From 2cc81c6992248ea37d0241bc325977bab310bc3b Mon Sep 17 00:00:00 2001 From: Xiaochen Shen Date: Wed, 12 Sep 2018 16:48:38 -0700 Subject: x86/intel_rdt: Show missing resctrl mount options In resctrl filesystem, mount options exist to enable L3/L2 CDP and MBA Software Controller features if the platform supports them: mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps]] /sys/fs/resctrl But currently only "cdp" option is displayed in /proc/mounts. "cdpl2" and "mba_MBps" options are not shown even when they are active. Before: # mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl # grep resctrl /proc/mounts /sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp 0 0 After: # mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl # grep resctrl /proc/mounts /sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp,mba_MBps 0 0 Signed-off-by: Xiaochen Shen Signed-off-by: Fenghua Yu Signed-off-by: Thomas Gleixner Cc: "H Peter Anvin" Cc: "Tony Luck" Link: https://lkml.kernel.org/r/1536796118-60135-1-git-send-email-fenghua.yu@intel.com --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/x86/kernel/cpu/intel_rdt_rdtgroup.c') diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 1b8e86a5d5e1..82a487840eb2 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -2795,6 +2795,13 @@ static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf) { if (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled) seq_puts(seq, ",cdp"); + + if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled) + seq_puts(seq, ",cdpl2"); + + if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA])) + seq_puts(seq, ",mba_MBps"); + return 0; } -- cgit v1.2.3 From 49e00eee00612b1357596fed8a88b621a7648c14 Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Thu, 4 Oct 2018 14:05:23 -0700 Subject: x86/intel_rdt: Fix out-of-bounds memory access in CBM tests While the DOC at the beginning of lib/bitmap.c explicitly states that "The number of valid bits in a given bitmap does _not_ need to be an exact multiple of BITS_PER_LONG.", some of the bitmap operations do indeed access BITS_PER_LONG portions of the provided bitmap no matter the size of the provided bitmap. For example, if bitmap_intersects() is provided with an 8 bit bitmap the operation will access BITS_PER_LONG bits from the provided bitmap. While the operation ensures that these extra bits do not affect the result, the memory is still accessed. The capacity bitmasks (CBMs) are typically stored in u32 since they can never exceed 32 bits. A few instances exist where a bitmap_* operation is performed on a CBM by simply pointing the bitmap operation to the stored u32 value. The consequence of this pattern is that some bitmap_* operations will access out-of-bounds memory when interacting with the provided CBM. This is confirmed with a KASAN test that reports: BUG: KASAN: stack-out-of-bounds in __bitmap_intersects+0xa2/0x100 and BUG: KASAN: stack-out-of-bounds in __bitmap_weight+0x58/0x90 Fix this by moving any CBM provided to a bitmap operation needing BITS_PER_LONG to an 'unsigned long' variable. [ tglx: Changed related function arguments to unsigned long and got rid of the _cbm extra step ] Fixes: 72d505056604 ("x86/intel_rdt: Add utilities to test pseudo-locked region possibility") Fixes: 49f7b4efa110 ("x86/intel_rdt: Enable setting of exclusive mode") Fixes: d9b48c86eb38 ("x86/intel_rdt: Display resource groups' allocations' size in bytes") Fixes: 95f0b77efa57 ("x86/intel_rdt: Initialize new resource group with sane defaults") Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/69a428613a53f10e80594679ac726246020ff94f.1538686926.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 36 ++++++++++++++++++++------------ 1 file changed, 23 insertions(+), 13 deletions(-) (limited to 'arch/x86/kernel/cpu/intel_rdt_rdtgroup.c') diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 1b8e86a5d5e1..b140c68bc14b 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -975,33 +975,34 @@ static int rdtgroup_mode_show(struct kernfs_open_file *of, * is false then overlaps with any resource group or hardware entities * will be considered. * + * @cbm is unsigned long, even if only 32 bits are used, to make the + * bitmap functions work correctly. + * * Return: false if CBM does not overlap, true if it does. */ bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d, - u32 _cbm, int closid, bool exclusive) + unsigned long cbm, int closid, bool exclusive) { - unsigned