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SubjectPATCH: rar and memrar updates
commit 1cb0e4339ecd39c62840c74b53546bd28c1ea1a9
Author: Alan Cox <alan@linux.intel.com>
Date: Tue May 4 20:38:47 2010 +0100

rar: perform a clean up pass

- Move to a registration model where each RAR is claimed/unclaimed
- Use that to fix the client stuff (one client per RAR so no need to queue stuff)
- Support unregister so drivers can rmmod themselves safely
- Fix locking hang on calling rar lock from rar callback
- Clean up
- Kerneldoc

Folded in the memrar update as Greg asked

- Fix various unload related bugs
- Use the per RAR allocator/deallocator
- Add kerneldoc

Signed-off-by: Alan Cox <alan@linux.intel.com>

diff --git a/drivers/staging/memrar/memrar_handler.c b/drivers/staging/memrar/memrar_handler.c
index 4bbf66f..281d8d7 100644
--- a/drivers/staging/memrar/memrar_handler.c
+++ b/drivers/staging/memrar/memrar_handler.c
@@ -114,6 +114,7 @@ struct memrar_rar_info {
struct memrar_allocator *allocator;
struct memrar_buffer_info buffers;
struct mutex lock;
+ int allocated; /* True if we own this RAR */
};

/*
@@ -150,11 +151,13 @@ static struct memrar_rar_info *memrar_get_rar_info(u32 vaddr)
return NULL;
}

-/*
- * Retrieve bus address from given handle.
+/**
+ * memrar_get_bus address - handle to bus address
+ *
+ * Retrieve bus address from given handle.
*
- * Returns address corresponding to given handle. Zero if handle is
- * invalid.
+ * Returns address corresponding to given handle. Zero if handle is
+ * invalid.
*/
static dma_addr_t memrar_get_bus_address(
struct memrar_rar_info *rar,
@@ -176,11 +179,13 @@ static dma_addr_t memrar_get_bus_address(
return rar->base + (vaddr - iobase);
}

-/*
- * Retrieve physical address from given handle.
+/**
+ * memrar_get_physical_address - handle to physical address
+ *
+ * Retrieve physical address from given handle.
*
- * Returns address corresponding to given handle. Zero if handle is
- * invalid.
+ * Returns address corresponding to given handle. Zero if handle is
+ * invalid.
*/
static dma_addr_t memrar_get_physical_address(
struct memrar_rar_info *rar,
@@ -195,11 +200,15 @@ static dma_addr_t memrar_get_physical_address(
return memrar_get_bus_address(rar, vaddr);
}

-/*
- * Core block release code.
+/**
+ * memrar_release_block - release a block to the pool
+ * @kref: kref of block
+ *
+ * Core block release code. A node has hit zero references so can
+ * be released and the lists must be updated.
*
- * Note: This code removes the node from a list. Make sure any list
- * iteration is performed using list_for_each_safe().
+ * Note: This code removes the node from a list. Make sure any list
+ * iteration is performed using list_for_each_safe().
*/
static void memrar_release_block_i(struct kref *ref)
{
@@ -224,10 +233,15 @@ static void memrar_release_block_i(struct kref *ref)
kfree(node);
}

-/*
- * Initialize RAR parameters, such as bus addresses, etc.
+/**
+ * memrar_init_rar_resources - configure a RAR
+ * @rarnum: rar that has been allocated
+ * @devname: name of our device
+ *
+ * Initialize RAR parameters, such as bus addresses, etc and make
+ * the resource accessible.
*/
-static int memrar_init_rar_resources(char const *devname)
+static int memrar_init_rar_resources(int rarnum, char const *devname)
{
/* ---- Sanity Checks ----
* 1. RAR bus addresses in both Lincroft and Langwell RAR
@@ -258,162 +272,95 @@ static int memrar_init_rar_resources(char const *devname)
*/
static size_t const RAR_BLOCK_SIZE = PAGE_SIZE;

- int z;
- int found_rar = 0;
+ dma_addr_t low, high;
+ struct memrar_rar_info * const rar = &memrars[rarnum];

BUG_ON(MRST_NUM_RAR != ARRAY_SIZE(memrars));
+ BUG_ON(!memrar_is_valid_rar_type(rarnum));
+ BUG_ON(rar->allocated);

- for (z = 0; z != MRST_NUM_RAR; ++z) {
- dma_addr_t low, high;
- struct memrar_rar_info * const rar = &memrars[z];
-
- BUG_ON(!memrar_is_valid_rar_type(z));
-
- mutex_init(&rar->lock);
-
- /*
- * Initialize the process table before we reach any
- * code that exit on failure since the finalization
- * code requires an initialized list.
- */
- INIT_LIST_HEAD(&rar->buffers.list);
-
- if (rar_get_address(z, &low, &high) != 0) {
- /* No RAR is available. */
- break;
- } else if (low == 0 || high == 0) {
- /*
- * We don't immediately break out of the loop
- * since the next type of RAR may be enabled.
- */
- rar->base = 0;
- rar->length = 0;
- rar->iobase = NULL;
- rar->allocator = NULL;
- continue;
- }
-
- /*
- * @todo Verify that LNC and LNW RAR register contents
- * addresses, security, etc are compatible and
- * consistent).
- */
-
- rar->length = high - low + 1;
-
- /* Claim RAR memory as our own. */
- if (request_mem_region(low, rar->length, devname) == NULL) {
- rar->length = 0;
-
- pr_err("%s: Unable to claim RAR[%d] memory.\n",
- devname,
- z);
- pr_err("%s: RAR[%d] disabled.\n", devname, z);
-
- /*
- * Rather than break out of the loop by
- * returning -EBUSY, for example, we may be
- * able to claim memory of the next RAR region
- * as our own.
- */
- continue;
- }
-
- rar->base = low;
-
- /*
- * Now map it into the kernel address space.
- *
- * Note that the RAR memory may only be accessed by IA
- * when debugging. Otherwise attempts to access the
- * RAR memory when it is locked down will result in
- * behavior similar to writing to /dev/null and
- * reading from /dev/zero. This behavior is enforced
- * by the hardware. Even if we don't access the
- * memory, mapping it into the kernel provides us with
- * a convenient RAR handle to bus address mapping.
- */
- rar->iobase = ioremap_nocache(rar->base, rar->length);
- if (rar->iobase == NULL) {
- pr_err("%s: Unable to map RAR memory.\n",
- devname);
- return -ENOMEM;
- }
-
- /* Initialize corresponding memory allocator. */
- rar->allocator = memrar_create_allocator(
- (unsigned long) rar->iobase,
- rar->length,
- RAR_BLOCK_SIZE);
- if (rar->allocator == NULL)
- return -1;
+ mutex_init(&rar->lock);

