[PATCH 2/6] sep: Basic infrastructure for SEP DMA access to non CPUregions

From: Alan Cox
Date: Fri Feb 10 2012 - 08:39:52 EST


From: Mark A. Allyn <mark.a.allyn@xxxxxxxxx>

[This is picked out of the differences between the upstream driver and
the staging driver. I'm resolving the differences as a series of updates -AC]

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---

drivers/staging/sep/sep_driver_api.h | 15 ++
drivers/staging/sep/sep_main.c | 233 ++++++++++++++++++++++++++++++----
2 files changed, 223 insertions(+), 25 deletions(-)


diff --git a/drivers/staging/sep/sep_driver_api.h b/drivers/staging/sep/sep_driver_api.h
index 78a4b69..8b797d5 100644
--- a/drivers/staging/sep/sep_driver_api.h
+++ b/drivers/staging/sep/sep_driver_api.h
@@ -61,7 +61,9 @@ enum hash_stage {
HASH_INIT,
HASH_UPDATE,
HASH_FINISH,
- HASH_DIGEST
+ HASH_DIGEST,
+ HASH_FINUP_DATA,
+ HASH_FINUP_FINISH
};

/*
@@ -205,6 +207,7 @@ struct sep_lli_entry {
*/
struct sep_fastcall_hdr {
u32 magic;
+ u32 secure_dma;
u32 msg_len;
u32 num_dcbs;
};
@@ -231,6 +234,8 @@ struct sep_dma_context {
u32 dmatables_len;
/* size of input data */
u32 input_data_len;
+ /* secure dma use (for imr memory restriced area in output */
+ bool secure_dma;
struct sep_dma_resource dma_res_arr[SEP_MAX_NUM_SYNC_DMA_OPS];
/* Scatter gather for kernel crypto */
struct scatterlist *src_sg;
@@ -317,6 +322,7 @@ ssize_t sep_activate_dcb_dmatables_context(struct sep_device *sep,
* @tail_block_size: u32; for size of tail block
* @isapplet: bool; to indicate external app
* @is_kva: bool; kernel buffer; only used for kernel crypto module
+ * @secure_dma; indicates whether this is secure_dma using IMR
*
* This function prepares the linked DMA tables and puts the
* address for the linked list of tables inta a DCB (data control
@@ -332,6 +338,7 @@ int sep_prepare_input_output_dma_table_in_dcb(struct sep_device *sep,
u32 tail_block_size,
bool isapplet,
bool is_kva,
+ bool secure_dma,
struct sep_dcblock *dcb_region,
void **dmatables_region,
struct sep_dma_context **dma_ctx,
@@ -386,4 +393,10 @@ int sep_wait_transaction(struct sep_device *sep);

struct sep_device;

+#define SEP_IOCPREPAREDCB_SECURE_DMA \
+ _IOW(SEP_IOC_MAGIC_NUMBER, 38, struct build_dcb_struct)
+
+#define SEP_IOCFREEDCB_SECURE_DMA \
+ _IO(SEP_IOC_MAGIC_NUMBER, 39)
+
#endif
diff --git a/drivers/staging/sep/sep_main.c b/drivers/staging/sep/sep_main.c
index 421a2b1..7d7cb48 100644
--- a/drivers/staging/sep/sep_main.c
+++ b/drivers/staging/sep/sep_main.c
@@ -485,8 +485,15 @@ int sep_free_dma_table_data_handler(struct sep_device *sep,
kfree(dma->in_map_array);
}

- /* Unmap output map array, DON'T free it yet */
- if (dma->out_map_array) {
+ /**
+ * Output is handled different. If
+ * this was a secure dma into restricted memory,
+ * then we skip this step altogether as restricted
+ * memory is not available to the o/s at all.
+ */
+ if (((*dma_ctx)->secure_dma == false) &&
+ (dma->out_map_array)) {
+
for (count = 0; count < dma->out_num_pages; count++) {
dma_unmap_page(&sep->pdev->dev,
dma->out_map_array[count].dma_addr,
@@ -505,7 +512,10 @@ int sep_free_dma_table_data_handler(struct sep_device *sep,
kfree(dma->in_page_array);
}

