[U-Boot] [PATCH v2 1/2] usb: align buffers at cacheline

puneets
2012-02-28T09:34:55Z

Hi Marek,
IMO, Simon has already mentioned the reason of using
ALLOC_CACHE_ALIGN_BUFFER,
Please find below my explanation about other doubts.
On Monday 27 February 2012 10:19 PM, Marek Vasut wrote:
>> As DMA expects the buffers to be equal and larger then
>> cache lines, This aligns buffers at cacheline.
>>
>> Signed-off-by: Puneet Saxena<puneets@nvidia.com>
>> Signed-off-by: Jim Lin<jilin@nvidia.com>
>> ---
>>
> First of all, thanks for this patch, it really helps. But, there are a few
> things that concern me.
>
>> Changes for V2:
>> - Use "ARCH_DMA_MINALIGN" directly
>> - Use "ALIGN" to align size as cacheline
>> - Removed headers from usb.h
>> - Send 8 bytes of device descriptor size to read
>> Max packet size
>> scsi.h header is needed to avoid extra memcpy from local buffer
>> to global buffer.
>>
>> common/cmd_usb.c | 3 +-
>> common/usb.c | 61
>> ++++++++++++++++++++++++------------------ common/usb_storage.c |
>> 59 +++++++++++++++++++---------------------- disk/part_dos.c |
>> 2 +-
>> drivers/usb/host/ehci-hcd.c | 8 +++++
>> include/scsi.h | 4 ++-
>> 6 files changed, 77 insertions(+), 60 deletions(-)
>>
>> diff --git a/common/cmd_usb.c b/common/cmd_usb.c
>> index 320667f..bca9d94 100644
>> --- a/common/cmd_usb.c
>> +++ b/common/cmd_usb.c
>> @@ -150,7 +150,8 @@ void usb_display_class_sub(unsigned char dclass,
>> unsigned char subclass,
>>
>> void usb_display_string(struct usb_device *dev, int index)
>> {
>> - char buffer[256];
>> + ALLOC_CACHE_ALIGN_BUFFER(char, buffer, 256);
> Why not memalign(), do you want to allocate on stack so badly ?
>
>> +
>> if (index != 0) {
>> if (usb_string(dev, index,&buffer[0], 256)> 0)
>> printf("String: \"%s\"", buffer);
>> diff --git a/common/usb.c b/common/usb.c
>> index 63a11c8..2279459 100644
>> --- a/common/usb.c
>> +++ b/common/usb.c
>> @@ -73,7 +73,6 @@ static struct usb_device usb_dev[USB_MAX_DEVICE];
>> static int dev_index;
>> static int running;
>> static int asynch_allowed;
>> -static struct devrequest setup_packet;
>>
>> char usb_started; /* flag for the started/stopped USB status */
>>
>> @@ -185,23 +184,25 @@ int usb_control_msg(struct usb_device *dev, unsigned
>> int pipe, unsigned short value, unsigned short index,
>> void *data, unsigned short size, int timeout)
>> {
>> + ALLOC_CACHE_ALIGN_BUFFER(struct devrequest, setup_packet,
>> + sizeof(struct devrequest));
> DTTO, btw does the setup packet need to be aligned too ?
>
We need to align setup packet as it's used for constructing SETUP
Transfer descriptor buffer.
Plz see the code - Ehci-hcd.c (drivers\usb\host) Line No - 402.