- /*
- * -------------------------------------------------
- * Make sure all RARs handled by us are locked down.
- * -------------------------------------------------
- */
+ /*
+ * Initialize the process table before we reach any
+ * code that exit on failure since the finalization
+ * code requires an initialized list.
+ */
+ INIT_LIST_HEAD(&rar->buffers.list);

- /* Enable RAR protection on the Lincroft side. */
- if (0) {
- /*
- * This is mostly a sanity check since the
- * vendor should have locked down RAR in the
- * SMIP header RAR configuration.
- */
- rar_lock(z);
- } else {
- pr_warning("%s: LNC RAR[%d] no lock sanity check.\n",
- devname,
- z);
- }
+ if (rar_get_address(rarnum, &low, &high) != 0)
+ /* No RAR is available. */
+ return -ENODEV;
+
+ if (low == 0 || high == 0) {
+ rar->base = 0;
+ rar->length = 0;
+ rar->iobase = NULL;
+ rar->allocator = NULL;
+ return -ENOSPC;
+ }

- /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
- /* |||||||||||||||||||||||||||||||||||||||||||||||||| */
+ /*
+ * @todo Verify that LNC and LNW RAR register contents
+ * addresses, security, etc are compatible and
+ * consistent).
+ */

- /*
- * It would be nice if we could verify that RAR
- * protection on the Langwell side is enabled, but
- * there is no way to do that from here. The
- * necessary Langwell RAR registers are not accessible
- * from the Lincroft (IA) side.
- *
- * Hopefully the ODM did the right thing and enabled
- * Langwell side RAR protection in the integrated
- * firmware SMIP header.
- */
+ rar->length = high - low + 1;

- pr_info("%s: BRAR[%d] bus address range = "
- "[0x%lx, 0x%lx]\n",
- devname,
- z,
- (unsigned long) low,
- (unsigned long) high);
+ /* Claim RAR memory as our own. */
+ if (request_mem_region(low, rar->length, devname) == NULL) {
+ rar->length = 0;
+ pr_err("%s: Unable to claim RAR[%d] memory.\n", devname, rarnum);
+ pr_err("%s: RAR[%d] disabled.\n", devname, rarnum);
+ return -EBUSY;
+ }

- pr_info("%s: BRAR[%d] size = %u KiB\n",
- devname,
- z,
- rar->allocator->capacity / 1024);
+ rar->base = low;

- found_rar = 1;
+ /*
+ * Now map it into the kernel address space.
+ *
+ * Note that the RAR memory may only be accessed by IA
+ * when debugging. Otherwise attempts to access the
+ * RAR memory when it is locked down will result in
+ * behavior similar to writing to /dev/null and
+ * reading from /dev/zero. This behavior is enforced
+ * by the hardware. Even if we don't access the
+ * memory, mapping it into the kernel provides us with
+ * a convenient RAR handle to bus address mapping.
+ */
+ rar->iobase = ioremap_nocache(rar->base, rar->length);
+ if (rar->iobase == NULL) {
+ pr_err("%s: Unable to map RAR memory.\n", devname);
+ release_mem_region(low, rar->length);
+ return -ENOMEM;
}

- if (!found_rar) {
- /*
- * No RAR support. Don't bother continuing.
- *
- * Note that this is not a failure.
- */
- pr_info("%s: No Moorestown RAR support available.\n",
- devname);
- return -ENODEV;
+ /* Initialize corresponding memory allocator. */
+ rar->allocator = memrar_create_allocator((unsigned long) rar->iobase,
+ rar->length, RAR_BLOCK_SIZE);
+ if (rar->allocator == NULL) {
+ iounmap(rar->iobase);
+ release_mem_region(low, rar->length);
+ return -ENOMEM;
}

+ pr_info("%s: BRAR[%d] bus address range = [0x%lx, 0x%lx]\n",
+ devname, rarnum, (unsigned long) low, (unsigned long) high);
+
+ pr_info("%s: BRAR[%d] size = %u KiB\n",
+ devname, rarnum, rar->allocator->capacity / 1024);
+
+ rar->allocated = 1;
return 0;
}

-/*
- * Finalize RAR resources.
+/**
+ * memrar_fini_rar_resources - free up RAR resources
+ *
+ * Finalize RAR resources. Free up the resource tables, hand the memory
+ * back to the kernel, unmap the device and release the address space.
*/
static void memrar_fini_rar_resources(void)
{
@@ -429,6 +376,9 @@ static void memrar_fini_rar_resources(void)
for (z = MRST_NUM_RAR; z-- != 0; ) {
struct memrar_rar_info * const rar = &memrars[z];

+ if (!rar->allocated)
+ continue;
+
/* Clean up remaining resources. */

list_for_each_entry_safe(pos,
@@ -442,15 +392,25 @@ static void memrar_fini_rar_resources(void)
rar->allocator = NULL;

iounmap(rar->iobase);
- rar->iobase = NULL;
-
release_mem_region(rar->base, rar->length);
- rar->base = 0;

+ rar->iobase = NULL;
+ rar->base = 0;
rar->length = 0;
+
+ unregister_rar(z);
}
}

+/**
+ * memrar_reserve_block - handle an allocation request
+ * @request: block being requested
+ * @filp: owner it is tied to
+ *
+ * Allocate a block of the requested RAR. If successful return the
+ * request object filled in and zero, if not report an error code
+ */
+
static long memrar_reserve_block(struct RAR_buffer *request,
struct file *filp)
{
@@ -465,6 +425,8 @@ static long memrar_reserve_block(struct RAR_buffer *request,
return -EINVAL;

rar = &memrars[rinfo->type];
+ if (!rar->allocated)
+ return -ENODEV;

/* Reserve memory in RAR. */
handle = memrar_allocator_alloc(rar->allocator, rinfo->size);
@@ -504,6 +466,14 @@ static long memrar_reserve_block(struct RAR_buffer *request,
return 0;
}

