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iommu/rockchip: Use iopoll helpers to wait for hardware
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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 <[email protected]>
Signed-off-by: Jeffy Chen <[email protected]>
Reviewed-by: Robin Murphy <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
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@tom3q @joergroedel
tom3q authored and joergroedel committed Mar 29, 2018
1 parent f6717d7 commit 0416bf6
Showing 1 changed file with 39 additions and 36 deletions.
75 changes: 39 additions & 36 deletions drivers/iommu/rockchip-iommu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand All @@ -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)
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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).
Expand Down Expand Up @@ -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;
Expand All @@ -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",
Expand All @@ -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",
Expand All @@ -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",
Expand All @@ -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",
Expand All @@ -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;
Expand All @@ -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;
Expand Down

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