[PATCH v2 06/13] iommu/rockchip: Use iopoll helpers to wait for hardware

Jeffy Chen
2018-01-16T13:25:33Z

From: Tomasz Figa <tfiga-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>

This patch converts the rockchip-iommu driver to use the in-kernel
iopoll helpers to wait for certain status bits to change in registers
instead of an open-coded custom macro.

Signed-off-by: Tomasz Figa <tfiga-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Signed-off-by: Jeffy Chen <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
---

Changes in v2: None

drivers/iommu/rockchip-iommu.c | 68 ++++++++++++++++++++----------------------
1 file changed, 32 insertions(+), 36 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index d2a0b0daf40d..8179306d464a 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -13,7 +13,7 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iommu.h>
-#include <linux/jiffies.h>
+#include <linux/iopoll.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/module.h>
@@ -37,7 +37,8 @@
#define RK_MMU_AUTO_GATING 0x24

#define DTE_ADDR_DUMMY 0xCAFEBABE
-#define FORCE_RESET_TIMEOUT 100 /* ms */
+#define FORCE_RESET_TIMEOUT 100000 /* us */
+#define POLL_TIMEOUT 1000 /* us */

/* RK_MMU_STATUS fields */
#define RK_MMU_STATUS_PAGING_ENABLED BIT(0)
@@ -74,8 +75,6 @@
*/
#define RK_IOMMU_PGSIZE_BITMAP 0x007ff000

-#define IOMMU_REG_POLL_COUNT_FAST 1000
-
struct rk_iommu_domain {
struct list_head iommus;
struct platform_device *pdev;
@@ -111,27 +110,6 @@ static struct rk_iommu_domain *to_rk_domain(struct iommu_domain *dom)
return container_of(dom, struct rk_iommu_domain, domain);
}

-/**
- * Inspired by _wait_for in intel_drv.h
- * This is NOT safe for use in interrupt context.
- *
- * Note that it's important that we check the condition again after having
- * timed out, since the timeout could be due to preemption or similar and
- * we've never had a chance to check the condition before the timeout.
- */
-#define rk_wait_for(COND, MS) ({ \
- unsigned long timeout__ = jiffies + msecs_to_jiffies(MS) + 1; \
- int ret__ = 0; \
- while (!(COND)) { \
- if (time_after(jiffies, timeout__)) { \
- ret__ = (COND) ? 0 : -ETIMEDOUT; \
- break; \
- } \
- usleep_range(50, 100); \
- } \
- ret__; \
-})
-
/*
* The Rockchip rk3288 iommu uses a 2-level page table.
* The first level is the "Directory Table" (DT).
@@ -335,9 +313,21 @@ static bool rk_iommu_is_paging_enabled(struct rk_iommu *iommu)
return enable;
}

+static bool rk_iommu_is_reset_done(struct rk_iommu *iommu)
+{
+ bool done = true;
+ int i;
+
+ for (i = 0; i < iommu->num_mmu; i++)
+ done &= rk_iommu_read(iommu->bases[i], RK_MMU_DTE_ADDR) == 0;
+
+ return done;
+}
+
static int rk_iommu_enable_stall(struct rk_iommu *iommu)
{
int ret, i;
+ bool val;

if (rk_iommu_is_stall_active(iommu))
return 0;
@@ -348,7 +338,8 @@ static int rk_iommu_enable_stall(struct rk_iommu *iommu)

rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_STALL);

- ret = rk_wait_for(rk_iommu_is_stall_active(iommu), 1);
+ ret = readx_poll_timeout(rk_iommu_is_stall_active, iommu, val,
+ val, 100, POLL_TIMEOUT);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Enable stall request timed out, status: %#08x\n",
@@ -360,13 +351,15 @@ static int rk_iommu_enable_stall(struct rk_iommu *iommu)
static int rk_iommu_disable_stall(struct rk_iommu *iommu)
{
int ret, i;
+ bool val;

if (!rk_iommu_is_stall_active(iommu))
return 0;

rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_STALL);

- ret = rk_wait_for(!rk_iommu_is_stall_active(iommu), 1);
+ ret = readx_poll_timeout(rk_iommu_is_stall_active, iommu, val,
+ !val, 100, POLL_TIMEOUT);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Disable stall request timed out, status: %#08x\n",
@@ -378,13 +371,15 @@ static int rk_iommu_disable_stall(struct rk_iommu *iommu)
static int rk_iommu_enable_paging(struct rk_iommu *iommu)
{
int ret, i;
+ bool val;

if (rk_iommu_is_paging_enabled(iommu))
return 0;

rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_PAGING);

- ret = rk_wait_for(rk_iommu_is_paging_enabled(iommu), 1);
+ ret = readx_poll_timeout(rk_iommu_is_paging_enabled, iommu, val,
+ val, 100, POLL_TIMEOUT);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Enable paging request timed out, status: %#08x\n",
@@ -396,13 +391,15 @@ static int rk_iommu_enable_paging(struct rk_iommu *iommu)
static int rk_iommu_disable_paging(struct rk_iommu *iommu)
{
int ret, i;
+ bool val;

if (!rk_iommu_is_paging_enabled(iommu))
return 0;

rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_PAGING);

- ret = rk_wait_for(!rk_iommu_is_paging_enabled(iommu), 1);
+ ret = readx_poll_timeout(rk_iommu_is_paging_enabled, iommu, val,
+ !val, 100, POLL_TIMEOUT);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Disable paging request timed out, status: %#08x\n",
@@ -415,6 +412,7 @@ static int rk_iommu_force_reset(struct rk_iommu *iommu)
{
int ret, i;
u32 dte_addr;
+ bool val;

if (iommu->reset_disabled)
return 0;
@@ -435,13 +433,11 @@ static int rk_iommu_force_reset(struct rk_iommu *iommu)

rk_iommu_command(iommu, RK_MMU_CMD_FORCE_RESET);

- for (i = 0; i < iommu->num_mmu; i++) {
- ret = rk_wait_for(rk_iommu_read(iommu->bases[i], RK_MMU_DTE_ADDR) == 0x00000000,
- FORCE_RESET_TIMEOUT);
- if (ret) {
- dev_err(iommu->dev, "FORCE_RESET command timed out\n");
- return ret;
- }
+ ret = readx_poll_timeout(rk_iommu_is_reset_done, iommu, val,
+ val, 100, FORCE_RESET_TIMEOUT);
+ if (ret) {
+ dev_err(iommu->dev, "FORCE_RESET command timed out\n");
+ return ret;
}

return 0;
--
2.11.0