afu_free(struct ocxl_fn *fn, u32 start, u32 size);
extern int ocxl_actag_afu_alloc(struct ocxl_fn *fn, u32 size);
diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
new file mode 100644
index 000000000000..2b66a2083a23
--- /dev/null
+++ b/include/misc/ocxl.h
@@ -0,0 +1,221 @@
+/*
+ * Copyright 2017 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.
+ */
+
+#ifndef _MISC_OCXL_H_
+#define _MISC_OCXL_H_
+
+#include <linux/pci.h>
+
+/*
+ * Opencapi drivers all need some common facilities, like parsing the
+ * device configuration space, adding a Process Element to the Shared
+ * Process Area, etc...
+ *
+ * The ocxl module provides a kernel API, to allow other drivers to
+ * reuse common code. A bit like a in-kernel library.
+ */
+
+#define OCXL_AFU_NAME_SZ (24+1) /* add 1 for NULL termination */
+
+/*
+ * The following 2 structures are a fairly generic way of representing
+ * the configuration data for a function and AFU, as read from the
+ * configuration space.
+ */
+struct ocxl_afu_config {
+ u8 idx;
+ int dvsec_afu_control_pos; /* offset of AFU control DVSEC */
+ char name[OCXL_AFU_NAME_SZ];
+ u8 version_major;
+ u8 version_minor;
+ u8 afuc_type;
+ u8 afum_type;
+ u8 profile;
+ u8 global_mmio_bar; /* global MMIO area */
+ u64 global_mmio_offset;
+ u32 global_mmio_size;
+ u8 pp_mmio_bar; /* per-process MMIO area */
+ u64 pp_mmio_offset;
+ u32 pp_mmio_stride;
+ u8 log_mem_size;
+ u8 pasid_supported_log;
+ u16 actag_supported;
+};
+
+struct ocxl_fn_config {
+ int dvsec_tl_pos; /* offset of the Transaction Layer DVSEC */
+ int dvsec_function_pos; /* offset of the Function DVSEC */
+ int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */
+ s8 max_pasid_log;
+ s8 max_afu_index;
+};
+
+/*
+ * Read the configuration space of a function and fill in a
+ * ocxl_fn_config structure with all the function details
+ */
+extern int ocxl_config_read_function(struct pci_dev *dev,
+ struct ocxl_fn_config *fn);
+
+/*
+ * Check if an AFU index is valid for the given function.
+ *
+ * AFU indexes can be sparse, so a driver should check all indexes up
+ * to the maximum found in the function description
+ */
+extern int ocxl_config_check_afu_index(struct pci_dev *dev,
+ struct ocxl_fn_config *fn, int afu_idx);
+
+/*
+ * Read the configuration space of a function for the AFU specified by
+ * the index 'afu_idx'. Fills in a ocxl_afu_config structure
+ */
+extern int ocxl_config_read_afu(struct pci_dev *dev,
+ struct ocxl_fn_config *fn,
+ struct ocxl_afu_config *afu,
+ u8 afu_idx);
+
+/*
+ * Get the max PASID value that can be used by the function
+ */
+extern int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count);
+
+/*
+ * Tell an AFU, by writing in the configuration space, the PASIDs that
+ * it can use. Range starts at 'pasid_base' and its size is a multiple
+ * of 2
+ *
+ * 'afu_control_offset' is the offset of the AFU control DVSEC which
+ * can be found in the function configuration
+ */
+extern void ocxl_config_set_afu_pasid(struct pci_dev *dev,
+ int afu_control_offset,
+ int pasid_base, u32 pasid_count_log);
+
+/*
+ * Get the actag configuration for the function:
+ * 'base' is the first actag value that can be used.
+ * 'enabled' it the number of actags available, starting from base.
+ * 'supported' is the total number of actags desired by all the AFUs
+ * of the function.