- if (dma->out_page_array) {
+ /* Again, we do this only for non secure dma */
+ if (((*dma_ctx)->secure_dma == false) &&
+ (dma->out_page_array)) {
+
for (count = 0; count < dma->out_num_pages; count++) {
if (!PageReserved(dma->out_page_array[count]))

@@ -1383,6 +1393,128 @@ end_function:
}

/**
+ * sep_lli_table_secure_dma - get lli array for IMR addresses
+ * @sep: pointer to struct sep_device
+ * @app_virt_addr: user memory data buffer
+ * @data_size: size of data buffer
+ * @lli_array_ptr: lli array
+ * @in_out_flag: not used
+ * @dma_ctx: pointer to struct sep_dma_context
+ *
+ * This function creates lli tables for outputting data to
+ * IMR memory, which is memory that cannot be accessed by the
+ * the x86 processor.
+ */
+static int sep_lli_table_secure_dma(struct sep_device *sep,
+ u32 app_virt_addr,
+ u32 data_size,
+ struct sep_lli_entry **lli_array_ptr,
+ int in_out_flag,
+ struct sep_dma_context *dma_ctx)
+
+{
+ int error = 0;
+ u32 count;
+ /* The the page of the end address of the user space buffer */
+ u32 end_page;
+ /* The page of the start address of the user space buffer */
+ u32 start_page;
+ /* The range in pages */
+ u32 num_pages;
+ /* Array of lli */
+ struct sep_lli_entry *lli_array;
+
+ /* Set start and end pages and num pages */
+ end_page = (app_virt_addr + data_size - 1) >> PAGE_SHIFT;
+ start_page = app_virt_addr >> PAGE_SHIFT;
+ num_pages = end_page - start_page + 1;
+
+ dev_dbg(&sep->pdev->dev, "[PID%d] lock user pages"
+ " app_virt_addr is %x\n", current->pid, app_virt_addr);
+
+ dev_dbg(&sep->pdev->dev, "[PID%d] data_size is (hex) %x\n",
+ current->pid, data_size);
+ dev_dbg(&sep->pdev->dev, "[PID%d] start_page is (hex) %x\n",
+ current->pid, start_page);
+ dev_dbg(&sep->pdev->dev, "[PID%d] end_page is (hex) %x\n",
+ current->pid, end_page);
+ dev_dbg(&sep->pdev->dev, "[PID%d] num_pages is (hex) %x\n",
+ current->pid, num_pages);
+
+ lli_array = kmalloc(sizeof(struct sep_lli_entry) * num_pages,
+ GFP_ATOMIC);
+
+ if (!lli_array) {
+ dev_warn(&sep->pdev->dev,
+ "[PID%d] kmalloc for lli_array failed\n",
+ current->pid);
+ return -ENOMEM;
+ }
+
+ /*
+ * Fill the lli_array
+ */
+ start_page = start_page << PAGE_SHIFT;
+ for (count = 0; count < num_pages; count++) {
+ /* Fill the lli array entry */
+ lli_array[count].bus_address = start_page;
+ lli_array[count].block_size = PAGE_SIZE;
+
+ start_page += PAGE_SIZE;
+
+ dev_dbg(&sep->pdev->dev,
+ "[PID%d] lli_array[%x].bus_address is %08lx, "
+ "lli_array[%x].block_size is (hex) %x\n",
+ current->pid,
+ count, (unsigned long)lli_array[count].bus_address,
+ count, lli_array[count].block_size);
+ }
+
+ /* Check the offset for the first page */
+ lli_array[0].bus_address =
+ lli_array[0].bus_address + (app_virt_addr & (~PAGE_MASK));
+
+ /* Check that not all the data is in the first page only */
+ if ((PAGE_SIZE - (app_virt_addr & (~PAGE_MASK))) >= data_size)
+ lli_array[0].block_size = data_size;
+ else
+ lli_array[0].block_size =
+ PAGE_SIZE - (app_virt_addr & (~PAGE_MASK));
+
+ dev_dbg(&sep->pdev->dev,
+ "[PID%d] After check if page 0 has all data\n"
+ "lli_array[0].bus_address is (hex) %08lx, "
+ "lli_array[0].block_size is (hex) %x\n",
+ current->pid,
+ (unsigned long)lli_array[0].bus_address,
+ lli_array[0].block_size);
+
+ /* Check the size of the last page */
+ if (num_pages > 1) {
+ lli_array[num_pages - 1].block_size =
+ (app_virt_addr + data_size) & (~PAGE_MASK);
+ if (lli_array[num_pages - 1].block_size == 0)
+ lli_array[num_pages - 1].block_size = PAGE_SIZE;
+
+ dev_dbg(&sep->pdev->dev,
+ "[PID%d] After last page size adjustment\n"
+ "lli_array[%x].bus_address is (hex) %08lx, "
+ "lli_array[%x].block_size is (hex) %x\n",
+ current->pid, num_pages - 1,
+ (unsigned long)lli_array[num_pages - 1].bus_address,
+ num_pages - 1,
+ lli_array[num_pages - 1].block_size);
+ }
+ *lli_array_ptr = lli_array;
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_num_pages = num_pages;
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_page_array = NULL;
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_map_array = NULL;
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_map_num_entries = 0;
+
+ return error;
+}
+
+/**
* sep_calculate_lli_table_max_size - size the LLI table
* @sep: pointer to struct sep_device
* @lli_in_array_ptr
@@ -1613,6 +1745,7 @@ static void sep_debug_print_lli_tables(struct sep_device *sep,
unsigned long num_table_entries,
unsigned long table_data_size)
{
+#ifdef DEBUG
unsigned long table_count = 1;
unsigned long entries_count = 0;