>> if ((timeout == 0)&& (!asynch_allowed)) {
>> /* request for a asynch control pipe is not allowed */
>> return -1;
>> }
>>
>> /* set setup command */
>> - setup_packet.requesttype = requesttype;
>> - setup_packet.request = request;
>> - setup_packet.value = cpu_to_le16(value);
>> - setup_packet.index = cpu_to_le16(index);
>> - setup_packet.length = cpu_to_le16(size);
>> + setup_packet->requesttype = requesttype;
>> + setup_packet->request = request;
>> + setup_packet->value = cpu_to_le16(value);
>> + setup_packet->index = cpu_to_le16(index);
>> + setup_packet->length = cpu_to_le16(size);
>> USB_PRINTF("usb_control_msg: request: 0x%X, requesttype: 0x%X, " \
>> "value 0x%X index 0x%X length 0x%X\n",
>> request, requesttype, value, index, size);
>> dev->status = USB_ST_NOT_PROC; /*not yet processed */
>>
>> - submit_control_msg(dev, pipe, data, size,&setup_packet);
>> + submit_control_msg(dev, pipe, data, size, setup_packet);
>> if (timeout == 0)
>> return (int)size;
>>
>> @@ -694,7 +695,7 @@ static int usb_string_sub(struct usb_device *dev,
>> unsigned int langid, */
>> int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
>> {
>> - unsigned char mybuf[USB_BUFSIZ];
>> + ALLOC_CACHE_ALIGN_BUFFER(unsigned char, mybuf, USB_BUFSIZ);
>> unsigned char *tbuf;
>> int err;
>> unsigned int u, idx;
>> @@ -794,7 +795,7 @@ int usb_new_device(struct usb_device *dev)
>> {
>> int addr, err;
>> int tmp;
>> - unsigned char tmpbuf[USB_BUFSIZ];
>> + ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ);
> Why not simply memalign() them all?
>> /* We still haven't set the Address yet */
>> addr = dev->devnum;
>> @@ -842,7 +843,10 @@ int usb_new_device(struct usb_device *dev)
>> dev->epmaxpacketin[0] = 64;
>> dev->epmaxpacketout[0] = 64;
>>
>> - err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
>> + desc->bMaxPacketSize0 = 0;
>> + /*8 bytes of the descriptor to read Max packet size*/
>> + err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc,
>> + 8);
>> if (err< 0) {
>> USB_PRINTF("usb_new_device: usb_get_descriptor() failed\n");
>> return 1;
>> @@ -905,7 +909,7 @@ int usb_new_device(struct usb_device *dev)
>> tmp = sizeof(dev->descriptor);
>>
>> err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
>> -&dev->descriptor, sizeof(dev->descriptor));
>> + desc, sizeof(dev->descriptor));
>> if (err< tmp) {
>> if (err< 0)
>> printf("unable to get device descriptor (error=%d)\n",
>> @@ -915,14 +919,18 @@ int usb_new_device(struct usb_device *dev)
>> "(expected %i, got %i)\n", tmp, err);
>> return 1;
>> }
>> + dev->descriptor.bcdUSB = desc->bcdUSB;
>> + dev->descriptor.idVendor = desc->idVendor;
>> + dev->descriptor.idProduct = desc->idProduct;
>> + dev->descriptor.bcdDevice = desc->bcdDevice;
> Isn't the above change unrelated?
>
Agreed. Its not useful here at least. Will incorporate in next patch
>> /* correct le values */
>> le16_to_cpus(&dev->descriptor.bcdUSB);
>> le16_to_cpus(&dev->descriptor.idVendor);
>> le16_to_cpus(&dev->descriptor.idProduct);
>> le16_to_cpus(&dev->descriptor.bcdDevice);
>> /* only support for one config for now */
>> - usb_get_configuration_no(dev,&tmpbuf[0], 0);
>> - usb_parse_config(dev,&tmpbuf[0], 0);
>> + usb_get_configuration_no(dev, tmpbuf, 0);
>> + usb_parse_config(dev, tmpbuf, 0);
>> usb_set_maxpacket(dev);
>> /* we set the default configuration here */
>> if (usb_set_configuration(dev, dev->config.desc.bConfigurationValue)) {
>> @@ -1076,7 +1084,7 @@ static int hub_port_reset(struct usb_device *dev, int
>> port, unsigned short *portstat)
>> {
>> int tries;
>> - struct usb_port_status portsts;
>> + ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
> Looking at all this stuff, it's already allocated on stack. Ok, I already
> outlined first option -- memalign(), but that'd really put quite a strain on the
> memory allocator -- the other option (and maybe even better) is to use
> __attribute__((aligned)), which will allow the compiler to reorder data
> allocated on the stack so the array you create is aligned and not much space
> around on the stack is wasted. Apparently, ALLOC_CACHE_ALIGN_BUFFER() wastes a
> lot of space on the stack.