+/**
+ * memrar_release_block - release a RAR block
+ * @addr: address in RAR space
+ *
+ * Release a previously allocated block. Releases act on complete
+ * blocks, partially freeing a block is not supported
+ */
+
static long memrar_release_block(u32 addr)
{
struct memrar_buffer_info *pos;
@@ -512,7 +482,7 @@ static long memrar_release_block(u32 addr)
long result = -EINVAL;

if (rar == NULL)
- return -EFAULT;
+ return -ENOENT;

mutex_lock(&rar->lock);

@@ -550,34 +520,48 @@ static long memrar_release_block(u32 addr)
return result;
}

+/**
+ * memrar_get_stats - read statistics for a RAR
+ * @r: statistics to be filled in
+ *
+ * Returns the statistics data for the RAR, or an error code if
+ * the request cannot be completed
+ */
static long memrar_get_stat(struct RAR_stat *r)
{
- long result = -EINVAL;
-
- if (likely(r != NULL) && memrar_is_valid_rar_type(r->type)) {
- struct memrar_allocator * const allocator =
- memrars[r->type].allocator;
-
- BUG_ON(allocator == NULL);
+ struct memrar_allocator *allocator;

- /*
- * Allocator capacity doesn't change over time. No
- * need to synchronize.
- */
- r->capacity = allocator->capacity;
+ if (!memrar_is_valid_rar_type(r->type))
+ return -EINVAL;

- mutex_lock(&allocator->lock);
+ if (!memrars[r->type].allocated)
+ return -ENODEV;

- r->largest_block_size = allocator->largest_free_area;
+ allocator = memrars[r->type].allocator;

- mutex_unlock(&allocator->lock);
+ BUG_ON(allocator == NULL);

- result = 0;
- }
+ /*
+ * Allocator capacity doesn't change over time. No
+ * need to synchronize.
+ */
+ r->capacity = allocator->capacity;

- return result;
+ mutex_lock(&allocator->lock);
+ r->largest_block_size = allocator->largest_free_area;
+ mutex_unlock(&allocator->lock);
+ return 0;
}

+/**
+ * memrar_ioctl - ioctl callback
+ * @filp: file issuing the request
+ * @cmd: command
+ * @arg: pointer to control information
+ *
+ * Perform one of the ioctls supported by the memrar device
+ */
+
static long memrar_ioctl(struct file *filp,
unsigned int cmd,
unsigned long arg)
@@ -640,6 +624,15 @@ static long memrar_ioctl(struct file *filp,
return 0;
}

+/**
+ * memrar_mmap - mmap helper for deubgging
+ * @filp: handle doing the mapping
+ * @vma: memory area
+ *
+ * Support the mmap operation on the RAR space for debugging systems
+ * when the memory is not locked down.
+ */
+
static int memrar_mmap(struct file *filp, struct vm_area_struct *vma)
{
/*
@@ -660,9 +653,12 @@ static int memrar_mmap(struct file *filp, struct vm_area_struct *vma)
unsigned long const handle = vma->vm_pgoff << PAGE_SHIFT;

struct memrar_rar_info * const rar = memrar_get_rar_info(handle);
-
unsigned long pfn;

+ /* Only allow priviledged apps to go poking around this way */
+ if (!capable(CAP_SYS_RAWIO))
+ return -EPERM;
+
/* Invalid RAR handle or size passed to mmap(). */
if (rar == NULL
|| handle == 0
@@ -698,13 +694,32 @@ static int memrar_mmap(struct file *filp, struct vm_area_struct *vma)
return 0;
}

+/**
+ * memrar_open - device open method
+ * @inode: inode to open
+ * @filp: file handle
+ *
+ * As we support multiple arbitary opens there is no work to be done
+ * really.
+ */
+
static int memrar_open(struct inode *inode, struct file *filp)
{
- /* Nothing to do yet. */
-
+ nonseekable_open(inode, filp);
return 0;
}

+/**
+ * memrar_release - close method for miscev
+ * @inode: inode of device
+ * @filp: handle that is going away
+ *
+ * Free up all the regions that belong to this file handle. We use
+ * the handle as a natural Linux style 'lifetime' indicator and to
+ * ensure resources are not leaked when their owner explodes in an
+ * unplanned fashion.
+ */
+
static int memrar_release(struct inode *inode, struct file *filp)
{
/* Free all regions associated with the given file handle. */
@@ -733,9 +748,15 @@ static int memrar_release(struct inode *inode, struct file *filp)
return 0;
}

-/*
- * This function is part of the kernel space memrar driver API.
+/**
+ * rar_reserve - reserve RAR memory
+ * @buffers: buffers to reserve
+ * @count: number wanted
+ *
+ * Reserve a series of buffers in the RAR space. Returns the number of
+ * buffers successfully allocated
*/
+
size_t rar_reserve(struct RAR_buffer *buffers, size_t count)
{
struct RAR_buffer * const end =
@@ -755,9 +776,14 @@ size_t rar_reserve(struct RAR_buffer *buffers, size_t count)
}
EXPORT_SYMBOL(rar_reserve);

-/*
- * This function is part of the kernel space memrar driver API.
+/**
+ * rar_release - return RAR buffers
+ * @buffers: buffers to release
+ * @size: size of released block
+ *
+ * Return a set of buffers to the RAR pool
*/
+
size_t rar_release(struct RAR_buffer *buffers, size_t count)
{
struct RAR_buffer * const end =
@@ -786,9 +812,16 @@ size_t rar_release(struct RAR_buffer *buffers, size_t count)
}
EXPORT_SYMBOL(rar_release);

-/*
- * This function is part of the kernel space driver API.
+/**
+ * rar_handle_to_bus - RAR to bus address
+ * @buffers: RAR buffer structure
+ * @count: number of buffers to convert
+ *
+ * Turn a list of RAR handle mappings into actual bus addresses. Note
+ * that when the device is locked down the bus addresses in question
+ * are not CPU accessible.
*/
+
size_t rar_handle_to_bus(struct RAR_buffer *buffers, size_t count)
{
struct RAR_buffer * const end =
@@ -878,43 +911,70 @@ static char const banner[] __initdata =
KERN_INFO
"Intel RAR Handler: " MEMRAR_VER " initialized.\n";

