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authorArnd Bergmann <arnd@arndb.de>2016-09-09 23:10:45 +0300
committerGuenter Roeck <linux@roeck-us.net>2016-09-10 00:54:53 +0300
commitc7cefce03e691270c0e5e117248e14661e9c9cad (patch)
treeac1c49d2f0d85bbba473455c741fbd47806d20a3 /drivers/hwmon/xgene-hwmon.c
parentc0a4b9ec1b43ebb9d5001e3bf86f58d4ca0ffe18 (diff)
downloadlinux-c7cefce03e691270c0e5e117248e14661e9c9cad.tar.xz
hwmon: (xgene) access mailbox as RAM
The newly added hwmon driver fails to build in an allmodconfig kernel: ERROR: "memblock_is_memory" [drivers/hwmon/xgene-hwmon.ko] undefined! According to comments in the code, the mailbox is a shared memory region, not a set of MMIO registers, so we should use memremap() for mapping it instead of ioremap or acpi_os_ioremap, and pointer dereferences instead of readl/writel. The driver already uses plain kernel pointers, so it's a bit unusual to work with functions that operate on __iomem pointers, and this fixes that part too. I'm using READ_ONCE/WRITE_ONCE here to keep the existing behavior regarding the ordering of the accesses from the CPU, but note that there are no barriers (also unchanged from before). I'm also keeping the endianness behavior, though I'm unsure whether the message data was supposed to be in LE32 format in the first place, it's possible this was meant to be interpreted as a byte stream instead. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Hoan Tran <hotran@apm.com> Tested-by: Hoan Tran <hotran@apm.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/xgene-hwmon.c')
-rw-r--r--drivers/hwmon/xgene-hwmon.c29
1 files changed, 15 insertions, 14 deletions
diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c
index aa44579a1e5a..9c0dbb8191ad 100644
--- a/drivers/hwmon/xgene-hwmon.c
+++ b/drivers/hwmon/xgene-hwmon.c
@@ -27,6 +27,7 @@
#include <linux/dma-mapping.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
+#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/kfifo.h>
#include <linux/mailbox_controller.h>
@@ -34,7 +35,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
-#include <acpi/acpi_io.h>
+
#include <acpi/pcc.h>
/* SLIMpro message defines */
@@ -126,10 +127,10 @@ static u16 xgene_word_tst_and_clr(u16 *addr, u16 mask)
{
u16 ret, val;
- val = readw_relaxed(addr);
+ val = le16_to_cpu(READ_ONCE(*addr));
ret = val & mask;
val &= ~mask;
- writew_relaxed(val, addr);
+ WRITE_ONCE(*addr, cpu_to_le16(val));
return ret;
}
@@ -137,7 +138,7 @@ static u16 xgene_word_tst_and_clr(u16 *addr, u16 mask)
static int xgene_hwmon_pcc_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
{
struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
- void *ptr = generic_comm_base + 1;
+ u32 *ptr = (void *)(generic_comm_base + 1);
int rc, i;
u16 val;
@@ -146,21 +147,21 @@ static int xgene_hwmon_pcc_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
ctx->resp_pending = true;
/* Write signature for subspace */
- writel_relaxed(PCC_SIGNATURE_MASK | ctx->mbox_idx,
- &generic_comm_base->signature);
+ WRITE_ONCE(generic_comm_base->signature,
+ cpu_to_le32(PCC_SIGNATURE_MASK | ctx->mbox_idx));
/* Write to the shared command region */
- writew_relaxed(MSG_TYPE(msg[0]) | PCCC_GENERATE_DB_INT,
- &generic_comm_base->command);
+ WRITE_ONCE(generic_comm_base->command,
+ cpu_to_le16(MSG_TYPE(msg[0]) | PCCC_GENERATE_DB_INT));
/* Flip CMD COMPLETE bit */
- val = readw_relaxed(&generic_comm_base->status);
+ val = le16_to_cpu(READ_ONCE(generic_comm_base->status));
val &= ~PCCS_CMD_COMPLETE;
- writew_relaxed(val, &generic_comm_base->status);
+ WRITE_ONCE(generic_comm_base->status, cpu_to_le16(val));
/* Copy the message to the PCC comm space */
for (i = 0; i < sizeof(struct slimpro_resp_msg) / 4; i++)
- writel_relaxed(msg[i], ptr + i * 4);
+ WRITE_ONCE(ptr[i], cpu_to_le32(msg[i]));
/* Ring the doorbell */
rc = mbox_send_message(ctx->mbox_chan, msg);
@@ -689,9 +690,9 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
*/
ctx->comm_base_addr = cppc_ss->base_address;
if (ctx->comm_base_addr) {
- ctx->pcc_comm_addr =
- acpi_os_ioremap(ctx->comm_base_addr,
- cppc_ss->length);
+ ctx->pcc_comm_addr = memremap(ctx->comm_base_addr,
+ cppc_ss->length,
+ MEMREMAP_WB);
} else {
dev_err(&pdev->dev, "Failed to get PCC comm region\n");
rc = -ENODEV;