linux/drivers/firmware/qcom_scm-32.c
Niklas Cassel 5ec3444c83 firmware: qcom: scm: Fix crash in qcom_scm_call_atomic1()
qcom_scm_call_atomic1() can crash with a NULL pointer dereference at
qcom_scm_call_atomic1+0x30/0x48.

disassembly of qcom_scm_call_atomic1():
...
<0xc08d73b0 <+12>: ldr r3, [r12]
... (no instruction explicitly modifies r12)
0xc08d73cc <+40>: smc 0
... (no instruction explicitly modifies r12)
0xc08d73d4 <+48>: ldr r3, [r12] <- crashing instruction
...

Since the first ldr is successful, and since r12 isn't explicitly
modified by any instruction between the first and the second ldr,
it must have been modified by the smc call, which is ok,
since r12 is caller save according to the AAPCS.

Add r12 to the clobber list so that the compiler knows that the
callee potentially overwrites the value in r12.
Clobber descriptions may not in any way overlap with an input or
output operand.

Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
2018-05-24 22:36:45 -05:00

630 lines
16 KiB
C

/* Copyright (c) 2010,2015, The Linux Foundation. All rights reserved.
* Copyright (C) 2015 Linaro Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/qcom_scm.h>
#include <linux/dma-mapping.h>
#include "qcom_scm.h"
#define QCOM_SCM_FLAG_COLDBOOT_CPU0 0x00
#define QCOM_SCM_FLAG_COLDBOOT_CPU1 0x01
#define QCOM_SCM_FLAG_COLDBOOT_CPU2 0x08
#define QCOM_SCM_FLAG_COLDBOOT_CPU3 0x20
#define QCOM_SCM_FLAG_WARMBOOT_CPU0 0x04
#define QCOM_SCM_FLAG_WARMBOOT_CPU1 0x02
#define QCOM_SCM_FLAG_WARMBOOT_CPU2 0x10
#define QCOM_SCM_FLAG_WARMBOOT_CPU3 0x40
struct qcom_scm_entry {
int flag;
void *entry;
};
static struct qcom_scm_entry qcom_scm_wb[] = {
{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU0 },
{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU1 },
{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU2 },
{ .flag = QCOM_SCM_FLAG_WARMBOOT_CPU3 },
};
static DEFINE_MUTEX(qcom_scm_lock);
/**
* struct qcom_scm_command - one SCM command buffer
* @len: total available memory for command and response
* @buf_offset: start of command buffer
* @resp_hdr_offset: start of response buffer
* @id: command to be executed
* @buf: buffer returned from qcom_scm_get_command_buffer()
*
* An SCM command is laid out in memory as follows:
*
* ------------------- <--- struct qcom_scm_command
* | command header |
* ------------------- <--- qcom_scm_get_command_buffer()
* | command buffer |
* ------------------- <--- struct qcom_scm_response and
* | response header | qcom_scm_command_to_response()
* ------------------- <--- qcom_scm_get_response_buffer()
* | response buffer |
* -------------------
*
* There can be arbitrary padding between the headers and buffers so
* you should always use the appropriate qcom_scm_get_*_buffer() routines
* to access the buffers in a safe manner.
*/
struct qcom_scm_command {
__le32 len;
__le32 buf_offset;
__le32 resp_hdr_offset;
__le32 id;
__le32 buf[0];
};
/**
* struct qcom_scm_response - one SCM response buffer
* @len: total available memory for response
* @buf_offset: start of response data relative to start of qcom_scm_response
* @is_complete: indicates if the command has finished processing
*/
struct qcom_scm_response {
__le32 len;
__le32 buf_offset;
__le32 is_complete;
};
/**
* qcom_scm_command_to_response() - Get a pointer to a qcom_scm_response
* @cmd: command
*
* Returns a pointer to a response for a command.