>
>> unsigned short portstatus, portchange;
>>
>> USB_HUB_PRINTF("hub_port_reset: resetting port %d...\n", port);
>> @@ -1085,13 +1093,13 @@ static int hub_port_reset(struct usb_device *dev,
>> int port, usb_set_port_feature(dev, port + 1, USB_PORT_FEAT_RESET);
>> wait_ms(200);
>>
>> - if (usb_get_port_status(dev, port + 1,&portsts)< 0) {
>> + if (usb_get_port_status(dev, port + 1, portsts)< 0) {
>> USB_HUB_PRINTF("get_port_status failed status %lX\n",
>> dev->status);
>> return -1;
>> }
>> - portstatus = le16_to_cpu(portsts.wPortStatus);
>> - portchange = le16_to_cpu(portsts.wPortChange);
>> + portstatus = le16_to_cpu(portsts->wPortStatus);
>> + portchange = le16_to_cpu(portsts->wPortChange);
>>
>> USB_HUB_PRINTF("portstatus %x, change %x, %s\n",
>> portstatus, portchange,
>> @@ -1129,19 +1137,19 @@ static int hub_port_reset(struct usb_device *dev,
>> int port, void usb_hub_port_connect_change(struct usb_device *dev, int
>> port) {
>> struct usb_device *usb;
>> - struct usb_port_status portsts;
>> + ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
>> unsigned short portstatus;
>>
>> /* Check status */
>> - if (usb_get_port_status(dev, port + 1,&portsts)< 0) {
>> + if (usb_get_port_status(dev, port + 1, portsts)< 0) {
>> USB_HUB_PRINTF("get_port_status failed\n");
>> return;
>> }
>>
>> - portstatus = le16_to_cpu(portsts.wPortStatus);
>> + portstatus = le16_to_cpu(portsts->wPortStatus);
>> USB_HUB_PRINTF("portstatus %x, change %x, %s\n",
>> portstatus,
>> - le16_to_cpu(portsts.wPortChange),
>> + le16_to_cpu(portsts->wPortChange),
>> portspeed(portstatus));
>>
>> /* Clear the connection change status */
>> @@ -1190,7 +1198,8 @@ void usb_hub_port_connect_change(struct usb_device
>> *dev, int port) int usb_hub_configure(struct usb_device *dev)
>> {
>> int i;
>> - unsigned char buffer[USB_BUFSIZ], *bitmap;
>> + ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, USB_BUFSIZ);
>> + unsigned char *bitmap;
>> struct usb_hub_descriptor *descriptor;
>> struct usb_hub_device *hub;
>> #ifdef USB_HUB_DEBUG
>> @@ -1312,16 +1321,16 @@ int usb_hub_configure(struct usb_device *dev)
>> usb_hub_power_on(hub);
>>
>> for (i = 0; i< dev->maxchild; i++) {
>> - struct usb_port_status portsts;
>> + ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
>> unsigned short portstatus, portchange;
>>
>> - if (usb_get_port_status(dev, i + 1,&portsts)< 0) {
>> + if (usb_get_port_status(dev, i + 1, portsts)< 0) {
>> USB_HUB_PRINTF("get_port_status failed\n");
>> continue;
>> }
>>
>> - portstatus = le16_to_cpu(portsts.wPortStatus);
>> - portchange = le16_to_cpu(portsts.wPortChange);
>> + portstatus = le16_to_cpu(portsts->wPortStatus);
>> + portchange = le16_to_cpu(portsts->wPortChange);
