{ [ 0 ... XFEATURE_MAX - 1] = -1};
static unsigned int xstate_sizes[XFEATURE_MAX] __ro_after_init =
{ [ 0 ... XFEATURE_MAX - 1] = -1};
-static unsigned int xstate_comp_offsets[XFEATURE_MAX] __ro_after_init =
- { [ 0 ... XFEATURE_MAX - 1] = -1};
-static unsigned int xstate_supervisor_only_offsets[XFEATURE_MAX] __ro_after_init =
- { [ 0 ... XFEATURE_MAX - 1] = -1};
+static unsigned int xstate_flags[XFEATURE_MAX] __ro_after_init;
+
+#define XSTATE_FLAG_SUPERVISOR BIT(0)
+#define XSTATE_FLAG_ALIGNED64 BIT(1)
/*
* Return whether the system supports a given xfeature.
}
EXPORT_SYMBOL_GPL(cpu_has_xfeatures);
+static bool xfeature_is_aligned64(int xfeature_nr)
+{
+ return xstate_flags[xfeature_nr] & XSTATE_FLAG_ALIGNED64;
+}
+
static bool xfeature_is_supervisor(int xfeature_nr)
{
+ return xstate_flags[xfeature_nr] & XSTATE_FLAG_SUPERVISOR;
+}
+
+static unsigned int xfeature_get_offset(u64 xcomp_bv, int xfeature)
+{
+ unsigned int offs, i;
+
/*
- * Extended State Enumeration Sub-leaves (EAX = 0DH, ECX = n, n > 1)
- * returns ECX[0] set to (1) for a supervisor state, and cleared (0)
- * for a user state.
+ * Non-compacted format and legacy features use the cached fixed
+ * offsets.
*/
- u32 eax, ebx, ecx, edx;
+ if (!cpu_feature_enabled(X86_FEATURE_XSAVES) || xfeature <= XFEATURE_SSE)
+ return xstate_offsets[xfeature];
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
- return ecx & 1;
+ /*
+ * Compacted format offsets depend on the actual content of the
+ * compacted xsave area which is determined by the xcomp_bv header
+ * field.
+ */
+ offs = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+ for_each_extended_xfeature(i, xcomp_bv) {
+ if (xfeature_is_aligned64(i))
+ offs = ALIGN(offs, 64);
+ if (i == xfeature)
+ break;
+ offs += xstate_sizes[i];
+ }
+ return offs;
}
/*
* Record the offsets and sizes of various xstates contained
* in the XSAVE state memory layout.
*/
-static void __init setup_xstate_features(void)
+static void __init setup_xstate_cache(void)
{
u32 eax, ebx, ecx, edx, i;
/* start at the beginning of the "extended state" */
cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
xstate_sizes[i] = eax;
+ xstate_flags[i] = ecx;
/*
* If an xfeature is supervisor state, the offset in EBX is
WARN_ON(nr >= XFEATURE_MAX); \
} while (0)
-/*
- * We could cache this like xstate_size[], but we only use
- * it here, so it would be a waste of space.
- */
-static int xfeature_is_aligned(int xfeature_nr)
-{
- u32 eax, ebx, ecx, edx;
-
- CHECK_XFEATURE(xfeature_nr);
-
- if (!xfeature_enabled(xfeature_nr)) {
- WARN_ONCE(1, "Checking alignment of disabled xfeature %d\n",
- xfeature_nr);
- return 0;
- }
-
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
- /*
- * The value returned by ECX[1] indicates the alignment
- * of state component 'i' when the compacted format
- * of the extended region of an XSAVE area is used:
- */
- return !!(ecx & 2);
-}
-
-/*
- * This function sets up offsets and sizes of all extended states in
- * xsave area. This supports both standard format and compacted format
- * of the xsave area.
- */
-static void __init setup_xstate_comp_offsets(void)
-{
- unsigned int next_offset;
- int i;
-
- /*
- * The FP xstates and SSE xstates are legacy states. They are always
- * in the fixed offsets in the xsave area in either compacted form
- * or standard form.
- */
- xstate_comp_offsets[XFEATURE_FP] = 0;
- xstate_comp_offsets[XFEATURE_SSE] = offsetof(struct fxregs_state,
- xmm_space);
-
- if (!cpu_feature_enabled(X86_FEATURE_XSAVES)) {
- for_each_extended_xfeature(i, fpu_kernel_cfg.max_features)
- xstate_comp_offsets[i] = xstate_offsets[i];
- return;
- }
-
- next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE;
-
- for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
- if (xfeature_is_aligned(i))
- next_offset = ALIGN(next_offset, 64);
-
- xstate_comp_offsets[i] = next_offset;
- next_offset += xstate_sizes[i];
- }
-}
-
-/*
- * Setup offsets of a supervisor-state-only XSAVES buffer:
- *
- * The offsets stored in xstate_comp_offsets[] only work for one specific
- * value of the Requested Feature BitMap (RFBM). In cases where a different
- * RFBM value is used, a different set of offsets is required. This set of
- * offsets is for when RFBM=xfeatures_mask_supervisor().