*/
static inline struct qcom_scm_response *qcom_scm_command_to_response(
const struct qcom_scm_command *cmd)
{
return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset);
}
/**
* qcom_scm_get_command_buffer() - Get a pointer to a command buffer
* @cmd: command
*
* Returns a pointer to the command buffer of a command.
*/
static inline void *qcom_scm_get_command_buffer(const struct qcom_scm_command *cmd)
{
return (void *)cmd->buf;
}
/**
* qcom_scm_get_response_buffer() - Get a pointer to a response buffer
* @rsp: response
*
* Returns a pointer to a response buffer of a response.
*/
static inline void *qcom_scm_get_response_buffer(const struct qcom_scm_response *rsp)
{
return (void *)rsp + le32_to_cpu(rsp->buf_offset);
}
static u32 smc(u32 cmd_addr)
{
int context_id;
register u32 r0 asm("r0") = 1;
register u32 r1 asm("r1") = (u32)&context_id;
register u32 r2 asm("r2") = cmd_addr;
do {
asm volatile(
__asmeq("%0", "r0")
__asmeq("%1", "r0")
__asmeq("%2", "r1")
__asmeq("%3", "r2")
#ifdef REQUIRES_SEC
".arch_extension sec\n"
#endif
"smc #0 @ switch to secure world\n"
: "=r" (r0)
: "r" (r0), "r" (r1), "r" (r2)
: "r3", "r12");
} while (r0 == QCOM_SCM_INTERRUPTED);
return r0;
}
/**
* qcom_scm_call() - Send an SCM command
* @dev: struct device
* @svc_id: service identifier
* @cmd_id: command identifier
* @cmd_buf: command buffer
* @cmd_len: length of the command buffer
* @resp_buf: response buffer
* @resp_len: length of the response buffer
*
* Sends a command to the SCM and waits for the command to finish processing.
*
* A note on cache maintenance:
* Note that any buffers that are expected to be accessed by the secure world
* must be flushed before invoking qcom_scm_call and invalidated in the cache
* immediately after qcom_scm_call returns. Cache maintenance on the command
* and response buffers is taken care of by qcom_scm_call; however, callers are
* responsible for any other cached buffers passed over to the secure world.
*/
static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
const void *cmd_buf, size_t cmd_len, void *resp_buf,
size_t resp_len)
{
int ret;
struct qcom_scm_command *cmd;
struct qcom_scm_response *rsp;
size_t alloc_len = sizeof(*cmd) + cmd_len + sizeof(*rsp) + resp_len;
dma_addr_t cmd_phys;
cmd = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL);
if (!cmd)
return -ENOMEM;
cmd->len = cpu_to_le32(alloc_len);
cmd->buf_offset = cpu_to_le32(sizeof(*cmd));
cmd->resp_hdr_offset = cpu_to_le32(sizeof(*cmd) + cmd_len);
cmd->id = cpu_to_le32((svc_id << 10) | cmd_id);
if (cmd_buf)
memcpy(qcom_scm_get_command_buffer(cmd), cmd_buf, cmd_len);
rsp = qcom_scm_command_to_response(cmd);
cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE);
if (dma_mapping_error(dev, cmd_phys)) {
kfree(cmd);
return -ENOMEM;
}
mutex_lock(&qcom_scm_lock);
ret = smc(cmd_phys);
if (ret < 0)
ret = qcom_scm_remap_error(ret);
mutex_unlock(&qcom_scm_lock);
if (ret)
goto out;
do {
dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len,
sizeof(*rsp), DMA_FROM_DEVICE);
} while (!rsp->is_complete);
if (resp_buf) {
dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len +
le32_to_cpu(rsp->buf_offset),
resp_len, DMA_FROM_DEVICE);
memcpy(resp_buf, qcom_scm_get_response_buffer(rsp),
resp_len);
}
out:
dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE);
kfree(cmd);
return ret;
}
#define SCM_CLASS_REGISTER (0x2 << 8)
#define SCM_MASK_IRQS BIT(5)
#define SCM_ATOMIC(svc, cmd, n) (((((svc) << 10)|((cmd) & 0x3ff)) << 12) | \
SCM_CLASS_REGISTER | \
SCM_MASK_IRQS | \
(n & 0xf))
/**
* qcom_scm_call_atomic1() - Send an atomic SCM command with one argument
* @svc_id: service identifier
* @cmd_id: command identifier
* @arg1: first argument
*
* This shall only be used with commands that are guaranteed to be
* uninterruptable, atomic and SMP safe.