+ */
+extern int ocxl_config_get_actag_info(struct pci_dev *dev,
+ u16 *base, u16 *enabled, u16 *supported);
+
+/*
+ * Tell a function, by writing in the configuration space, the actags
+ * it can use.
+ *
+ * 'func_offset' is the offset of the Function DVSEC that can found in
+ * the function configuration
+ */
+extern void ocxl_config_set_actag(struct pci_dev *dev, int func_offset,
+ u32 actag_base, u32 actag_count);
+
+/*
+ * Tell an AFU, by writing in the configuration space, the actags it
+ * can use.
+ *
+ * 'afu_control_offset' is the offset of the AFU control DVSEC for the
+ * desired AFU. It can be found in the AFU configuration
+ */
+extern void ocxl_config_set_afu_actag(struct pci_dev *dev,
+ int afu_control_offset,
+ int actag_base, int actag_count);
+
+/*
+ * Enable/disable an AFU, by writing in the configuration space.
+ *
+ * 'afu_control_offset' is the offset of the AFU control DVSEC for the
+ * desired AFU. It can be found in the AFU configuration
+ */
+extern void ocxl_config_set_afu_state(struct pci_dev *dev,
+ int afu_control_offset, int enable);
+
+/*
+ * Set the Transaction Layer configuration in the configuration space.
+ * Only needed for function 0.
+ *
+ * It queries the host TL capabilities, find some common ground
+ * between the host and device, and set the Transaction Layer on both
+ * accordingly.
+ */
+extern int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec);
+
+/*
+ * Request an AFU to terminate a PASID.
+ * Will return once the AFU has acked the request, or an error in case
+ * of timeout.
+ *
+ * The hardware can only terminate one PASID at a time, so caller must
+ * guarantee some kind of serialization.
+ *
+ * 'afu_control_offset' is the offset of the AFU control DVSEC for the
+ * desired AFU. It can be found in the AFU configuration
+ */
+extern int ocxl_config_terminate_pasid(struct pci_dev *dev,
+ int afu_control_offset, int pasid);
+
+/*
+ * Set up the opencapi link for the function.
+ *
+ * When called for the first time for a link, it sets up the Shared
+ * Process Area for the link and the interrupt handler to process
+ * translation faults.
+ *
+ * Returns a 'link handle' that should be used for further calls for
+ * the link
+ */
+extern int ocxl_link_setup(struct pci_dev *dev, int PE_mask,
+ void **link_handle);
+
+/*
+ * Remove the association between the function and its link.
+ */
+extern void ocxl_link_release(struct pci_dev *dev, void *link_handle);
+
+/*
+ * Add a Process Element to the Shared Process Area for a link.
+ * The process is defined by its PASID, pid, tid and its mm_struct.
+ *
+ * 'xsl_err_cb' is an optional callback if the driver wants to be
+ * notified when the translation fault interrupt handler detects an
+ * address error.
+ * 'xsl_err_data' is an argument passed to the above callback, if
+ * defined
+ */
+extern int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
+ u64 amr, struct mm_struct *mm,
+ void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),
+ void *xsl_err_data);
+
+/*
+ * Remove a Process Element from the Shared Process Area for a link
+ */
+extern int ocxl_link_remove_pe(void *link_handle, int pasid);
+
+/*
+ * Allocate an AFU interrupt associated to the link.
+ *
+ * 'hw_irq' is the hardware interrupt number
+ * 'obj_handle' is the 64-bit object handle to be passed to the AFU to
+ * trigger the interrupt.
+ * On P9, 'obj_handle' is an address, which, if written, triggers the
+ * interrupt. It is an MMIO address which needs to be remapped (one
+ * page).
+ */
+extern int ocxl_link_irq_alloc(void *link_handle, int *hw_irq,
+ u64 *obj_handle);
+
+/*
+ * Free a previously allocated AFU interrupt
+ */
+extern void ocxl_link_free_irq(void *link_handle, int hw_irq);
+
+#endif /* _MISC_OCXL_H_ */
--
2.14.1
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