>> USB_HUB_PRINTF("Port %d Status %X Change %X\n",
>> i + 1, portstatus, portchange);
>>
>> diff --git a/common/usb_storage.c b/common/usb_storage.c
>> index de84c8d..88ca390 100644
>> --- a/common/usb_storage.c
>> +++ b/common/usb_storage.c
>> @@ -79,8 +79,7 @@ static const unsigned char us_direction[256/8] = {
>> };
>> #define US_DIRECTION(x) ((us_direction[x>>3]>> (x& 7))& 1)
>>
>> -static unsigned char usb_stor_buf[512];
>> -static ccb usb_ccb;
>> +static ccb usb_ccb __attribute__((aligned(ARCH_DMA_MINALIGN)));
>>
>> /*
>> * CBI style
>> @@ -210,17 +209,17 @@ int usb_stor_info(void)
>> static unsigned int usb_get_max_lun(struct us_data *us)
>> {
>> int len;
>> - unsigned char result;
>> + ALLOC_CACHE_ALIGN_BUFFER(unsigned char, result, 1);
>> len = usb_control_msg(us->pusb_dev,
>> usb_rcvctrlpipe(us->pusb_dev, 0),
>> US_BBB_GET_MAX_LUN,
>> USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
>> 0, us->ifnum,
>> -&result, sizeof(result),
>> + result, sizeof(char),
>> USB_CNTL_TIMEOUT * 5);
>> USB_STOR_PRINTF("Get Max LUN -> len = %i, result = %i\n",
>> - len, (int) result);
>> - return (len> 0) ? result : 0;
>> + len, (int) *result);
>> + return (len> 0) ? *result : 0;
>> }
>>
>> /*************************************************************************
>> ****** @@ -233,9 +232,6 @@ int usb_stor_scan(int mode)
>> unsigned char i;
>> struct usb_device *dev;
>>
>> - /* GJ */
>> - memset(usb_stor_buf, 0, sizeof(usb_stor_buf));
>> -
>> if (mode == 1)
>> printf(" scanning bus for storage devices... ");
>>
>> @@ -499,7 +495,7 @@ int usb_stor_BBB_comdat(ccb *srb, struct us_data *us)
>> int actlen;
>> int dir_in;
>> unsigned int pipe;
>> - umass_bbb_cbw_t cbw;
>> + ALLOC_CACHE_ALIGN_BUFFER(umass_bbb_cbw_t, cbw, 1);
>>
>> dir_in = US_DIRECTION(srb->cmd[0]);
>>
>> @@ -522,16 +518,16 @@ int usb_stor_BBB_comdat(ccb *srb, struct us_data *us)
>> /* always OUT to the ep */
>> pipe = usb_sndbulkpipe(us->pusb_dev, us->ep_out);
>>
>> - cbw.dCBWSignature = cpu_to_le32(CBWSIGNATURE);
>> - cbw.dCBWTag = cpu_to_le32(CBWTag++);
>> - cbw.dCBWDataTransferLength = cpu_to_le32(srb->datalen);
>> - cbw.bCBWFlags = (dir_in ? CBWFLAGS_IN : CBWFLAGS_OUT);
>> - cbw.bCBWLUN = srb->lun;
>> - cbw.bCDBLength = srb->cmdlen;
>> + cbw->dCBWSignature = cpu_to_le32(CBWSIGNATURE);
>> + cbw->dCBWTag = cpu_to_le32(CBWTag++);
>> + cbw->dCBWDataTransferLength = cpu_to_le32(srb->datalen);
>> + cbw->bCBWFlags = (dir_in ? CBWFLAGS_IN : CBWFLAGS_OUT);
>> + cbw->bCBWLUN = srb->lun;
>> + cbw->bCDBLength = srb->cmdlen;
>> /* copy the command data into the CBW command data buffer */
>> /* DST SRC LEN!!! */
>> - memcpy(cbw.CBWCDB, srb->cmd, srb->cmdlen);