@@ -1686,6 +1819,7 @@ static void sep_debug_print_lli_tables(struct sep_device *sep,
}
dev_dbg(&sep->pdev->dev, "[PID%d] sep_debug_print_lli_tables end\n",
current->pid);
+#endif
}


@@ -1956,8 +2090,10 @@ update_dcb_counter:
end_function_error:
/* Free all the allocated resources */
kfree(dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_map_array);
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_map_array = NULL;
kfree(lli_array_ptr);
kfree(dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_page_array);
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_page_array = NULL;

end_function:
return error;
@@ -2360,20 +2496,42 @@ static int sep_prepare_input_output_dma_table(struct sep_device *sep,
goto end_function;
}

- dev_dbg(&sep->pdev->dev, "[PID%d] Locking user output pages\n",
+ if (dma_ctx->secure_dma == true) {
+ /* secure_dma requires use of non accessible memory */
+ dev_dbg(&sep->pdev->dev, "[PID%d] in secure_dma\n",
+ current->pid);
+ error = sep_lli_table_secure_dma(sep,
+ app_virt_out_addr, data_size, &lli_out_array,
+ SEP_DRIVER_OUT_FLAG, dma_ctx);
+ if (error) {
+ dev_warn(&sep->pdev->dev,
+ "[PID%d] secure dma table setup "
+ " for output virtual buffer failed\n",
+ current->pid);
+
+ goto end_function_free_lli_in;
+ }
+ } else {
+ /* For normal, non-secure dma */
+ dev_dbg(&sep->pdev->dev, "[PID%d] not in secure_dma\n",
current->pid);

- error = sep_lock_user_pages(sep, app_virt_out_addr,
+ dev_dbg(&sep->pdev->dev,
+ "[PID%d] Locking user output pages\n",
+ current->pid);
+
+ error = sep_lock_user_pages(sep, app_virt_out_addr,
data_size, &lli_out_array, SEP_DRIVER_OUT_FLAG,
dma_ctx);

- if (error) {
- dev_warn(&sep->pdev->dev,
+ if (error) {
+ dev_warn(&sep->pdev->dev,
"[PID%d] sep_lock_user_pages"
" for output virtual buffer failed\n",
current->pid);

