Patch "mmc: dw_mmc: use resource_size_t to store physical address" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

mmc: dw_mmc: use resource_size_t to store physical address

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mmc-dw_mmc-use-resource_size_t-to-store-physical-address.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Arnd Bergmann <[email protected]>
Date: Thu, 12 Nov 2015 15:14:23 +0100
Subject: mmc: dw_mmc: use resource_size_t to store physical address

From: Arnd Bergmann <[email protected]>

commit 260b31643691e8a58683a4ccc3bdf7abfd86f54a upstream.

The dw_mmc driver stores the physical address of the MMIO registers in a pointer, which requires the use of type casts, and is actually broken if anyone ever has this device on a 32-bit SoC in registers above 4GB. Gcc warns about this possibility when the driver is built with ARM LPAE enabled:

mmc/host/dw_mmc.c: In function 'dw_mci_edmac_start_dma':
mmc/host/dw_mmc.c:702:17: warning: cast from pointer to integer of different size

  cfg.dst_addr = (dma_addr_t)(host->phy_regs + fifo_offset);
                 ^

mmc/host/dw_mmc-pltfm.c: In function 'dw_mci_pltfm_register':
mmc/host/dw_mmc-pltfm.c:63:19: warning: cast to pointer from integer of different size
host->phy_regs = (void *)(regs->start);

This changes the code to use resource_size_t, which gets rid of the warning, the bug and the useless casts.

---
 drivers/mmc/host/dw_mmc-pltfm.c |    2 +-
 drivers/mmc/host/dw_mmc.c       |    2 +-
 include/linux/mmc/dw_mmc.h      |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

@@ -60,7 +60,7 @@ int dw_mci_pltfm_register(struct platfor
 
 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	/* Get registers' physical base address */
-	host->phy_regs = (void *)(regs->start);
+	host->phy_regs = regs->start;
 	host->regs = devm_ioremap_resource(&pdev->dev, regs);
 	if (IS_ERR(host->regs))
 		return PTR_ERR(host->regs);

@@ -699,7 +699,7 @@ static int dw_mci_edmac_start_dma(struct
 	int ret = 0;
 
 	/* Set external dma config: burst size, burst width */
-	cfg.dst_addr = (dma_addr_t)(host->phy_regs + fifo_offset);
+	cfg.dst_addr = host->phy_regs + fifo_offset;
 	cfg.src_addr = cfg.dst_addr;
 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;

@@ -172,7 +172,7 @@ struct dw_mci {
 	/* For edmac */
 	struct dw_mci_dma_slave *dms;
 	/* Registers's physical base address */
-	void                    *phy_regs;
+	resource_size_t		phy_regs;
 
 	u32			cmd_status;
 	u32			data_status;

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/mmc-dw_mmc-use-resource_size_t-to-store-physical-address.patch queue-4.4/net-simplify-napi_synchronize-to-avoid-warnings.patch queue-4.4/soc-qcom-spm-shut-up-uninitialized-variable-warning.patch queue-4.4/kconfig-tinyconfig-provide-whole-choice-blocks-to-avoid-warnings.patch queue-4.4/pinctrl-at91-pio4-use-pr-format-string-for-resource.patch