>> - result = usb_bulk_msg(us->pusb_dev, pipe,&cbw, UMASS_BBB_CBW_SIZE,
>> + memcpy(cbw->CBWCDB, srb->cmd, srb->cmdlen);
>> + result = usb_bulk_msg(us->pusb_dev, pipe, cbw, UMASS_BBB_CBW_SIZE,
>> &actlen, USB_CNTL_TIMEOUT * 5);
>> if (result< 0)
>> USB_STOR_PRINTF("usb_stor_BBB_comdat:usb_bulk_msg error\n");
>> @@ -675,7 +671,7 @@ int usb_stor_BBB_transport(ccb *srb, struct us_data
>> *us) int dir_in;
>> int actlen, data_actlen;
>> unsigned int pipe, pipein, pipeout;
>> - umass_bbb_csw_t csw;
>> + ALLOC_CACHE_ALIGN_BUFFER(umass_bbb_csw_t, csw, 1);
>> #ifdef BBB_XPORT_TRACE
>> unsigned char *ptr;
>> int index;
>> @@ -733,7 +729,7 @@ st:
>> retry = 0;
>> again:
>> USB_STOR_PRINTF("STATUS phase\n");
>> - result = usb_bulk_msg(us->pusb_dev, pipein,&csw, UMASS_BBB_CSW_SIZE,
>> + result = usb_bulk_msg(us->pusb_dev, pipein, csw, UMASS_BBB_CSW_SIZE,
>> &actlen, USB_CNTL_TIMEOUT*5);
>>
>> /* special handling of STALL in STATUS phase */
>> @@ -753,28 +749,28 @@ again:
>> return USB_STOR_TRANSPORT_FAILED;
>> }
>> #ifdef BBB_XPORT_TRACE
>> - ptr = (unsigned char *)&csw;
>> + ptr = (unsigned char *)csw;
>> for (index = 0; index< UMASS_BBB_CSW_SIZE; index++)
>> printf("ptr[%d] %#x ", index, ptr[index]);
>> printf("\n");
>> #endif
>> /* misuse pipe to get the residue */
>> - pipe = le32_to_cpu(csw.dCSWDataResidue);
>> + pipe = le32_to_cpu(csw->dCSWDataResidue);
>> if (pipe == 0&& srb->datalen != 0&& srb->datalen - data_actlen != 0)
>> pipe = srb->datalen - data_actlen;
>> - if (CSWSIGNATURE != le32_to_cpu(csw.dCSWSignature)) {
>> + if (CSWSIGNATURE != le32_to_cpu(csw->dCSWSignature)) {
>> USB_STOR_PRINTF("!CSWSIGNATURE\n");
>> usb_stor_BBB_reset(us);
>> return USB_STOR_TRANSPORT_FAILED;
>> - } else if ((CBWTag - 1) != le32_to_cpu(csw.dCSWTag)) {
>> + } else if ((CBWTag - 1) != le32_to_cpu(csw->dCSWTag)) {
>> USB_STOR_PRINTF("!Tag\n");
>> usb_stor_BBB_reset(us);
>> return USB_STOR_TRANSPORT_FAILED;
>> - } else if (csw.bCSWStatus> CSWSTATUS_PHASE) {
>> + } else if (csw->bCSWStatus> CSWSTATUS_PHASE) {
>> USB_STOR_PRINTF(">PHASE\n");
>> usb_stor_BBB_reset(us);
>> return USB_STOR_TRANSPORT_FAILED;
>> - } else if (csw.bCSWStatus == CSWSTATUS_PHASE) {
>> + } else if (csw->bCSWStatus == CSWSTATUS_PHASE) {
>> USB_STOR_PRINTF("=PHASE\n");
>> usb_stor_BBB_reset(us);
>> return USB_STOR_TRANSPORT_FAILED;
>> @@ -782,7 +778,7 @@ again:
>> USB_STOR_PRINTF("transferred %dB instead of %ldB\n",
>> data_actlen, srb->datalen);
>> return USB_STOR_TRANSPORT_FAILED;
>> - } else if (csw.bCSWStatus == CSWSTATUS_FAILED) {
>> + } else if (csw->bCSWStatus == CSWSTATUS_FAILED) {
>> USB_STOR_PRINTF("FAILED\n");
>> return USB_STOR_TRANSPORT_FAILED;
>> }
>> @@ -1343,7 +1339,8 @@ int usb_stor_get_info(struct usb_device *dev, struct