long *cbm = (unsigned long *)&_cbm; - unsigned long *ctrl_b; enum rdtgrp_mode mode; + unsigned long ctrl_b; u32 *ctrl; int i; /* Check for any overlap with regions used by hardware directly */ if (!exclusive) { - if (bitmap_intersects(cbm, - (unsigned long *)&r->cache.shareable_bits, - r->cache.cbm_len)) + ctrl_b = r->cache.shareable_bits; + if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) return true; } /* Check for overlap with other resource groups */ ctrl = d->ctrl_val; for (i = 0; i < closids_supported(); i++, ctrl++) { - ctrl_b = (unsigned long *)ctrl; + ctrl_b = *ctrl; mode = rdtgroup_mode_by_closid(i); if (closid_allocated(i) && i != closid && mode != RDT_MODE_PSEUDO_LOCKSETUP) { - if (bitmap_intersects(cbm, ctrl_b, r->cache.cbm_len)) { + if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) { if (exclusive) { if (mode == RDT_MODE_EXCLUSIVE) return true; @@ -1138,15 +1139,18 @@ out: * computed by first dividing the total cache size by the CBM length to * determine how many bytes each bit in the bitmask represents. The result * is multiplied with the number of bits set in the bitmask. + * + * @cbm is unsigned long, even if only 32 bits are used to make the + * bitmap functions work correctly. */ unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, - struct rdt_domain *d, u32 cbm) + struct rdt_domain *d, unsigned long cbm) { struct cpu_cacheinfo *ci; unsigned int size = 0; int num_b, i; - num_b = bitmap_weight((unsigned long *)&cbm, r->cache.cbm_len); + num_b = bitmap_weight(&cbm, r->cache.cbm_len); ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask)); for (i = 0; i < ci->num_leaves; i++) { if (ci->info_list[i].level == r->cache_level) { @@ -2353,6 +2357,7 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) u32 used_b = 0, unused_b = 0; u32 closid = rdtgrp->closid; struct rdt_resource *r; + unsigned long tmp_cbm; enum rdtgrp_mode mode; struct rdt_domain *d; int i, ret; @@ -2390,9 +2395,14 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) * modify the CBM based on system availability. */ cbm_ensure_valid(&d->new_ctrl, r); - if (bitmap_weight((unsigned long *) &d->new_ctrl, - r->cache.cbm_len) < - r->cache.min_cbm_bits) { + /* + * Assign the u32 CBM to an unsigned long to ensure + * that bitmap_weight() does not access out-of-bound + * memory. + */ + tmp_cbm = d->new_ctrl; + if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < + r->cache.min_cbm_bits) { rdt_last_cmd_printf("no space on %s:%d\n", r->name, d->id); return -ENOSPC; -- cgit v1.2.3 From 521348b011d64cf3febb10b64ba5b472681bef94 Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Wed, 3 Oct 2018 15:17:01 -0700 Subject: x86/intel_rdt: Introduce utility to obtain CDP peer Introduce a utility that, when provided with a RDT resource and an instance of this RDT resource (a RDT domain), would return pointers to the RDT resource and RDT domain that share the same hardware. This is specific to the CDP resources that share the same hardware. For example, if a pointer to the RDT_RESOURCE_L2DATA resource (struct rdt_resource) and a pointer to an instance of this resource (struct rdt_domain) is provided, then it will return a pointer to the RDT_RESOURCE_L2CODE resource as well as the specific instance that shares the same hardware as the provided rdt_domain. This utility is created in support of the "exclusive" resource group mode where overlap of resource allocation between resource groups need to be avoided. The overlap test need to consider not just the matching resources, but also the resources that share the same hardware. Temporarily mark it as unused in support of patch testing to avoid compile warnings until it is used. Fixes: 49f7b4efa110 ("x86/intel_rdt: Enable setting of exclusive mode") Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Tested-by: Jithu Joseph Acked-by: Fenghua Yu Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/9b4bc4d59ba2e903b6a3eb17e16ef41a8e7b7c3e.1538603665.