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Merge pull request #106 from al1img/fix_optee
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optee fixes
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klogg authored May 13, 2021
2 parents 79b42d9 + 143ed7b commit 3dca59c
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Showing 24 changed files with 1,846 additions and 796 deletions.
8 changes: 8 additions & 0 deletions drivers/tee/optee/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -5,3 +5,11 @@ config OPTEE
help
This implements the OP-TEE Trusted Execution Environment (TEE)
driver.

config OPTEE_SHM_NUM_PRIV_PAGES
int "Private Shared Memory Pages"
default 1
depends on OPTEE
help
This sets the number of private shared memory pages to be
used by OP-TEE TEE driver.
3 changes: 2 additions & 1 deletion drivers/tee/optee/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -4,4 +4,5 @@ optee-objs += core.o
optee-objs += call.o
optee-objs += rpc.o
optee-objs += supp.o
optee-objs += rcar.o
optee-objs += shm_pool.o
optee-objs += device.o
220 changes: 219 additions & 1 deletion drivers/tee/optee/call.c
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
#include <linux/device.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include <linux/types.h>
Expand Down Expand Up @@ -135,6 +136,7 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
struct optee *optee = tee_get_drvdata(ctx->teedev);
struct optee_call_waiter w;
struct optee_rpc_param param = { };
struct optee_call_ctx call_ctx = { };
u32 ret;

param.a0 = OPTEE_SMC_CALL_WITH_ARG;
Expand All @@ -159,13 +161,14 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
param.a1 = res.a1;
param.a2 = res.a2;
param.a3 = res.a3;
optee_handle_rpc(ctx, &param);
optee_handle_rpc(ctx, &param, &call_ctx);
} else {
ret = res.a0;
break;
}
}

optee_rpc_finalize_call(&call_ctx);
/*
* We're done with our thread in secure world, if there's any
* thread waiters wake up one.
Expand Down Expand Up @@ -442,3 +445,218 @@ void optee_disable_shm_cache(struct optee *optee)
}
optee_cq_wait_final(&optee->call_queue, &w);
}

#define PAGELIST_ENTRIES_PER_PAGE \
((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)

/**
* optee_fill_pages_list() - write list of user pages to given shared
* buffer.
*
* @dst: page-aligned buffer where list of pages will be stored
* @pages: array of pages that represents shared buffer
* @num_pages: number of entries in @pages
* @page_offset: offset of user buffer from page start
*
* @dst should be big enough to hold list of user page addresses and
* links to the next pages of buffer
*/
void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
size_t page_offset)
{
int n = 0;
phys_addr_t optee_page;
/*
* Refer to OPTEE_MSG_ATTR_NONCONTIG description in optee_msg.h
* for details.
*/
struct {
u64 pages_list[PAGELIST_ENTRIES_PER_PAGE];
u64 next_page_data;
} *pages_data;

/*
* Currently OP-TEE uses 4k page size and it does not looks
* like this will change in the future. On other hand, there are
* no know ARM architectures with page size < 4k.
* Thus the next built assert looks redundant. But the following
* code heavily relies on this assumption, so it is better be
* safe than sorry.
*/
BUILD_BUG_ON(PAGE_SIZE < OPTEE_MSG_NONCONTIG_PAGE_SIZE);

pages_data = (void *)dst;
/*
* If linux page is bigger than 4k, and user buffer offset is
* larger than 4k/8k/12k/etc this will skip first 4k pages,
* because they bear no value data for OP-TEE.
*/
optee_page = page_to_phys(*pages) +
round_down(page_offset, OPTEE_MSG_NONCONTIG_PAGE_SIZE);

while (true) {
pages_data->pages_list[n++] = optee_page;

if (n == PAGELIST_ENTRIES_PER_PAGE) {
pages_data->next_page_data =
virt_to_phys(pages_data + 1);
pages_data++;
n = 0;
}

optee_page += OPTEE_MSG_NONCONTIG_PAGE_SIZE;
if (!(optee_page & ~PAGE_MASK)) {
if (!--num_pages)
break;
pages++;
optee_page = page_to_phys(*pages);
}
}
}

