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Subject[PATCH v8 05/14] iommu/rockchip: Use iopoll helpers to wait for hardware
Date
From: Tomasz Figa <tfiga@chromium.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@chromium.org>
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---

Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5:
Use RK_MMU_POLL_PERIOD_US instead of 100.

Changes in v4: None
Changes in v3: None
Changes in v2: None

drivers/iommu/rockchip-iommu.c | 75 ++++++++++++++++++++++--------------------
1 file changed, 39 insertions(+), 36 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 5cbd5ceeb039..7130d92ff79c 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>
@@ -36,7 +36,10 @@
#define RK_MMU_AUTO_GATING 0x24

#define DTE_ADDR_DUMMY 0xCAFEBABE
-#define FORCE_RESET_TIMEOUT 100 /* ms */
+
+#define RK_MMU_POLL_PERIOD_US 100
+#define RK_MMU_FORCE_RESET_TIMEOUT_US 100000
+#define RK_MMU_POLL_TIMEOUT_US 1000

/* RK_MMU_STATUS fields */
#define RK_MMU_STATUS_PAGING_ENABLED BIT(0)
@@ -73,8 +76,6 @@
*/
#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;
@@ -109,27 +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).
@@ -333,9 +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;
@@ -346,7 +338,9 @@ 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, RK_MMU_POLL_PERIOD_US,
+ RK_MMU_POLL_TIMEOUT_US);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Enable stall request timed out, status: %#08x\n",
@@ -358,13 +352,16 @@ 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, RK_MMU_POLL_PERIOD_US,
+ RK_MMU_POLL_TIMEOUT_US);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Disable stall request timed out, status: %#08x\n",
@@ -376,13 +373,16 @@ 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, RK_MMU_POLL_PERIOD_US,
+ RK_MMU_POLL_TIMEOUT_US);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Enable paging request timed out, status: %#08x\n",
@@ -394,13 +394,16 @@ 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, RK_MMU_POLL_PERIOD_US,
+ RK_MMU_POLL_TIMEOUT_US);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Disable paging request timed out, status: %#08x\n",
@@ -413,6 +416,7 @@ static int rk_iommu_force_reset(struct rk_iommu *iommu)
{
int ret, i;
u32 dte_addr;
+ bool val;

if (iommu->reset_disabled)
return 0;
@@ -433,13 +437,12 @@ 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, RK_MMU_FORCE_RESET_TIMEOUT_US,
+ RK_MMU_POLL_TIMEOUT_US);
+ if (ret) {
+ dev_err(iommu->dev, "FORCE_RESET command timed out\n");
+ return ret;
}

return 0;
--
2.11.0

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