-static int memrar_registration_callback(void *ctx)
+/**
+ * memrar_registration_callback - RAR obtained
+ * @rar: RAR number
+ *
+ * We have been granted ownership of the RAR. Add it to our memory
+ * management tables
+ */
+
+static int memrar_registration_callback(unsigned long rar)
{
/*
* We initialize the RAR parameters early on so that we can
* discontinue memrar device initialization and registration
* if suitably configured RARs are not available.
*/
- int result = memrar_init_rar_resources(memrar_miscdev.name);
+ return memrar_init_rar_resources(rar, memrar_miscdev.name);
+}

- if (result != 0)
- return result;
+/**
+ * memrar_init - initialise RAR support
+ *
+ * Initialise support for RAR handlers. This may get loaded before
+ * the RAR support is activated, but the callbacks on the registration
+ * will handle that situation for us anyway.
+ */

- result = misc_register(&memrar_miscdev);
+static int __init memrar_init(void)
+{
+ int err;

- if (result != 0) {
- pr_err("%s: misc_register() failed.\n",
- memrar_miscdev.name);
+ printk(banner);

- /* Clean up resources previously reserved. */
- memrar_fini_rar_resources();
- }
+ err = misc_register(&memrar_miscdev);
+ if (err)
+ return err;

- return result;
-}
+ /* Now claim the two RARs we want */
+ err = register_rar(0, memrar_registration_callback, 0);
+ if (err)
+ goto fail;

-static int __init memrar_init(void)
-{
- printk(banner);
+ err = register_rar(1, memrar_registration_callback, 1);
+ if (err == 0)
+ return 0;

- return register_rar(&memrar_registration_callback, 0);
+ /* It is possible rar 0 registered and allocated resources then rar 1
+ failed so do a full resource free */
+ memrar_fini_rar_resources();
+fail:
+ misc_deregister(&memrar_miscdev);
+ return err;
}

+/**
+ * memrar_exit - unregister and unload
+ *
+ * Unregister the device and then unload any mappings and release
+ * the RAR resources
+ */
+
static void __exit memrar_exit(void)
{
- memrar_fini_rar_resources();
-
misc_deregister(&memrar_miscdev);
+ memrar_fini_rar_resources();
}


@@ -925,7 +985,6 @@ module_exit(memrar_exit);
MODULE_AUTHOR("Ossama Othman <ossama.othman@intel.com>");
MODULE_DESCRIPTION("Intel Restricted Access Region Handler");
MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(MISC_DYNAMIC_MINOR);
MODULE_VERSION(MEMRAR_VER);


diff --git a/drivers/staging/rar_register/rar_register.c b/drivers/staging/rar_register/rar_register.c
index bfc0e31..618503f 100644
--- a/drivers/staging/rar_register/rar_register.c
+++ b/drivers/staging/rar_register/rar_register.c
@@ -51,98 +51,159 @@
#include <linux/kernel.h>

/* === Lincroft Message Bus Interface === */
-/* Message Control Register */
-#define LNC_MCR_OFFSET 0xD0
-
-/* Maximum number of clients (other drivers using this driver) */
-#define MAX_RAR_CLIENTS 10
-
-/* Message Data Register */
-#define LNC_MDR_OFFSET 0xD4
+#define LNC_MCR_OFFSET 0xD0 /* Message Control Register */
+#define LNC_MDR_OFFSET 0xD4 /* Message Data Register */

/* Message Opcodes */
-#define LNC_MESSAGE_READ_OPCODE 0xD0
+#define LNC_MESSAGE_READ_OPCODE 0xD0
#define LNC_MESSAGE_WRITE_OPCODE 0xE0

/* Message Write Byte Enables */
-#define LNC_MESSAGE_BYTE_WRITE_ENABLES 0xF
+#define LNC_MESSAGE_BYTE_WRITE_ENABLES 0xF

/* B-unit Port */
-#define LNC_BUNIT_PORT 0x3
+#define LNC_BUNIT_PORT 0x3

/* === Lincroft B-Unit Registers - Programmed by IA32 firmware === */
-#define LNC_BRAR0L 0x10
-#define LNC_BRAR0H 0x11
-#define LNC_BRAR1L 0x12
-#define LNC_BRAR1H 0x13
-
+#define LNC_BRAR0L 0x10
+#define LNC_BRAR0H 0x11
+#define LNC_BRAR1L 0x12
+#define LNC_BRAR1H 0x13
/* Reserved for SeP */
-#define LNC_BRAR2L 0x14
-#define LNC_BRAR2H 0x15
+#define LNC_BRAR2L 0x14
+#define LNC_BRAR2H 0x15

/* Moorestown supports three restricted access regions. */
#define MRST_NUM_RAR 3

-
/* RAR Bus Address Range */
-struct RAR_address_range {
+struct rar_addr {
dma_addr_t low;
dma_addr_t high;
};

-/* Structure containing low and high RAR register offsets. */
-struct RAR_offsets {
- u32 low; /* Register offset for low RAR bus address. */
- u32 high; /* Register offset for high RAR bus address. */
-};
-
+/*
+ * We create one of these for each RAR
+ */
struct client {
- int (*client_callback)(void *client_data);
- void *customer_data;
- int client_called;
- };
+ int (*callback)(unsigned long data);
+ unsigned long driver_priv;
+ bool busy;
+};

static DEFINE_MUTEX(rar_mutex);
static DEFINE_MUTEX(lnc_reg_mutex);

-struct RAR_device {
- struct RAR_offsets const rar_offsets[MRST_NUM_RAR];
- struct RAR_address_range rar_addr[MRST_NUM_RAR];
+/*
+ * One per RAR device (currently only one device)
+ */
+struct rar_device {
+ struct rar_addr rar_addr[MRST_NUM_RAR];
struct pci_dev *rar_dev;
bool registered;
- };
-
-/* this platform has only one rar_device for 3 rar regions */
-static struct RAR_device my_rar_device = {
- .rar_offsets = {
- [0].low = LNC_BRAR0L,
- [0].high = LNC_BRAR0H,
- [1].low = LNC_BRAR1L,
- [1].high = LNC_BRAR1H,
- [2].low = LNC_BRAR2L,
- [2].high = LNC_BRAR2H
- }
+ bool allocated;
+ struct client client[MRST_NUM_RAR];
};