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 72 ++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) (limited to 'arch/x86/kernel/cpu/intel_rdt_rdtgroup.c') diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 643670fb8943..9d59ee1c444e 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -960,6 +960,78 @@ static int rdtgroup_mode_show(struct kernfs_open_file *of, return 0; } +/** + * rdt_cdp_peer_get - Retrieve CDP peer if it exists + * @r: RDT resource to which RDT domain @d belongs + * @d: Cache instance for which a CDP peer is requested + * @r_cdp: RDT resource that shares hardware with @r (RDT resource peer) + * Used to return the result. + * @d_cdp: RDT domain that shares hardware with @d (RDT domain peer) + * Used to return the result. + * + * RDT resources are managed independently and by extension the RDT domains + * (RDT resource instances) are managed independently also. The Code and + * Data Prioritization (CDP) RDT resources, while managed independently, + * could refer to the same underlying hardware. For example, + * RDT_RESOURCE_L2CODE and RDT_RESOURCE_L2DATA both refer to the L2 cache. + * + * When provided with an RDT resource @r and an instance of that RDT + * resource @d rdt_cdp_peer_get() will return if there is a peer RDT + * resource and the exact instance that shares the same hardware. + * + * Return: 0 if a CDP peer was found, <0 on error or if no CDP peer exists. + * If a CDP peer was found, @r_cdp will point to the peer RDT resource + * and @d_cdp will point to the peer RDT domain. + */ +static int __attribute__((unused)) rdt_cdp_peer_get(struct rdt_resource *r, + struct rdt_domain *d, + struct rdt_resource **r_cdp, + struct rdt_domain **d_cdp) +{ + struct rdt_resource *_r_cdp = NULL; + struct rdt_domain *_d_cdp = NULL; + int ret = 0; + + switch (r->rid) { + case RDT_RESOURCE_L3DATA: + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3CODE]; + break; + case RDT_RESOURCE_L3CODE: + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3DATA]; + break; + case RDT_RESOURCE_L2DATA: + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2CODE]; + break; + case RDT_RESOURCE_L2CODE: + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2DATA]; + break; + default: + ret = -ENOENT; + goto out; + } + + /* + * When a new CPU comes online and CDP is enabled then the new + * RDT domains (if any) associated with both CDP RDT resources + * are added in the same CPU online routine while the + * rdtgroup_mutex is held. It should thus not happen for one + * RDT domain to exist and be associated with its RDT CDP + * resource but there is no RDT domain associated with the + * peer RDT CDP resource. Hence the WARN. + */ + _d_cdp = rdt_find_domain(_r_cdp, d->id, NULL); + if (WARN_ON(!_d_cdp)) { + _r_cdp = NULL; + ret = -EINVAL; + } + +out: + *r_cdp = _r_cdp; + *d_cdp = _d_cdp; + + return ret; +} + /** * rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other * @r: Resource to which domain instance @d belongs. -- cgit v1.2.3 From e5f3530c391105fdd6174852e3ea6136d073b45a Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Wed, 3 Oct 2018 15:17:02 -0700 Subject: x86/intel_rdt: CBM overlap should also check for overlap with CDP peer The CBM overlap test is used to manage the allocations of RDT resources where overlap is possible between resource groups. When a resource group is in exclusive mode then there should be no overlap between resource groups. The current overlap test only considers overlap between the same resources, for example, that usage of a RDT_RESOURCE_L2DATA resource in one resource group does not overlap with usage of a RDT_RESOURCE_L2DATA resource in another resource group. The problem with this is that it allows overlap between a RDT_RESOURCE_L2DATA resource in one resource group with a RDT_RESOURCE_L2CODE resource in another resource group - even if both resource groups are in exclusive mode. This is a problem because even though these appear to be different resources they end up sharing the same underlying hardware and thus does not fulfill the user's request for exclusive use of hardware resources. Fix this by including the CDP peer (if there is one) in every CBM overlap test. This does not impact the overlap between resources within the same exclusive resource group that is allowed. Fixes: 49f7b4efa110 ("x86/intel_rdt: Enable setting of exclusive mode") Reported-by: Jithu Joseph Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Tested-by: Jithu Joseph Acked-by: Fenghua Yu Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/e538b7f56f7ca15963dce2e00ac3be8edb8a68e1.1538603665.