RE: [PATCH] dmaengine: dw-edma: fix __iomem type confusion

From: Gustavo Pimentel
Date: Fri Jun 21 2019 - 04:53:58 EST

On Mon, Jun 17, 2019 at 14:18:43, Arnd Bergmann <arnd@xxxxxxxx> wrote:

> The new driver mixes up dma_addr_t and __iomem pointers, which results
> in warnings on some 32-bit architectures, like:
>
> drivers/dma/dw-edma/dw-edma-v0-core.c: In function '__dw_regs':
> drivers/dma/dw-edma/dw-edma-v0-core.c:28:9: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
> return (struct dw_edma_v0_regs __iomem *)dw->rg_region.vaddr;
>
> Make it use __iomem pointers consistently here, and avoid using dma_addr_t
> for __iomem tokens altogether.
>
> A small complication here is the debugfs code, which passes an __iomem
> token as the private data for debugfs files, requiring the use of
> extra __force.
>
> Fixes: 7e4b8a4fbe2c ("dmaengine: Add Synopsys eDMA IP version 0 support")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/dma/dw-edma/dw-edma-core.h | 2 +-
> drivers/dma/dw-edma/dw-edma-pcie.c | 18 ++++++++--------
> drivers/dma/dw-edma/dw-edma-v0-core.c | 10 ++++-----
> drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 27 ++++++++++++------------
> 4 files changed, 29 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
> index b6cc90cbc9dc..d03a6ad263bd 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.h
> +++ b/drivers/dma/dw-edma/dw-edma-core.h
> @@ -50,7 +50,7 @@ struct dw_edma_burst {
>
> struct dw_edma_region {
> phys_addr_t paddr;
> - dma_addr_t vaddr;
> + void __iomem * vaddr;
> size_t sz;
> };
>
> diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
> index 4c96e1c948f2..dc85f55e1bb8 100644
> --- a/drivers/dma/dw-edma/dw-edma-pcie.c
> +++ b/drivers/dma/dw-edma/dw-edma-pcie.c
> @@ -130,19 +130,19 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
> chip->id = pdev->devfn;
> chip->irq = pdev->irq;
>
> - dw->rg_region.vaddr = (dma_addr_t)pcim_iomap_table(pdev)[pdata->rg_bar];
> + dw->rg_region.vaddr = pcim_iomap_table(pdev)[pdata->rg_bar];
> dw->rg_region.vaddr += pdata->rg_off;
> dw->rg_region.paddr = pdev->resource[pdata->rg_bar].start;
> dw->rg_region.paddr += pdata->rg_off;
> dw->rg_region.sz = pdata->rg_sz;
>
> - dw->ll_region.vaddr = (dma_addr_t)pcim_iomap_table(pdev)[pdata->ll_bar];
> + dw->ll_region.vaddr = pcim_iomap_table(pdev)[pdata->ll_bar];
> dw->ll_region.vaddr += pdata->ll_off;
> dw->ll_region.paddr = pdev->resource[pdata->ll_bar].start;
> dw->ll_region.paddr += pdata->ll_off;
> dw->ll_region.sz = pdata->ll_sz;
>
> - dw->dt_region.vaddr = (dma_addr_t)pcim_iomap_table(pdev)[pdata->dt_bar];
> + dw->dt_region.vaddr = pcim_iomap_table(pdev)[pdata->dt_bar];
> dw->dt_region.vaddr += pdata->dt_off;
> dw->dt_region.paddr = pdev->resource[pdata->dt_bar].start;
> dw->dt_region.paddr += pdata->dt_off;
> @@ -158,17 +158,17 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
> pci_dbg(pdev, "Mode:\t%s\n",
> dw->mode == EDMA_MODE_LEGACY ? "Legacy" : "Unroll");
>
> - pci_dbg(pdev, "Registers:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%pa, p=%pa)\n",
> + pci_dbg(pdev, "Registers:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
> pdata->rg_bar, pdata->rg_off, pdata->rg_sz,
> - &dw->rg_region.vaddr, &dw->rg_region.paddr);
> + dw->rg_region.vaddr, &dw->rg_region.paddr);
>
> - pci_dbg(pdev, "L. List:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%pa, p=%pa)\n",
> + pci_dbg(pdev, "L. List:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
> pdata->ll_bar, pdata->ll_off, pdata->ll_sz,
> - &dw->ll_region.vaddr, &dw->ll_region.paddr);
> + dw->ll_region.vaddr, &dw->ll_region.paddr);
>
> - pci_dbg(pdev, "Data:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%pa, p=%pa)\n",
> + pci_dbg(pdev, "Data:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
> pdata->dt_bar, pdata->dt_off, pdata->dt_sz,
> - &dw->dt_region.vaddr, &dw->dt_region.paddr);
> + dw->dt_region.vaddr, &dw->dt_region.paddr);
>
> pci_dbg(pdev, "Nr. IRQs:\t%u\n", dw->nr_irqs);
>
> diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
> index 8cafd51ff9ec..d670ebcc37b3 100644
> --- a/drivers/dma/dw-edma/dw-edma-v0-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
> @@ -25,7 +25,7 @@ enum dw_edma_control {
>
> static inline struct dw_edma_v0_regs __iomem *__dw_regs(struct dw_edma *dw)
> {
> - return (struct dw_edma_v0_regs __iomem *)dw->rg_region.vaddr;
> + return dw->rg_region.vaddr;
> }
>
> #define SET(dw, name, value) \
> @@ -192,13 +192,13 @@ u32 dw_edma_v0_core_status_abort_int(struct dw_edma *dw, enum dw_edma_dir dir)
> static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> {
> struct dw_edma_burst *child;
> - struct dw_edma_v0_lli *lli;
> - struct dw_edma_v0_llp *llp;
> + struct dw_edma_v0_lli __iomem *lli;
> + struct dw_edma_v0_llp __iomem *llp;
> u32 control = 0, i = 0;
> uintptr_t sar, dar, addr;
> int j;
>
> - lli = (struct dw_edma_v0_lli *)chunk->ll_region.vaddr;
> + lli = chunk->ll_region.vaddr;
>
> if (chunk->cb)
> control = DW_EDMA_V0_CB;
> @@ -224,7 +224,7 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> i++;
> }
>
> - llp = (struct dw_edma_v0_llp *)&lli[i];
> + llp = (void __iomem *)&lli[i];
> control = DW_EDMA_V0_LLP | DW_EDMA_V0_TCB;
> if (!chunk->cb)
> control |= DW_EDMA_V0_CB;
> diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
> index 5728b6fe938c..42739508c0d8 100644
> --- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
> +++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
> @@ -14,7 +14,7 @@
> #include "dw-edma-core.h"
>
> #define REGS_ADDR(name) \
> - ((dma_addr_t *)&regs->name)
> + ((void __force *)&regs->name)
> #define REGISTER(name) \
> { #name, REGS_ADDR(name) }
>
> @@ -40,11 +40,11 @@
>
> static struct dentry *base_dir;
> static struct dw_edma *dw;
> -static struct dw_edma_v0_regs *regs;
> +static struct dw_edma_v0_regs __iomem *regs;