>> us_data *ss, block_dev_desc_t *dev_desc)
>> {
>> unsigned char perq, modi;
>> - unsigned long cap[2];
>> + ALLOC_CACHE_ALIGN_BUFFER(unsigned long, cap, 2);
>> + ALLOC_CACHE_ALIGN_BUFFER(unsigned char, usb_stor_buf, 36);
>> unsigned long *capacity, *blksz;
>> ccb *pccb =&usb_ccb;
>>
>> @@ -1367,9 +1364,9 @@ int usb_stor_get_info(struct usb_device *dev, struct
>> us_data *ss, /* drive is removable */
>> dev_desc->removable = 1;
>> }
>> - memcpy(&dev_desc->vendor[0],&usb_stor_buf[8], 8);
>> - memcpy(&dev_desc->product[0],&usb_stor_buf[16], 16);
>> - memcpy(&dev_desc->revision[0],&usb_stor_buf[32], 4);
>> + memcpy(&dev_desc->vendor[0], (const void *)&usb_stor_buf[8], 8);
>> + memcpy(&dev_desc->product[0], (const void *)&usb_stor_buf[16], 16);
>> + memcpy(&dev_desc->revision[0], (const void *)&usb_stor_buf[32], 4);
>> dev_desc->vendor[8] = 0;
>> dev_desc->product[16] = 0;
>> dev_desc->revision[4] = 0;
>> diff --git a/disk/part_dos.c b/disk/part_dos.c
>> index b5bcb37..70211ee 100644
>> --- a/disk/part_dos.c
>> +++ b/disk/part_dos.c
>> @@ -87,7 +87,7 @@ static int test_block_type(unsigned char *buffer)
>>
>> int test_part_dos (block_dev_desc_t *dev_desc)
>> {
>> - unsigned char buffer[dev_desc->blksz];
>> + ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
>>
>> if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *) buffer) != 1)
> ||
>> (buffer[DOS_PART_MAGIC_OFFSET + 0] != 0x55) ||
>> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
>> index d893b2a..eb5220b 100644
>> --- a/drivers/usb/host/ehci-hcd.c
>> +++ b/drivers/usb/host/ehci-hcd.c
>> @@ -120,6 +120,14 @@ static struct descriptor {
>> */
>> static void flush_invalidate(u32 addr, int size, int flush)
>> {
>> + /*
>> + * Size is the bytes actually moved during transaction,
>> + * which may not equal to the cache line. This results
>> + * stop address passed for invalidating cache may not be aligned.
>> + * Therfore making size as multiple of cache line size.
>> + */
>> + size = ALIGN(size, ARCH_DMA_MINALIGN);
>> +
>> if (flush)
>> flush_dcache_range(addr, addr + size);
>> else
>> diff --git a/include/scsi.h b/include/scsi.h
>> index c52759c..89ae45f 100644
>> --- a/include/scsi.h
>> +++ b/include/scsi.h
>> @@ -26,7 +26,9 @@
>>
>> typedef struct SCSI_cmd_block{
>> unsigned char cmd[16];
> /* command */
>> - unsigned char sense_buf[64]; /* for request sense */
>> + /* for request sense */
>> + unsigned char sense_buf[64]
>> + __attribute__((aligned(ARCH_DMA_MINALIGN)));
>> unsigned char status;
> /* SCSI Status */
>> unsigned char target;
> /* Target ID */
>> unsigned char lun;
> /* Target LUN */
>
> Thanks!
Thanx,
Puneet

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