-/* this data is for handling requests from other drivers which arrive
- * prior to this driver initializing
+/* Current platforms have only one rar_device for 3 rar regions */
+static struct rar_device my_rar_device;
+
+/*
+ * Abstract out multiple device support. Current platforms only
+ * have a single RAR device.
*/

-static struct client clients[MAX_RAR_CLIENTS];
-static int num_clients;
+/**
+ * alloc_rar_device - return a new RAR structure
+ *
+ * Return a new (but not yet ready) RAR device object
+ */
+static struct rar_device *alloc_rar_device(void)
+{
+ if (my_rar_device.allocated)
+ return NULL;
+ my_rar_device.allocated = 1;
+ return &my_rar_device;
+}

-/*
- * This function is used to retrieved RAR info using the Lincroft
- * message bus interface.
+/**
+ * free_rar_device - free a RAR object
+ * @rar: the RAR device being freed
+ *
+ * Release a RAR object and any attached resources
*/
-static int retrieve_rar_addr(struct pci_dev *pdev,
- int offset,
- dma_addr_t *addr)
+static void free_rar_device(struct rar_device *rar)
+{
+ pci_dev_put(rar->rar_dev);
+ rar->allocated = 0;
+}
+
+/**
+ * _rar_to_device - return the device handling this RAR
+ * @rar: RAR number
+ * @off: returned offset
+ *
+ * Internal helper for looking up RAR devices. This and alloc are the
+ * two functions that need touching to go to multiple RAR devices.
+ */
+static struct rar_device *_rar_to_device(int rar, int *off)
+{
+ if (rar >= 0 && rar <= 3) {
+ *off = rar;
+ return &my_rar_device;
+ }
+ return NULL;
+}
+
+
+/**
+ * rar_to_device - return the device handling this RAR
+ * @rar: RAR number
+ * @off: returned offset
+ *
+ * Return the device this RAR maps to if one is present, otherwise
+ * returns NULL. Reports the offset relative to the base of this
+ * RAR device in off.
+ */
+static struct rar_device *rar_to_device(int rar, int *off)
+{
+ struct rar_device *rar_dev = _rar_to_device(rar, off);
+ if (rar_dev == NULL || !rar_dev->registered)
+ return NULL;
+ return rar_dev;
+}
+
+/**
+ * rar_to_client - return the client handling this RAR
+ * @rar: RAR number
+ *
+ * Return the client this RAR maps to if a mapping is known, otherwise
+ * returns NULL.
+ */
+static struct client *rar_to_client(int rar)
+{
+ int idx;
+ struct rar_device *r = _rar_to_device(rar, &idx);
+ if (r != NULL)
+ return &r->client[idx];
+ return NULL;
+}
+
+/**
+ * rar_read_addr - retrieve a RAR mapping
+ * @pdev: PCI device for the RAR
+ * @offset: offset for message
+ * @addr: returned address
+ *
+ * Reads the address of a given RAR register. Returns 0 on success
+ * or an error code on failure.
+ */
+static int rar_read_addr(struct pci_dev *pdev, int offset, dma_addr_t *addr)
{
/*
* ======== The Lincroft Message Bus Interface ========
- * Lincroft registers may be obtained from the PCI
- * (the Host Bridge) using the Lincroft Message Bus
+ * Lincroft registers may be obtained via PCI from
+ * the host bridge using the Lincroft Message Bus
* Interface. That message bus interface is generally
* comprised of two registers: a control register (MCR, 0xDO)
* and a data register (MDR, 0xD4).
@@ -182,6 +243,7 @@ static int retrieve_rar_addr(struct pci_dev *pdev,
*/

int result;
+ u32 addr32;

/* Construct control message */
u32 const message =
@@ -192,11 +254,6 @@ static int retrieve_rar_addr(struct pci_dev *pdev,

dev_dbg(&pdev->dev, "Offset for 'get' LNC MSG is %x\n", offset);

- if (addr == 0) {
- WARN_ON(1);
- return -EINVAL;
- }
-
/*
* We synchronize access to the Lincroft MCR and MDR registers
* until BOTH the command is issued through the MCR register
@@ -209,26 +266,25 @@ static int retrieve_rar_addr(struct pci_dev *pdev,

/* Send the control message */
result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);
-
- dev_dbg(&pdev->dev, "Result from send ctl register is %x\n", result);
-
if (!result) {
- result = pci_read_config_dword(pdev, LNC_MDR_OFFSET,
- (u32 *)addr);
- dev_dbg(&pdev->dev,
- "Result from read data register is %x\n", result);
-
- dev_dbg(&pdev->dev,
- "Value read from data register is %lx\n",
- (unsigned long)*addr);
+ /* Read back the address as a 32bit value */
+ result = pci_read_config_dword(pdev, LNC_MDR_OFFSET, &addr32);
+ *addr = (dma_addr_t)addr32;
}
-
mutex_unlock(&lnc_reg_mutex);
-
return result;
}

-static int set_rar_address(struct pci_dev *pdev,
+/**
+ * rar_set_addr - Set a RAR mapping
+ * @pdev: PCI device for the RAR
+ * @offset: offset for message
+ * @addr: address to set
+ *
+ * Sets the address of a given RAR register. Returns 0 on success
+ * or an error code on failure.
+ */
+static int rar_set_addr(struct pci_dev *pdev,
int offset,
dma_addr_t addr)
{
@@ -236,11 +292,11 @@ static int set_rar_address(struct pci_dev *pdev,
* Data being written to this register must be written before
* writing the appropriate control message to the MCR
* register.
- * @note See rar_get_address() for a description of the
+ * See rar_get_addrs() for a description of the
* message bus interface being used here.
*/

- int result = 0;
+ int result;

/* Construct control message */
u32 const message = (LNC_MESSAGE_WRITE_OPCODE << 24)
@@ -248,13 +304,6 @@ static int set_rar_address(struct pci_dev *pdev,
| (offset << 8)
| (LNC_MESSAGE_BYTE_WRITE_ENABLES << 4);

