From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hoan Tran Subject: Re: [PATCH] hwmon: xgene: access mailbox as RAM Date: Fri, 9 Sep 2016 10:05:13 -0700 Message-ID: References: <1469134557-26869-1-git-send-email-hotran@apm.com> <13081573.BbD3TmEU5Y@wuerfel> <20160907223705.GA31582@roeck-us.net> <2529114.aAikiSWl11@wuerfel> <20160909165855.GB18952@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <20160909165855.GB18952-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Guenter Roeck Cc: Arnd Bergmann , Jean Delvare , Jonathan Corbet , Rob Herring , Jassi Brar , Ashwin Chaugule , Duc Dang , Loc Ho , linux-hwmon-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lkml , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Devicetree List List-Id: devicetree@vger.kernel.org On Fri, Sep 9, 2016 at 9:58 AM, Guenter Roeck wrote: > Hi Arnd, > > On Fri, Sep 09, 2016 at 05:38:58PM +0200, Arnd Bergmann wrote: >> The newly added hwmon driver fails to build in an allmodconfig >> kernel: >> >> 1 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 endianess 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 >> > > Thanks a lot for looking into this. > > I'll apply this patch to address the build problem. Much better than > my rude "depends on BROKEN". It would be great to get a Tested-by: > from someone with access to the hardware. > Hi Arnd and Guenter, Thanks for the patch. I'm testing it out. Hoan > Guenter > >> diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c >> index bc78a5d10182..e834dfb3acca 100644 >> --- a/drivers/hwmon/xgene-hwmon.c >> +++ b/drivers/hwmon/xgene-hwmon.c >> @@ -34,7 +34,8 @@ >> #include >> #include >> #include >> -#include >> +#include >> + >> #include >> >> /* 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); >> @@ -652,9 +653,9 @@ 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_WT); >> } else { >> dev_err(&pdev->dev, "Failed to get PCC comm region\n"); >> rc = -ENODEV; >> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html