Re: [RESEND][PATCH 7/8][SCSI]mpt3sas: Added Reply Descriptor Post Queue (RDPQ) Array support

From: Tomas Henzl
Date: Tue Aug 05 2014 - 11:25:05 EST


On 06/25/2014 12:41 PM, Reddy, Sreekanth wrote:
> Up to now, Driver allocates a single contiguous block of memory
> pool for all reply queues and passes down a single address in the
> ReplyDescriptorPostQueueAddress field of the IOC Init Request
> Message to the firmware.
>
> When firmware receives this address, it will program each of the
> Reply Descriptor Post Queue registers, as each reply queue has its
> own register. Thus the firmware, starting from a base address it
> determines the starting address of the subsequent reply queues
> through some simple arithmetic calculations.
>
> The size of this contiguous block of memory pool is directly proportional
> to number of MSI-X vectors and the HBA queue depth. For example higher
> MSIX vectors requires larger contiguous block of memory pool.
>
> But some of the OS kernels are unable to allocate this larger
> contiguous block of memory pool.
>
> So, the proposal is to allocate memory independently for each
> Reply Queue and pass down all of the addresses to the firmware.
> Then the firmware will just take each address and program the value
> into the correct register.
>
> When HBAs with older firmware(i.e. without RDPQ capability) is used
> with this new driver then the max_msix_vectors value would be set
> to 8 by default.
>
> Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@xxxxxxxxxxxxx>
> ---
> drivers/scsi/mpt3sas/mpt3sas_base.c | 916 ++++++++++++++++++++---------------
> drivers/scsi/mpt3sas/mpt3sas_base.h | 19 +-
> 2 files changed, 543 insertions(+), 392 deletions(-)
>
...
> +static int
> +_base_handshake_req_reply_wait(struct MPT3SAS_ADAPTER *ioc, int request_bytes,
> + u32 *request, int reply_bytes, u16 *reply, int timeout, int sleep_flag)
> +{
> + MPI2DefaultReply_t *default_reply = (MPI2DefaultReply_t *)reply;
> + int i;
> + u8 failed;
> + u16 dummy;
> + __le32 *mfp;
> +
> + /* make sure doorbell is not in use */
> + if ((readl(&ioc->chip->Doorbell) & MPI2_DOORBELL_USED)) {

if (readl(&ioc->chip->Doorbell) & MPI2_DOORBELL_USED) {
I think it's equal and better looking with less parentheses, but
it's a personal preference so you can ignore it.

> + pr_err(MPT3SAS_FMT "doorbell is in use (line=%d)\n",
> + ioc->name, __LINE__);
> + return -EFAULT;
> + }
> +
> + /* clear pending doorbell interrupts from previous state changes */
> + if (readl(&ioc->chip->HostInterruptStatus) &
> + MPI2_HIS_IOC2SYS_DB_STATUS)
> + writel(0, &ioc->chip->HostInterruptStatus);
> +
> + /* send message to ioc */
> + writel(((MPI2_FUNCTION_HANDSHAKE<<MPI2_DOORBELL_FUNCTION_SHIFT) |
> + ((request_bytes/4)<<MPI2_DOORBELL_ADD_DWORDS_SHIFT)),
> + &ioc->chip->Doorbell);
> +
> + if ((_base_wait_for_doorbell_int(ioc, 5, NO_SLEEP))) {

Most likely not a problem, but why NO_SLEEP and not the sleep_flag ?

> + pr_err(MPT3SAS_FMT "doorbell handshake int failed (line=%d)\n",
> + ioc->name, __LINE__);
> + return -EFAULT;
> + }
> + writel(0, &ioc->chip->HostInterruptStatus);
> +
> + if ((_base_wait_for_doorbell_ack(ioc, 5, sleep_flag))) {
> + pr_err(MPT3SAS_FMT "doorbell handshake ack failed (line=%d)\n",
> + ioc->name, __LINE__);
> + return -EFAULT;
> + }
> +
> + /* send message 32-bits at a time */
> + for (i = 0, failed = 0; i < request_bytes/4 && !failed; i++) {
> + writel(cpu_to_le32(request[i]), &ioc->chip->Doorbell);
> + if ((_base_wait_for_doorbell_ack(ioc, 5, sleep_flag)))
> + failed = 1;
> + }
...

@@ -2945,39 +3307,82 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc, int sleep_flag)
ioc->name, (unsigned long long)ioc->reply_free_dma));
total_sz += sz;

- /* reply post queue, 16 byte align */
- reply_post_free_sz = ioc->reply_post_queue_depth *
- sizeof(Mpi2DefaultReplyDescriptor_t);
- if (_base_is_controller_msix_enabled(ioc))
- sz = reply_post_free_sz * ioc->reply_queue_count;
- else
+ if (ioc->rdpq_array_enable) {
+ ioc->reply_post = kcalloc(ioc->reply_queue_count,
+ sizeof(struct reply_post_struct), GFP_KERNEL);
+ /* reply post queue, 16 byte align */
+ reply_post_free_sz = ioc->reply_post_queue_depth *
+ sizeof(Mpi2DefaultReplyDescriptor_t);
sz = reply_post_free_sz;
- ioc->reply_post_free_dma_pool = pci_pool_create("reply_post_free pool",
- ioc->pdev, sz, 16, 0);
- if (!ioc->reply_post_free_dma_pool) {
- pr_err(MPT3SAS_FMT
- "reply_post_free pool: pci_pool_create failed\n",
- ioc->name);
- goto out;
- }
- ioc->reply_post_free = pci_pool_alloc(ioc->reply_post_free_dma_pool ,
- GFP_KERNEL, &ioc->reply_post_free_dma);
- if (!ioc->reply_post_free) {
- pr_err(MPT3SAS_FMT
- "reply_post_free pool: pci_pool_alloc failed\n",
- ioc->name);
- goto out;
+ ioc->reply_post_free_dma_pool =
+ pci_pool_create("reply_post_free pool", ioc->pdev, sz,
+ 16, 2147483648);

Few lines below with older firmware you don't need this rather
high boundary of 2^31, why is it needed here?

Besides that, checkpatch shows 11 warnings and some of them might be functional -
"WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers"
please clean your patch next time.

Cheers,
Tomas

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