- if (addr == 0) {
- WARN_ON(1);
- return -EINVAL;
- }
-
- dev_dbg(&pdev->dev, "Offset for 'set' LNC MSG is %x\n", offset);
-
/*
* We synchronize access to the Lincroft MCR and MDR registers
* until BOTH the command is issued through the MCR register
@@ -267,32 +316,27 @@ static int set_rar_address(struct pci_dev *pdev,

/* Send the control message */
result = pci_write_config_dword(pdev, LNC_MDR_OFFSET, addr);
-
- dev_dbg(&pdev->dev, "Result from write data register is %x\n", result);
-
- if (!result) {
- dev_dbg(&pdev->dev,
- "Value written to data register is %lx\n",
- (unsigned long)addr);
-
+ if (!result)
+ /* And address */
result = pci_write_config_dword(pdev, LNC_MCR_OFFSET, message);

- dev_dbg(&pdev->dev, "Result from send ctl register is %x\n",
- result);
- }
-
mutex_unlock(&lnc_reg_mutex);
-
return result;
}

/*
-* Initialize RAR parameters, such as bus addresses, etc.
-*/
-static int init_rar_params(struct pci_dev *pdev)
+ * rar_init_params - Initialize RAR parameters
+ * @rar: RAR device to initialise
+ *
+ * Initialize RAR parameters, such as bus addresses, etc. Returns 0
+ * on success, or an error code on failure.
+ */
+static int init_rar_params(struct rar_device *rar)
{
+ struct pci_dev *pdev = rar->rar_dev;
unsigned int i;
int result = 0;
+ int offset = 0x10; /* RAR 0 to 2 in order low/high/low/high/... */

/* Retrieve RAR start and end bus addresses.
* Access the RAR registers through the Lincroft Message Bus
@@ -300,15 +344,16 @@ static int init_rar_params(struct pci_dev *pdev)
*/

for (i = 0; i < MRST_NUM_RAR; ++i) {
- struct RAR_offsets const *offset =
- &my_rar_device.rar_offsets[i];
- struct RAR_address_range *addr = &my_rar_device.rar_addr[i];
-
- if ((retrieve_rar_addr(pdev, offset->low, &addr->low) != 0)
- || (retrieve_rar_addr(pdev, offset->high, &addr->high) != 0)) {
- result = -1;
- break;
- }
+ struct rar_addr *addr = &rar->rar_addr[i];
+
+ result = rar_read_addr(pdev, offset++, &addr->low);
+ if (result != 0)
+ return result;
+
+ result = rar_read_addr(pdev, offset++, &addr->high);
+ if (result != 0)
+ return result;
+

/*
* Only the upper 22 bits of the RAR addresses are
@@ -336,201 +381,237 @@ static int init_rar_params(struct pci_dev *pdev)
/* Done accessing the device. */

if (result == 0) {
- int z;
- for (z = 0; z != MRST_NUM_RAR; ++z) {
+ for (i = 0; i != MRST_NUM_RAR; ++i) {
/*
* "BRAR" refers to the RAR registers in the
* Lincroft B-unit.
*/
dev_info(&pdev->dev, "BRAR[%u] bus address range = "
- "[%lx, %lx]\n", z,
- (unsigned long)my_rar_device.rar_addr[z].low,
- (unsigned long)my_rar_device.rar_addr[z].high);
+ "[%lx, %lx]\n", i,
+ (unsigned long)rar->rar_addr[i].low,
+ (unsigned long)rar->rar_addr[i].high);
}
}
-
return result;
}

-/*
- * The rar_get_address function is used by other device drivers
- * to obtain RAR address information on a RAR. It takes three
- * parameters:
+/**
+ * rar_get_address - get the bus address in a RAR
+ * @start: return value of start address of block
+ * @end: return value of end address of block
*
- * int rar_index
- * The rar_index is an index to the rar for which you wish to retrieve
- * the address information.
- * Values can be 0,1, or 2.
+ * The rar_get_address function is used by other device drivers
+ * to obtain RAR address information on a RAR. It takes three
+ * parameters:
*
- * The function returns a 0 upon success or a -1 if there is no RAR
- * facility on this system.
+ * The function returns a 0 upon success or an error if there is no RAR
+ * facility on this system.
*/
-int rar_get_address(int rar_index,
- dma_addr_t *start_address,
- dma_addr_t *end_address)
+int rar_get_address(int rar_index, dma_addr_t *start, dma_addr_t *end)
{
- int result = -ENODEV;
-
- if (my_rar_device.registered) {
- if (start_address == 0 || end_address == 0
- || rar_index >= MRST_NUM_RAR || rar_index < 0) {
- result = -EINVAL;
- } else {
- *start_address =
- my_rar_device.rar_addr[rar_index].low;
- *end_address =
- my_rar_device.rar_addr[rar_index].high;
-
- result = 0;
- }
+ int idx;
+ struct rar_device *rar = rar_to_device(rar_index, &idx);
+
+ if (rar == NULL) {
+ WARN_ON(1);
+ return -ENODEV;
}

- return result;
+ *start = rar->rar_addr[idx].low;
+ *end = rar->rar_addr[idx].high;
+ return 0;
}
EXPORT_SYMBOL(rar_get_address);

-/*
- * The rar_lock function is ued by other device drivers to lock an RAR.
- * once an RAR is locked, it stays locked until the next system reboot.
- * The function takes one parameter:
+/**
+ * rar_lock - lock a RAR register
+ * @rar_index: RAR to lock (0-2)
*
- * int rar_index
- * The rar_index is an index to the rar that you want to lock.
- * Values can be 0,1, or 2.
+ * The rar_lock function is ued by other device drivers to lock an RAR.
+ * once a RAR is locked, it stays locked until the next system reboot.
*
- * The function returns a 0 upon success or a -1 if there is no RAR
- * facility on this system.
+ * The function returns a 0 upon success or an error if there is no RAR
+ * facility on this system, or the locking fails
*/
int rar_lock(int rar_index)
{
- int result = -ENODEV;
-
- if (rar_index >= MRST_NUM_RAR || rar_index < 0) {
- result = -EINVAL;
- return result;
- }
-
- dev_dbg(&my_rar_device.rar_dev->dev, "rar_lock mutex locking\n");
- mutex_lock(&rar_mutex);
+ struct rar_device *rar;
+ int result;
+ int idx;
+ dma_addr_t low, high;

- if (my_rar_device.registered) {
+ rar = rar_to_device(rar_index, &idx);