- */
-static void __init setup_supervisor_only_offsets(void)
-{
- unsigned int next_offset;
- int i;
-
- next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE;
-
- for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
- if (!xfeature_is_supervisor(i))
- continue;
-
- if (xfeature_is_aligned(i))
- next_offset = ALIGN(next_offset, 64);
-
- xstate_supervisor_only_offsets[i] = next_offset;
- next_offset += xstate_sizes[i];
- }
-}
-
/*
* Print out xstate component offsets and sizes
*/
for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) {
pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n",
- i, xstate_comp_offsets[i], i, xstate_sizes[i]);
+ i, xfeature_get_offset(fpu_kernel_cfg.max_features, i),
+ i, xstate_sizes[i]);
}
}
if (!boot_cpu_has(X86_FEATURE_XSAVE))
return;
- setup_xstate_features();
print_xstate_features();
xstate_init_xcomp_bv(&init_fpstate.regs.xsave, fpu_kernel_cfg.max_features);
fxsave(&init_fpstate.regs.fxsave);
}
-static int xfeature_uncompacted_offset(int xfeature_nr)
-{
- u32 eax, ebx, ecx, edx;
-
- /*
- * Only XSAVES supports supervisor states and it uses compacted
- * format. Checking a supervisor state's uncompacted offset is
- * an error.
- */
- if (XFEATURE_MASK_SUPERVISOR_ALL & BIT_ULL(xfeature_nr)) {
- WARN_ONCE(1, "No fixed offset for xstate %d\n", xfeature_nr);
- return -1;
- }
-
- CHECK_XFEATURE(xfeature_nr);
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
- return ebx;
-}
-
int xfeature_size(int xfeature_nr)
{
u32 eax, ebx, ecx, edx;
static unsigned int xstate_calculate_size(u64 xfeatures, bool compacted)
{
- unsigned int size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
- int i;
+ unsigned int topmost = fls64(xfeatures) - 1;
+ unsigned int offset = xstate_offsets[topmost];
- for_each_extended_xfeature(i, xfeatures) {
- /* Align from the end of the previous feature */
- if (xfeature_is_aligned(i))
- size = ALIGN(size, 64);
- /*
- * In compacted format the enabled features are packed,
- * i.e. disabled features do not occupy space.
- *
- * In non-compacted format the offsets are fixed and
- * disabled states still occupy space in the memory buffer.
- */
- if (!compacted)
- size = xfeature_uncompacted_offset(i);
- /*
- * Add the feature size even for non-compacted format
- * to make the end result correct
- */
- size += xfeature_size(i);
- }
- return size;
+ if (topmost <= XFEATURE_SSE)
+ return sizeof(struct xregs_state);
+
+ if (compacted)
+ offset = xfeature_get_offset(xfeatures, topmost);
+ return offset + xstate_sizes[topmost];
}
/*
/* Enable xstate instructions to be able to continue with initialization: */
fpu__init_cpu_xstate();
+
+ /* Cache size, offset and flags for initialization */
+ setup_xstate_cache();
+
err = init_xstate_size();
if (err)
goto out_disable;
fpu_user_cfg.max_features);
setup_init_fpu_buf();
- setup_xstate_comp_offsets();
- setup_supervisor_only_offsets();
/*
* Paranoia check whether something in the setup modified the
*/
static void *__raw_xsave_addr(struct xregs_state *xsave, int xfeature_nr)
{
- if (!xfeature_enabled(xfeature_nr)) {
- WARN_ON_FPU(1);
+ u64 xcomp_bv = xsave->header.xcomp_bv;
+
+ if (WARN_ON_ONCE(!xfeature_enabled(xfeature_nr)))
return NULL;
+
+ if (cpu_feature_enabled(X86_FEATURE_XSAVES)) {
+ if (WARN_ON_ONCE(!(xcomp_bv & BIT_ULL(xfeature_nr))))
+ return NULL;
}
- return (void *)xsave + xstate_comp_offsets[xfeature_nr];
+ return (void *)xsave + xfeature_get_offset(xcomp_bv, xfeature_nr);
}
+
/*
* Given the xsave area and a state inside, this function returns the
* address of the state.
* We should not ever be requesting features that we
* have not enabled.
*/
- WARN_ONCE(!(fpu_kernel_cfg.max_features & BIT_ULL(xfeature_nr)),
- "get of unsupported state");
+ if (WARN_ON_ONCE(!xfeature_enabled(xfeature_nr)))
+ return NULL;
+
/*
* This assumes the last 'xsave*' instruction to
* have requested that 'xfeature_nr' be saved.
/* Calculate the resulting kernel state size */
mask = permitted | requested;
+ /* Take supervisor states into account on the host */
+ if (!guest)
+ mask |= xfeatures_mask_supervisor();
ksize = xstate_calculate_size(mask, compacted);
/* Calculate the resulting user state size */
perm = guest ? &fpu->guest_perm : &fpu->perm;
/* Pairs with the READ_ONCE() in xstate_get_group_perm() */
- WRITE_ONCE(perm->__state_perm, requested);
+ WRITE_ONCE(perm->__state_perm, mask);
/* Protected by sighand lock */
perm->__state_size = ksize;
perm->__user_state_size = usize;
projects / linux-2.6-microblaze.git / blobdiff