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 48 +++++++++++++++++++++++++++----- 1 file changed, 41 insertions(+), 7 deletions(-) (limited to 'arch/x86/kernel/cpu/intel_rdt_rdtgroup.c') diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 9d59ee1c444e..49c479822844 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -983,10 +983,9 @@ static int rdtgroup_mode_show(struct kernfs_open_file *of, * If a CDP peer was found, @r_cdp will point to the peer RDT resource * and @d_cdp will point to the peer RDT domain. */ -static int __attribute__((unused)) rdt_cdp_peer_get(struct rdt_resource *r, - struct rdt_domain *d, - struct rdt_resource **r_cdp, - struct rdt_domain **d_cdp) +static int rdt_cdp_peer_get(struct rdt_resource *r, struct rdt_domain *d, + struct rdt_resource **r_cdp, + struct rdt_domain **d_cdp) { struct rdt_resource *_r_cdp = NULL; struct rdt_domain *_d_cdp = NULL; @@ -1033,7 +1032,7 @@ out: } /** - * rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other + * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other * @r: Resource to which domain instance @d belongs. * @d: The domain instance for which @closid is being tested. * @cbm: Capacity bitmask being tested. @@ -1052,8 +1051,8 @@ out: * * Return: false if CBM does not overlap, true if it does. */ -bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d, - unsigned long cbm, int closid, bool exclusive) +static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d, + unsigned long cbm, int closid, bool exclusive) { enum rdtgrp_mode mode; unsigned long ctrl_b; @@ -1088,6 +1087,41 @@ bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d, return false; } +/** + * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware + * @r: Resource to which domain instance @d belongs. + * @d: The domain instance for which @closid is being tested. + * @cbm: Capacity bitmask being tested. + * @closid: Intended closid for @cbm. + * @exclusive: Only check if overlaps with exclusive resource groups + * + * Resources that can be allocated using a CBM can use the CBM to control + * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test + * for overlap. Overlap test is not limited to the specific resource for + * which the CBM is intended though - when dealing with CDP resources that + * share the underlying hardware the overlap check should be performed on + * the CDP resource sharing the hardware also. + * + * Refer to description of __rdtgroup_cbm_overlaps() for the details of the + * overlap test. + * + * Return: true if CBM overlap detected, false if there is no overlap + */ +bool rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d, + unsigned long cbm, int closid, bool exclusive) +{ + struct rdt_resource *r_cdp; + struct rdt_domain *d_cdp; + + if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, exclusive)) + return true; + + if (rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp) < 0) + return false; + + return __rdtgroup_cbm_overlaps(r_cdp, d_cdp, cbm, closid, exclusive); +} + /** * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive * -- cgit v1.2.3 From 2a7adf6ce643fdeec051dc88e5250b08c83bbb67 Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Wed, 3 Oct 2018 15:17:03 -0700 Subject: x86/intel_rdt: Fix initial allocation to consider CDP When a new resource group is created it is initialized with a default allocation that considers which portions of cache are currently available for sharing across all resource groups or which portions of cache are currently unused. If a CDP allocation forms part of a resource group that is in exclusive mode then it should be ensured that no new allocation overlaps with any resource that shares the underlying hardware. The current initial allocation does not take this sharing of hardware into account and a new allocation in a resource that shares the same hardware would affect the exclusive resource group. Fix this by considering the allocation of a peer RDT domain - a RDT domain sharing the same hardware - as part of the test to determine which portion of cache is in use and available for use. Fixes: 95f0b77efa57 ("x86/intel_rdt: Initialize new resource group with sane defaults") Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Acked-by: Fenghua Yu Cc: tony.luck@intel.com Cc: jithu.joseph@intel.com Cc: gavin.hindman@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/b1f7ec08b1695be067de416a4128466d49684317.1538603665.