* PATCH: Fix up memrar to the new RAR API
@ 2010-05-04 9:52 Alan Cox
2010-05-04 15:52 ` Greg KH
0 siblings, 1 reply; 2+ messages in thread
From: Alan Cox @ 2010-05-04 9:52 UTC (permalink / raw)
To: greg, linux-kernel
memrar: rework to match the RAR API changes
From: Alan Cox <alan@linux.intel.com>
Fix various unload related bugs
Use the per RAR allocator/deallocator
Add kerneldoc
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
drivers/staging/memrar/memrar_handler.c | 469 +++++++++++++++++--------------
1 files changed, 264 insertions(+), 205 deletions(-)
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);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: PATCH: Fix up memrar to the new RAR API
2010-05-04 9:52 PATCH: Fix up memrar to the new RAR API Alan Cox
@ 2010-05-04 15:52 ` Greg KH
0 siblings, 0 replies; 2+ messages in thread
From: Greg KH @ 2010-05-04 15:52 UTC (permalink / raw)
To: Alan Cox; +Cc: linux-kernel
On Tue, May 04, 2010 at 10:52:13AM +0100, Alan Cox wrote:
> memrar: rework to match the RAR API changes
>
> From: Alan Cox <alan@linux.intel.com>
>
> Fix various unload related bugs
> Use the per RAR allocator/deallocator
> Add kerneldoc
This doesn't apply now that the previous patch could not be applied due
to the build error.
Care to fix these two up and send them again?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 2+ messages in thread
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2010-05-04 9:52 PATCH: Fix up memrar to the new RAR API Alan Cox
2010-05-04 15:52 ` Greg KH
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