- dma_addr_t low = my_rar_device.rar_addr[rar_index].low &
- 0xfffffc00u;
+ if (rar == NULL) {
+ WARN_ON(1);
+ return -EINVAL;
+ }

- dma_addr_t high = my_rar_device.rar_addr[rar_index].high &
- 0xfffffc00u;
+ low = rar->rar_addr[idx].low & 0xfffffc00u;
+ high = rar->rar_addr[idx].high & 0xfffffc00u;

- /*
- * Only allow I/O from the graphics and Langwell;
- * Not from the x96 processor
- */
- if (rar_index == (int)RAR_TYPE_VIDEO) {
- low |= 0x00000009;
- high |= 0x00000015;
- }
+ /*
+ * Only allow I/O from the graphics and Langwell;
+ * not from the x86 processor
+ */

- else if (rar_index == (int)RAR_TYPE_AUDIO) {
- /* Only allow I/O from Langwell; nothing from x86 */
- low |= 0x00000008;
- high |= 0x00000018;
- }
+ if (rar_index == RAR_TYPE_VIDEO) {
+ low |= 0x00000009;
+ high |= 0x00000015;
+ } else if (rar_index == RAR_TYPE_AUDIO) {
+ /* Only allow I/O from Langwell; nothing from x86 */
+ low |= 0x00000008;
+ high |= 0x00000018;
+ } else
+ /* Read-only from all agents */
+ high |= 0x00000018;

- else
- /* Read-only from all agents */
- high |= 0x00000018;
+ /*
+ * Now program the register using the Lincroft message
+ * bus interface.
+ */
+ result = rar_set_addr(rar->rar_dev,
+ 2 * idx, low);

- /*
- * Now program the register using the Lincroft message
- * bus interface.
- */
- result = set_rar_address(my_rar_device.rar_dev,
- my_rar_device.rar_offsets[rar_index].low,
- low);
-
- if (result == 0)
- result = set_rar_address(
- my_rar_device.rar_dev,
- my_rar_device.rar_offsets[rar_index].high,
- high);
- }
+ if (result == 0)
+ result = rar_set_addr(rar->rar_dev,
+ 2 * idx + 1, high);

- dev_dbg(&my_rar_device.rar_dev->dev, "rar_lock mutex unlocking\n");
- mutex_unlock(&rar_mutex);
return result;
}
EXPORT_SYMBOL(rar_lock);

-/* The register_rar function is to used by other device drivers
- * to ensure that this driver is ready. As we cannot be sure of
- * the compile/execute order of dirvers in ther kernel, it is
- * best to give this driver a callback function to call when
- * it is ready to give out addresses. The callback function
- * would have those steps that continue the initialization of
- * a driver that do require a valid RAR address. One of those
- * steps would be to call rar_get_address()
- * This function return 0 on success an -1 on failure.
-*/
-int register_rar(int (*callback)(void *yourparameter), void *yourparameter)
+/**
+ * register_rar - register a RAR handler
+ * @num: RAR we wish to register for
+ * @callback: function to call when RAR support is available
+ * @data: data to pass to this function
+ *
+ * The register_rar function is to used by other device drivers
+ * to ensure that this driver is ready. As we cannot be sure of
+ * the compile/execute order of drivers in ther kernel, it is
+ * best to give this driver a callback function to call when
+ * it is ready to give out addresses. The callback function
+ * would have those steps that continue the initialization of
+ * a driver that do require a valid RAR address. One of those
+ * steps would be to call rar_get_address()
+ *
+ * This function return 0 on success an error code on failure.
+ */
+int register_rar(int num, int (*callback)(unsigned long data),
+ unsigned long data)
{
-
- int result = -ENODEV;
-
- if (callback == NULL)
- return -EINVAL;
+ /* For now we hardcode a single RAR device */
+ struct rar_device *rar;
+ struct client *c;
+ int idx;
+ int retval = 0;

mutex_lock(&rar_mutex);

- if (my_rar_device.registered) {
+ /* Do we have a client mapping for this RAR number ? */
+ c = rar_to_client(num);
+ if (c == NULL) {
+ retval = -ERANGE;
+ goto done;
+ }
+ /* Is it claimed ? */
+ if (c->busy) {
+ retval = -EBUSY;
+ goto done;
+ }
+ c->busy = 1;
+
+ /* See if we have a handler for this RAR yet, if we do then fire it */
+ rar = rar_to_device(num, &idx);

- mutex_unlock(&rar_mutex);
+ if (rar) {
/*
* if the driver already registered, then we can simply
* call the callback right now
*/
-
- return (*callback)(yourparameter);
- }
-
- if (num_clients < MRST_NUM_RAR) {
-
- clients[num_clients].client_callback = callback;
- clients[num_clients].customer_data = yourparameter;
- num_clients += 1;
- result = 0;
+ (*callback)(data);
+ goto done;
}

+ /* Arrange to be called back when the hardware is found */
+ c->callback = callback;
+ c->driver_priv = data;
+done:
mutex_unlock(&rar_mutex);
- return result;
-
+ return retval;
}
EXPORT_SYMBOL(register_rar);

-/* Suspend - returns -ENOSYS */
-static int rar_suspend(struct pci_dev *dev, pm_message_t state)
+/**
+ * unregister_rar - release a RAR allocation
+ * @num: RAR number
+ *
+ * Releases a RAR allocation, or pending allocation. If a callback is
+ * pending then this function will either complete before the unregister
+ * returns or not at all.
+ */
+
+void unregister_rar(int num)
{
- return -ENOSYS;
+ struct client *c;
+
+ mutex_lock(&rar_mutex);
+ c = rar_to_client(num);
+ if (c == NULL || !c->busy)
+ WARN_ON(1);
+ else
+ c->busy = 0;
+ mutex_unlock(&rar_mutex);
}
+EXPORT_SYMBOL(unregister_rar);

-static int rar_resume(struct pci_dev *dev)
+/**
+ * rar_callback - Process callbacks
+ * @rar: new RAR device
+ *
+ * Process the callbacks for a newly found RAR device.
+ */
+
+static void rar_callback(struct rar_device *rar)
{
- return -ENOSYS;
+ struct client *c = &rar->client[0];
+ int i;
+
+ mutex_lock(&rar_mutex);
+
+ rar->registered = 1; /* Ensure no more callbacks queue */
+
+ for (i = 0; i < MRST_NUM_RAR; i++) {
+ if (c->callback && c->busy) {
+ c->callback(c->driver_priv);
+ c->callback = NULL;
+ }
+ c++;
+ }
+ mutex_unlock(&rar_mutex);
}