- goto end_function_free_lli_in;
+ goto end_function_free_lli_in;
+ }
}
}

@@ -2421,13 +2579,17 @@ update_dcb_counter:

end_function_with_error:
kfree(dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_map_array);
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_map_array = NULL;
kfree(dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_page_array);
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].out_page_array = NULL;
kfree(lli_out_array);


end_function_free_lli_in:
kfree(dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_map_array);
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_map_array = NULL;
kfree(dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_page_array);
+ dma_ctx->dma_res_arr[dma_ctx->nr_dcb_creat].in_page_array = NULL;
kfree(lli_in_array);

end_function:
@@ -2445,6 +2607,7 @@ end_function:
* @tail_block_size: u32; for size of tail block
* @isapplet: bool; to indicate external app
* @is_kva: bool; kernel buffer; only used for kernel crypto module
+ * @secure_dma; indicates whether this is secure_dma using IMR
*
* This function prepares the linked DMA tables and puts the
* address for the linked list of tables inta a DCB (data control
@@ -2460,6 +2623,7 @@ int sep_prepare_input_output_dma_table_in_dcb(struct sep_device *sep,
u32 tail_block_size,
bool isapplet,
bool is_kva,
+ bool secure_dma,
struct sep_dcblock *dcb_region,
void **dmatables_region,
struct sep_dma_context **dma_ctx,
@@ -2534,6 +2698,8 @@ int sep_prepare_input_output_dma_table_in_dcb(struct sep_device *sep,
current->pid, *dma_ctx);
}

+ (*dma_ctx)->secure_dma = secure_dma;
+
/* these are for kernel crypto only */
(*dma_ctx)->src_sg = src_sg;
(*dma_ctx)->dst_sg = dst_sg;
@@ -2690,6 +2856,7 @@ int sep_prepare_input_output_dma_table_in_dcb(struct sep_device *sep,

end_function_error:
kfree(*dma_ctx);
+ *dma_ctx = NULL;

end_function:
return error;
@@ -2719,15 +2886,22 @@ static int sep_free_dma_tables_and_dcb(struct sep_device *sep, bool isapplet,
dev_dbg(&sep->pdev->dev, "[PID%d] sep_free_dma_tables_and_dcb\n",
current->pid);

- if (isapplet == true) {
+ if (((*dma_ctx)->secure_dma == false) && (isapplet == true)) {
+ dev_dbg(&sep->pdev->dev, "[PID%d] handling applet\n",
+ current->pid);
+
+ /* Tail stuff is only for non secure_dma */
/* Set pointer to first DCB table */
dcb_table_ptr = (struct sep_dcblock *)
(sep->shared_addr +
SEP_DRIVER_SYSTEM_DCB_MEMORY_OFFSET_IN_BYTES);

- /* Go over each DCB and see if tail pointer must be updated */
- for (i = 0;
- i < (*dma_ctx)->nr_dcb_creat; i++, dcb_table_ptr++) {
+ /**
+ * Go over each DCB and see if
+ * tail pointer must be updated
+ */
+ for (i = 0; dma_ctx && *dma_ctx &&
+ i < (*dma_ctx)->nr_dcb_creat; i++, dcb_table_ptr++) {
if (dcb_table_ptr->out_vr_tail_pt) {
pt_hold = (unsigned long)dcb_table_ptr->
out_vr_tail_pt;
@@ -2749,6 +2923,7 @@ static int sep_free_dma_tables_and_dcb(struct sep_device *sep, bool isapplet,
}
}
}
+
/* Free the output pages, if any */
sep_free_dma_table_data_handler(sep, dma_ctx);

@@ -2762,11 +2937,13 @@ static int sep_free_dma_tables_and_dcb(struct sep_device *sep, bool isapplet,
* sep_prepare_dcb_handler - prepare a control block
* @sep: pointer to struct sep_device
* @arg: pointer to user parameters
+ * @secure_dma: indicate whether we are using secure_dma on IMR
*
* This function will retrieve the RAR buffer physical addresses, type
* & size corresponding to the RAR handles provided in the buffers vector.
*/
static int sep_prepare_dcb_handler(struct sep_device *sep, unsigned long arg,
+ bool secure_dma,
struct sep_dma_context **dma_ctx)
{
int error;
@@ -2812,7 +2989,7 @@ static int sep_prepare_dcb_handler(struct sep_device *sep, unsigned long arg,
command_args.data_in_size, command_args.block_size,
command_args.tail_block_size,
command_args.is_applet, false,
- NULL, NULL, dma_ctx, NULL, NULL);
+ secure_dma, NULL, NULL, dma_ctx, NULL, NULL);

