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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
powerpc/pseries/vas: Add hcall wrappers for VAS handling
This patch adds the following hcall wrapper functions to allocate,
modify and deallocate VAS windows, and retrieve VAS capabilities.
H_ALLOCATE_VAS_WINDOW: Allocate VAS window
H_DEALLOCATE_VAS_WINDOW: Close VAS window
H_MODIFY_VAS_WINDOW: Setup window before using
H_QUERY_VAS_CAPABILITIES: Get VAS capabilities
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/40fb02a4d56ca4e240b074a15029082055be5997.camel@linux.ibm.com
authored by
Haren Myneni
and committed by
Michael Ellerman
f33ecfde
540761b7
+147
+147
arch/powerpc/platforms/pseries/vas.c
+147
arch/powerpc/platforms/pseries/vas.c
···
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright 2020-21 IBM Corp.
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*/
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#define pr_fmt(fmt) "vas: " fmt
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/types.h>
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#include <linux/delay.h>
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#include <asm/hvcall.h>
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#include <asm/plpar_wrappers.h>
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#include <asm/vas.h>
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#include "vas.h"
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#define VAS_INVALID_WIN_ADDRESS 0xFFFFFFFFFFFFFFFFul
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#define VAS_DEFAULT_DOMAIN_ID 0xFFFFFFFFFFFFFFFFul
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/* The hypervisor allows one credit per window right now */
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#define DEF_WIN_CREDS 1
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static long hcall_return_busy_check(long rc)
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{
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/* Check if we are stalled for some time */
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if (H_IS_LONG_BUSY(rc)) {
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msleep(get_longbusy_msecs(rc));
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rc = H_BUSY;
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} else if (rc == H_BUSY) {
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cond_resched();
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}
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return rc;
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}
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/*
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* Allocate VAS window hcall
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*/
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static int h_allocate_vas_window(struct pseries_vas_window *win, u64 *domain,
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u8 wintype, u16 credits)
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{
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long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
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long rc;
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do {
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rc = plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, wintype,
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credits, domain[0], domain[1], domain[2],
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domain[3], domain[4], domain[5]);
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rc = hcall_return_busy_check(rc);
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} while (rc == H_BUSY);
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if (rc == H_SUCCESS) {
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if (win->win_addr == VAS_INVALID_WIN_ADDRESS) {
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pr_err("H_ALLOCATE_VAS_WINDOW: COPY/PASTE is not supported\n");
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return -ENOTSUPP;
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}
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win->vas_win.winid = retbuf[0];
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win->win_addr = retbuf[1];
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win->complete_irq = retbuf[2];
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win->fault_irq = retbuf[3];
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return 0;
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}
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pr_err("H_ALLOCATE_VAS_WINDOW error: %ld, wintype: %u, credits: %u\n",
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rc, wintype, credits);
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return -EIO;
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}
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/*
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* Deallocate VAS window hcall.
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*/
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static int h_deallocate_vas_window(u64 winid)
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{
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long rc;
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do {
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rc = plpar_hcall_norets(H_DEALLOCATE_VAS_WINDOW, winid);
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rc = hcall_return_busy_check(rc);
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} while (rc == H_BUSY);
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if (rc == H_SUCCESS)
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return 0;
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pr_err("H_DEALLOCATE_VAS_WINDOW error: %ld, winid: %llu\n",
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rc, winid);
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return -EIO;
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}
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/*
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* Modify VAS window.
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* After the window is opened with allocate window hcall, configure it
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* with flags and LPAR PID before using.
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*/
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static int h_modify_vas_window(struct pseries_vas_window *win)
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{
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long rc;
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u32 lpid = mfspr(SPRN_PID);
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/*
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* AMR value is not supported in Linux VAS implementation.
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* The hypervisor ignores it if 0 is passed.
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*/
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do {
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rc = plpar_hcall_norets(H_MODIFY_VAS_WINDOW,
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win->vas_win.winid, lpid, 0,
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VAS_MOD_WIN_FLAGS, 0);
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rc = hcall_return_busy_check(rc);
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} while (rc == H_BUSY);
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if (rc == H_SUCCESS)
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return 0;
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pr_err("H_MODIFY_VAS_WINDOW error: %ld, winid %u lpid %u\n",
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rc, win->vas_win.winid, lpid);
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return -EIO;
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}
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/*
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* This hcall is used to determine the capabilities from the hypervisor.
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* @hcall: H_QUERY_VAS_CAPABILITIES or H_QUERY_NX_CAPABILITIES
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* @query_type: If 0 is passed, the hypervisor returns the overall
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* capabilities which provides all feature(s) that are
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* available. Then query the hypervisor to get the
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* corresponding capabilities for the specific feature.
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* Example: H_QUERY_VAS_CAPABILITIES provides VAS GZIP QoS
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* and VAS GZIP Default capabilities.
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* H_QUERY_NX_CAPABILITIES provides NX GZIP
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* capabilities.
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* @result: Return buffer to save capabilities.
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*/
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int h_query_vas_capabilities(const u64 hcall, u8 query_type, u64 result)
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{
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long rc;
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rc = plpar_hcall_norets(hcall, query_type, result);
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if (rc == H_SUCCESS)
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return 0;
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pr_err("HCALL(%llx) error %ld, query_type %u, result buffer 0x%llx\n",
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hcall, rc, query_type, result);
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return -EIO;
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}