[RFC PATCH v12 12/17] dlb: add register operations for port management

Mike Ximing Chen
2021-12-21T06:51:27Z

Add the low-level code for configuring a new port, programming the
device-wide poll mode setting, and resetting a port.

The low-level port configuration functions program the device based on the
user-supplied parameters (from configfs attributes). These parameter are
first verified, e.g. to ensure that the port's CQ base address is properly
cache-line aligned.

During domain reset, each port is drained until its inflight count and
owed-token count reaches 0, reflecting an empty CQ. Once the ports are
drained, the domain reset operation disables them from being candidates
for future scheduling decisions -- until they are re-assigned to a new
scheduling domain in the future and re-enabled.

Signed-off-by: Mike Ximing Chen <mike.ximing.chen@intel.com>
---
drivers/misc/dlb/dlb_resource.c | 418 +++++++++++++++++++++++++++++++-
1 file changed, 417 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/dlb/dlb_resource.c b/drivers/misc/dlb/dlb_resource.c
index 3521ae2ca76b..d1e1d1efe8c7 100644
--- a/drivers/misc/dlb/dlb_resource.c
+++ b/drivers/misc/dlb/dlb_resource.c
@@ -1217,6 +1217,296 @@ static void dlb_dir_port_cq_disable(struct dlb_hw *hw,
dlb_flush_csr(hw);
}