/*
* The final entry in each pagelist page is a pointer to the next
* pagelist page.
*/
static size_t get_pages_list_size(size_t num_entries)
{
int pages = DIV_ROUND_UP(num_entries, PAGELIST_ENTRIES_PER_PAGE);

return pages * OPTEE_MSG_NONCONTIG_PAGE_SIZE;
}

u64 *optee_allocate_pages_list(size_t num_entries)
{
return alloc_pages_exact(get_pages_list_size(num_entries), GFP_KERNEL);
}

void optee_free_pages_list(void *list, size_t num_entries)
{
free_pages_exact(list, get_pages_list_size(num_entries));
}

static bool is_normal_memory(pgprot_t p)
{
#if defined(CONFIG_ARM)
return (pgprot_val(p) & L_PTE_MT_MASK) == L_PTE_MT_WRITEALLOC;
#elif defined(CONFIG_ARM64)
return (pgprot_val(p) & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL);
#else
#error "Unuspported architecture"
#endif
}

static int __check_mem_type(struct vm_area_struct *vma, unsigned long end)
{
while (vma && is_normal_memory(vma->vm_page_prot)) {
if (vma->vm_end >= end)
return 0;
vma = vma->vm_next;
}

return -EINVAL;
}

static int check_mem_type(unsigned long start, size_t num_pages)
{
struct mm_struct *mm = current->mm;
int rc;

down_read(&mm->mmap_sem);
rc = __check_mem_type(find_vma(mm, start),
start + num_pages * PAGE_SIZE);
up_read(&mm->mmap_sem);

return rc;
}

int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
struct page **pages, size_t num_pages,
unsigned long start)
{
struct tee_shm *shm_arg = NULL;
struct optee_msg_arg *msg_arg;
u64 *pages_list;
phys_addr_t msg_parg;
int rc;

if (!num_pages)
return -EINVAL;

rc = check_mem_type(start, num_pages);
if (rc)
return rc;

pages_list = optee_allocate_pages_list(num_pages);
if (!pages_list)
return -ENOMEM;

shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
if (IS_ERR(shm_arg)) {
rc = PTR_ERR(shm_arg);
goto out;
}

optee_fill_pages_list(pages_list, pages, num_pages,
tee_shm_get_page_offset(shm));

msg_arg->cmd = OPTEE_MSG_CMD_REGISTER_SHM;
msg_arg->params->attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
OPTEE_MSG_ATTR_NONCONTIG;
msg_arg->params->u.tmem.shm_ref = (unsigned long)shm;
msg_arg->params->u.tmem.size = tee_shm_get_size(shm);
/*
* In the least bits of msg_arg->params->u.tmem.buf_ptr we
* store buffer offset from 4k page, as described in OP-TEE ABI.
*/
msg_arg->params->u.tmem.buf_ptr = virt_to_phys(pages_list) |
(tee_shm_get_page_offset(shm) & (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));

if (optee_do_call_with_arg(ctx, msg_parg) ||
msg_arg->ret != TEEC_SUCCESS)
rc = -EINVAL;

tee_shm_free(shm_arg);
out:
optee_free_pages_list(pages_list, num_pages);
return rc;
}

int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
{
struct tee_shm *shm_arg;
struct optee_msg_arg *msg_arg;
phys_addr_t msg_parg;
int rc = 0;

shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
if (IS_ERR(shm_arg))
return PTR_ERR(shm_arg);

msg_arg->cmd = OPTEE_MSG_CMD_UNREGISTER_SHM;

msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
msg_arg->params[0].u.rmem.shm_ref = (unsigned long)shm;

if (optee_do_call_with_arg(ctx, msg_parg) ||
msg_arg->ret != TEEC_SUCCESS)
rc = -EINVAL;
tee_shm_free(shm_arg);
return rc;
}

int optee_shm_register_supp(struct tee_context *ctx, struct tee_shm *shm,
struct page **pages, size_t num_pages,
unsigned long start)
{
/*
* We don't want to register supplicant memory in OP-TEE.
* Instead information about it will be passed in RPC code.
*/
return check_mem_type(start, num_pages);
}

int optee_shm_unregister_supp(struct tee_context *ctx, struct tee_shm *shm)
{
return 0;
}
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