-/*
- * This function registers the driver with the device subsystem (
- * either PCI, USB, etc).
- * Function that is activaed on the succesful probe of the RAR device
- * (Moorestown host controller).
+/**
+ * rar_probe - PCI probe callback
+ * @dev: PCI device
+ * @id: matching entry in the match table
+ *
+ * A RAR device has been discovered. Initialise it and if successful
+ * process any pending callbacks that can now be completed.
*/
static int rar_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
int error;
- int counter;
+ struct rar_device *rar;

dev_dbg(&dev->dev, "PCI probe starting\n");

- /* enable the device */
+ rar = alloc_rar_device();
+ if (rar == NULL)
+ return -EBUSY;
+
+ /* Enable the device */
error = pci_enable_device(dev);
if (error) {
dev_err(&dev->dev,
@@ -538,50 +619,30 @@ static int rar_probe(struct pci_dev *dev, const struct pci_device_id *id)
goto end_function;
}

- /* we have only one device; fill in the rar_device structure */
- my_rar_device.rar_dev = dev;
+ /* Fill in the rar_device structure */
+ rar->rar_dev = pci_dev_get(dev);
+ pci_set_drvdata(dev, rar);

/*
- * Initialize the RAR parameters, which have to be retrieved
- * via the message bus interface.
- */
- error = init_rar_params(dev);
+ * Initialize the RAR parameters, which have to be retrieved
+ * via the message bus interface.
+ */
+ error = init_rar_params(rar);
if (error) {
pci_disable_device(dev);
-
- dev_err(&dev->dev,
- "Error retrieving RAR addresses\n");
-
+ dev_err(&dev->dev, "Error retrieving RAR addresses\n");
goto end_function;
}
-
- dev_dbg(&dev->dev, "PCI probe locking\n");
- mutex_lock(&rar_mutex);
- my_rar_device.registered = 1;
-
/* now call anyone who has registered (using callbacks) */
- for (counter = 0; counter < num_clients; counter += 1) {
- if (clients[counter].client_callback) {
- error = (*clients[counter].client_callback)(
- clients[counter].customer_data);
- /* set callback to NULL to indicate it has been done */
- clients[counter].client_callback = NULL;
- dev_dbg(&my_rar_device.rar_dev->dev,
- "Callback called for %d\n",
- counter);
- }
- }
-
- dev_dbg(&dev->dev, "PCI probe unlocking\n");
- mutex_unlock(&rar_mutex);
-
+ rar_callback(rar);
+ return 0;
end_function:
-
+ free_rar_device(rar);
return error;
}

const struct pci_device_id rar_pci_id_tbl[] = {
- { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_RAR_DEVICE_ID) },
+ { PCI_VDEVICE(INTEL, 0x4110) },
{ 0 }
};

@@ -594,8 +655,7 @@ static struct pci_driver rar_pci_driver = {
.name = "rar_register_driver",
.id_table = rar_pci_id_tbl,
.probe = rar_probe,
- .suspend = rar_suspend,
- .resume = rar_resume
+ /* Cannot be unplugged - no remove */
};

static int __init rar_init_handler(void)
diff --git a/drivers/staging/rar_register/rar_register.h b/drivers/staging/rar_register/rar_register.h
index 29ade0f..ffa8057 100644
--- a/drivers/staging/rar_register/rar_register.h
+++ b/drivers/staging/rar_register/rar_register.h
@@ -21,63 +21,23 @@
#ifndef _RAR_REGISTER_H
#define _RAR_REGISTER_H

-# include <linux/types.h>
+#include <linux/types.h>

/* following are used both in drivers as well as user space apps */
-enum RAR_type {
- RAR_TYPE_VIDEO = 0,
- RAR_TYPE_AUDIO,
- RAR_TYPE_IMAGE,
- RAR_TYPE_DATA
-};

-#ifdef __KERNEL__
+#define RAR_TYPE_VIDEO 0
+#define RAR_TYPE_AUDIO 1
+#define RAR_TYPE_IMAGE 2
+#define RAR_TYPE_DATA 3

-/* PCI device id for controller */
-#define PCI_RAR_DEVICE_ID 0x4110
+#ifdef __KERNEL__

-/* The register_rar function is to used by other device drivers
- * to ensure that this driver is ready. As we cannot be sure of
- * the compile/execute order of dirvers in ther kernel, it is
- * best to give this driver a callback function to call when
- * it is ready to give out addresses. The callback function
- * would have those steps that continue the initialization of
- * a driver that do require a valid RAR address. One of those
- * steps would be to call get_rar_address()
- * This function return 0 on success an -1 on failure.
- */
-int register_rar(int (*callback)(void *yourparameter), void *yourparameter);
+struct rar_device;

-/* The get_rar_address function is used by other device drivers
- * to obtain RAR address information on a RAR. It takes two
- * parameter:
- *
- * int rar_index
- * The rar_index is an index to the rar for which you wish to retrieve
- * the address information.
- * Values can be 0,1, or 2.
- *
- * struct RAR_address_struct is a pointer to a place to which the function
- * can return the address structure for the RAR.
- *
- * The function returns a 0 upon success or a -1 if there is no RAR
- * facility on this system.
- */
-int rar_get_address(int rar_index,
- dma_addr_t *start_address,
- dma_addr_t *end_address);
-
-/* The lock_rar function is ued by other device drivers to lock an RAR.
- * once an RAR is locked, it stays locked until the next system reboot.
- * The function takes one parameter:
- *
- * int rar_index
- * The rar_index is an index to the rar that you want to lock.
- * Values can be 0,1, or 2.
- *
- * The function returns a 0 upon success or a -1 if there is no RAR
- * facility on this system.
- */
+int register_rar(int num,
+ int (*callback)(unsigned long data), unsigned long data);
+void unregister_rar(int num);
+int rar_get_address(int rar_index, dma_addr_t *start, dma_addr_t *end);
int rar_lock(int rar_index);

#endif /* __KERNEL__ */

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