+static void dlb_ldb_port_configure_pp(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain,
+ struct dlb_ldb_port *port)
+{
+ u32 reg;
+
+ reg = FIELD_PREP(SYS_LDB_PP2VAS_VAS, domain->id);
+ DLB_CSR_WR(hw, SYS_LDB_PP2VAS(port->id), reg);
+
+ reg = 0;
+ reg |= SYS_LDB_PP_V_PP_V;
+ DLB_CSR_WR(hw, SYS_LDB_PP_V(port->id), reg);
+}
+
+static int dlb_ldb_port_configure_cq(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain,
+ struct dlb_ldb_port *port,
+ uintptr_t cq_dma_base,
+ struct dlb_create_ldb_port_args *args)
+{
+ u32 hl_base = 0;
+ u32 reg = 0;
+ u32 ds, n;
+
+ /* The CQ address is 64B-aligned, and the DLB only wants bits [63:6] */
+ reg = FIELD_PREP(SYS_LDB_CQ_ADDR_L_ADDR_L, cq_dma_base >> 6);
+ DLB_CSR_WR(hw, SYS_LDB_CQ_ADDR_L(port->id), reg);
+
+ reg = cq_dma_base >> 32;
+ DLB_CSR_WR(hw, SYS_LDB_CQ_ADDR_U(port->id), reg);
+
+ /*
+ * 'ro' == relaxed ordering. This setting allows DLB to write
+ * cache lines out-of-order (but QEs within a cache line are always
+ * updated in-order).
+ */
+ reg = FIELD_PREP(SYS_LDB_CQ2VF_PF_RO_IS_PF, 1);
+ reg |= SYS_LDB_CQ2VF_PF_RO_RO;
+
+ DLB_CSR_WR(hw, SYS_LDB_CQ2VF_PF_RO(port->id), reg);
+
+ if (!dlb_cq_depth_is_valid(args->cq_depth)) {
+ dev_err(hw_to_dev(hw),
+ "[%s():%d] Internal error: invalid CQ depth\n",
+ __func__, __LINE__);
+ return -EINVAL;
+ }
+
+ if (args->cq_depth <= 8) {
+ ds = 1;
+ } else {
+ n = ilog2(args->cq_depth);
+ ds = (n - 2) & 0x0f;
+ }
+
+ reg = FIELD_PREP(CHP_LDB_CQ_TKN_DEPTH_SEL_TOKEN_DEPTH_SELECT, ds);
+ DLB_CSR_WR(hw, CHP_LDB_CQ_TKN_DEPTH_SEL(port->id), reg);
+
+ /*
+ * To support CQs with depth less than 8, program the token count
+ * register with a non-zero initial value. Operations such as domain
+ * reset must take this initial value into account when quiescing the
+ * CQ.
+ */
+ port->init_tkn_cnt = 0;
+
+ if (args->cq_depth < 8) {
+ port->init_tkn_cnt = 8 - args->cq_depth;
+
+ reg = FIELD_PREP(LSP_CQ_LDB_TKN_CNT_TOKEN_COUNT, port->init_tkn_cnt);
+ DLB_CSR_WR(hw, LSP_CQ_LDB_TKN_CNT(port->id), reg);
+ } else {
+ DLB_CSR_WR(hw,
+ LSP_CQ_LDB_TKN_CNT(port->id),
+ LSP_CQ_LDB_TKN_CNT_RST);
+ }
+
+ reg = FIELD_PREP(LSP_CQ_LDB_TKN_DEPTH_SEL_TOKEN_DEPTH_SELECT, ds);
+ DLB_CSR_WR(hw, LSP_CQ_LDB_TKN_DEPTH_SEL(port->id), reg);
+
+ /* Reset the CQ write pointer */
+ DLB_CSR_WR(hw,
+ CHP_LDB_CQ_WPTR(port->id),
+ CHP_LDB_CQ_WPTR_RST);
+
+ reg = FIELD_PREP(CHP_HIST_LIST_LIM_LIMIT, port->hist_list_entry_limit - 1);
+ DLB_CSR_WR(hw, CHP_HIST_LIST_LIM(port->id), reg);
+
+ hl_base = FIELD_PREP(CHP_HIST_LIST_BASE_BASE, port->hist_list_entry_base);
+ DLB_CSR_WR(hw, CHP_HIST_LIST_BASE(port->id), hl_base);
+
+ /*
+ * The inflight limit sets a cap on the number of QEs for which this CQ
+ * can owe completions at one time.
+ */
+ reg = FIELD_PREP(LSP_CQ_LDB_INFL_LIM_LIMIT, args->cq_history_list_size);
+ DLB_CSR_WR(hw, LSP_CQ_LDB_INFL_LIM(port->id), reg);
+
+ reg = FIELD_PREP(CHP_HIST_LIST_PUSH_PTR_PUSH_PTR,
+ FIELD_GET(CHP_HIST_LIST_BASE_BASE, hl_base));
+ DLB_CSR_WR(hw, CHP_HIST_LIST_PUSH_PTR(port->id), reg);
+
+ reg = FIELD_PREP(CHP_HIST_LIST_POP_PTR_POP_PTR,
+ FIELD_GET(CHP_HIST_LIST_BASE_BASE, hl_base));
+ DLB_CSR_WR(hw, CHP_HIST_LIST_POP_PTR(port->id), reg);
+
+ /*
+ * Address translation (AT) settings: 0: untranslated, 2: translated
+ * (see ATS spec regarding Address Type field for more details)
+ */
+
+ reg = 0;
+ DLB_CSR_WR(hw, SYS_LDB_CQ_AT(port->id), reg);
+ DLB_CSR_WR(hw, SYS_LDB_CQ_PASID(port->id), reg);
+
+ reg = FIELD_PREP(CHP_LDB_CQ2VAS_CQ2VAS, domain->id);
+ DLB_CSR_WR(hw, CHP_LDB_CQ2VAS(port->id), reg);
+
+ /* Disable the port's QID mappings */
+ reg = 0;
+ DLB_CSR_WR(hw, LSP_CQ2PRIOV(port->id), reg);
+
+ return 0;
+}
+
+static int dlb_configure_ldb_port(struct dlb_hw *hw, struct dlb_hw_domain *domain,
+ struct dlb_ldb_port *port,
+ uintptr_t cq_dma_base,
+ struct dlb_create_ldb_port_args *args)
+{
+ int ret, i;
+
+ port->hist_list_entry_base = domain->hist_list_entry_base +
+ domain->hist_list_entry_offset;
+ port->hist_list_entry_limit = port->hist_list_entry_base +