end_function:
return error;
@@ -2829,21 +3006,18 @@ end_function:
static int sep_free_dcb_handler(struct sep_device *sep,
struct sep_dma_context **dma_ctx)
{
- int error = 0;
-
if (!dma_ctx || !(*dma_ctx)) {
- dev_dbg(&sep->pdev->dev, "[PID%d] no dma context defined, nothing to free\n",
+ dev_dbg(&sep->pdev->dev,
+ "[PID%d] no dma context defined, nothing to free\n",
current->pid);
- return error;
+ return -EINVAL;
}

dev_dbg(&sep->pdev->dev, "[PID%d] free dcbs num of DCBs %x\n",
current->pid,
(*dma_ctx)->nr_dcb_creat);

- error = sep_free_dma_tables_and_dcb(sep, false, false, dma_ctx);
-
- return error;
+ return sep_free_dma_tables_and_dcb(sep, false, false, dma_ctx);
}

/**
@@ -2931,7 +3105,7 @@ static long sep_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
goto end_function;
}

- error = sep_prepare_dcb_handler(sep, arg, dma_ctx);
+ error = sep_prepare_dcb_handler(sep, arg, false, dma_ctx);
dev_dbg(&sep->pdev->dev, "[PID%d] SEP_IOCPREPAREDCB end\n",
current->pid);
break;
@@ -3170,13 +3344,14 @@ end_function:
* @dma_ctx: DMA context buf to create for current transaction
* @user_dcb_args: User arguments for DCB/MLLI creation
* @num_dcbs: Number of DCBs to create
+ * @secure_dma: Indicate use of IMR restricted memory secure dma
*/
static ssize_t sep_create_dcb_dmatables_context(struct sep_device *sep,
struct sep_dcblock **dcb_region,
void **dmatables_region,
struct sep_dma_context **dma_ctx,
const struct build_dcb_struct __user *user_dcb_args,
- const u32 num_dcbs)
+ const u32 num_dcbs, bool secure_dma)
{
int error = 0;
int i = 0;
@@ -3231,7 +3406,7 @@ static ssize_t sep_create_dcb_dmatables_context(struct sep_device *sep,
dcb_args[i].block_size,
dcb_args[i].tail_block_size,
dcb_args[i].is_applet,
- false,
+ false, secure_dma,
*dcb_region, dmatables_region,
dma_ctx,
NULL,
@@ -3242,6 +3417,9 @@ static ssize_t sep_create_dcb_dmatables_context(struct sep_device *sep,
current->pid);
goto end_function;
}
+
+ if (dcb_args[i].app_in_address != 0)
+ (*dma_ctx)->input_data_len += dcb_args[i].data_in_size;
}

end_function:
@@ -3311,6 +3489,7 @@ int sep_create_dcb_dmatables_context_kernel(struct sep_device *sep,
dcb_data->tail_block_size,
dcb_data->is_applet,
true,
+ false,
*dcb_region, dmatables_region,
dma_ctx,
dcb_data->src_sg,
@@ -3597,6 +3776,7 @@ static ssize_t sep_write(struct file *filp,
struct sep_dcblock *dcb_region = NULL;
ssize_t error = 0;
struct sep_queue_info *my_queue_elem = NULL;
+ bool my_secure_dma; /* are we using secure_dma (IMR)? */

dev_dbg(&sep->pdev->dev, "[PID%d] sep dev is 0x%p\n",
current->pid, sep);
@@ -3609,6 +3789,11 @@ static ssize_t sep_write(struct file *filp,

buf_user += sizeof(struct sep_fastcall_hdr);

+ if (call_hdr.secure_dma == 0)
+ my_secure_dma = false;
+ else
+ my_secure_dma = true;
+
/*
* Controlling driver memory usage by limiting amount of
* buffers created. Only SEP_DOUBLEBUF_USERS_LIMIT number
@@ -3636,7 +3821,7 @@ static ssize_t sep_write(struct file *filp,
&dma_ctx,
(const struct build_dcb_struct __user *)
buf_user,
- call_hdr.num_dcbs);
+ call_hdr.num_dcbs, my_secure_dma);
if (error)
goto end_function_error_doublebuf;


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