Shouldn't the __iomem be next to dw_edma_v0_regs instead of the variable
name? I saw other drivers putting the __iomem next to the variable type,
therefore I assume it's the typical coding style.

>
> static struct {
> - void *start;
> - void *end;
> + void __iomem *start;
> + void __iomem *end;

Ditto.

> } lim[2][EDMA_V0_MAX_NR_CH];
>
> struct debugfs_entries {
> @@ -54,22 +54,23 @@ struct debugfs_entries {
>
> static int dw_edma_debugfs_u32_get(void *data, u64 *val)
> {
> + void __iomem *reg = (void __force __iomem *)data;
> if (dw->mode == EDMA_MODE_LEGACY &&
> - data >= (void *)&regs->type.legacy.ch) {
> - void *ptr = (void *)&regs->type.legacy.ch;
> + reg >= (void __iomem *)&regs->type.legacy.ch) {
> + void __iomem *ptr = &regs->type.legacy.ch;
> u32 viewport_sel = 0;
> unsigned long flags;
> u16 ch;
>
> for (ch = 0; ch < dw->wr_ch_cnt; ch++)
> - if (lim[0][ch].start >= data && data < lim[0][ch].end) {
> - ptr += (data - lim[0][ch].start);
> + if (lim[0][ch].start >= reg && reg < lim[0][ch].end) {
> + ptr += (reg - lim[0][ch].start);
> goto legacy_sel_wr;
> }
>
> for (ch = 0; ch < dw->rd_ch_cnt; ch++)
> - if (lim[1][ch].start >= data && data < lim[1][ch].end) {
> - ptr += (data - lim[1][ch].start);
> + if (lim[1][ch].start >= reg && reg < lim[1][ch].end) {
> + ptr += (reg - lim[1][ch].start);
> goto legacy_sel_rd;
> }
>
> @@ -86,7 +87,7 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
>
> raw_spin_unlock_irqrestore(&dw->lock, flags);
> } else {
> - *val = readl(data);
> + *val = readl(reg);
> }
>
> return 0;
> @@ -105,7 +106,7 @@ static void dw_edma_debugfs_create_x32(const struct debugfs_entries entries[],
> }
> }
>
> -static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs *regs,
> +static void dw_edma_debugfs_regs_ch(struct dw_edma_v0_ch_regs __iomem *regs,
> struct dentry *dir)
> {
> int nr_entries;
> @@ -288,7 +289,7 @@ void dw_edma_v0_debugfs_on(struct dw_edma_chip *chip)
> if (!dw)
> return;
>
> - regs = (struct dw_edma_v0_regs *)dw->rg_region.vaddr;
> + regs = dw->rg_region.vaddr;
> if (!regs)
> return;
>
> --
> 2.20.0