+ args->cq_history_list_size;
+
+ domain->hist_list_entry_offset += args->cq_history_list_size;
+ domain->avail_hist_list_entries -= args->cq_history_list_size;
+
+ ret = dlb_ldb_port_configure_cq(hw,
+ domain,
+ port,
+ cq_dma_base,
+ args);
+ if (ret)
+ return ret;
+
+ dlb_ldb_port_configure_pp(hw, domain, port);
+
+ dlb_ldb_port_cq_enable(hw, port);
+
+ for (i = 0; i < DLB_MAX_NUM_QIDS_PER_LDB_CQ; i++)
+ port->qid_map[i].state = DLB_QUEUE_UNMAPPED;
+ port->num_mappings = 0;
+
+ port->enabled = true;
+
+ port->configured = true;
+
+ return 0;
+}
+
+static void dlb_dir_port_configure_pp(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain,
+ struct dlb_dir_pq_pair *port)
+{
+ u32 reg;
+
+ reg = FIELD_PREP(SYS_DIR_PP2VAS_VAS, domain->id);
+ DLB_CSR_WR(hw, SYS_DIR_PP2VAS(port->id), reg);
+
+ reg = 0;
+ reg |= SYS_DIR_PP_V_PP_V;
+ DLB_CSR_WR(hw, SYS_DIR_PP_V(port->id), reg);
+}
+
+static int dlb_dir_port_configure_cq(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain,
+ struct dlb_dir_pq_pair *port,
+ uintptr_t cq_dma_base,
+ struct dlb_create_dir_port_args *args)
+{
+ u32 reg;
+ u32 ds, n;
+
+ /* The CQ address is 64B-aligned, and the DLB only wants bits [63:6] */
+ reg = FIELD_PREP(SYS_DIR_CQ_ADDR_L_ADDR_L, cq_dma_base >> 6);
+ DLB_CSR_WR(hw, SYS_DIR_CQ_ADDR_L(port->id), reg);
+
+ reg = cq_dma_base >> 32;
+ DLB_CSR_WR(hw, SYS_DIR_CQ_ADDR_U(port->id), reg);
+
+ /*
+ * 'ro' == relaxed ordering. This setting allows DLB to write
+ * cache lines out-of-order (but QEs within a cache line are always
+ * updated in-order).
+ */
+ reg = FIELD_PREP(SYS_DIR_CQ2VF_PF_RO_IS_PF, 1);
+ reg |= SYS_DIR_CQ2VF_PF_RO_RO;
+
+ DLB_CSR_WR(hw, SYS_DIR_CQ2VF_PF_RO(port->id), reg);
+
+ if (!dlb_cq_depth_is_valid(args->cq_depth)) {
+ dev_err(hw_to_dev(hw),
+ "[%s():%d] Internal error: invalid CQ depth\n",
+ __func__, __LINE__);
+ return -EINVAL;
+ }
+
+ if (args->cq_depth <= 8) {
+ ds = 1;
+ } else {
+ n = ilog2(args->cq_depth);
+ ds = (n - 2) & 0x0f;
+ }
+
+ reg = FIELD_PREP(CHP_DIR_CQ_TKN_DEPTH_SEL_TOKEN_DEPTH_SELECT, ds);
+ DLB_CSR_WR(hw, CHP_DIR_CQ_TKN_DEPTH_SEL(port->id), reg);
+
+ /*
+ * To support CQs with depth less than 8, program the token count
+ * register with a non-zero initial value. Operations such as domain
+ * reset must take this initial value into account when quiescing the
+ * CQ.
+ */
+ port->init_tkn_cnt = 0;
+
+ if (args->cq_depth < 8) {
+ port->init_tkn_cnt = 8 - args->cq_depth;
+
+ reg = FIELD_PREP(LSP_CQ_DIR_TKN_CNT_COUNT, port->init_tkn_cnt);
+ DLB_CSR_WR(hw, LSP_CQ_DIR_TKN_CNT(port->id), reg);
+ } else {
+ DLB_CSR_WR(hw,
+ LSP_CQ_DIR_TKN_CNT(port->id),
+ LSP_CQ_DIR_TKN_CNT_RST);
+ }
+
+ reg = FIELD_PREP(LSP_CQ_DIR_TKN_DEPTH_SEL_DSI_TOKEN_DEPTH_SELECT, ds);
+ DLB_CSR_WR(hw, LSP_CQ_DIR_TKN_DEPTH_SEL_DSI(port->id), reg);
+
+ /* Reset the CQ write pointer */
+ DLB_CSR_WR(hw,
+ CHP_DIR_CQ_WPTR(port->id),
+ CHP_DIR_CQ_WPTR_RST);
+
+ /* Virtualize the PPID */
+ reg = 0;
+ DLB_CSR_WR(hw, SYS_DIR_CQ_FMT(port->id), reg);
+
+ /*
+ * Address translation (AT) settings: 0: untranslated, 2: translated
+ * (see ATS spec regarding Address Type field for more details)
+ */
+ reg = 0;
+ DLB_CSR_WR(hw, SYS_DIR_CQ_AT(port->id), reg);
+
+ DLB_CSR_WR(hw, SYS_DIR_CQ_PASID(port->id), reg);
+
+ reg = FIELD_PREP(CHP_DIR_CQ2VAS_CQ2VAS, domain->id);
+ DLB_CSR_WR(hw, CHP_DIR_CQ2VAS(port->id), reg);
+
+ return 0;
+}
+
+static int dlb_configure_dir_port(struct dlb_hw *hw, struct dlb_hw_domain *domain,
+ struct dlb_dir_pq_pair *port,
+ uintptr_t cq_dma_base,
+ struct dlb_create_dir_port_args *args)
+{
+ int ret;
+
+ ret = dlb_dir_port_configure_cq(hw, domain, port, cq_dma_base,
+ args);
+
+ if (ret)
+ return ret;
+
+ dlb_dir_port_configure_pp(hw, domain, port);
+
+ dlb_dir_port_cq_enable(hw, port);
+
+ port->enabled = true;
+
+ port->port_configured = true;
+
+ return 0;
+}
+
static void
dlb_log_create_sched_domain_args(struct dlb_hw *hw,
struct dlb_create_sched_domain_args *args)
@@ -1503,6 +1793,11 @@ int dlb_hw_create_ldb_port(struct dlb_hw *hw, u32 domain_id,
if (ret)
return ret;

