[PATCH v4 10/11] VAS: Define vas_tx_win_open()

Sukadev Bhattiprolu
2017-03-31T05:14:30Z

Define an interface to open a VAS send window. This interface is
intended to be used the Nest Accelerator (NX) driver(s) to open
a send window and use it to submit compression/encryption requests
to a VAS receive window.

The receive window, identified by the [vasid, cop] parameters, must
already be open in VAS (i.e connected to an NX engine).

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>

---
Changelog [v3]:
- Distinguish between hardware PID (SPRN_PID) and Linux pid.
- Use macros rather than enum for threshold-control mode
- Set the pid of send window from attr (needed for user space
send windows).
- Ignore irq port setting for now. They are needed for user space
windows and will be added later
---
arch/powerpc/include/asm/vas.h | 42 ++++++++
arch/powerpc/platforms/powernv/vas-window.c | 157 ++++++++++++++++++++++++++++
2 files changed, 199 insertions(+)

diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index c923b8f..944bb4b 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -61,6 +61,29 @@ struct vas_rx_win_attr {
};

/*
+ * Window attributes specified by the in-kernel owner of a send window.
+ */
+struct vas_tx_win_attr {
+ enum vas_cop_type cop;
+ int wcreds_max;
+ int lpid;
+ int pidr; /* hardware PID (from SPRN_PID) */
+ int pid; /* linux process id */
+ int pswid;
+ int rsvd_txbuf_count;
+ int tc_mode;
+
+ bool user_win;
+ bool pin_win;
+ bool rej_no_credit;
+ bool rsvd_txbuf_enable;
+ bool tx_wcred_mode;
+ bool rx_wcred_mode;
+ bool tx_win_ord_mode;
+ bool rx_win_ord_mode;
+};
+
+/*
* Helper to initialize receive window attributes to defaults for an
* NX window.
*/
@@ -77,6 +100,25 @@ extern struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
struct vas_rx_win_attr *attr);

/*
+ * Helper to initialize send window attributes to defaults for an NX window.
+ */
+extern void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr,
+ enum vas_cop_type cop);
+
+/*
+ * Open a VAS send window for the instance of VAS identified by @vasid
+ * and the co-processor type @cop. Use @attr to initialize attributes
+ * of the window.
+ *
+ * Note: The instance of VAS must already have an open receive window for
+ * the coprocessor type @cop.
+ *
+ * Return a handle to the send window or ERR_PTR() on error.
+ */
+struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
+ struct vas_tx_win_attr *attr);
+
+/*
* Close the send or receive window identified by @win. For receive windows
* return -EAGAIN if there are active send windows attached to this receive
* window.
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 7b1a36c..4f4c134 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -709,6 +709,163 @@ struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
return ERR_PTR(rc);
}