*/
static s32 qcom_scm_call_atomic1(u32 svc, u32 cmd, u32 arg1)
{
int context_id;
register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 1);
register u32 r1 asm("r1") = (u32)&context_id;
register u32 r2 asm("r2") = arg1;
asm volatile(
__asmeq("%0", "r0")
__asmeq("%1", "r0")
__asmeq("%2", "r1")
__asmeq("%3", "r2")
#ifdef REQUIRES_SEC
".arch_extension sec\n"
#endif
"smc #0 @ switch to secure world\n"
: "=r" (r0)
: "r" (r0), "r" (r1), "r" (r2)
: "r3", "r12");
return r0;
}
/**
* qcom_scm_call_atomic2() - Send an atomic SCM command with two arguments
* @svc_id: service identifier
* @cmd_id: command identifier
* @arg1: first argument
* @arg2: second argument
*
* This shall only be used with commands that are guaranteed to be
* uninterruptable, atomic and SMP safe.
*/
static s32 qcom_scm_call_atomic2(u32 svc, u32 cmd, u32 arg1, u32 arg2)
{
int context_id;
register u32 r0 asm("r0") = SCM_ATOMIC(svc, cmd, 2);
register u32 r1 asm("r1") = (u32)&context_id;
register u32 r2 asm("r2") = arg1;
register u32 r3 asm("r3") = arg2;
asm volatile(
__asmeq("%0", "r0")
__asmeq("%1", "r0")
__asmeq("%2", "r1")
__asmeq("%3", "r2")
__asmeq("%4", "r3")
#ifdef REQUIRES_SEC
".arch_extension sec\n"
#endif
"smc #0 @ switch to secure world\n"
: "=r" (r0)
: "r" (r0), "r" (r1), "r" (r2), "r" (r3)
: "r12");
return r0;
}
u32 qcom_scm_get_version(void)
{
int context_id;
static u32 version = -1;
register u32 r0 asm("r0");
register u32 r1 asm("r1");
if (version != -1)
return version;
mutex_lock(&qcom_scm_lock);
r0 = 0x1 << 8;
r1 = (u32)&context_id;
do {
asm volatile(
__asmeq("%0", "r0")
__asmeq("%1", "r1")
__asmeq("%2", "r0")
__asmeq("%3", "r1")
#ifdef REQUIRES_SEC
".arch_extension sec\n"
#endif
"smc #0 @ switch to secure world\n"
: "=r" (r0), "=r" (r1)
: "r" (r0), "r" (r1)
: "r2", "r3", "r12");
} while (r0 == QCOM_SCM_INTERRUPTED);
version = r1;
mutex_unlock(&qcom_scm_lock);
return version;
}
EXPORT_SYMBOL(qcom_scm_get_version);
/**
* qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
* @entry: Entry point function for the cpus
* @cpus: The cpumask of cpus that will use the entry point
*
* Set the cold boot address of the cpus. Any cpu outside the supported
* range would be removed from the cpu present mask.