+ ret = dlb_configure_ldb_port(hw, domain, port, cq_dma_base,
+ args);
+ if (ret)
+ return ret;
+
/*
* Configuration succeeded, so move the resource from the 'avail' to
* the 'used' list.
@@ -1571,6 +1866,11 @@ int dlb_hw_create_dir_port(struct dlb_hw *hw, u32 domain_id,
if (ret)
return ret;

+ ret = dlb_configure_dir_port(hw, domain, port, cq_dma_base,
+ args);
+ if (ret)
+ return ret;
+
/*
* Configuration succeeded, so move the resource from the 'avail' to
* the 'used' list (if it's not already there).
@@ -1670,6 +1970,33 @@ static void dlb_drain_ldb_cq(struct dlb_hw *hw, struct dlb_ldb_port *port)
}
}

+static int dlb_domain_wait_for_ldb_cqs_to_empty(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain)
+{
+ struct dlb_ldb_port *port;
+ int i;
+
+ for (i = 0; i < DLB_NUM_COS_DOMAINS; i++) {
+ list_for_each_entry(port, &domain->used_ldb_ports[i], domain_list) {
+ int j;
+
+ for (j = 0; j < DLB_MAX_CQ_COMP_CHECK_LOOPS; j++) {
+ if (dlb_ldb_cq_inflight_count(hw, port) == 0)
+ break;
+ }
+
+ if (j == DLB_MAX_CQ_COMP_CHECK_LOOPS) {
+ dev_err(hw_to_dev(hw),
+ "[%s()] Internal error: failed to flush load-balanced port %d's completions.\n",
+ __func__, port->id);
+ return -EFAULT;
+ }
+ }
+ }
+
+ return 0;
+}
+
/*
* dlb_domain_reset_software_state() - returns domain's resources
* @hw: dlb_hw handle for a particular device.
@@ -2348,7 +2675,10 @@ static u32 dlb_dir_cq_token_count(struct dlb_hw *hw,
static int dlb_domain_verify_reset_success(struct dlb_hw *hw,
struct dlb_hw_domain *domain)
{
+ struct dlb_dir_pq_pair *dir_port;
+ struct dlb_ldb_port *ldb_port;
struct dlb_ldb_queue *queue;
+ int i;

/*
* Confirm that all the domain's queue's inflight counts and AQED
@@ -2363,6 +2693,35 @@ static int dlb_domain_verify_reset_success(struct dlb_hw *hw,
}
}