+void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr, enum vas_cop_type cop)
+{
+ memset(txattr, 0, sizeof(*txattr));
+
+ if (cop == VAS_COP_TYPE_842 || cop == VAS_COP_TYPE_842_HIPRI) {
+ txattr->rej_no_credit = false;
+ txattr->rx_wcred_mode = true;
+ txattr->tx_wcred_mode = true;
+ txattr->rx_win_ord_mode = true;
+ txattr->tx_win_ord_mode = true;
+ }
+}
+
+static void init_winctx_for_txwin(struct vas_window *txwin,
+ struct vas_tx_win_attr *txattr,
+ struct vas_winctx *winctx)
+{
+ /*
+ * We first zero all fields and only set non-zero ones. Following
+ * are some fields set to 0/false for the stated reason:
+ *
+ * ->notify_os_intr_reg In powerNV, send intrs to HV
+ * ->rsvd_txbuf_count Not supported yet.
+ * ->notify_disable False for NX windows
+ * ->xtra_write False for NX windows
+ * ->notify_early NA for NX windows
+ * ->lnotify_lpid NA for Tx windows
+ * ->lnotify_pid NA for Tx windows
+ * ->lnotify_tid NA for Tx windows
+ * ->tx_win_cred_mode Ignore for now for NX windows
+ * ->rx_win_cred_mode Ignore for now for NX windows
+ */
+ memset(winctx, 0, sizeof(struct vas_winctx));
+
+ winctx->wcreds_max = txattr->wcreds_max ?: VAS_WCREDS_DEFAULT;
+
+ winctx->user_win = txattr->user_win;
+ winctx->nx_win = txwin->rxwin->nx_win;
+ winctx->pin_win = txattr->pin_win;
+
+ winctx->rx_wcred_mode = txattr->rx_wcred_mode;
+ winctx->tx_wcred_mode = txattr->tx_wcred_mode;
+ winctx->rx_word_mode = txattr->rx_win_ord_mode;
+ winctx->tx_word_mode = txattr->tx_win_ord_mode;
+
+ if (winctx->nx_win) {
+ winctx->data_stamp = true;
+ winctx->intr_disable = true;
+ }
+
+ winctx->lpid = txattr->lpid;
+ winctx->pidr = txattr->pidr;
+ winctx->rx_win_id = txwin->rxwin->winid;
+ winctx->fault_win_id = fault_winid;
+
+ winctx->dma_type = VAS_DMA_TYPE_INJECT;
+ winctx->tc_mode = txattr->tc_mode;
+ winctx->min_scope = VAS_SCOPE_LOCAL;
+ winctx->max_scope = VAS_SCOPE_VECTORED_GROUP;
+}
+
+static bool tx_win_args_valid(enum vas_cop_type cop,
+ struct vas_tx_win_attr *attr)
+{
+ if (attr->tc_mode != VAS_THRESH_DISABLED)
+ return false;
+
+ if (cop > VAS_COP_TYPE_MAX)
+ return false;
+
+ if (attr->user_win) {
+ if (cop != VAS_COP_TYPE_GZIP && cop != VAS_COP_TYPE_GZIP_HIPRI)
+ return false;
+
+ if (attr->rsvd_txbuf_count != 0)
+ return false;
+ }
+
+ return true;
+}
+
+struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
+ struct vas_tx_win_attr *attr)
+{
+ int rc, winid;
+ struct vas_instance *vinst;
+ struct vas_window *txwin;
+ struct vas_window *rxwin;
+ struct vas_winctx winctx;
+ int size;
+ char *name;
+ uint64_t paste_busaddr;
+
+ if (!vas_initialized())
+ return ERR_PTR(-EAGAIN);
+
+ if (!tx_win_args_valid(cop, attr))
+ return ERR_PTR(-EINVAL);
+
+ vinst = find_vas_instance(vasid);
+ if (!vinst) {
+ pr_devel("VAS: vasid %d not found!\n", vasid);
+ return ERR_PTR(-EINVAL);
+ }
+
+ rxwin = get_vinstance_rxwin(vinst, cop);
+ if (!rxwin) {
+ pr_devel("VAS: No RxWin for vasid %d, cop %d\n", vasid, cop);
+ return ERR_PTR(-EINVAL);
+ }
+
+ rc = -EAGAIN;
+ winid = vas_assign_window_id(&vinst->ida);
+ if (winid < 0)
+ goto put_rxwin;
+
+ rc = -ENOMEM;
+ txwin = vas_window_alloc(vinst, winid);
+ if (!txwin)
+ goto release_winid;
+
+ txwin->tx_win = 1;
+ txwin->rxwin = rxwin;
+ txwin->nx_win = txwin->rxwin->nx_win;
+ txwin->pid = attr->pid;
+
+ init_winctx_for_txwin(txwin, attr, &winctx);
+
+ init_winctx_regs(txwin, &winctx);
+
+ name = kasprintf(GFP_KERNEL, "window-v%d-w%d", vasid, winid);
+ if (!name)
+ goto release_winid;
+
+ txwin->paste_addr_name = name;
+ compute_paste_address(txwin, &paste_busaddr, &size);
+
+ txwin->paste_kaddr = map_mmio_region(name, paste_busaddr, size);
+ if (!txwin->paste_kaddr)
+ goto free_name;
+
+ pr_devel("VAS: mapped paste addr 0x%llx to kaddr 0x%p\n",
+ paste_busaddr, txwin->paste_kaddr);
+ return txwin;
+
+free_name:
+ kfree(txwin->paste_addr_name);
+
+release_winid:
+ vas_release_window_id(&vinst->ida, txwin->winid);
+
+put_rxwin:
+ put_rx_win(rxwin);
+ return ERR_PTR(rc);
+
+}
+
static void poll_window_busy_state(struct vas_window *window)
{
int busy;
--
2.7.4