*/
int __qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
{
int flags = 0;
int cpu;
int scm_cb_flags[] = {
QCOM_SCM_FLAG_COLDBOOT_CPU0,
QCOM_SCM_FLAG_COLDBOOT_CPU1,
QCOM_SCM_FLAG_COLDBOOT_CPU2,
QCOM_SCM_FLAG_COLDBOOT_CPU3,
};
if (!cpus || (cpus && cpumask_empty(cpus)))
return -EINVAL;
for_each_cpu(cpu, cpus) {
if (cpu < ARRAY_SIZE(scm_cb_flags))
flags |= scm_cb_flags[cpu];
else
set_cpu_present(cpu, false);
}
return qcom_scm_call_atomic2(QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR,
flags, virt_to_phys(entry));
}
/**
* qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus
* @entry: Entry point function for the cpus
* @cpus: The cpumask of cpus that will use the entry point
*
* Set the Linux entry point for the SCM to transfer control to when coming
* out of a power down. CPU power down may be executed on cpuidle or hotplug.
*/
int __qcom_scm_set_warm_boot_addr(struct device *dev, void *entry,
const cpumask_t *cpus)
{
int ret;
int flags = 0;
int cpu;
struct {
__le32 flags;
__le32 addr;
} cmd;
/*
* Reassign only if we are switching from hotplug entry point
* to cpuidle entry point or vice versa.
*/
for_each_cpu(cpu, cpus) {
if (entry == qcom_scm_wb[cpu].entry)
continue;
flags |= qcom_scm_wb[cpu].flag;
}
/* No change in entry function */
if (!flags)
return 0;
cmd.addr = cpu_to_le32(virt_to_phys(entry));
cmd.flags = cpu_to_le32(flags);
ret = qcom_scm_call(dev, QCOM_SCM_SVC_BOOT, QCOM_SCM_BOOT_ADDR,
&cmd, sizeof(cmd), NULL, 0);
if (!ret) {
for_each_cpu(cpu, cpus)
qcom_scm_wb[cpu].entry = entry;
}
return ret;
}
/**
* qcom_scm_cpu_power_down() - Power down the cpu
* @flags - Flags to flush cache
*
* This is an end point to power down cpu. If there was a pending interrupt,
* the control would return from this function, otherwise, the cpu jumps to the
* warm boot entry point set for this cpu upon reset.
*/
void __qcom_scm_cpu_power_down(u32 flags)
{
qcom_scm_call_atomic1(QCOM_SCM_SVC_BOOT, QCOM_SCM_CMD_TERMINATE_PC,
flags & QCOM_SCM_FLUSH_FLAG_MASK);
}
int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, u32 cmd_id)
{
int ret;
__le32 svc_cmd = cpu_to_le32((svc_id << 10) | cmd_id);
__le32 ret_val = 0;
ret = qcom_scm_call(dev, QCOM_SCM_SVC_INFO, QCOM_IS_CALL_AVAIL_CMD,
&svc_cmd, sizeof(svc_cmd), &ret_val,
sizeof(ret_val));
if (ret)
return ret;
return le32_to_cpu(ret_val);
}
int __qcom_scm_hdcp_req(struct device *dev, struct qcom_scm_hdcp_req *req,
u32 req_cnt, u32 *resp)
{
if (req_cnt > QCOM_SCM_HDCP_MAX_REQ_CNT)
return -ERANGE;
return qcom_scm_call(dev, QCOM_SCM_SVC_HDCP, QCOM_SCM_CMD_HDCP,
req, req_cnt * sizeof(*req), resp, sizeof(*resp));
}
void __qcom_scm_init(void)
{
}
bool __qcom_scm_pas_supported(struct device *dev, u32 peripheral)
{
__le32 out;
__le32 in;
int ret;
in = cpu_to_le32(peripheral);
ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL,
QCOM_SCM_PAS_IS_SUPPORTED_CMD,
&in, sizeof(in),
&out, sizeof(out));
return ret ? false : !!out;
}
int __qcom_scm_pas_init_image(struct device *dev, u32 peripheral,
dma_addr_t metadata_phys)
{
