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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 16:13:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-03 16:13:28 -0700
commit1a4a2bc460721bc8f91e4c1294d39b38e5af132f (patch)
treefe646d05f6e17f05601e0a32cc796bec718ab6e7 /drivers
parent110a9e42b68719f584879c5c5c727bbae90d15f9 (diff)
parent1ef55be16ed69538f89e0a6508be5e62fdc9851c (diff)
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull low-level x86 updates from Ingo Molnar: "In this cycle this topic tree has become one of those 'super topics' that accumulated a lot of changes: - Add CONFIG_VMAP_STACK=y support to the core kernel and enable it on x86 - preceded by an array of changes. v4.8 saw preparatory changes in this area already - this is the rest of the work. Includes the thread stack caching performance optimization. (Andy Lutomirski) - switch_to() cleanups and all around enhancements. (Brian Gerst) - A large number of dumpstack infrastructure enhancements and an unwinder abstraction. The secret long term plan is safe(r) live patching plus maybe another attempt at debuginfo based unwinding - but all these current bits are standalone enhancements in a frame pointer based debug environment as well. (Josh Poimboeuf) - More __ro_after_init and const annotations. (Kees Cook) - Enable KASLR for the vmemmap memory region. (Thomas Garnier)" [ The virtually mapped stack changes are pretty fundamental, and not x86-specific per se, even if they are only used on x86 right now. ] * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) x86/asm: Get rid of __read_cr4_safe() thread_info: Use unsigned long for flags x86/alternatives: Add stack frame dependency to alternative_call_2() x86/dumpstack: Fix show_stack() task pointer regression x86/dumpstack: Remove dump_trace() and related callbacks x86/dumpstack: Convert show_trace_log_lvl() to use the new unwinder oprofile/x86: Convert x86_backtrace() to use the new unwinder x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder perf/x86: Convert perf_callchain_kernel() to use the new unwinder x86/unwind: Add new unwind interface and implementations x86/dumpstack: Remove NULL task pointer convention fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK lib/syscall: Pin the task stack in collect_syscall() x86/process: Pin the target stack in get_wchan() x86/dumpstack: Pin the target stack when dumping it kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function sched/core: Add try_get_task_stack() and put_task_stack() x86/entry/64: Fix a minor comment rebase error iommu/amd: Don't put completion-wait semaphore on stack ...
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/amd_iommu.c51
-rw-r--r--drivers/iommu/amd_iommu_types.h2
2 files changed, 37 insertions, 16 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 96de97a46079..4025291ea0ae 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -940,15 +940,13 @@ static void build_inv_irt(struct iommu_cmd *cmd, u16 devid)
* Writes the command to the IOMMUs command buffer and informs the
* hardware about the new command.
*/
-static int iommu_queue_command_sync(struct amd_iommu *iommu,
- struct iommu_cmd *cmd,
- bool sync)
+static int __iommu_queue_command_sync(struct amd_iommu *iommu,
+ struct iommu_cmd *cmd,
+ bool sync)
{
u32 left, tail, head, next_tail;
- unsigned long flags;
again:
- spin_lock_irqsave(&iommu->lock, flags);
head = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
tail = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
@@ -957,15 +955,14 @@ again:
if (left <= 2) {
struct iommu_cmd sync_cmd;
- volatile u64 sem = 0;
int ret;
- build_completion_wait(&sync_cmd, (u64)&sem);
- copy_cmd_to_buffer(iommu, &sync_cmd, tail);
+ iommu->cmd_sem = 0;
- spin_unlock_irqrestore(&iommu->lock, flags);
+ build_completion_wait(&sync_cmd, (u64)&iommu->cmd_sem);
+ copy_cmd_to_buffer(iommu, &sync_cmd, tail);
- if ((ret = wait_on_sem(&sem)) != 0)
+ if ((ret = wait_on_sem(&iommu->cmd_sem)) != 0)
return ret;
goto again;
@@ -976,9 +973,21 @@ again:
/* We need to sync now to make sure all commands are processed */
iommu->need_sync = sync;
+ return 0;
+}
+
+static int iommu_queue_command_sync(struct amd_iommu *iommu,
+ struct iommu_cmd *cmd,
+ bool sync)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&iommu->lock, flags);
+ ret = __iommu_queue_command_sync(iommu, cmd, sync);
spin_unlock_irqrestore(&iommu->lock, flags);
- return 0;
+ return ret;
}
static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
@@ -993,19 +1002,29 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
static int iommu_completion_wait(struct amd_iommu *iommu)
{
struct iommu_cmd cmd;
- volatile u64 sem = 0;
+ unsigned long flags;
int ret;
if (!iommu->need_sync)
return 0;
- build_completion_wait(&cmd, (u64)&sem);
- ret = iommu_queue_command_sync(iommu, &cmd, false);
+ build_completion_wait(&cmd, (u64)&iommu->cmd_sem);
+
+ spin_lock_irqsave(&iommu->lock, flags);
+
+ iommu->cmd_sem = 0;
+
+ ret = __iommu_queue_command_sync(iommu, &cmd, false);
if (ret)
- return ret;
+ goto out_unlock;
+
+ ret = wait_on_sem(&iommu->cmd_sem);
- return wait_on_sem(&sem);
+out_unlock:
+ spin_unlock_irqrestore(&iommu->lock, flags);
+
+ return ret;
}
static int iommu_flush_dte(struct amd_iommu *iommu, u16 devid)
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index caf5e3822715..9652848e3155 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -524,6 +524,8 @@ struct amd_iommu {
struct irq_domain *ir_domain;
struct irq_domain *msi_domain;
#endif
+
+ volatile u64 __aligned(8) cmd_sem;
};
#define ACPIHID_UID_LEN 256