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/cpu/intel_rdt_rdtgroup.c') diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 49c479822844..dbc7fc98b60a 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -2460,14 +2460,16 @@ static void cbm_ensure_valid(u32 *_val, struct rdt_resource *r) */ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) { + struct rdt_resource *r_cdp = NULL; + struct rdt_domain *d_cdp = NULL; u32 used_b = 0, unused_b = 0; u32 closid = rdtgrp->closid; struct rdt_resource *r; unsigned long tmp_cbm; enum rdtgrp_mode mode; struct rdt_domain *d; + u32 peer_ctl, *ctrl; int i, ret; - u32 *ctrl; for_each_alloc_enabled_rdt_resource(r) { /* @@ -2477,6 +2479,7 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) if (r->rid == RDT_RESOURCE_MBA) continue; list_for_each_entry(d, &r->domains, list) { + rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp); d->have_new_ctrl = false; d->new_ctrl = r->cache.shareable_bits; used_b = r->cache.shareable_bits; @@ -2486,9 +2489,19 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) mode = rdtgroup_mode_by_closid(i); if (mode == RDT_MODE_PSEUDO_LOCKSETUP) break; - used_b |= *ctrl; + /* + * If CDP is active include peer + * domain's usage to ensure there + * is no overlap with an exclusive + * group. + */ + if (d_cdp) + peer_ctl = d_cdp->ctrl_val[i]; + else + peer_ctl = 0; + used_b |= *ctrl | peer_ctl; if (mode == RDT_MODE_SHAREABLE) - d->new_ctrl |= *ctrl; + d->new_ctrl |= *ctrl | peer_ctl; } } if (d->plr && d->plr->cbm > 0) -- cgit v1.2.3 From b61b8bba18fe2b63d38fdaf9b83de25e2d787dfe Mon Sep 17 00:00:00 2001 From: Jithu Joseph Date: Fri, 12 Oct 2018 15:51:01 -0700 Subject: x86/intel_rdt: Prevent pseudo-locking from using stale pointers When the last CPU in an rdt_domain goes offline, its rdt_domain struct gets freed. Current pseudo-locking code is unaware of this scenario and tries to dereference the freed structure in a few places. Add checks to prevent pseudo-locking code from doing this. While further work is needed to seamlessly restore resource groups (not just pseudo-locking) to their configuration when the domain is brought back online, the immediate issue of invalid pointers is addressed here. Fixes: f4e80d67a5274 ("x86/intel_rdt: Resctrl files reflect pseudo-locked information") Fixes: 443810fe61605 ("x86/intel_rdt: Create debugfs files for pseudo-locking testing") Fixes: 746e08590b864 ("x86/intel_rdt: Create character device exposing pseudo-locked region") Fixes: 33dc3e410a0d9 ("x86/intel_rdt: Make CPU information accessible for pseudo-locked regions") Signed-off-by: Jithu Joseph Signed-off-by: Reinette Chatre Signed-off-by: Thomas Gleixner Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/231f742dbb7b00a31cc104416860e27dba6b072d.1539384145.git.reinette.chatre@intel.com --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 38 +++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 10 deletions(-) (limited to 'arch/x86/kernel/cpu/intel_rdt_rdtgroup.c') diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index dbc7fc98b60a..f27b8115ffa2 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -268,17 +268,27 @@ static int rdtgroup_cpus_show(struct kernfs_open_file *of, struct seq_file *s, void *v) { struct rdtgroup *rdtgrp; + struct cpumask *mask; int ret = 0; rdtgrp = rdtgroup_kn_lock_live(of->kn); if (rdtgrp) { - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) - seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n", - cpumask_pr_args(&rdtgrp->plr->d->cpu_mask)); - else + if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + mask = &rdtgrp->plr->d->cpu_mask; + seq_printf(s, is_cpu_list(of) ? + "%*pbl\n" : "%*pb\n", + cpumask_pr_args(mask)); + } + } else { seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n", cpumask_pr_args(&rdtgrp->cpu_mask)); + } } else { ret = -ENOENT; } @@ -1282,6 +1292,7 @@ static int rdtgroup_size_show(struct kernfs_open_file *of, struct rdt_resource *r; struct rdt_domain *d; unsigned int size; + int ret = 0; bool sep; u32 ctrl; @@ -1292,11 +1303,18 @@ static int rdtgroup_size_show(struct kernfs_open_file *of, } if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - seq_printf(s, "%*s:", max_name_width, rdtgrp->plr->r->name); - size = rdtgroup_cbm_to_size(rdtgrp->plr->r, - rdtgrp->plr->d, - rdtgrp->plr->cbm); - seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size); + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + seq_printf(s, "%*s:", max_name_width, + rdtgrp->plr->r->name); + size = rdtgroup_cbm_to_size(rdtgrp->plr->r, + rdtgrp->plr->d, + rdtgrp->plr->cbm); + seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size); + } goto out; } @@ -1326,7 +1344,7 @@ static int rdtgroup_size_show(struct kernfs_open_file *of, out: rdtgroup_kn_unlock(of->kn); - return 0; + return ret; } /* rdtgroup information files for one cache resource. */ -- cgit v1.2.3