diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/papr-vpd.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/papr-vpd.c | 352 |
1 files changed, 45 insertions, 307 deletions
diff --git a/arch/powerpc/platforms/pseries/papr-vpd.c b/arch/powerpc/platforms/pseries/papr-vpd.c index c86950d7105a..f38c188fc4a1 100644 --- a/arch/powerpc/platforms/pseries/papr-vpd.c +++ b/arch/powerpc/platforms/pseries/papr-vpd.c @@ -2,7 +2,6 @@ #define pr_fmt(fmt) "papr-vpd: " fmt -#include <linux/anon_inodes.h> #include <linux/build_bug.h> #include <linux/file.h> #include <linux/fs.h> @@ -20,14 +19,7 @@ #include <asm/rtas-work-area.h> #include <asm/rtas.h> #include <uapi/asm/papr-vpd.h> - -/* - * Function-specific return values for ibm,get-vpd, derived from PAPR+ - * v2.13 7.3.20 "ibm,get-vpd RTAS Call". - */ -#define RTAS_IBM_GET_VPD_COMPLETE 0 /* All VPD has been retrieved. */ -#define RTAS_IBM_GET_VPD_MORE_DATA 1 /* More VPD is available. */ -#define RTAS_IBM_GET_VPD_START_OVER -4 /* VPD changed, restart call sequence. */ +#include "papr-rtas-common.h" /** * struct rtas_ibm_get_vpd_params - Parameters (in and out) for ibm,get-vpd. @@ -91,13 +83,14 @@ static int rtas_ibm_get_vpd(struct rtas_ibm_get_vpd_params *params) case RTAS_INVALID_PARAMETER: ret = -EINVAL; break; - case RTAS_IBM_GET_VPD_START_OVER: + case RTAS_SEQ_START_OVER: ret = -EAGAIN; + pr_info_ratelimited("VPD changed during retrieval, retrying\n"); break; - case RTAS_IBM_GET_VPD_MORE_DATA: + case RTAS_SEQ_MORE_DATA: params->sequence = rets[0]; fallthrough; - case RTAS_IBM_GET_VPD_COMPLETE: + case RTAS_SEQ_COMPLETE: params->written = rets[1]; /* * Kernel or firmware bug, do not continue. @@ -119,91 +112,6 @@ static int rtas_ibm_get_vpd(struct rtas_ibm_get_vpd_params *params) } /* - * Internal VPD "blob" APIs for accumulating ibm,get-vpd results into - * an immutable buffer to be attached to a file descriptor. - */ -struct vpd_blob { - const char *data; - size_t len; -}; - -static bool vpd_blob_has_data(const struct vpd_blob *blob) -{ - return blob->data && blob->len; -} - -static void vpd_blob_free(const struct vpd_blob *blob) -{ - if (blob) { - kvfree(blob->data); - kfree(blob); - } -} - -/** - * vpd_blob_extend() - Append data to a &struct vpd_blob. - * @blob: The blob to extend. - * @data: The new data to append to @blob. - * @len: The length of @data. - * - * Context: May sleep. - * Return: -ENOMEM on allocation failure, 0 otherwise. - */ -static int vpd_blob_extend(struct vpd_blob *blob, const char *data, size_t len) -{ - const size_t new_len = blob->len + len; - const size_t old_len = blob->len; - const char *old_ptr = blob->data; - char *new_ptr; - - new_ptr = kvrealloc(old_ptr, new_len, GFP_KERNEL_ACCOUNT); - if (!new_ptr) - return -ENOMEM; - - memcpy(&new_ptr[old_len], data, len); - blob->data = new_ptr; - blob->len = new_len; - return 0; -} - -/** - * vpd_blob_generate() - Construct a new &struct vpd_blob. - * @generator: Function that supplies the blob data. - * @arg: Context pointer supplied by caller, passed to @generator. - * - * The @generator callback is invoked until it returns NULL. @arg is - * passed to @generator in its first argument on each call. When - * @generator returns data, it should store the data length in its - * second argument. - * - * Context: May sleep. - * Return: A completely populated &struct vpd_blob, or NULL on error. - */ -static const struct vpd_blob * -vpd_blob_generate(const char * (*generator)(void *, size_t *), void *arg) -{ - struct vpd_blob *blob; - const char *buf; - size_t len; - int err = 0; - - blob = kzalloc(sizeof(*blob), GFP_KERNEL_ACCOUNT); - if (!blob) - return NULL; - - while (err == 0 && (buf = generator(arg, &len))) - err = vpd_blob_extend(blob, buf, len); - - if (err != 0 || !vpd_blob_has_data(blob)) - goto free_blob; - - return blob; -free_blob: - vpd_blob_free(blob); - return NULL; -} - -/* * Internal VPD sequence APIs. A VPD sequence is a series of calls to * ibm,get-vpd for a given location code. The sequence ends when an * error is encountered or all VPD for the location code has been @@ -211,30 +119,14 @@ free_blob: */ /** - * struct vpd_sequence - State for managing a VPD sequence. - * @error: Shall be zero as long as the sequence has not encountered an error, - * -ve errno otherwise. Use vpd_sequence_set_err() to update this. - * @params: Parameter block to pass to rtas_ibm_get_vpd(). - */ -struct vpd_sequence { - int