__le32 scm_ret;
int ret;
struct {
__le32 proc;
__le32 image_addr;
} request;
request.proc = cpu_to_le32(peripheral);
request.image_addr = cpu_to_le32(metadata_phys);
ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL,
QCOM_SCM_PAS_INIT_IMAGE_CMD,
&request, sizeof(request),
&scm_ret, sizeof(scm_ret));
return ret ? : le32_to_cpu(scm_ret);
}
int __qcom_scm_pas_mem_setup(struct device *dev, u32 peripheral,
phys_addr_t addr, phys_addr_t size)
{
__le32 scm_ret;
int ret;
struct {
__le32 proc;
__le32 addr;
__le32 len;
} request;
request.proc = cpu_to_le32(peripheral);
request.addr = cpu_to_le32(addr);
request.len = cpu_to_le32(size);
ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL,
QCOM_SCM_PAS_MEM_SETUP_CMD,
&request, sizeof(request),
&scm_ret, sizeof(scm_ret));
return ret ? : le32_to_cpu(scm_ret);
}
int __qcom_scm_pas_auth_and_reset(struct device *dev, u32 peripheral)
{
__le32 out;
__le32 in;
int ret;
in = cpu_to_le32(peripheral);
ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL,
QCOM_SCM_PAS_AUTH_AND_RESET_CMD,
&in, sizeof(in),
&out, sizeof(out));
return ret ? : le32_to_cpu(out);
}
int __qcom_scm_pas_shutdown(struct device *dev, u32 peripheral)
{
__le32 out;
__le32 in;
int ret;
in = cpu_to_le32(peripheral);
ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL,
QCOM_SCM_PAS_SHUTDOWN_CMD,
&in, sizeof(in),
&out, sizeof(out));
return ret ? : le32_to_cpu(out);
}
int __qcom_scm_pas_mss_reset(struct device *dev, bool reset)
{
__le32 out;
__le32 in = cpu_to_le32(reset);
int ret;
ret = qcom_scm_call(dev, QCOM_SCM_SVC_PIL, QCOM_SCM_PAS_MSS_RESET,
&in, sizeof(in),
&out, sizeof(out));
return ret ? : le32_to_cpu(out);
}
int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
{
return qcom_scm_call_atomic2(QCOM_SCM_SVC_BOOT, QCOM_SCM_SET_DLOAD_MODE,
enable ? QCOM_SCM_SET_DLOAD_MODE : 0, 0);
}
int __qcom_scm_set_remote_state(struct device *dev, u32 state, u32 id)
{
struct {
__le32 state;
__le32 id;
} req;
__le32 scm_ret = 0;
int ret;
req.state = cpu_to_le32(state);
req.id = cpu_to_le32(id);
ret = qcom_scm_call(dev, QCOM_SCM_SVC_BOOT, QCOM_SCM_SET_REMOTE_STATE,
&req, sizeof(req), &scm_ret, sizeof(scm_ret));
return ret ? : le32_to_cpu(scm_ret);
}
int __qcom_scm_assign_mem(struct device *dev, phys_addr_t mem_region,
size_t mem_sz, phys_addr_t src, size_t src_sz,
phys_addr_t dest, size_t dest_sz)
{
return -ENODEV;
}
int __qcom_scm_restore_sec_cfg(struct device *dev, u32 device_id,
u32 spare)
{
return -ENODEV;
}
int __qcom_scm_iommu_secure_ptbl_size(struct device *dev, u32 spare,
size_t *size)
{
return -ENODEV;
}
int __qcom_scm_iommu_secure_ptbl_init(struct device *dev, u64 addr, u32 size,
u32 spare)
{
return -ENODEV;
}
int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr,
unsigned int *val)
{
int ret;
ret = qcom_scm_call_atomic1(QCOM_SCM_SVC_IO, QCOM_SCM_IO_READ, addr);
if (ret >= 0)
*val = ret;
return ret < 0 ? ret : 0;
}
int __qcom_scm_io_writel(struct device *dev, phys_addr_t addr, unsigned int val)
{
return qcom_scm_call_atomic2(QCOM_SCM_SVC_IO, QCOM_SCM_IO_WRITE,
addr, val);
}