+ /* Confirm that all the domain's CQs inflight and token counts are 0. */
+ for (i = 0; i < DLB_NUM_COS_DOMAINS; i++) {
+ list_for_each_entry(ldb_port, &domain->used_ldb_ports[i], domain_list) {
+ if (dlb_ldb_cq_inflight_count(hw, ldb_port) ||
+ dlb_ldb_cq_token_count(hw, ldb_port)) {
+ dev_err(hw_to_dev(hw),
+ "[%s()] Internal error: failed to empty ldb port %d\n",
+ __func__, ldb_port->id);
+ return -EFAULT;
+ }
+ }
+ }
+
+ list_for_each_entry(dir_port, &domain->used_dir_pq_pairs, domain_list) {
+ if (!dlb_dir_queue_is_empty(hw, dir_port)) {
+ dev_err(hw_to_dev(hw),
+ "[%s()] Internal error: failed to empty dir queue %d\n",
+ __func__, dir_port->id);
+ return -EFAULT;
+ }
+
+ if (dlb_dir_cq_token_count(hw, dir_port)) {
+ dev_err(hw_to_dev(hw),
+ "[%s()] Internal error: failed to empty dir port %d\n",
+ __func__, dir_port->id);
+ return -EFAULT;
+ }
+ }
+
return 0;
}

@@ -2580,6 +2939,51 @@ static int dlb_domain_drain_dir_queues(struct dlb_hw *hw,
return 0;
}

+static void
+dlb_domain_disable_dir_producer_ports(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain)
+{
+ struct dlb_dir_pq_pair *port;
+ u32 pp_v = 0;
+
+ list_for_each_entry(port, &domain->used_dir_pq_pairs, domain_list) {
+ DLB_CSR_WR(hw, SYS_DIR_PP_V(port->id), pp_v);
+ }
+}
+
+static void
+dlb_domain_disable_ldb_producer_ports(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain)
+{
+ struct dlb_ldb_port *port;
+ u32 pp_v = 0;
+ int i;
+
+ for (i = 0; i < DLB_NUM_COS_DOMAINS; i++) {
+ list_for_each_entry(port, &domain->used_ldb_ports[i], domain_list) {
+ DLB_CSR_WR(hw,
+ SYS_LDB_PP_V(port->id),
+ pp_v);
+ }
+ }
+}
+
+static void dlb_domain_disable_ldb_seq_checks(struct dlb_hw *hw,
+ struct dlb_hw_domain *domain)
+{
+ struct dlb_ldb_port *port;
+ u32 chk_en = 0;
+ int i;
+
+ for (i = 0; i < DLB_NUM_COS_DOMAINS; i++) {
+ list_for_each_entry(port, &domain->used_ldb_ports[i], domain_list) {
+ DLB_CSR_WR(hw,
+ CHP_SN_CHK_ENBL(port->id),
+ chk_en);
+ }
+ }
+}
+
static void
dlb_domain_disable_ldb_queue_write_perms(struct dlb_hw *hw,
struct dlb_hw_domain *domain)
@@ -2697,6 +3101,9 @@ int dlb_reset_domain(struct dlb_hw *hw, u32 domain_id)

dlb_domain_disable_ldb_queue_write_perms(hw, domain);

+ /* Turn off completion tracking on all the domain's PPs. */
+ dlb_domain_disable_ldb_seq_checks(hw, domain);
+
/*
* Disable the LDB CQs and drain them in order to complete the map and
* unmap procedures, which require zero CQ inflights and zero QID
@@ -2706,6 +3113,10 @@ int dlb_reset_domain(struct dlb_hw *hw, u32 domain_id)

dlb_domain_drain_ldb_cqs(hw, domain, false);

+ ret = dlb_domain_wait_for_ldb_cqs_to_empty(hw, domain);
+ if (ret)
+ return ret;
+
/* Re-enable the CQs in order to drain the mapped queues. */
dlb_domain_enable_ldb_cqs(hw, domain);

@@ -2721,6 +3132,11 @@ int dlb_reset_domain(struct dlb_hw *hw, u32 domain_id)
/* Done draining DIR QEs, so disable the CQs. */
dlb_domain_disable_dir_cqs(hw, domain);

+ /* Disable PPs */
+ dlb_domain_disable_dir_producer_ports(hw, domain);
+
+ dlb_domain_disable_ldb_producer_ports(hw, domain);
+
ret = dlb_domain_verify_reset_success(hw, domain);
if (ret)
return ret;
@@ -2752,7 +3168,7 @@ void dlb_clr_pmcsr_disable(struct dlb_hw *hw)

/**
* dlb_hw_enable_sparse_ldb_cq_mode() - enable sparse mode for load-balanced
- * ports.
+ * ports.
* @hw: dlb_hw handle for a particular device.
*
* This function must be called prior to configuring scheduling domains.
--
2.27.0