error; - struct rtas_ibm_get_vpd_params params; -}; - -/** * vpd_sequence_begin() - Begin a VPD retrieval sequence. - * @seq: Uninitialized sequence state. - * @loc_code: Location code that defines the scope of the VPD to return. - * - * Initializes @seq with the resources necessary to carry out a VPD - * sequence. Callers must pass @seq to vpd_sequence_end() regardless - * of whether the sequence succeeds. + * @seq: vpd call parameters from sequence struct * * Context: May sleep. */ -static void vpd_sequence_begin(struct vpd_sequence *seq, - const struct papr_location_code *loc_code) +static void vpd_sequence_begin(struct papr_rtas_sequence *seq) { + struct rtas_ibm_get_vpd_params *vpd_params; /* * Use a static data structure for the location code passed to * RTAS to ensure it's in the RMA and avoid a separate work @@ -242,6 +134,7 @@ static void vpd_sequence_begin(struct vpd_sequence *seq, */ static struct papr_location_code static_loc_code; + vpd_params = (struct rtas_ibm_get_vpd_params *)seq->params; /* * We could allocate the work area before acquiring the * function lock, but that would allow concurrent requests to @@ -249,14 +142,12 @@ static void vpd_sequence_begin(struct vpd_sequence *seq, * allocate the work area under the lock. */ mutex_lock(&rtas_ibm_get_vpd_lock); - static_loc_code = *loc_code; - *seq = (struct vpd_sequence) { - .params = { - .work_area = rtas_work_area_alloc(SZ_4K), - .loc_code = &static_loc_code, - .sequence = 1, - }, - }; + static_loc_code = *(struct papr_location_code *)vpd_params->loc_code; + vpd_params = (struct rtas_ibm_get_vpd_params *)seq->params; + vpd_params->work_area = rtas_work_area_alloc(SZ_4K); + vpd_params->loc_code = &static_loc_code; + vpd_params->sequence = 1; + vpd_params->status = 0; } /** @@ -265,180 +156,39 @@ static void vpd_sequence_begin(struct vpd_sequence *seq, * * Releases resources obtained by vpd_sequence_begin(). */ -static void vpd_sequence_end(struct vpd_sequence *seq) +static void vpd_sequence_end(struct papr_rtas_sequence *seq) { - rtas_work_area_free(seq->params.work_area); - mutex_unlock(&rtas_ibm_get_vpd_lock); -} - -/** - * vpd_sequence_should_stop() - Determine whether a VPD retrieval sequence - * should continue. - * @seq: VPD sequence state. - * - * Examines the sequence error state and outputs of the last call to - * ibm,get-vpd to determine whether the sequence in progress should - * continue or stop. - * - * Return: True if the sequence has encountered an error or if all VPD for - * this sequence has been retrieved. False otherwise. - */ -static bool vpd_sequence_should_stop(const struct vpd_sequence *seq) -{ - bool done; - - if (seq->error) - return true; + struct rtas_ibm_get_vpd_params *vpd_params; - switch (seq->params.status) { - case 0: - if (seq->params.written == 0) - done = false; /* Initial state. */ - else - done = true; /* All data consumed. */ - break; - case 1: - done = false; /* More data available. */ - break; - default: - done = true; /* Error encountered. */ - break; - } - - return done; -} - -static int vpd_sequence_set_err(struct vpd_sequence *seq, int err) -{ - /* Preserve the first error recorded. */ - if (seq->error == 0) - seq->error = err; - - return seq->error; + vpd_params = (struct rtas_ibm_get_vpd_params *)seq->params; + rtas_work_area_free(vpd_params->work_area); + mutex_unlock(&rtas_ibm_get_vpd_lock); } /* - * Generator function to be passed to vpd_blob_generate(). + * Generator function to be passed to papr_rtas_blob_generate(). */ -static const char *vpd_sequence_fill_work_area(void *arg, size_t *len) +static const char *vpd_sequence_fill_work_area(struct papr_rtas_sequence *seq, + size_t *len) { - struct vpd_sequence *seq = arg; - struct rtas_ibm_get_vpd_params *p = &seq->params; + struct rtas_ibm_get_vpd_params *p; + bool init_state; - if (vpd_sequence_should_stop(seq)) + p = (struct rtas_ibm_get_vpd_params *)seq->params; + init_state = (p->written == 0) ? true : false; + + if (papr_rtas_sequence_should_stop(seq, p->status, init_state)) return NULL; - if (vpd_sequence_set_err(seq, rtas_ibm_get_vpd(p))) + if (papr_rtas_sequence_set_err(seq, rtas_ibm_get_vpd(p))) return NULL; *len = p->written; return rtas_work_area_raw_buf(p->work_area); } -/* - * Higher-level VPD retrieval code below. These functions use the - * vpd_blob_* and vpd_sequence_* APIs defined above to create fd-based - * VPD handles for consumption by user space. - */ - -/** - * papr_vpd_run_sequence() - Run a single VPD retrieval sequence. - * @loc_code: Location code that defines the scope of VPD to return. - * - * Context: May sleep. Holds a mutex and an RTAS work area for its - * duration. Typically performs multiple sleepable slab - * allocations. - * - * Return: A populated &struct vpd_blob on success. Encoded error - * pointer otherwise. - */ -static const struct vpd_blob *papr_vpd_run_sequence(const struct papr_location_code *loc_code) -{ - const struct vpd_blob *blob; - struct vpd_sequence seq; - - vpd_sequence_begin(&seq, loc_code); - blob = vpd_blob_generate(vpd_sequence_fill_work_area, &seq); - if (!blob) - vpd_sequence_set_err(&seq, -ENOMEM); - vpd_sequence_end(&seq); - - if (seq.error) { - vpd_blob_free(blob); - return ERR_PTR(seq.error); - } - - return blob; -} - -/** - * papr_vpd_retrieve() - Return the VPD for a location code. - * @loc_code: Location code that defines the scope of VPD to return. - * - * Run VPD sequences against @loc_code until a blob is successfully - * instantiated, or a hard error is encountered, or a fatal signal is - * pending. - * - * Context: May sleep. - * Return: A fully populated VPD blob when successful. Encoded error - * pointer otherwise. - */ -static const struct vpd_blob *papr_vpd_retrieve(const struct papr_location_code *loc_code) -{ - const struct vpd_blob *blob; - - /* - * EAGAIN means the sequence errored with a -4 (VPD changed) - * status from ibm,get-vpd, and we should attempt a new - * sequence. PAPR+ v2.13 R1–7.3.20–5 indicates that this - * should be a transient condition, not something that happens - * continuously. But we'll stop trying on a fatal signal. - */ - do { - blob = papr_vpd_run_sequence(loc_code); - if (!IS_ERR(blob)) /* Success. */ - break; - if (PTR_ERR(blob) != -EAGAIN) /* Hard error. */ - break; - pr_info_ratelimited("VPD changed during retrieval, retrying\n"); - cond_resched(); - } while (!fatal_signal_pending(current)); - - return blob; -} - -static ssize_t papr_vpd_handle_read(struct file *file, char __user *buf, size_t size, loff_t *off) -{ - const struct vpd_blob *blob = file->private_data; - - /* bug: we should not instantiate a handle without any data attached. */ - if (!vpd_blob_has_data(blob)) { - pr_err_once("handle without data\n"); - return -EIO; - } - - return simple_read_from_buffer(buf, size, off, blob->data, blob->len); -} - -static int papr_vpd_handle_release(struct inode *inode, struct file *file) -{ - const struct vpd_blob *blob = file->private_data; - - vpd_blob_free(blob); - - return 0; -} - -static loff_t papr_vpd_handle_seek(struct file *file, loff_t off, int whence) -{ - const struct vpd_blob *blob = file->private_data; - - return fixed_size_llseek(file, off, whence, blob->len); -} - - static const struct file_operations papr_vpd_handle_ops = { - .read = papr_vpd_handle_read, - .llseek = papr_vpd_handle_seek, - .release = papr_vpd_handle_release, + .read = papr_rtas_common_handle_read, + .llseek = papr_rtas_common_handle_seek, + .release = papr_rtas_common_handle_release, }; /** @@ -460,10 +210,9 @@ static const struct file_operations papr_vpd_handle_ops = { */ static long papr_vpd_create_handle(struct papr_location_code __user *ulc) { + struct rtas_ibm_get_vpd_params vpd_params = {}; + struct papr_rtas_sequence seq = {}; struct papr_location_code klc; - const struct vpd_blob *blob; - struct file *file; - long err; int fd; if (copy_from_user(&klc, ulc, sizeof(klc))) @@ -472,30 +221,19 @@ static long papr_vpd_create_handle(struct papr_location_code __user *ulc) if (!string_is_terminated(klc.str, ARRAY_SIZE(klc.str))) return -EINVAL; - blob = papr_vpd_retrieve(&klc); - if (IS_ERR(blob)) - return PTR_ERR(blob); + seq = (struct papr_rtas_sequence) { + .begin = vpd_sequence_begin, + .end = vpd_sequence_end, + .work = vpd_sequence_fill_work_area, + }; - fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); - if (fd < 0) { - err = fd; - goto free_blob; - } + vpd_params.loc_code = &klc; + seq.params = (void *)&vpd_params; + + fd = papr_rtas_setup_file_interface(&seq, &papr_vpd_handle_ops, + "[papr-vpd]"); - file = anon_inode_getfile_fmode("[papr-vpd]", &papr_vpd_handle_ops, - (void *)blob, O_RDONLY, - FMODE_LSEEK | FMODE_PREAD); - if (IS_ERR(file)) { - err = PTR_ERR(file); - goto put_fd; - } - fd_install(fd, file); return fd; -put_fd: - put_unused_fd(fd); -free_blob: - vpd_blob_free(blob); - return err; } /* |