From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan.Cameron@huawei.com (Jonathan Cameron) Date: Thu, 17 May 2018 09:14:33 +0100 Subject: [PATCH 1/8] firmware: arm_scmi: improve code readability using bitfield accessor macros In-Reply-To: <1525885634-22348-2-git-send-email-sudeep.holla@arm.com> References: <1525885634-22348-1-git-send-email-sudeep.holla@arm.com> <1525885634-22348-2-git-send-email-sudeep.holla@arm.com> Message-ID: <20180517091433.0000513b@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 9 May 2018 18:07:07 +0100 Sudeep Holla wrote: > By using FIELD_{FIT,GET,PREP} and GENMASK macro accessors we can avoid > some clumpsy custom shifting and masking macros and also improve the > code better readability. > > Signed-off-by: Sudeep Holla Hi Sudeep, A minor comment inline. Jonathan > --- > drivers/firmware/arm_scmi/common.h | 9 +++++---- > drivers/firmware/arm_scmi/driver.c | 31 ++++++++++++++----------------- > 2 files changed, 19 insertions(+), 21 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h > index 0c30234f9098..e8f332c9c469 100644 > --- a/drivers/firmware/arm_scmi/common.h > +++ b/drivers/firmware/arm_scmi/common.h > @@ -7,6 +7,7 @@ > * Copyright (C) 2018 ARM Ltd. > */ > > +#include > #include > #include > #include > @@ -14,10 +15,10 @@ > #include > #include > > -#define PROTOCOL_REV_MINOR_BITS 16 > -#define PROTOCOL_REV_MINOR_MASK ((1U << PROTOCOL_REV_MINOR_BITS) - 1) > -#define PROTOCOL_REV_MAJOR(x) ((x) >> PROTOCOL_REV_MINOR_BITS) > -#define PROTOCOL_REV_MINOR(x) ((x) & PROTOCOL_REV_MINOR_MASK) > +#define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0) > +#define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16) > +#define PROTOCOL_REV_MAJOR(x) (u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x))) > +#define PROTOCOL_REV_MINOR(x) (u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x))) > #define MAX_PROTOCOLS_IMP 16 > #define MAX_OPPS 16 > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 14b147135a0c..917786d91f55 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -29,16 +29,12 @@ > > #include "common.h" > > -#define MSG_ID_SHIFT 0 > -#define MSG_ID_MASK 0xff > -#define MSG_TYPE_SHIFT 8 > -#define MSG_TYPE_MASK 0x3 > -#define MSG_PROTOCOL_ID_SHIFT 10 > -#define MSG_PROTOCOL_ID_MASK 0xff > -#define MSG_TOKEN_ID_SHIFT 18 > -#define MSG_TOKEN_ID_MASK 0x3ff > -#define MSG_XTRACT_TOKEN(header) \ > - (((header) >> MSG_TOKEN_ID_SHIFT) & MSG_TOKEN_ID_MASK) > +#define MSG_ID_MASK GENMASK(7, 0) > +#define MSG_TYPE_MASK GENMASK(9, 8) > +#define MSG_PROTOCOL_ID_MASK GENMASK(17, 10) > +#define MSG_TOKEN_ID_MASK GENMASK(27, 18) > +#define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr)) > +#define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1) This feels a little odd. It's not the Max value, I think, but rather one more than it. I would set it to this -1 and use > than in the test below. > > enum scmi_error_codes { > SCMI_SUCCESS = 0, /* Success */ > @@ -255,9 +251,9 @@ static void scmi_rx_callback(struct mbox_client *cl, void *m) > */ > static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr) > { > - return ((hdr->id & MSG_ID_MASK) << MSG_ID_SHIFT) | > - ((hdr->seq & MSG_TOKEN_ID_MASK) << MSG_TOKEN_ID_SHIFT) | > - ((hdr->protocol_id & MSG_PROTOCOL_ID_MASK) << MSG_PROTOCOL_ID_SHIFT); > + return FIELD_PREP(MSG_ID_MASK, hdr->id) | > + FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) | > + FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id); > } > > /** > @@ -621,9 +617,9 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo) > struct scmi_xfers_info *info = &sinfo->minfo; > > /* Pre-allocated messages, no more than what hdr.seq can support */ > - if (WARN_ON(desc->max_msg >= (MSG_TOKEN_ID_MASK + 1))) { > - dev_err(dev, "Maximum message of %d exceeds supported %d\n", > - desc->max_msg, MSG_TOKEN_ID_MASK + 1); > + if (WARN_ON(desc->max_msg >= MSG_TOKEN_MAX)) { > + dev_err(dev, "Maximum message of %d exceeds supported %ld\n", > + desc->max_msg, MSG_TOKEN_MAX); > return -EINVAL; > } > > @@ -840,7 +836,8 @@ static int scmi_probe(struct platform_device *pdev) > if (of_property_read_u32(child, "reg", &prot_id)) > continue; > > - prot_id &= MSG_PROTOCOL_ID_MASK; > + if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id)) > + dev_err(dev, "Out of range protocol %d\n", prot_id); > > if (!scmi_is_protocol_implemented(handle, prot_id)) { > dev_err(dev, "SCMI protocol %d not implemented\n",